Journal articles: 'Forging valve'

1

Dworzak, Łukasz, Marek Hawryluk, and Marta Janik. "The Impact of the Lubricant Dose on the Reduction of Wear Dies Used in the Forging Process of the Valve Forging." Materials 14, no. 1 (January 4, 2021): 212. http://dx.doi.org/10.3390/ma14010212.

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The paper presents the results of research on the influence of the settings of lubrication and cooling system parameters (solenoid valve opening time and lubricant feed pressure in terms of its quantity) in order to select the optimal lubricating conditions and thus reduce the wear of the dies used in the first forging operation of the valve forging made of high-nickel steel. Based on the observation of lubrication in the industrial process, it was found that a significant part of the lubricant fails to reach the die cavity, reaching the outside of it, which causes die wear due to seizure resulting from adhesion of the forging material to the tool surface as well as high lubricant consumption and dirt in the press chamber. The authors proposed their own mobile lubricating and cooling system, which allows for a wide range of adjustments and provided with automatic cleaning procedures of the entire system, unlike the fixed lubrication system used so far in the industrial process. First, tests were carried out in laboratory conditions to determine the highest wettability and the lubricant remaining inside the tool cavity. These tests determined the lubrication system parameter settings that ensured that the greatest amount of lubricant remains in the cold die cavity without the forging process. Then, to verify the obtained results, tests were carried out in the industrial process of hot die forging of valve forgings for short production runs of up to 500 forgings. The results were compared with the measurement of changes in the geometry of tools and forgings based on 3D scanning and surface topography analysis with the use of SEM (Scanning Electron Microscope). For the best results (the variant of the setting of the dose and the time of exposure to lubricant), the forging process was carried out with the use of a new tool up to the maximum service life.

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Huang, Zhi De. "Microstructure and Properties of Forging Engine Valve Seat." Advanced Materials Research 335-336 (September 2011): 552–55. http://dx.doi.org/10.4028/www.scientific.net/amr.335-336.552.

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Microstructure and properties of Forging high Cr cast iron were investigated according to the requirements for production and application of engine valve seat. It is found that the microstructure of Forging high Cr cast iron consists of tempering martensite, M7C3 carbide and austenite. The strength ,and plasticity and hardness of Forging high Cr cast iron after heat treating is higher than that of centrifugal casting high Cr cast iron. So the Forging high Cr cast iron can meet the application demand of the engine valve seat.

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Dong, Rong Bao, Zheng Chun Li, Wen Xin Xu, and Miao Xie. "Simulation Analysis of Large Forging Equipment Cartridge Valve." Advanced Materials Research 619 (December 2012): 439–42. http://dx.doi.org/10.4028/www.scientific.net/amr.619.439.

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For the purpose of optimizing the dynamic characteristics of large forging equipment multilevel cartridge valves, according to the structure and principle of the Rexroth’s LC series cartridge elements, using AMESim simulation software, the influence of forging equipment cartridge valves switching characteristics be discussed respectively from the damping R2, the damping R1, the load pressure. The results show that the damping R1, the damping R2, the system pressure, and the work load to cartridge valves switching characteristics have certain effect. The research gives a method for analyzing and adjusting the cartridge valve response characteristics.

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Yang, Yang, Li Wen Zhang, Zhi Zhu, and Jian Lin Zhang. "FE Simulation of Die Forging Process for High Pressure Valve Body." Advanced Materials Research 763 (September 2013): 207–10. http://dx.doi.org/10.4028/www.scientific.net/amr.763.207.

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In this paper, based on the finite element (FE) software Deform 3D, the simulation of the die forging process of a high pressure valve body was conducted. The deformation field and the metal flow field of billet were obtained and analyzed in detail. In addition, the effect of upsetting depth on the die forging process of high pressure valve body was also discussed. This study can provide a good guide for the following researches and practical industry.

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Zhang, Jian Lin, Li Wen Zhang, Yang Yang, and Zhi Zhu. "Simulation and Optimization of Die Forging Process for High Pressure Valve Bonnet." Advanced Materials Research 652-654 (January 2013): 2053–56. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.2053.

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In this paper, the multi-stage die forging process of a high pressure valve bonnet was simulated by 3D coupled thermal-mechanical rigid-viscoplastic finite element (FE) method. The deformation and the metal flow field of billet were obtained. Based on the simulation, two optimized schemes were put forward for improving the yield. Both of them can save material and ensure the stability of billet during the forging process. The study can provide scientific theory foundation for practical engineering applications.

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6

CZYŻEWSKI, P., and A. KOCAŃDA. "Computer modelling of valve lever forging with various preforms." Archives of Civil and Mechanical Engineering 8, no. 3 (January 2008): 33–40. http://dx.doi.org/10.1016/s1644-9665(12)60161-7.

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7

Gontarz, A. "Forming process of valve drop forging with three cavities." Journal of Materials Processing Technology 177, no. 1-3 (July 2006): 228–32. http://dx.doi.org/10.1016/j.jmatprotec.2006.04.053.

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8

Pham, D. T., and M. H. Wu. "Diagnosis of Faults in the Fuel Injection System of a Forging Machine Using Fuzzy Sets Theory." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 208, no. 2 (May 1994): 123–29. http://dx.doi.org/10.1243/pime_proc_1994_208_316_02.

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This paper describes a diagnostic system for the fuel injection module in a high-speed forging machine. The system is based on the use of fuzzy sets techniques, with a fuzzy set representing each fault in the module. Empirical membership functions for the different fuzzy sets are employed to locate faults according to conditions observed on the forging machine. Two types of faults can be handled: faults due to one of more valves in the fuel injection module remaining in their unenergized state and faults caused by a valve being stuck in the energized state. Details of the diagnostic methods for both fault types are presented following a brief review of the operating principle of the forging machine.

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9

Jeong, H. S., J. R. Cho, Nak Kyu Lee, and H. C. Park. "Simulation of Electric Upsetting and Forging Process for Large Marine Diesel Engine Exhaust Valves." Materials Science Forum 510-511 (March 2006): 142–45. http://dx.doi.org/10.4028/www.scientific.net/msf.510-511.142.

