Journal articles: 'Low-temperature tempering'

1

Peet, Mathew J., Sudarsanam Suresh Babu, Mike K. Miller, and H. K. D. H. Bhadeshia. "Tempering of Low-Temperature Bainite." Metallurgical and Materials Transactions A 48, no. 7 (April 10, 2017): 3410–18. http://dx.doi.org/10.1007/s11661-017-4086-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Ivanov, Yu F., and É. V. Kozlov. "Low-temperature tempering kinetics of hardened steel 38KhN3MFA." Russian Physics Journal 36, no. 2 (February 1993): 132–36. http://dx.doi.org/10.1007/bf00574093.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Worasaen, Kaweewat, Andreas Stark, Karuna Tuchinda, and Piyada Suwanpinij. "Performance of a Matrix Type High Speed Steel after Deep Cryogenic and Low Tempering Temperature." Materials Science Forum 1016 (January 2021): 1423–29. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.1423.

Full text

Abstract:

A matrix type high speed steel YXR3 designed for a combination of wear resistance and toughness is investigated for its mechanical properties after hardening by deep cryogenic treatment follow by tempering. The deep cryogenic quenching carried out at -200 °C for 36 hours and the single step tempering results in an obvious improvement in wear resistance while balancing the toughness, comparing with the conventional quenching followed by a double tempering treatment. The quantitative image analysis reveals little difference in the MC carbide size distribution between tempering at different temperatures. The synchrotron high energy XRD confirms the MC type carbide with some evolution in its orientation together with tempered martensite approaching the BCC structure at higher temperatures. In contrary to the conventional quenching and tempering, the lowest tempering temperature at 200 °C yields a moderate drop in hardness with increase in surface toughness proportionally while exhibiting exceptional wear resistance. Such thermal cycle can be recommended for the industry both for the practicality and improved tool life.

APA, Harvard, Vancouver, ISO, and other styles

4

Liu, Sheng Xu, Yi Qiang Xiao, Ming Long Kang, Jian Min Zeng, Guo An Wang, Qiu Hong Meng, and Ying Zhang Deng. "Effect of Different Tempering Temperatures on Microstructure and Impact Property of 20CrMnTi Steel." Advanced Materials Research 900 (February 2014): 92–95. http://dx.doi.org/10.4028/www.scientific.net/amr.900.92.

Full text

Abstract:

The effect of different tempering temperatures on microstructure and impact property of 20CrMnTi steel has been studied on Zwick/roell Amsler PKP 450 pendulum machine, SU-8020 scanning electron microscope (SEM) and optical microscope. The results shows that the impact property of 20CrMnTi steel is dramatically improved after high-temperature tempering. However, the minimum value occurs when it was tempered at 350°C because of low-temperature tempering brittlement at this degree. The SEM fracture morphology was typical dimples after high temperature tempering, and the type of fracture was ductile fracture; the type of cleavage characteristic and quasi cleavage characteristic were generated on the fracture morphology at low-temperature and medium-temperature tempering respectively, and the type of fracture was brittle.

APA, Harvard, Vancouver, ISO, and other styles

5

Wang, Ke Lu, Xin Li, and Xian Juan Dong. "Effect of Tempering Temperature on Mechanical Properties and Microstructures of 800MPa Microalloy Low Carbon Bainitic Steel." Advanced Materials Research 893 (February 2014): 406–9. http://dx.doi.org/10.4028/www.scientific.net/amr.893.406.

Full text

Abstract:

The effect of tempering temperature on the microstructures and mechanical properties of a microalloy low carbon bainitic steel was investigated by microscopic analysis and testing of mechanical properties. The results show that the microstructures of the tested steel primarily consists of lath bainite, granular bainite, quasipolygonal ferrite and little acicular ferrite at different tempering temperatures. With the tempering temperature increasing, the proportion of lath bainitie decreases, while the volume of granular bainite and quasipolygonal ferrite increases. At the tempering temperatures of 550-650°C and tempering time of 1 hour, the steel was mostly composed of granular bainite, quasipolygonal ferrite and a little lath bainite, which a good combination of strength and toughness can be obtained.

APA, Harvard, Vancouver, ISO, and other styles

6

Wang, Xue Min, and Hui Zhao. "The Tempering on Microstructure and the Yield-to-Tensile Ratio of High Performance Steels." Advanced Materials Research 535-537 (June 2012): 655–58. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.655.

Full text

Abstract:

The effects of tempering temperature on the microstructure and mechanical properties of 600MPa grade low carbon bainitic steel were investigated. The cause for the microstructure evolution has been investigated and the best tempering process was chosen to decrease the yield ratio of the steel. The influence of tempering process on the yield-to-tensile ratio of steels has been investigated by the aid of optical microscopy, SEM and XRD. The results show that after the TMCP processing the microstructure of steels mainly consist of lath martensite and bainite. The bainite and martensite have been refined markedly after the relaxation processing, therefore the properties of steels has been improved evidently. In order to decrease the yield-to-tensile ratio the steels underwent high temperature tempering. It has been found that during the tempering with the tempering temperature increased the yield-to-tensile ratio of steels decreased. The XRD and EBSD results show tempering temperature has considerable influence on the yield strength, but the influence on the tensile strength is not considerable. With the increase in tempering temperature, the low temperature toughness of steel can be improved considerably. The yield ratio of the steel was reduced after tempering at 650 °C and higher temperatures due to reversed austenitic phase transformation.

APA, Harvard, Vancouver, ISO, and other styles

7

Liu, E., Feng Lan Wei, and Li Chun Qiu. "Orthogonal Test on Heat Treatment Parameters of Modified Low Chromium White Cast Iron." Advanced Materials Research 399-401 (November 2011): 268–72. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.268.

Full text

Abstract:

The effect of austenitizing temperature, heating time and tempering temperature on hardness and impact toughness of low chromium white cast iron was studied by orthogonal test. The optical microstructure was used to analyze the reasons of changes on mechanical properties. The results showed that the hardness increases at beginning and then decreases with the increase of each parameter, high impact toughness can be obtained at high tempering temperature and high austenitizing temperature, the descending order of influence on hardness and impact toughness is austenitizing temperature, heating time, tempering temperature.

APA, Harvard, Vancouver, ISO, and other styles

8

Haiko, Oskari, Antti Kaijalainen, Sakari Pallaspuro, Jaakko Hannula, David Porter, Tommi Liimatainen, and Jukka Kömi. "The Effect of Tempering on the Microstructure and Mechanical Properties of a Novel 0.4C Press-Hardening Steel." Applied Sciences 9, no. 20 (October 10, 2019): 4231. http://dx.doi.org/10.3390/app9204231.

Full text

Abstract:

In this paper, the effects of different tempering temperatures on a recently developed ultrahigh-strength steel with 0.4 wt.% carbon content were studied. The steel is designed to be used in press-hardening for different wear applications, which require high surface hardness (650 HV/58 HRC). Hot-rolled steel sheet from a hot strip mill was austenitized, water quenched and subjected to 2-h tempering at different temperatures ranging from 150 °C to 400 °C. Mechanical properties, microstructure, dislocation densities, and fracture surfaces of the steels were characterized. Tensile strength greater than 2200 MPa and hardness above 650 HV/58 HRC were measured for the as-quenched variant. Tempering decreased the tensile strength and hardness, but yield strength increased with low-temperature tempering (150 °C and 200 °C). Charpy-V impact toughness improved with low-temperature tempering, but tempered martensite embrittlement at 300 °C and 400 °C decreased the impact toughness at −40 °C. Dislocation densities as estimated using X-ray diffraction showed a linear decrease with increasing tempering temperature. Retained austenite was present in the water quenched and low-temperature tempered samples, but no retained austenite was found in samples subjected to tempering at 300 °C or higher. The substantial changes in the microstructure of the steels caused by the tempering are discussed.

APA, Harvard, Vancouver, ISO, and other styles

9

Liu, Chen Xi, Ze Sheng Yan, Zhi Zhong Dong, Yong Chang Liu, and Bao Qun Ning. "Effects of Two-Step Tempering Treatment on the Microstructural Formation of T91 Ferritic Steels." Solid State Phenomena 172-174 (June 2011): 875–80. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.875.

Full text

Abstract:

As a representative type of high Cr ferritic heat-resistant steels, T91 steels (ASME SA-213 T91/P91) has been recognized as the preferable materials and widely used in high-temperature structural components such as header and main steam pipe in advanced power plants. For the service condition is tempered martensites, its corresponding microstructure and mechanical performance are mainly adjusted by the tempering treatment. After exploring the size and number of MX and M23C6precipitating particles and the width of martensitic lath as a function of tempering temperature, it is recognized that the high tempering temperature leads to an increase of secondary hardening effect, while the low tempering temperature brings a high dislocation density and a small martensitic lath. Hence, a two-step tempering treatment was developed after the traditional normalizing process, in which the T91 steels sample was firstly tempered at a low temperature in order to form some precipitates and then tempered at a high temperature. Those firstly-formed precipitates would pin the dislocations and martensitic laths on the subsequent tempering process, which finally leads to more precipitates, higher dislocation density and smaller martensitic lath width than that obtained from the traditional tempering process.

APA, Harvard, Vancouver, ISO, and other styles

10

Zuo, Long Fei, Li Li Qiu, Bin Hou, Xiao Hua Chen, Ming Wen Chen, and Zi Dong Wang. "Study of Nano-Precipitate in High Strength Low Carbon Steel during Tempering by TEM." Applied Mechanics and Materials 327 (June 2013): 123–27. http://dx.doi.org/10.4028/www.scientific.net/amm.327.123.

Full text

Abstract:

The behavior of nanoprecipitates of 800Mpa grade high strength low carbon steel during tempering has been studied. Transmission electron microscope (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive spectrometry (EDS) were used to systematically analyze the morphology of precipitates and their grain orientation with matrix at different tempering temperatures. Experimental results confirm that the composition of these nanometer sized particles in the matrix was compound carbonitrides containing Ti, V, Mo and other elements. The precipitates of the as-received steel are (Nb,Ti)(C,N) at low tempering temperature, while those at high tempering temperature are composite carbides containing a variety of elements such as Mo, V, Ti and Nb. On the other hand, as tempering temperature increases, precipitates in the steel were slowly growing up and roughening according with the typical Oswald ripening mechanism; a sharp orientation relationship exists between precipitates and matrix.

APA, Harvard, Vancouver, ISO, and other styles

11

Ruiz-Jimenez, Victor, Matthias Kuntz, Thomas Sourmail, Francisca G. Caballero, Jose A. Jimenez, and Carlos Garcia-Mateo. "Retained Austenite Destabilization during Tempering of Low-Temperature Bainite." Applied Sciences 10, no. 24 (December 13, 2020): 8901. http://dx.doi.org/10.3390/app10248901.

Full text

Abstract:

The thermal stability of nanostructured microstructures consisting of a mixture of bainitic ferrite and carbon-enriched retained austenite has been studied in two steels containing 0.6 C (wt %) by tempering cycles of 1 h at temperatures ranging from 450 to 650 °C. Volume changes due to microstructural transformations during thermal treatments were measured by high-resolution dilatometry. The correlation of these results with the detailed microstructural characterization performed by X-ray diffraction and scanning electron microscope examination showed a sequence of different decomposition events beginning with the precipitation of very fine cementite particles. This precipitation, which starts in the austenite thin films and then continues in retained austenite blocks, decreases the carbon content in this phase so that fresh martensite can form from the low-carbon austenite on cooling to room temperature. In a subsequent tempering stage, the remaining austenite decomposes into ferrite and cementite, and due to carbide precipitation, the bainitic ferrite loses its tetragonality, its dislocation density is reduced, and the bainitic laths coarsen.

APA, Harvard, Vancouver, ISO, and other styles

12

Maulidin, Achmad Fitrah, Leopold Oscar Nelwan, and Rokhani Hasbullah. "Kajian Pengeringan Bak Gabah Secara Intermittent Terhadap Mutu Beras." Jurnal Keteknikan Pertanian 7, no. 3 (April 1, 2020): 171–78. http://dx.doi.org/10.19028/jtep.07.3.171-178.