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The manufacturing process of the exhaust valve in large marine diesel engines consists of an upset forging and final forming process. In the past, the exhaust valves in large marine diesel engines have been made through free forging by using the stretch forming method. This method has used the ingot and the billet as a preliminary forming process. Nimonic 80A, a superalloy, is presently used for the material of the exhaust valve. For the forming method of the valve, the electric upset method is used. Solid bar is raised up to the forming temperature by using electric energy and is continually deformed by upset pressure. The electric upsetting processing is a useful method for the high quality of exhaust valves in large marine diesel engines. It can keep the continuous grain flow, excellent mechanical property, and corrosion resistance because of the elaborate macrostructure of the valve face. The purpose of this paper is to predict the optimum process condition through simulation of the exhaust valve with a diameter of 73mm. The experimental result of an exhaust valve with a diameter of 19mm is in good agreement with the simulation result using the “QForm” that can solve electric upsetting problems. Finally, the optimal manufacturing process of the electric current and the upset load are surveyed.

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10

Yu, Hai Ning. "The Engine Valve Umbrella Head Hot Forging Die Improvement Measures." Advanced Materials Research 740 (August 2013): 694–97. http://dx.doi.org/10.4028/www.scientific.net/amr.740.694.

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When using monolithic hot die to forge the umbrella head of valve parts, hot die of a short life. Through the analysis of factors caused by mold, the structure design, mold material, mold manufacturing and use to take certain measures, the production practice showed that die fatigue crack generation and extended time to prolong service life, obviously improved.

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11

Oh, Seung Hwan, Joon Hong Park, Kwon Hee Lee, Dong Hun Kang, Xue Guan Song, Jung Ho Kang, and Young Chul Park. "Optimization of Preform in Forging Process Using Kriging Model." Advanced Materials Research 26-28 (October 2007): 977–80. http://dx.doi.org/10.4028/www.scientific.net/amr.26-28.977.

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The welding process, a conventional production method of gate valves, has advantages such as light weight, but it also has disadvantages such high production price. However, the forging process, has economic merits and mass production capability. The main focus of this paper is the optimization of the preform in the forging process. This paper proposes an optimal design of the preform to improve the mechanical efficiency of the gate valve made by the forging method. The design of the preform is optimized by the use of the real response model to the Kriging model by computer simulation. Also, the optimized results were used to verify the response model. The verified response model confirmed the usefulness and reliability of the Kriging method in optimum structural design of preform achieved by finite element analysis and Kriging equations.

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12

Yan, Xiaopeng, and Baijin Chen. "Analysis of a Novel Automatic Control Approach for the Free Forging Hammer." Applied Sciences 10, no. 24 (December 21, 2020): 9127. http://dx.doi.org/10.3390/app10249127.

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This paper proposes an electro-hydraulic servo control method and realizes the automatic control and remote control of free forging hammers for the first time. A configuration and control strategy for the program-control free forging hammer are constructed. Based on the configuration, a single-acting differential servo cylinder system is proposed to drive the follow-up spool valve and then control the motion state of the hammerhead. Furthermore, a non-contact measurement method is adopted to detect the real-time position of the hammerhead, and the installation position of the measuring sensor is isolated from the hammer body and foundation, thereby reducing the influence of vibration and impact on the accuracy of the feedback signal and ensuring the successive forming process of the forging hammer. In addition, a blow energy model of the forging hammer processing system is established, and a fuzzy-PID control scheme for the forging hammer is then adopted. Based on the control strategy, the striking accuracy of the proposed automatic forging hammer is significantly improved compared with the traditional forging hammer. Finally, the method is applied to an 8 MN forging hammer, and the results show its better processing performance than traditional hammers in terms of all indices.

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13

Xu, Xiaodan, Zhifeng Bai, and Yuanyuan Shao. "Synchronization Control Algorithm of Double-Cylinder Forging Hydraulic Press Based on Fuzzy Neural Network." Algorithms 12, no. 3 (March 14, 2019): 63. http://dx.doi.org/10.3390/a12030063.

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In order to solve the poor control accuracy problem of the traditional synchronous control algorithm for a double-cylinder forging hydraulic press, a synchronous control algorithm for double-cylinder forging hydraulic press based on a fuzzy neural network was proposed. According to the flow equation of valve and hydraulic cylinder, the balance equation and force balance equation of forging hydraulic cylinder are established by using the theory of electro-hydraulic servo systems, and the cylinder-controlled transfer function of forging hydraulic cylinder is deduced. By properly simplifying the transfer function, the mathematical model of synchronous control of double cylinder forging hydraulic press is established. According to the implementation process of traditional fuzzy neural networks, the properties of compensation operation are introduced. The traditional fuzzy neural network is optimized, and the optimized neural network is used to realize the synchronous control of the double cylinder forging hydraulic press. The experimental results show that the amplitude curve of the algorithm is very close to the expected amplitude curve, the error amplitude is only 0.3 mm, and the average control time is about 140 s, which fully shows that the algorithm has high accuracy and a good control effect.

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14

Azam, Farooq I., Ahmad Majdi Abdul Rani, Khurram Altaf, and Haizum Aimi Zaharin. "ADDITIVE MANUFACTURING DESIGN OF GLOBE VALVE FOR OPTIMIZED FLOW." Transactions of the Canadian Society for Mechanical Engineering 41, no. 5 (December 2017): 717–23. http://dx.doi.org/10.1139/tcsme-2017-506.

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Valves have wide usage in industries ranging from food industries to petrochemical industries. Existing manufacturing processes, such as casting and forging, limit the design of globe valve to design for manufacturing. The purpose of this study is to optimize the design of current globe valve for optimized flow path. Current design of valve was modelled in CAD software and CFD analysis was performed on its geometry to identify the optimization points. Results obtained from simulations show significant increase in valve’s performance, flow efficiency and decreases in pressure drop. Comparison of flow coefficient between original design and new design show approx. 35% increase in efficiency. Proposed design can be manufactured using additive manufacturing to overcome the manufacturing constraints.

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15

Tzou, Gow-Yi, Shih-Hsien Lin, Dyi-Cheng Chen, and Un-Chin Chai. "Die stress analysis and improvement of the welding valve fastener in multi-stage forging." Transactions of the Canadian Society for Mechanical Engineering 44, no. 2 (June 1, 2020): 263–71. http://dx.doi.org/10.1139/tcsme-2019-0087.

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This study explores the multi-stage cold forming die of a welding valve fastener using simulation software. It is possible to understand the various stress intensities of the die core bore and the corresponding distributions during each forging stage so as to improve the service life of the die. These stresses include radial stress, axial stress, hoop stress, and maximum principal stress, as well as the different types of stresses that could cause different fractures of the die core. Therefore, it is necessary to use different die design methods to improve the fracture issues for different die cores. For example, shrink fit can be used between the die core and die case. By adjusting the size of the shrink fit, tensile hoop stress can be converted into compressive hoop stress, which can avoid the generation of axial cracking of the die during the forging formation. In addition, drastic changes in axial stress caused by the stress concentration on the die core can yield a transverse crack of the die core. Thus adopting preventative measures by split such a stress concentration into two sections reduces the drastic changes in axial stress on that section.