Full text

Abstract:

Grain drying with bed dryer is generally effective with high temperatures, but this can increase fissured rice percentage. This can be overcome by combining drying method with tempering. These study were aim to examine drying temperature and duration on bed dryer using intermittent high temperature dryer, and its effect on quality variety of Ciherang with 20-22% moisture content. These research method consists of drying treatment without tempering using 35°C, 60°C and 80°C temperatures to 14% moisture content. Drying treatment with tempering consists of initial drying process-initial tempering-second drying- second tempering or without tempering, where the first drying temperature were 80°C for 20 minutes, 60°C for 30 minutes and second drying temperature were 60 °C and 35°C to 14% moisture content. The tempering duration used was 90 minutes. Results showed the grain drying method without tempering 35°C gave the highest percentage of head rice. However, the use of tempering had significantly reduced cracking and increased head rice percentage compared without tempering at the same temperature. Initial drying of 60°C for 30 minutes-tempering for 90 minutes-drying both temperatures of 35°C to 14% moisture content had been able to produce high head rice and low fissured rice percentage respectively 81.41% and 10%.

APA, Harvard, Vancouver, ISO, and other styles

13

Fan, Hui Ji, Bo Chen, Jun Wen, and Xin Jin. "Effect of Tempering Process on Microstructure and Mechanical Properties of Low Alloyed Cast Steel." Key Engineering Materials 871 (January 2021): 40–45. http://dx.doi.org/10.4028/www.scientific.net/kem.871.40.

Full text

Abstract:

The effect of tempering process on the microstructure and properties of low alloyed cast steel was studied. The results show that tempered at (200~400)°C, the M/A island of the granular bainite decomposes and carbide precipitates. When the tempering temperature rises to (500~600)°C, the M/A island is completely decomposed, and the carbide aggregates and gradually spheroidizes. With the increasing of tempering temperature, the tensile strength increases first and then decreases, elongation and impact energy show a trend of increasing at first, then decreasing and then increasing. The tempering brittleness occurs at 400°C.

APA, Harvard, Vancouver, ISO, and other styles

14

Zhang, Xiao Hai, Wen Bo Xu, Jia Wei Gu, and Shi Hang Jiang. "Influence of Quench and Tempering Temperature on the Microstructure and Properties of 20SiMn2MoVA Steel." Advanced Materials Research 1120-1121 (July 2015): 978–82. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.978.

Full text

Abstract:

Using optical microscopy、impact and tensile test,Study the effects of different quenching and tempering temperature on the microstructure and mechanical properties of the steel 20SiMn2MoVA.The results showed that, at the test temperature range,with the rise of quenching temperature the tensile strength of steel 20SiMn2MoVA declining, Low-temperature impact energy along with the quenching temperature rise was increasing. After quenching at 920°Cand tempering at different temperatures, with increasing tempering temperature, the tensile strength of the material showed a declining trend, impact toughness values were rising trend has decreased, 220°Ctempered impact toughness appear peak. Below 300°C tempering is tempered martensite and a small amount of residual austenite; More than 300°C tempering, residual austenite begins to decompose, carbide separeated out, 400°Ctempering is tempered flexor s body. Test material at 920°Cafter quenching and tempering 220°C, has good strength and toughness, specific properties: tensile strength 1506 MPa and temperature impact toughness Akv 35.6J.

APA, Harvard, Vancouver, ISO, and other styles

15

Nusratovna, Sabirova Nargiza. "Cotton Oil Shortenings And Optimal Parameters Of Their Temperature Process." American Journal of Engineering And Techonology 02, no. 10 (October 30, 2020): 28–32. http://dx.doi.org/10.37547/tajet/volume02issue10-06.

Full text

Abstract:

The tempering properties of shortening of fats based on cottonseed oil and products of its processing were studied. It has been experimentally established that the tempering of hard shortening has several advantages. The tempering temperature is carefully selected to obtain the desired crystal matrix in shortening. In the absence of this step, the crystal structure in the product continues to change with time and temperature during storage and transportation. The consistency of the shortening changes at influence of high or low temperatures even with proper tempering. However, there is always some recovery of consistency when the product returns to its primary storage temperature. Properly tempered shortening shows plasticity over a wider temperature range, as well as storage temperature fluctuations.

APA, Harvard, Vancouver, ISO, and other styles

16

Wei, Jun Hu, Xu Ran, and Han Ying. "Effect of Tempering Temperature on Microstructure and Properties of Low Carbon High Silicon Alloy Steel Treated by Q-P-T Process." Materials Science Forum 993 (May 2020): 592–96. http://dx.doi.org/10.4028/www.scientific.net/msf.993.592.

Full text

Abstract:

The mechanical properties and microstructure of low-carbon high-silicon alloy steel were examined under various tempering temperatures using the quenching, partitioning and tempering (Q–P–T) process. The performance changed with the variation in tempering temperature. The results show that the microstructure of low carbon high silicon alloy steel treated by Q-P-T process was mainly ferrite, martensite, carbide-free bainite and film-like retained austenite. This alloys exhibited good mechanical properties at tempering temperature of 300 °C. The product of strength and elongation were 33.7 GPa%. Specifically, the Ultimate tensile strength were 1508 MPa, the yield strength were 1048 MPa, and the elongation were 22.4%. At this temperature of 300 °C, the volume fraction of retained austenite reached 10.4%.

APA, Harvard, Vancouver, ISO, and other styles

17

Liu, Zhi Xue, and Ju Qiang Cheng. "Effect of Tempering Temperature on Microstructure and Properties of Cold Deformed Low Carbon Bainitic Steel." Advanced Materials Research 602-604 (December 2012): 305–8. http://dx.doi.org/10.4028/www.scientific.net/amr.602-604.305.

Full text

Abstract:

In order to research the cold deformation work hardening characteristic of new type low carbon bainitic steel, this article studies the effect of different degrees of cold deformation (elongation and compression) and different tempering temperatures on microstructure and mechanical properties of 15SiMn2Mo low carbon beinaitic steel. The results showed that with the tempering temperature increasing after 10% pre-tension deformation, the tensile strength and yield strength of the test material increased first and then decreased, and reached its peak value at 300°C, roughly the same as the strength of hot-rolling and 300°C tempering. With the compression deformation degree rising, the hardness of test material increased and showed the test material has good work hardening performance. Streamline and "z" shape ferrite banding appeared in microstructure. With the tempering temperature increasing, the microstructure of compressed deformation steel recoveried and recrystallized, the tendency of ferrite along the streamline was weakened, the new refining granular phase was enhanced and uniformity of microstructure was improved. The microstructure refinement was significantly increased with the compressive deformation degree rising.