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16

Yang, Ji Dong, and Xin Chen. "Giant Die Forging Press Machine Main Circuit Electromechanical Hydraulic Servo Control System Modeling and Simulation." Advanced Materials Research 317-319 (August 2011): 655–60. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.655.

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This paper research on an electromechanical hydraulic mixture control system used in large scale die-forging press, based on the national major science and technology project (2009ZX04005-011). This mixture control system used in press machine accomplishes pressing, pressure-keeping, return. The control system uses hydraulic oil to control three-position five-path slide valve as hydraulic system main valve, for drive system of giant die forging press is characteristic of ultrahigh pressure and large flow, high power. This control system consists of two parts: firstly, establishing electromechanical hydraulic mixture control model by adding electronics and feedback section to servo slide system. Secondly, combining existing slide control hydraulic cylinder model and server slide system form main circuit closed-loop control system. The last but not least, Computer simulation was conducted by matlab got the ideal control curve.

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17

YAMAMOTO, Yuichi, Shoitsu SEO, Jirou MATSUMOTO, Yoshikuni KADOYA, Toshinari NISHIMURA, and Ryotarou MAGOSHI. "Production and Properties of Modified 9Cr-1Mo Steel Forging (F91) for Valve Bodies." Tetsu-to-Hagane 85, no. 7 (1999): 558–63. http://dx.doi.org/10.2355/tetsutohagane1955.85.7_558.

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18

Kim, Dong Kwon, Dong Young Kim, Seog Hyeon Ryu, and Dong Jin Kim. "Application of nimonic 80A to the hot forging of an exhaust valve head." Journal of Materials Processing Technology 113, no. 1-3 (June 2001): 148–52. http://dx.doi.org/10.1016/s0924-0136(01)00700-2.

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19

Zhu, Yuanzhi, Yin Zhimin, and Xu Jiangpin. "Microstructural mapping in closed die forging process of superalloy Nimonic 80a valve head." Journal of Alloys and Compounds 509, no. 20 (May 2011): 6106–12. http://dx.doi.org/10.1016/j.jallcom.2011.03.038.

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20

Zhu, Muzhi, Jintao Liang, and Shengdun Zhao. "Designing of an electromagnetic driver for the reversing valve of CNC die forging hammer." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 2 (November 14, 2016): 358–68. http://dx.doi.org/10.1177/0954406216679437.

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This paper is aimed at the solution of the driving actuator of the reversing valve, which is the core component of CNC die forging hammer. The proposed electromagnetic drive method contributes to a precise control of the valve spool position and eliminates the transmission mechanism and hydraulic circuits. The complete structure and the topology structure of the electromagnetic part are designed to guarantee its high controllability and robustness. The structure parameters of the electromagnetic part are calculated based on the driving requirement of the reversing valve. With the finite element analysis of the direct driving part, saturation phenomenon of the magnetic circuit is eliminated and optimization of the output force ripple is performed. The output force of the electromagnetic part is simulated to reach 1000 N with a rated speed of 0.55 m/s, which satisfies the drive demand of the reversing valve spool and the ripple amplitude of the output force is reduced by 43.9%. The operational test of the electromagnetic direct drive component is conducted to verify the finite element method simulation method and shows an expected performance.

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21

Choi, Hyoung Jin, Beong Bok Hwang, B. D. Ko, D. H. Jang, and Joong Yeon Lim. "A Study on the Process Design of Cold-Forged Automobile Parts." Materials Science Forum 449-452 (March 2004): 105–8. http://dx.doi.org/10.4028/www.scientific.net/msf.449-452.105.

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The cold forging processes of automobile parts such as piston-pin, valve-spring retainer(VSR) and power-assisted steering part (PAS) are analyzed by the rigid-plastic finite element method. The results of the simulation on the piston-pin are summarized in terms of the strain distribution and load-stroke relationship. Based on the analysis on the current processes of VSR and PAS, the new novel processes for improving the conventional process sequences are designed. As a design criterion, the improved processes satisfy the new condition such as an initial billet size, the production time and the limit value of forming load and pressure etc. The present simulation results and the newly developed process gave rise to an improvement in manufacturing processes for cold-forged automobile parts. Furthermore, the numerical analysis for the processes in this study provides a new design concept for forming processes and a basis for the selection of forging equipments.

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22

Jeong, H. S., J. R. Cho, and H. C. Park. "Microstructure prediction of Nimonic 80A for large exhaust valve during hot closed die forging." Journal of Materials Processing Technology 162-163 (May 2005): 504–11. http://dx.doi.org/10.1016/j.jmatprotec.2005.02.101.

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23

Song, Seung-Eun, and Hyuk-Hong Kwon. "A Study on the Cold Forging Development of Guide Valve for the Fuel Pressure Regulator." Journal of manufacturing engineering & technology 21, no. 2 (April 15, 2012): 331–36. http://dx.doi.org/10.7735/ksmte.2012.21.2.331.

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24

Ji, Hongchao, Xiaomin Huang, Chenjun Ma, Weichi Pei, Jinping Liu, and Baoyu Wang. "Predicting the Microstructure of a Valve Head during the Hot Forging of Steel 21-4N." Metals 8, no. 6 (May 28, 2018): 391. http://dx.doi.org/10.3390/met8060391.

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Ko, B. D., Hyoung Jin Choi, Beong Bok Hwang, S. H. Kim, and Sun Keun Hwang. "A Design of Manufacturing Processes for Valve-Spring Retainer Component." Materials Science Forum 475-479 (January 2005): 3271–74. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.3271.

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New manufacturing processes for a valve-spring retainer (VSR) are proposed by replacing the initial solid billet for commercially available thick-walled pipes. The rigid-plastic FEM has been applied to simulate the conventional five-stage manufacturing process for VSR component. The existing process includes mainly backward extrusion and heading operations. A process design methodology is proposed and applied for the analysis. The process design criteria are the maximum force requirement within the available press limit, and the material saving by reducing the wastes from the process. As a result, several simulations of one-step process from selected stocks to the final product shape are performed for a possibly better process than the conventional one. Statistics among different processes are summarized and compared each other in terms of number of required operations for final product, forging load, material waste, number of individual die, process time, and even the possibility of fracture during service. Experiment also has been conducted to ensure that the proposed one-step process is safe operation without geometrical defects.

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26

Yan, Guan Hai, Sheng Dun Zhao, and Zheng Hui Sha. "Parameters Optimization of Semisolid Diecasting Process for Air-Conditioner’s Triple Valve in HPb59-1 Alloy." Advanced Materials Research 129-131 (August 2010): 936–41. http://dx.doi.org/10.4028/www.scientific.net/amr.129-131.936.

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The disadvantages of air-conditioner’s triple valve in HPb59-1 alloy processed by traditional solid state hot forging, such as larger forming loads, lower material utilization, larger subsequent machining allowance, nonuniform microstructure, are put forward. However, semisolid diecasting forming which can overcome the above shortcomings is a fascinating technology. The process paremeters which had a larger influence on filling ability of semisolid slurry and casting quality, such as pouring temperature, shot velocity and preheated temperature of the die, were chosen. Furthermore, based on orthogonal test, the semisolid diecasting process of a certain type triple valve was simulated with FLOW-3D. According to the analysis of temperature field, pressure field and surface defect concentration, the optimal process parameters such as pouring temperature 897.25 °C, shot velocity 1.5 m/s and preheated temperature of the die 260 °C, were obtained, and the effectiveness of the technology was well demonstrated by numerical simulation.

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27

Liu, Shuangyu, Jiandong Hu, Hongying Wang, Zuoxing Guo, Cai Yu, A. N. Chumakov, and A. Bosak. "A study on microstructures and properties of P/M valve seats of hot forging by laser irradiation." Optics & Laser Technology 39, no. 4 (June 2007): 758–62. http://dx.doi.org/10.1016/j.optlastec.2006.03.004.

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28

Ardi, Syahril, and Apit Hidayat. "OTOMATISASI SISTEM KONTROL MESIN TURNING HEAD NTVS-485 BERBASIS SISTEM KENDALI PLC OMRON CS1G-CPU42H." SINERGI 19, no. 2 (June 1, 2015): 159. http://dx.doi.org/10.22441/sinergi.2015.2.011.

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Meningkatnya penjualan kendaraan berdampak pada meningkatnya permintaan produksi engine valve dari customer. Salah satu perusahaan manufaktur produsen engine valve, melalui Maintenance Department melakukan rekondisi dan atau improvement terhadap beberapa mesin untuk memenuhi permintaan customer. Secara garis besar, proses pembuatan engine valve terdiri dari: forging, stellite welding, heat treatment, dan machining. Salah satu mesin pada proses machining adalah mesin turning head NTVS-485 yang dipakai untuk proses turning head di Seat Stellite Line. Sistem kontrol mesin berbasis relay akan diubah menjadi berbasis kendali PLC (Programmable Logic Controller). Kendali PLC yang akan digunakan adalah PLC Omron CS1G-CPU42H. Perubahan sistem kontrol meliputi: perancangan, pembuatan wiring komponen, dan pemrograman kendali PLC CS1G-CPU42H. Tujuan otomatisasi sistem kontrol ini adalah untuk memudahkan proses penyelesaian kerusakan pada sistem elektrikal sehingga mengurangi waktu downtime elektrikal. Waktu downtime elektrikal pada mesin turning head NTVS-485 rata-rata sepanjang bulan Juli-Desember 2013 adalah sebesar 159.5 menit/bulan, atau turun sebesar 81% menjadi 29 menit pada bulan Mei 2014 setelah dilakukan otomatisasi.

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Kareva, Nadezhda T., Djomi T. Chungakov, and Nikita A. Zavartsev. "The Research of Heat-Resistant Layer Defects Formed during the Surfacing of Nickel Alloy on the Exhaust Valve Chamfer." Materials Science Forum 989 (May 2020): 133–38. http://dx.doi.org/10.4028/www.scientific.net/msf.989.133.

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The final set of properties of the exhaust valve is formed in the course of the entire set of processes, the most important is the build-up of the valve chamfer which is subjected to constant high temperatures, gas flow and thermal cycling, therefore strict adherence to the whole complex of properties is necessary. In the study two materials were investigated: the deformable part of the base material (steel grade 40X10C2M (EN steel grade X40CrSiMo10)) and surfacing (alloy EP616A), used to manufacture the exhaust valve of the internal-combustion engine.The study was carried out at different stages of valve manufacturing: after electro-forging during the formation of a valve head from a rod, subsequent heat treatment (quenching + high tempering), after surfacing a ring with the heat-resistant alloy. The chemical composition of phases, inclusions, and sections of EP616A alloy around the shrink-hole were determined by the method of micro-X-ray analysis. The results indicate a shortage of visual inspection, and that conducting a selective destructive method does not ensure the full probability of detecting internal defects. It is advisable instead of destructive control to introduce ultrasonic flaw detection.

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Kapustova, Maria. "The Verification of Material Plastic Flow at Optimal Warm Forging Temperature Using Computer Simulation." Applied Mechanics and Materials 421 (September 2013): 229–34. http://dx.doi.org/10.4028/www.scientific.net/amm.421.229.

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Warm forging is most commonly used for production of die forgings which are manufactured by means of precise forging. As compared to cold forging, warm forging enables to reduce forging forces size considerably. Development of warm forging technology is connected to formability and plasticity research of forged material at warm temperatures. This contribution brings a methodology for optimal forging temperature determination from recommended interval of warm temperatures used for chromium-manganic steel 16MnCr5. The given steel is appropriate for case hardening and precise die forgings production. For the purpose of verification of steel forgeability at the recommended interval of warm forging temperatures 600, 650, 700 and 750 °C technological test of upsetting according to Zidek is used. The main factor of plasticity for optimal warm temperature selection from examined temperature interval is value of reduction of area that was determined by tensile test. Numeric simulation of forging process in closed die confirmed correct plastic flow of steel 16MnCr5 at recommended forging temperature 700 degrees of Celsius.

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Huang, Shu Hai, and Xiang Sheng Xia. "Quality Cost Analysis of Typical Forging Based on SPC and DEA Model." Advanced Materials Research 1095 (March 2015): 808–15. http://dx.doi.org/10.4028/www.scientific.net/amr.1095.808.

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In order to control the quality costs of forgings efficiently and ensure the optimization of enterprise production value input and benefit output, using piston, output shaft and other typical forgings as application objects, choosing cold and warm forging process instead of the former single hot forging or cold forging process, reinforcing Statistical Process Control (SPC) of processing quality and appropriately distributing quality failure cost and quality assurance cost in order to efficiently match the total cost of quality, quality process capacity index and production program so that the stability of forging quality can be improved. Using Data Envelopment Analysis (DEA) to contrast and analysis the quality cost data of new process and old process, of which the result shows that the technical input and benefit output of new process accord with mass production requirements in the prior period of enterprise industrialization.