APA, Harvard, Vancouver, ISO, and other styles

18

Saravanan, K., R. Suresh Kumar, V. M. J. Sharma, D. Sivakumar, P. Ramkumar, P. Ramesh Narayanan, K. Sreekumar, and Parameshwar Prasad Sinha. "Effect of Tempering Temperature on Strength and Fracture Toughness of 0.3C-CrMoV(ESR) Steel." Materials Science Forum 710 (January 2012): 433–38. http://dx.doi.org/10.4028/www.scientific.net/msf.710.433.

Full text

Abstract:

0.3C-CrMoV(ESR) steel is an ultra-high strength low alloy steel indigenously developed by ISRO for space applications. The steel is used in the form of rings of 2.8 m diameter also. In this paper, the effect of tempering temperature on ring rolled steel for the best combination of fracture toughness and strength properties is studied. The tensile properties and fracture toughness of the steel were evaluated in the as quenched and tempered conditions through the specimens drawn in radial direction of the ring segment. Five tempering temperatures were used in the study: 200, 450, 475, 500 and 510°C. Tensile strength of the steel showed continuous decrease with increasing tempering temperature, but yield strength increased reaching maximum when tempered at 450°C and further decreased with increasing tempering temperature. The elongation was higher for higher tempering temperature. The strain hardening exponent decreased with increasing tempering temperature. The fracture toughness test results showed that tempering between 475 and 510°C exhibited better combination of fracture toughness and strength.

APA, Harvard, Vancouver, ISO, and other styles

19

Zhang, Yongjian, Weijun Hui, Xiaoli Zhao, Cunyu Wang, and Han Dong. "Effects of Hot Stamping and Tempering on Hydrogen Embrittlement of a Low-Carbon Boron-Alloyed Steel." Materials 11, no. 12 (December 10, 2018): 2507. http://dx.doi.org/10.3390/ma11122507.

Full text

Abstract:

The effects of hot stamping (HS) and tempering on the hydrogen embrittlement (HE) behavior of a low-carbon boron-alloyed steel were studied by using slow strain rate tensile (SSRT) tests on notched sheet specimens. It was found that an additional significant hydrogen desorption peak at round 65–80 °C appeared after hydrogen-charging, the corresponding hydrogen concentration (CHr) of the HS specimen was higher than that of the directed quenched (DQ) specimen, and subsequent low-temperature tempering gave rise to a decrease of CHr. The DQ specimen exhibited a comparatively high HE susceptibility, while tempering treatment at 100 °C could notably alleviate it by a relative decrease of ~24% at no expanse of strength and ductility. The HS specimen demonstrated much lower HE susceptibility compared with the DQ specimen, and tempering at 200 °C could further alleviate its HE susceptibility. SEM analysis of fractured SSRT surfaces revealed that the DQ specimen showed a mixed transgranular-intergranular fracture, while the HS and low-temperature tempered specimens exhibited a predominant quasi-cleavage transgranular fracture. Based on the obtained results, we propose that a modified HS process coupled with low-temperature tempering treatment is a promising and feasible approach to ensure a low HE susceptibility for high-strength automobile parts made of this type of steel.

APA, Harvard, Vancouver, ISO, and other styles

20

Tang, Qibing, Xuejiao Wei, Hao Li, Xinyue Qiu, Xiaojun Xu, Guoqing Gou, Wei Xu, and Minhao Zhu. "Influence of tempering temperature on the fretting wear of low alloyed martensitic construction steel." International Journal of Modern Physics B 34, no. 18 (May 13, 2020): 2050164. http://dx.doi.org/10.1142/s0217979220501647.

Full text

Abstract:

An experimental investigation was conducted to study the fretting wear behavior of low alloyed construction steel in the tempered fully martensitic state. The resulting damage mechanism and the resistance to fretting wear of martensitic steels subjected to different tempering temperature was evaluated and compared with the virgin (un-tempered) martensitic steel under the different loading conditions. The results show that the friction coefficient increases with the increase of the tempering temperature for all the applied loads. The fretting wear resistance mainly depends on the tempering temperature. Compared to the virgin (un-tempered) full martensite, most of the tempered martensites have better fretting wear resistance, in which the tempered martensitic (TM) steel of [Formula: see text] due to a good balance of strength and ductility has a super fretting wear resistance for all loading conditions. In addition, the correlation of fretting wear resistance with the initial hardness was discussed.

APA, Harvard, Vancouver, ISO, and other styles

21

Suwanpatcharakul, Kittipat, Nithi Saenarjhan, Nathi Nakthong, Anchaleeporn Waritswat Lothongkum, and Gobboon Lothongkum. "Effect of tempering temperature on impact energy of AISI 410 martensitic stainless steel at low temperatures." Materials Testing 63, no. 8 (August 1, 2021): 699–704. http://dx.doi.org/10.1515/mt-2020-0114.

Full text

Abstract:

Abstract AISI 410 martensitic stainless-steel specimens were austenitized at 1253 K then oil quenched and tempered at 573, 673, 773 and 923 K for 3600 s. The impact energy of the specimens was tested at 298, 253, 223, 213 K and measured using ASTM E23 standard. After austenitizing and tempering, the microstructure of the specimens showed carbide precipitation. Tempering at 773 K resulted in the highest hardness due to secondary hardening, while tempering at 923 K resulted in the lowest hardness due to brittle carbide precipitation at the grain boundary which caused softening of the matrix by decreasing the solute carbon content. By contrast, the change in impact energy is inversely proportional to the hardness values. The impact surface of specimens tempered at 573, 673 and 773 K revealed transgranular fracture; on the other hand, the impact surface of the specimen tempered at 923 K revealed intergranular fracture. From our experimental results, the appropriate hardening and tempering procedure of AISI 410 for low temperatures applications is selectable.

APA, Harvard, Vancouver, ISO, and other styles

22

Tseng, Ta Hung, Chieh Yu, Ren Kae Shiue, Tze Ching Yang, and Ching Yuan Huang. "The Effect of Tempering on Low-Temperature Toughness of the Direct Quenched High-Strength Offshore Steel." Key Engineering Materials 735 (May 2017): 49–53. http://dx.doi.org/10.4028/www.scientific.net/kem.735.49.

Full text

Abstract:

Microstructures, Vickers depth profiles and low-temperature toughness of the tempered direct water quenched steels have been evaluated in the experiment. Martensite dominates the direct quenched specimen, and it is brittle at low-temperature toughness test. The toughness of direct quenched steel is improved when it is tempered at 500 °C for 1800 s. However, increasing the tempering temperature from 500 °C to 660 °C has little effect on low-temperature toughness of the steel. The application of offshore steel must avoid bainite formation. Tempering treatment is very effective to improve low-temperature toughness of the martensite dominated structure.