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F. Bairamov, Bulat, Artur A. Fardeev, and Albert R. Fardeev. "Mathematical Model of the Controlled Object when Regulating the Working Volume of the Manipulator Pump." International Journal of Engineering & Technology 7, no. 4.36 (December 9, 2018): 1058. http://dx.doi.org/10.14419/ijet.v7i4.36.24953.

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This paper describes the constructed mathematical model of the controlled object of the automated system for controlling the displacement volume of the manipulator pump. The change in pump displacement volume is performed in order to save energy by minimizing the fluid drain through the overflow valve. The use of the considered manipulator is intended in the process of automated supply of blanks to the working area of a press used in forging and hot stamping processes. The reactive forces acting on the moving parts of the mobility modules from the fixed parts of the manipulator are determined. Conversion of the useful power of the pump into the useful power of hydraulic motors is performed. This takes into account the losses using efficiency. An equation describing the mathematical model of the controlled object is obtained. This equation is represented in relative variables. The derivation of this equation and the determination of the reactive forces are made on the basis of the assumption that all transport degrees of freedom are translational. This limitation is caused by the peculiarities of the working area of the press used in technological processes of forging and hot forming of blanks. The working zone is a deep horizontal tunnel, the movement of the working object in which is possible only with translational degrees of freedom.

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Ma, Bao Cong, and Xiang Ke Tian. "The Application and Research on Manufacturing Technology of the Heavy Forging." Advanced Materials Research 941-944 (June 2014): 1692–95. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.1692.

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For large forging is high-tech product of material, smelting, forging, heat treatment and it is the bottleneck which restricts the development of the modern heavy equipment manufacturing industry. The key technology such as forging and heat treatment of large forgings is researched. Finally, with the ultra supercritical power generation units of low-pressure rotor, the production process control technology such as smelting, forging and heat treatment is introduced. The method provides a reliable basis for the localization of production of ultra supercritical steam turbine rotor and has the important practical application value.

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Gontarz, Andrzej, Krzysztof Drozdowski, Anna Dziubinska, and Grzegorz Winiarski. "A study of a new screw press forging process for producing aircraft drop forgings made of magnesium alloy AZ61A." Aircraft Engineering and Aerospace Technology 90, no. 3 (April 9, 2018): 559–65. http://dx.doi.org/10.1108/aeat-11-2016-0238.

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Purpose The aim of this study is to develop a die forging process for producing aircraft components made of magnesium alloy AZ61A using a screw press. Design/methodology/approach The proposed forging technique has been developed based on the results of a numerical and experimental research. The required forging temperature has been determined by upsetting cylindrical specimens on a screw press to examine both plasticity of the alloy and the quality of its microstructure. The next stage involved performing numerical simulations of the designed forging processes for producing forgings of a door handle and a bracket, both made of magnesium alloy AZ61A. The finite element method based on simulation programme, Deform 3D has been used for numerical modelling. The numerical results revealed that the forgings are free from material overheating and shape defects. In addition to this, the results have also helped determine the regions that are the most prone to cracking. The final stage of the research involved performing forging tests on a screw press under industrial conditions. The forgings of door handles and brackets were made, and then these were tested for their mechanical and structural properties. The results served as a basis for assessing both the viability of the designed technique and the quality of the produced parts. Findings The experimental results demonstrate that aircraft components made of magnesium alloy AZ61A can be produced by die forging on screw presses. The results have been used to determine the fundamental parameters of the process such as the optimum forging temperature, the method of tool heating, the way of cooling parts after the forging process, and the method of thermal treatment. The results of the mechanical and structural tests confirm that the products meet the required quality standards. Practical implications The developed forging technique for alloy AZ61A has been implemented by the forging plant ZOP Co. Ltd in Swidnik (Poland), which specializes in the manufacturing of aircraft components made of non-ferrous metal alloys. Originality/value Currently, the global tendency is to forge magnesium alloys (including alloy AZ61A) on free hydraulic presses using expensive die-heating systems. For this reason, the production efficiency of such forging processes is low, while the manufacturing costs are high. The proposed forging technique for alloy AZ61A is an innovative method for producing forgings using relatively fast and efficient machines (screw presses). The proposed forging method can be implemented by forging plants equipped with standard stocks of tools, which increases the range of potential manufacturers of magnesium alloy products. In addition, this technology is highly efficient and ensures reduced manufacturing costs.

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Timata, Manit, and Charnnarong Saikaew. "Experimental and Simulation Study on Tool Life Models in Drilling of Forging Brass Using Uncoated-WC and AlCrN Coated-WC Tools." Coatings 9, no. 12 (December 13, 2019): 853. http://dx.doi.org/10.3390/coatings9120853.

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Burr is an undesirable phenomenon occurring in drilling operation which is one of the essential operations in the machining industry since it is directly influencing the operating costs. Exit burr height (EBH) values as the function of drilling time during drilling the specific holes of the forging brass workpieces used for producing the water-valve components with the uncoated- tungsten carbide (WC) and the AlCrN coated-WC drills were discussed. The data sets of drilling time, corresponding to EBH values at the appropriate criterion were used to develop the tool life models in terms of cutting speed and feed rate using Taylor’s equation. Monte Carlo simulation was adopted to study the uncertainty of cutting speed and feed rate on tool life predictions for sensitivity analysis. The results showed that drilling with a low feed rate decreased the averages of EBH. The predicted tool life values of the AlCrN coated-WC drills were higher than those of the uncoated-WC ones based on the results of tool life predictions. The appropriate operating condition of the cutting speed of 60 m/min and the feed rate of 0.2 mm/rev was recommended for manufacturers in the drilling of the forging brass workpieces using the AlCrN coated-WC drills. Moreover, the predicted tool life values for the uncoated-WC and the AlCrN coated-WC drills were about 600 and 800 min, respectively. This indicated that the AlCrN coated-WC drill increased tool life by 30%.

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Lecadet, J., R. Forestier, and P. Delaborde. "Advances and Breakthroughs in Titanium forgings for critical structural parts." MATEC Web of Conferences 321 (2020): 02005. http://dx.doi.org/10.1051/matecconf/202032102005.