APA, Harvard, Vancouver, ISO, and other styles

23

Gaivoronskyi, O. A., V. D. Poznyakov, O. M. Berdnikova, T. O. Alekseenko, and O. S. Shyshkevych. "Influence of low-temperature tempering on structure and properties of welded joints of high-strength steel 30Kh2N2MF." Paton Welding Journal 2020, no. 6 (June 28, 2020): 20–26. http://dx.doi.org/10.37434/tpwj2020.06.04.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Talebi, Seyyed, Mohammad Jahazi, and Haikouhi Melkonyan. "Retained Austenite Decomposition and Carbide Precipitation during Isothermal Tempering of a Medium-Carbon Low-Alloy Bainitic Steel." Materials 11, no. 8 (August 15, 2018): 1441. http://dx.doi.org/10.3390/ma11081441.

Full text

Abstract:

The effect of isothermal tempering on retained austenite decomposition and carbide precipitation were investigated in a medium-carbon low-alloy bainitic steel. High-resolution dilatometry was used to perform isothermal tempering at 350 °C, 550 °C and 600 °C for different holding times up to 16 h. The decomposition of retained austenite, morphology and composition of carbides were investigated by analyzing the dilatometric curves and were confirmed through scanning and transmission electron microscopy observations. The decomposition behavior of retained austenite varied significantly as a function of the tempering temperature with a full decomposition observed at 600 °C. It was also found that by increasing the tempering temperature from 550 °C to 600 °C, carbides precipitate approximately twice as fast, and evolve from M3C type to Cr7C3 and Cr23C6 after 16 h of tempering at 600 °C.

APA, Harvard, Vancouver, ISO, and other styles

25

Zhou, Wen Hao, Hui Guo, and Cheng Jia Shang. "Effect of Tempering Temperature on the Microstructure and Mechanical Properties of a 0.1C Steel with High Strength and Low Yield Ratio." Advanced Materials Research 535-537 (June 2012): 601–4. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.601.

Full text

Abstract:

The influence of tempering temperature on the microstructure and mechanical properties of low carbon low alloy steel was investigated. The results show that tempering temperature has considerable influence on both yield strength and tensile strength. With the increase in tempering temperature, the yield strength increases first and then decreases after it reaches the highest point at 600°C with a strength of 843MPa, while the tensile strength decreases fastly from 550°C to 650°C and keeps stable after increasing drastically at 720°C. The yield ratio is about 0.60 except at 600°C and 650°C with a high yield ratio of 0.90, while the total elongation has little change. It is concluded that the major change of mechanical properties after tempering has a connection with the decomposition of M/A(martensite/austenite) islands, the recovery of dislocations and the precipitation of alloy elements.

APA, Harvard, Vancouver, ISO, and other styles

26

Bi, Hong Xia, Ming Hua Tang, Zhi Lan Ren, and Yong Zhou. "Effects of Tempering Temperature on the Microstructure and Mechanical Properties of Low Alloy Ultra-High Strength 45CrNiSiMnMoVA Steel." Materials Science Forum 1036 (June 29, 2021): 11–19. http://dx.doi.org/10.4028/www.scientific.net/msf.1036.11.

Full text

Abstract:

The effects of different tempering temperatures on the microstructure evolution and mechanical properties of the new low-alloy ultra-high-strength 45CrNiSiMnMoVA steel after quenching were investigated by mechanical property tests, SEM and TEM. The results show that a complex phase organization consisting of martensite/ lower bainite of the tested steel after treated at 920°C×1h+(320~380)°C×4h was obtained, and the partition interface of the lath martensite bundle became blurred from clear with the increase of tempering temperature; In the proposed tempering temperature range, the toughness of the alloy has become better while maintain the strength without decreasing basically, and when the tempering temperature is 350°C, the alloy has the optimal comprehensive mechanical properties of strength, plasticity and toughness together. The analysis concluded that the strong toughening of the tested steel was mainly attributed to the coupling effect of the alloying elements in the steel and the composite toughening of the nano-precipitated phases, among other aspects.

APA, Harvard, Vancouver, ISO, and other styles

27

Du, Pengju, Peng Chen, Devesh K. Misra, Di Wu, and Hongliang Yi. "Transformation-Induced Ductility of Reverse Austenite Evolved by Low-Temperature Tempering of Martensite." Metals 10, no. 10 (October 7, 2020): 1343. http://dx.doi.org/10.3390/met10101343.

Full text

Abstract:

A novel steel combining the “quenching and tempering (Q&T)” process was exploited that can achieve the enhancement of austenite by interface migration during tempering the martensitic matrix mixed with films of austenite. A high uniform elongation (12%) combined with high yield tensile strength (1500 MPa) was obtained, which showed distinct advantages over all the other advanced high strength steels under development for a lightweight car body. Furthermore, the effect of austenite on enhancement of ductility in “Q&T” steels with a martensite matrix was elucidated, which suggested that the ductility was promoted by enhancing boundary sliding and delaying work hardening of the martensitic matrix.

APA, Harvard, Vancouver, ISO, and other styles

28

Janjusevic, Zoran, Zvonko Gulisija, Marija Mihailovic, and Aleksandra Pataric. "The investigation of applicability of the Hollomon-Jaffe equation on tempering the HSLA steel." Chemical Industry and Chemical Engineering Quarterly 15, no. 3 (2009): 131–36. http://dx.doi.org/10.2298/ciceq0903131j.

Full text

Abstract:

High strength low-alloyed (HSLA) Cr-Mn-Si steels belong to a group of steels that can reach their full mechanical properties after quenching and tempering. Those properties depend both on the temperature and time of tempering. Knowing the tempering parameters, it is possible to reach the desired properties of the treated steel. Some results on investigating the Hollomon-Jaffe equation (in parametric form) application for tempering of HSLA steel, are shown in this paper. The experiments were performed in real production conditions, using a standard material. The quenching was performed at 870?C, the heating period was always 30 min, with subsequent cooling into the oil bath. The tempering was carried out in temperature range from 480 to 680?C, while tempering time varied from 15 min to 24 h. The degree of tempering is referred through the hardness values changing. The experimental results have shown a pretty well agreement to tempering parameters, included in Hollomon-Jaffe equation, for this kind of HSLA steel.