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Assuming the high level of properties and reliability of titanium forgings, strong drivers of research and development for forgings are the pressure on cost, the buy to fly ratio reduction and the life cycle. This presentation discusses the potential of optimizations to address these challenges. The first way to concretely answer the question of the cost and of the life cycle is the recycling of manufacturing scrap and end-of-life products, using the concept of circular economy and implementing a short loop from end user to melters. This is a considerable opportunity to mitigate the risks related to the supply of primary material and to the erratic fluctuations of raw material prices. The second step to optimize both the added value and the material consumption consists in adapting accurately the melting and ingot conversion processes to the actual needs of the application and the subsequent transformation processes. Considering the close die forging step, the use of the concept of Design for forging has also a great potential to optimize the cost and the functions of the forgings. Near Net Shape Forging of titanium, using high temperature close die forging is a great opportunity to make a breakthrough in terms of buy to fly ratio. In addition to all these improvements, the use of high-power hydraulic presses is a key element to take full advantage of them and to manufacture large critical parts with more functions. All together these levers could provide drastic cost reductions, and a considerable reduction in the environmental impact, keeping the advantages of titanium forgings in terms of metallurgical integrity, residual stresses and properties. The implementation of these improvements will require continuous efforts of development from the whole titanium supply chain, and collaboration between integrated titanium forgings suppliers and the OEMs.

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Xia, Qin Xiang, Zhe Lin Li, Wei Qi Zong, and He Qing Xie. "Contour Extraction for Images of High Temperature Long Shaft Heavy Forgings." Advanced Materials Research 562-564 (August 2012): 1655–59. http://dx.doi.org/10.4028/www.scientific.net/amr.562-564.1655.

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Non-contact measuring method based on CCD camera is desirable for product quality of high temperature long-shaft heavy forgings. In the light of the characteristics of RGB primary color and halation in forging image, the mean red gray value in the high temperature area is proposed as the dynamic threshold to acquire external contours. Internal edges in the image of the hot forging are blurry and discontinuous. For these characteristics, a method based on quadratic B-spline curve is employed to extract and fit the internal contours. Experiments show that this method can effectively remove pseudo features and extract accurate internal and external contours for images of high temperature squaring and chamfering forgings of 900 0C to 1050 0C.

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Yan, Xiaopeng, and Baijin Chen. "Energy-Efficiency Improvement and Processing Performance Optimization of Forging Hydraulic Presses Based on an Energy-Saving Buffer System." Applied Sciences 10, no. 17 (August 31, 2020): 6020. http://dx.doi.org/10.3390/app10176020.

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This paper proposes an energy-saving system based on a prefill system and a buffer system to improve the energy efficiency and the processing performance of hydraulic presses. Saving energy by integrating such systems into the cooling system of a hydraulic press has not been previously reported. A prefill system, powered by the power unit of the cooling system, is used to supply power simultaneously with the traditional power unit during the pressurization stage, thus reducing the usage of pumps and installed power of the hydraulic press. In contrast to the traditional prefill system, the proposed energy-saving system is controlled by a servo valve to adjust flow according to the load profile. In addition, a buffer system is employed to the cooling system to absorb the hydraulic shock generated at the unloading stage, store those shares of hydraulic energy as a recovery accumulator, and then release this energy to power the prefill system and the hydraulic actuator in the subsequent productive process. Finally, through a series of comparative experiments, it was preliminarily validated that the proposed system could reduce the installed power and pressure shock by up to 22.85% and 41%, respectively, increase energy efficiency by up to 26.71%, and provide the same processing characteristics and properties as the traditional hydraulic press.

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Kitashima, Tomonori, Lingjian Meng, and Makoto Watanabe. "Deformation-Induced Grain-Interior α Precipitation and β Texture Evolution during the β-Processed Forging of a Near-β Titanium Alloy." Metals 11, no. 9 (September 6, 2021): 1405. http://dx.doi.org/10.3390/met11091405.

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The effect of grain-interior α precipitation on the β texture evolution of the near-β Ti-6246 alloy during through-transus forging was investigated in two-step sequential forgings. The microstructure and texture were analyzed using scanning electron microscopy, electron-backscatter diffraction, and X-ray diffraction. The previous β forging was performed at 1253 K at 0.01/s, while the subsequent forging in the (α + β) region was conducted at 1073 K at 0.01/s. The forging in the β region facilitated the penetration of the interior α phase into β grains and reduced the formation of grain boundary α. The {001} texture intensity increased during the forging in the single β region. By contrast, the increase in the {001} texture intensity was moderate at a lower temperature (1073 K) because the Schmid factor (SF) value of the {110}<111> slip system drastically decreased, but those of the {112}<111> and {123}<111> slip systems increased before α precipitation. During α precipitation for all β forging ratios, the {110}<111> slip system was activated, resulting in a lowering of the {001} texture intensity. The lower the forging temperature before interior α precipitation under a constant total forging ratio, the more the {001} texture intensity was suppressed in the final β texture, accompanied by interior α precipitation.

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Dyl, Tomasz Cyryl, Robert Starosta, and Robert Skoblik. "Effect of the Unit Pressure on the Selection Parameters of Intermetallic Coatings NiAl and Ni₃Al after Plastic Working." Solid State Phenomena 165 (June 2010): 19–24. http://dx.doi.org/10.4028/www.scientific.net/ssp.165.19.

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Modern materials on intermetallic matrix are in the scope of research of many scientific – research centers in Poland [1]. Intermetallic systematic alloys containing aluminium have high resistance to oxidation, abrasive corrosion and fatigue as well as heat resistance. That is why they are applied in the production of machine parts used in hard service conditions (internal combustion turbine blades, exhaust valves, turbo-blower rotors) [2]. Intermetallic coatings can be obtained by means of plasma spraying. Thermal spraying technology is widely used due to the possibility of increasing the service properties in surface layers (strength property, tribological, anti-corrosive and decorative property) as well as coating application on machine parts elements, on tools for plastic working (forging moulds busters, piston rods, gear wheels teeth, crank journals, valve seats, and combustion engine cylinders) [3, 4]. NiAl and Ni3Al coatings are characterized by high fatigue resistance, heat resistance and considerable corrosion resistance [5]. Coatings obtained by thermal spraying have high surface roughness. Thus, subsequent plastic treatment is advisable for plasma-sprayed intermetallic coatings. Therefore it is vital to define to what extent the change of unit pressure will influence reduction of surface roughness of intermetallic coatings. For this purpose experimental upsetting research was carried out on C45 steel samples having NiAl and Ni3Al coatings for the following unit pressures p = 500 MPa, p = 800 MPa, p = 1100 MPa.

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Dziubińska, Anna, and Andrzej Gontarz. "New Method for Forming Brackets with a Triangular Rib." Key Engineering Materials 622-623 (September 2014): 217–22. http://dx.doi.org/10.4028/www.scientific.net/kem.622-623.217.