APA, Harvard, Vancouver, ISO, and other styles

29

Chaouch, Djamel, Ahmed Sadok, Seif-Eddine Bendaoudi, and Abdallah Chaouch. "Effect of Charpy Impact Test on Microstructure Properties of AISI4140 Steel." Mechanics and Mechanical Engineering 22, no. 4 (September 2, 2020): 1463–70. http://dx.doi.org/10.2478/mme-2018-0114.

Full text

Abstract:

AbstractIn this paper, the mechanical properties and microstructures of AISI4140 low alloy steel under different tempering conditions are investigated. The samples are quenched, tempered to a martensite structure and loaded to fracture by means of Charpy machine according to standard test. Fractography analysis showed that the morphology fracture surface was changed by increasing tempering temperature. The variation of energy of Charpy impact fracture as a function of tempering temperature exhibits minimum values at 300 °C, which suggests the occurrence of temper embrittlement.

APA, Harvard, Vancouver, ISO, and other styles

30

Firrao, D., P. Matteis, and A. De Sario. "Exploring the low temperature tempering range of low alloy quenched and tempered steels." Procedia Structural Integrity 18 (2019): 703–10. http://dx.doi.org/10.1016/j.prostr.2019.08.218.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Hu, Xiongfeng, Fuqiang Lai, Shengguan Qu, Yalong Zhang, Haipeng Liu, and Zhibing Wu. "Effects of Microstructure Evolution on Fretting Wear Behaviors of 25CrNi2MoVE Steel under Different Tempering States." Metals 10, no. 3 (March 8, 2020): 351. http://dx.doi.org/10.3390/met10030351.

Full text

Abstract:

Increasing load requirements and harsh operating conditions have worsened the wear of drive shafts in special field vehicles. In this paper, the evolution of the microstructure and fretting wear behaviors of 25CrNi2MoVE torsion shaft steel and their influence on the wear mechanisms were investigated as a function of tempering temperature. The results showed that the coarse grain size, low matrix hardness and non-metallic inclusions in the as-received state lead to a high wear rate and serious adhesive wear. The grain refinement after normalizing and the formed M5C2 carbide and bainite helped to improve the wear resistance and worn surface quality. Low temperature tempering is conducive to further improve the wear resistance of normalized samples, and the wear rate and worn surface roughness are increased gradually after tempering temperature increases. For quenching, although martensite structure can achieve a lower wear rate, the coefficient of friction is much higher; the wear mechanisms are primarily fatigue wear and adhesive wear. Although the adhesive wear degree and worn surface roughness were increased, the optimal anti-wear performances are obtained under tempering at 350 °C with good continuity of the surface oxide film. Excessive tempering temperature will make the softened matrix unable to form a beneficial “third-body wear”.

APA, Harvard, Vancouver, ISO, and other styles

32

Dai, Yu Mei, Yong Qing Ma, Yan Bin Wu, and Ya Nan Ji. "A Study on the Microstructure and Hardness Feature of 6CrW2MoVSi Steel after Heat Treatment." Advanced Materials Research 887-888 (February 2014): 223–27. http://dx.doi.org/10.4028/www.scientific.net/amr.887-888.223.

Full text

Abstract:

6CrW2MoVSi steel has a refined and even microstructure after heat treatment, the average size of annealing carbide is 0.6 μm; quenching martensite is mainly lath-shaped martensite and only a small amount of acicular martensite, and the size of quenching acicular at 950 °C is smaller than 2.5 μm. The curve of quenching hardness increasing with quenching temperature rising is divided into three sections. In the middle section of quenching between 910 °C ~ 980 °C, quenching hardness presents slow rising trend. After higher temperature quenching, there are low and high temperature tempering precipitation hardening zones. At 220 °C ~ 240 °C tempering temperature, precipitation hardness is HRC54 ~ 58. At 540 °C ~ 570 °C tempering temperature, precipitation hardness is HRC52 ~ 56.

APA, Harvard, Vancouver, ISO, and other styles

33

Dudko, Valeriy, Andrey Belyakov, and Rustam Kaibyshev. "Effect of Tempering on Mechanical Properties and Microstructure of a 9% Cr Heat Resistant Steel." Materials Science Forum 706-709 (January 2012): 841–46. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.841.

Full text

Abstract:

Effect of tempering temperature ranged from 400 to 720°C on mechanical properties and microstructure of a P92-type creep resistant steel was investigated. The hardness value of 400 HB, which was obtained after solution treatment, increased to 430 HB with increasing the tempering temperature to 525°С. Further increase in the tempering temperature resulted in gradual decrease in hardness, which approached a level of about 220 HB after tempering at 720°С. The equiaxed particles of MX-type carbonitrides with a size of about 30 nm were precipitated randomly after tempering under all conditions. At temperatures below 525°C, the tempered martensite lath structure (TMLS) was characterized by a random distribution of fine M3C-type carbides and MX-type carbonitrides. The precipitation of M23C6 was observed after tempering at T ≥ 525°C. At 525°C, the M23C6 carbides appeared as thin films on high-angle boundaries (HAB), while M23C6 particles having almost equiaxed shape and located on various boundaries including low-angle lath boundaries precipitate at higher temperatures.

APA, Harvard, Vancouver, ISO, and other styles

34

Zhu, Yue Bin, and Xue Min Wang. "Microstructure and Properties of High Performance Steels by Controlled Rolling." Applied Mechanics and Materials 459 (October 2013): 87–90. http://dx.doi.org/10.4028/www.scientific.net/amm.459.87.

Full text

Abstract:

High performancesteels (HPS) require low yield ratio, high uniform elongation and high low temperature impact toughness in addition to higher strength. In this paper,experimental steelswere produced by controlled rolling and tempering to meet high performance requirements. Itwasconcluded that experimental steels by controlled rolling and tempering had similar performance with quenched and tempered steel (QT).

APA, Harvard, Vancouver, ISO, and other styles

35

Jena, Pradipta Kumar, K. Siva Kumar, and A. K. Singh. "Effect of Tempering Temperature on Microstructure, Texture and Mechanical Properties of a High Strength Steel." International Journal of Manufacturing, Materials, and Mechanical Engineering 4, no. 3 (July 2014): 33–49. http://dx.doi.org/10.4018/ijmmme.2014070102.

Full text

Abstract:

This work describes the microstructure, texture and anisotropy in mechanical behavior of a high strength steel in various tempered conditions. The microstructures and mechanical properties change considerably with varying tempering temperatures. The material exhibits low in-plane anisotropy and low anisotropic index in terms of yield strength and elongation with increase in tempering temperature. The anisotropy of the material displays similar behavior to that of the yield strength.

APA, Harvard, Vancouver, ISO, and other styles

36

Kaputkina, Lyudmila M., Vera Prokoshkina, and Grigory Khadeev. "Effect of Nitrogen Addition on Tempering and Strain Aging Processes of Thermomechanically Strengthened Structural Steels." Materials Science Forum 738-739 (January 2013): 573–78. http://dx.doi.org/10.4028/www.scientific.net/msf.738-739.573.

Full text

Abstract:

Mechanical behavior of structural nitrogen-containing steels with various structures and compositions, including the same steels with different summary C+N content and C/N ratio were studied using pressing tests in a wide temperature range, tensile tests, impact bending tests, hardness measurements and shock-wave loading resistance. The tempering and aging under load processes after quenching or thermomechanical treatment with various regimes have been investigated using optical and electron microscopies, X-ray diffraction analysis, calorimetric and dilatometric analyses. Hot strain resistance of the austenite is determined essentially by the steel composition, while the final structure and mechanical properties of hot-deformed austenite are determine mainly by hot deformation conditions. The higher the nitrogen content and C/N ratio, the higher hot strain resistance was and earlier the softening processes start, especially recrystallization process. The nitrogen microalloying of low-alloyed structural steels changes kinetics of the martensite tempering. Application of the high temperature thermomechanical treatment or combined thermomechanical strengthening with following tempering under load allows the use of these steels in a high-strength state after low-temperature tempering.

APA, Harvard, Vancouver, ISO, and other styles

37

Preciado, M., P. M. Bravo, and J. M. Alegre. "Effect of low temperature tempering prior cryogenic treatment on carburized steels." Journal of Materials Processing Technology 176, no. 1-3 (June 2006): 41–44. http://dx.doi.org/10.1016/j.jmatprotec.2006.01.011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Kang, Sung S., Amir Bolouri, and Chung-Gil Kang. "The effect of heat treatment on the mechanical properties of a low carbon steel (0.1%) for offshore structural application." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 226, no. 3 (April 25, 2012): 242–51. http://dx.doi.org/10.1177/1464420712438502.

Full text

Abstract:

In this study, a low carbon cast steel (0.1% C) alloy designed for offshore structures, and the mechanical properties of the alloy under different heat treatment cycles have been evaluated. The effect of austenitizing time on the austenite grain size was studied. Subsequently, the quenched samples with minimum austenite grain size subjected to tempering experiments at different tempering temperatures (450 °C, 550 °C, and 650 °C) and cooling rates (0.23, 36, and 50 °C/s) from the temperature. The results showed that by increasing the austenitizing time, the austenite grain size initially decreased and reached the minimum value with ASTM number of 6.35 and then followed by an increase. When the tempering temperature increased, yield and tensile strengths decreased, whereas the ductility properties improved. In addition, yield and tensile strengths were not affected by cooling rate from tempering temperature, whereas the ductility properties were slightly affected. The increase in tempering temperature significantly led to improvement in the toughness to fracture of the alloy. The effect of cooling rate on impact energy for the samples tempered at 450 °C and 550 °C was negligible. By the contrast, impact energy for the samples tempered at 650 °C was markedly affected by cooling rate, in which the highest value was achieved for a cooling rate of 50 °C/s.

APA, Harvard, Vancouver, ISO, and other styles

39

Tekeli, Süleyman, Ahmet Güral, and Metin Gürü. "Influence of Tempering Temperature and Microstructure on Wear Properties of Low Alloy PM Steel with 1-2 % Ni Addition." Materials Science Forum 534-536 (January 2007): 629–32. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.629.

Full text

Abstract:

The effect of tempering temperature and microstructure on dry sliding wear behavior of quenched and tempered PM steels was investigated. For this purpose, atomized iron powder was mixed with 0.3 % graphite and 1-2 % Ni powders. The mixed powders were cold pressed and sintered at 1200°C. The sintered specimens were quenched from 890°C and then tempered at 200°C and 600°C for 1 hr. Wear tests were carried out on the quenched+tempered specimens under dry sliding wear conditions using a pin-on-disk type machine at constant load and speed. The experimental results showed that the wear coefficient effectively increased with increasing tempering temperature. With increasing Ni content, the wear coefficient slightly decreased at all tempering temperatures due to the high amount of Ni-rich austenitic areas.

APA, Harvard, Vancouver, ISO, and other styles

40

Miao, Jun, Li Jun Wang, and Chun Ming Liu. "Effect of Microstructure and Mechanical Properties on Two Body Abrasive Wear Resistance of Medium-Carbon Low-Alloy Steel." Applied Mechanics and Materials 52-54 (March 2011): 1247–52. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.1247.

Full text

Abstract:

The effect of microstructure and mechanical properties on abrasion resistance of the medium-carbon low-alloy steel has been investigated under two body abrasive wear conditions. The results show that the microstructure of the test steel is mastenite and bainite/mastenite when the specimen subjected to water quenching and blow cooling respectively. The hardness of the test steel was over 52HRC when the specimen subjected to water quenching and blow cooling, however, effect of tempering temperature on hardness is slightly. The strength of the test steel is increased with the tempering temperature increased and the impact toughness change slightly under the blow cooling condition. The tensile strength of the test steel is decreased and the yield strength is increased with the tempering temperature increased when the specimen subjected to water quenching and followed tempering. The wear rate is increased with load and the wear mechanism is micro-cutting and microploughing. The wear resistance of bainite/martensite is better than single-phase martensite. The hardness and impact toughness are important factor under two body abrasive wear condition.

APA, Harvard, Vancouver, ISO, and other styles

41

Shibata, Kosuke, Takuya Hiramatsu, Atsuhiro Shiraki, Junichiro Kinugasa, Tatsuya Asai, Yukihiro Utsumi, and Toshio Murakami. "Effects of Microstructure on the Hydrogen Embrittlement Resistance of Ultra High Strength Martensitic Steel Sheets." Materials Science Forum 1016 (January 2021): 1331–36. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.1331.