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This paper presents the experimental research results concerning a new method of forming of brackets with a triangular rib. The forging process of products with ribs was conducted applying a three-slide forging press (TSFP) on material model in the form of lead plates. During the experiment, the influence of the process particular parameters on the obtained products quality was analyzed. On the basis of the research results the main failure modes of the material during processing were determined. The limiting value of the plate upsetting coefficient depending on its length was given. Considering conducted research works, it was stated that it is possible to form such brackets forgings in TSFP in accordance with the worked out method.

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Joshy, Sam, Jayadevan K.R., Ramesh A., and Mahipal D. "Microstructural evolution and microhardness response of H11 hot forging dies." World Journal of Engineering 16, no. 5 (October 7, 2019): 573–81. http://dx.doi.org/10.1108/wje-09-2018-0334.

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Purpose The prime task of research in hot forging industry is to improve the service life of forging dies. The in-service microstructural changes that may occur in a die during hot forging is expected to significantly affect the service life. The purpose of this work is to analyse the microstructural evolution of double tempered hot forging dies in a real industrial environment, and the correlation of microstructural and microhardness evolution to the in-service wear and plastic deformation. Design/methodology/approach Specific hot forging tests were carried out on double tempered AISI H11 chromium tool steel for 100, 500 and 1,000 forging strokes. Macro analysis was conducted on die cross section to analyse the wear and plastic deformation at different stages of forging cycles. Microhardness and microstructural analyses were performed on the die surface after these forging tests. Findings The macro analysis on the transverse section of dies shows that wear is predominant during initial forging strokes, whereas plastic deformation is observed in later stages. Microstructural analyses demonstrate that during first 500 forging cycles, carbide population decreases at 63 per cent higher rate as compared to corresponding drop during 501 to 1,000 forging cycles. Additionally, the carbide size increases at all stages of forging cycle. Further, microstructural images from dies after 1,000 forging strokes show clustering and spherodisation of carbides by which the “blocky”-shaped carbides in pre-forging samples had spherodised to form “elongated spherical” structures. Practical implications The findings of this work can be used in hot forging industries to predict amount of wear and plastic deformation at different stages of service. From the results of this work, the service life of double tempered H11 hot forging dies used in forging without lubrication is within 501 to 1,000 forgings. Originality/value Most of the literatures are focussed on the cyclic softening of material at constant temperature. This work analyses the microstructural evolution of double tempered hot forging dies in a real industrial environment and correlates the microstructural and microhardness evolution to the in-service wear and plastic deformation.

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Hawryluk, Marek, Zbigniew Gronostajski, Jacek Ziemba, Marta Janik, Piotr Górski, and Miłosz Lisowski. "Support Possibilities for 3D Scanning of Forging Tools with Deep and Slim Impressions for an Evaluation of Wear by Means of Replication Methods." Materials 13, no. 8 (April 17, 2020): 1881. http://dx.doi.org/10.3390/ma13081881.

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This article discusses the problems related to the use of non-contact 3D scanning techniques and their support by means of replication methods for the analysis of the geometrical changes in deep tool impressions used for the forward extrusion of valve-type elements assigned for motor truck engines. The 3D scanning method, despite its unquestionable advantages, also has certain limitations, such as scanning the inner surfaces of deep cavities. This is caused by the fact that the larger the angle between the reflected laser light and the normal direction to the measured surface, the larger the area covered for the analysis, yet at the same time, the higher the measurement error. The authors performed an analysis of the geometrical loss of the tools as well as the corresponding replication masses, together with a discussion of the results related to minimization of the measuring errors. For the analyzed tool, the maximum angle during direct scanning was 40 degrees, which unfortunately does not enable an analysis of the entire pattern, while for larger angles, it is necessary to make the measurement by indirect scanning, i.e., by replicating the cavity imprint of the tool. Therefore, for a given geometry, the reflection angle should be determined individually.

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Petrov, Michael A., Timophey S. Basyuk, Pavel A. Petrov, and Alexander N. Petrov. "Experimental Investigations on the Relation of the Lubricant’s Flash Point and Quality of the Piston Made from Aluminium Alloy for its Application in Internal Combustion Engines." Key Engineering Materials 651-653 (July 2015): 297–304. http://dx.doi.org/10.4028/www.scientific.net/kem.651-653.297.

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In the current paper there was made an attempt to develop an experimental method of physical (lubricant’s flash point Tfp) and subjective (forgings’ quality) parameters coupling for hot isothermal-like forging operation. The quality forgings could be manufactured both by high and low lubricant’s flash point. The increase of Tfp value in exothermal reaction follows to the increase of the released heat amount by the lubricant, because it needs more initial activation energy transmitted from the external source to initialize transformation of the material from one aggregate state into another (from liquid or solid into gaseous or sol-like). This can prevent the temperature decrease on the punch due to strong convective heat transfer with the environment through the building of the isolation temperature shield on the punch contact surface at the beginning of the punch stroke. On the other hand it can cause the defect building on the forgings like penetrations, which could not be eliminated during cleaning operation before mechanical treatment due to chemical interactions of the dissolved active agents, or unfilled sections.

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Kitashima, Tomonori, Yoshinori Yoshida, and Ryo Matsumoto. "Temperature Increase during Isothermal Forging of Ti-5Al-2Sn-2Zr-4Cr-4Mo Alloy Using a 1500-Ton Forging Press." Materials Science Forum 1016 (January 2021): 702–7. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.702.

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In this study, the temperature increase of the Ti-17 alloy (Ti–5Al–2Sn–2Zr–4Cr–4Mo, wt.%) during isothermal forging in the (α + β) dual-phase region was investigated using large-size workpieces forged between hot dies in a 1500-ton forging press. The temperature increase was predicted using finite element analysis (FEA). The tip of a thermocouple was inserted into the center of the workpiece (diameter: 100 mm; height: 50 mm). The forging temperatures were 1023 K (750 °C) and 1073 K (800 °C) in the (α + β) dual-phase region. The strain rate was 0.05 s−1 and 0.5 s−1 at each temperature. Meanwhile, the compression percentage was 75%. The true stress–true strain curves were inversely obtained by fitting the load–stroke curves using the FEA. The predicted temperature was in a good agreement with that in the experimental results when the value of 1.0 was used as the conversion factor for plastic deformation energy to heat energy in the FEA under the current forging conditions. At the strain rate of 0.5 s−1, the temperature instantly increased to a β-transus temperature in 3 s at 1073 K (800 °C). In contrast, the temperature logarithmically increased at both 1023 K (750 °C) and 1073 K (800 °C) at 0.05 s−1 in 28 s (e.g., 42 K at 1023 K (750 °C)). The obtained true stress–true strain curves indicate that flow softening occurred during the forgings, which is attributed to dynamic recrystallization and/or dynamic recovery. The temperature increase in the Ti-17 alloy was smaller than that in the Ti–6Al–4V alloy under the same forging condition.

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Kukuryk, Marcin. "Experimental and FEM Analysis of Void Closure in the Hot Cogging Process of Tool Steel." Metals 9, no. 5 (May 10, 2019): 538. http://dx.doi.org/10.3390/met9050538.

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In the present study, a new complex methodology for the analysis the closure of voids and a new forging system were developed and tested. The efficiency of the forging parameters and the effective geometric shapes of anvils to improve void closure were determined. A new cogging process provided a complete closure of an ingot’s axial defects, as confirmed by experimental tests. The evolution behavior of these defects with different sizes was investigated during the hot cogging process by means of the professional plastic forming software Deform-3D. A comprehensive procedure was developed using the finite-element method (FEM) for the three-dimensional cogging process and laboratory experimentation to predict the degree of void closure. The hot multi-pass cogging process was used to eliminate void defects in the forgings so as to obtain sound products. In the compression process, the effects of the reduction ratio and forging ratio, the void size, and the types of anvil were discussed to obtain the effective elimination of a void. For the purpose of the assessment of the effectiveness of the void closure process, the following indices were introduced: the relative void volume evolution ratio, the relative void diameter ratio, and the internal void closure evaluation index. Moreover, the void closure process was assessed on the basis of stress triaxiality, hydrostatic stress, forging ratio, value of local effective strain around the void, and critical reduction ratio. The results of this research were complemented by experiments predicting the formation of fractures in the regions near the void and in the volume of the forging in the course of the cogging process. The comparison between the predicted and the experimental results showed a good agreement.

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Xiao, Shi Cheng, L. P. Zhang, Li Yong Ni, Wen Hua Yang, and H. L. Liu. "Comparison of Stretching with Horizontal V-Shaped Anvils and Common Flat Anvils." Materials Science Forum 628-629 (August 2009): 611–16. http://dx.doi.org/10.4028/www.scientific.net/msf.628-629.611.

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Research was conducted for stretching with horizontal V-shaped anvils (HVA) and common flat anvils (FA). The forgoing research gave the simulation results of single blowing during stretching, and did not pay attention to the influence of the deformation, resulting from the previous blowing, upon the next blowing. ANSYS software is adopted to simulate the through-continuous blowing of HVA and FA forging methods. The transversal stress distribution along the horizontal central axis on the crosssection of the stretched forging is analyzed. The simulation results show that during the stretching with flat anvils, when the ratio of the flat anvil width to the billet height is 1.0 and the ratio of the billet width to the billet height is 0.5, the transversal stress is tensile all the time, and increases as the stretching goes. On the contrary, during the HVA stretching, the stress is compressive and its absolute value increases gradually. The results show that the HVA stretching method is prior to the FA stretching method in the controlling of transversal stress. Conducted physical experiment verified the results.

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Kunčická, Lenka, Michal Jambor, Adam Weiser, and Jiří Dvořák. "Structural Factors Inducing Cracking of Brass Fittings." Materials 14, no. 12 (June 12, 2021): 3255. http://dx.doi.org/10.3390/ma14123255.

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Cu–Zn–Pb brasses are popular materials, from which numerous industrially and commercially used components are fabricated. These alloys are typically subjected to multiple-step processing—involving casting, extrusion, hot forming, and machining—which can introduce various defects to the final product. The present study focuses on the detailed characterization of the structure of a brass fitting—i.e., a pre-shaped medical gas valve, produced by hot die forging—and attempts to assess the factors beyond local cracking occurring during processing. The analyses involved characterization of plastic flow via optical microscopy, and investigations of the phenomena in the vicinity of the crack, for which we used scanning and transmission electron microscopy. Numerical simulation was implemented not only to characterize the plastic flow more in detail, but primarily to investigate the probability of the occurrence of cracking based on the presence of stress. Last, but not least, microhardness in specific locations of the fitting were examined. The results reveal that the cracking occurring in the location with the highest probability of the occurrence of defects was most likely induced by differences in the chemical composition; the location the crack in which developed exhibited local changes not only in chemical composition—which manifested as the presence of brittle precipitates—but also in beta phase depletion. Moreover, as a result of the presence of oxidic precipitates and the hard and brittle alpha phase, the vicinity of the crack exhibited an increase in microhardness, which contributed to local brittleness.

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Hawryluk, M., and B. Mrzyglod. "A system of analysis and prediction of the loss of forging tool material applying artificial neural networks." Journal of Mining and Metallurgy, Section B: Metallurgy 54, no. 3 (2018): 323–37. http://dx.doi.org/10.2298/jmmb180417023h.

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The article presents the use of artificial neural networks (ANN) to build a system of analysis and forecasting of the durability of forging tools and the process of acquiring the source knowledge necessary for the network learning process. In particular, the study focuses on the prediction of the geometrical loss of the tool material after different surface treatment variants.The methodology of developing neural network models and their quality parameters is also presented. The standard single-layer MLP networks were used here; their quality parameters are at a high level and the results presented with their participation give satisfactory results in line with technological practice. The data used in the learning process come from extensive comprehensive performance tests of forging tools operating under extreme operating conditions (cyclic mechanical and thermal loads). The parameterization of the factors important for the selected forging process was made and a database was developed, including 900 knowledge vectors, each of which provided information on the size of the geometrical loss of the tool material (explained variables). The value of wear was determined for the set values of explanatory variables such as: number of forgings, pressure, temperature on selected tool surfaces, friction path and the variant of the applied surface treatment. The results presented in the study, confirmed by expert technologists, have a clear applicational character, because based on the presented solutions, the optimal treatment can be chosen and the appropriate preventive measures applied, which will extend the service life.

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Mccullough, Michael E., and Everett L. Worthington. "Encouraging Clients to Forgive People who have Hurt Them: Review, Critique, and Research Prospectus." Journal of Psychology and Theology 22, no. 1 (March 1994): 3–20. http://dx.doi.org/10.1177/009164719402200101.

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The literature addressing forgiving and its use as a counseling technique is reviewed. Forgiving is hypothesized to yield cognitive, emotional, and interpersonal benefits to individuals who forgive others of significant interpersonal offenses, though little evidence supports these claims. Religious counselors and clients value forgiveness and its implementation in counseling, and forgiveness is frequently encouraged in religious counseling. However, forgiveness receives little attention from many non-religious professionals and remains to be investigated critically. In light of the potential benefits associated with forgiving, researchers and practitioners are encouraged to consider forgiveness as a therapeutic technique and to investigate its effects scientifically.

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Journal articles on the topic 'Forging valve'

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