Full text

Abstract:

In this study, the relationship between hydrogen embrittlement resistance (HER) and the microstructure of low temperature tempered martensite was investigated using steel sheets which were controlled by carbon content and tempering conditions. Focusing on transition carbides and interstitial carbon content which are peculiar microstructures to low temperature tempered martensite, microstructure was evaluated by synchrotron radiation X-ray diffraction (SR-XRD). The HER was evaluated by U-bending and fracture surface was observed after the slow strain rate test (SSRT). As the result, the HER was improved and fracture morphology was changed from intergranular to quasi-cleavage when the high carbon content and high temperature tempering were adopted. In the steels improved the HER, the increase of the volume fraction of transition carbides and the decrease of interstitial carbon content was confirmed. Hydrogen trapping by the transition carbides could explain the change of the HER and fracture morphology. These results suggested that the hydrogen trapping by the transition carbides was effective to improve the HER of the low temperature tempering martensitic steels.

APA, Harvard, Vancouver, ISO, and other styles

42

Kresser, S., R. Schneider, H. Zunko, and C. Sommitsch. "A Model to Predict the Microstructural Constituents after Quenching and Partitioning of Martensitic Stainless Steels." HTM Journal of Heat Treatment and Materials 76, no. 2 (April 1, 2021): 120–31. http://dx.doi.org/10.1515/htm-2020-0008.

Full text

Abstract:

Abstract The typical heat treatment of martensitic stainless steels comprises hardening and subsequent tempering. Depending on the application and size of the component, tempering is carried out either at low temperatures (< 300 °C) or at high temperatures (> 500 °C). In this paper, tempering at lower temperatures is examined. First, the austenitizing step is considered in greater detail and an optimized formula for the calculation of the MS temperature of such steel grades is created in order to enable to be modelled. For the calculations, the austenite composition is determined at different austenitizing temperatures using thermodynamic simulation. Furthermore, the transformation of austenite into martensite during quenching is described with the help of the Koistinen-Marburger equation. The second part deals with effects in the material at low holding temperatures. Here, the influence of different hardening temperatures and interception temperatures of the quenching procedure is investigated. There is no complete partitioning at temperatures of 300 °C. Certain tempering processes can also take place, such as the formation of transition carbides, so-called M3C carbides. A typical tempering with formation of stable Cr-rich carbides does not occur at this low temperature. Finally, the calculated results of the model correlate well with microstructural investigations (XRD, LOM). ◼

APA, Harvard, Vancouver, ISO, and other styles

43

Sun, Chen, Pai-Xian Fu, Hong-Wei Liu, Hang-Hang Liu, and Ning-Yu Du. "Effect of Tempering Temperature on the Low Temperature Impact Toughness of 42CrMo4-V Steel." Metals 8, no. 4 (April 2, 2018): 232. http://dx.doi.org/10.3390/met8040232.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

MORENO, J. J., HELMUT G. KATZGRABER, and ALEXANDER K. HARTMANN. "FINDING LOW-TEMPERATURE STATES WITH PARALLEL TEMPERING, SIMULATED ANNEALING AND SIMPLE MONTE CARLO." International Journal of Modern Physics C 14, no. 03 (March 2003): 285–302. http://dx.doi.org/10.1142/s0129183103004498.

Full text

Abstract:

Monte Carlo simulation techniques, like simulated annealing and parallel tempering, are often used to evaluate low-temperature properties and find ground states of disordered systems. Here we compare these methods using direct calculations of ground states for three-dimensional Ising diluted antiferromagnets in a field (DAFF) and three-dimensional Ising spin glasses (ISG). For the DAFF, we find that, with respect to obtaining ground states, parallel tempering is superior to simple Monte Carlo and to simulated annealing. However, equilibration becomes more difficult with increasing magnitude of the externally applied field. For the ISG with bimodal couplings, which exhibits a high degeneracy, we conclude that finding true ground states is easy for small systems, as is already known. But finding each of the degenerate ground states with the same probability (or frequency), as required by Boltzmann statistics, is considerably harder and becomes almost impossible for larger systems.

APA, Harvard, Vancouver, ISO, and other styles

45

Bai, Jiaojiao, Wanli Zhang, Yuhui Wang, Cunyu Wang, Xingpin Chen, Zhiyue Shi, Hui Wang, and Wenquan Cao. "On the Unique Microstructure and Properties of Ultra-High Carbon Bearing Steel Alloyed with Different Aluminum Contents." Metals 11, no. 7 (July 12, 2021): 1116. http://dx.doi.org/10.3390/met11071116.

Full text

Abstract:

In this study, ultra-high-carbon steels with 1.4% carbon content alloyed with three different aluminum contents, 2.0%, 4.0% and 6.0%, were studied on their tempering stability and temperature resistance. The results showed that the addition of Al significantly enhanced the tempering stability and temperature resistance of ultra-high-carbon steel. The addition of Al inhibited the transformation of ε-carbide to cementite, suppressed the transition of martensite to ferrite and thus, endowed ultra-high carbon steels to maintain very high hardness during tempering within a wide range of temperature up to 500 °C. The present work provides a useful basis on which to develop bearing steel materials with low density and high hardness.

APA, Harvard, Vancouver, ISO, and other styles

46

Sun, Lin, Zhi Yi Zhao, Xiao Zhen Yang, and Run Dong Xue. "Effect of Tempering Process on Residual Stress in Hot Rolled Low Carbon Martensite High-Strength Steel Strip." Advanced Materials Research 690-693 (May 2013): 222–26. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.222.

Full text

Abstract:

Distribution of residual stress in hot rolled low carbon martensite high-strength steel strip was measured by means of blind-hole method in the steel before and after tempering. The hot rolled low carbon martensite high-strength steel strip was tempered at 450°C, 500°C, 550°C or 600°C. Before tempering, the value of the residual stress along the width direction is maximum at the edge, intermediate at the center, minimum at the 1/4 of the strip. The figure of the residual stress distribution along the width direction is like the shape of the letter M. Residual stress of the strip is reduced after tempering. When tempering at 450°C or 500°C, evolution of residual stress is caused by changes of thermal stress. Distribution of residual stress becomes gentle. With tempering temperature increasing, distribution of residual stress is reversed, because evolution of thermal stress and phase transition stress changes in different time.

APA, Harvard, Vancouver, ISO, and other styles

47

Hu, Shu E., Wei Hua Sun, Xiao Dong Liu, Feng Qiang Xiao, Deng Yi Hou, Dong Hua Hou, and Guo Dong Wang. "A Study on Grade 1000MPa High Performance Steel Plate Processing by Direct Quenching." Materials Science Forum 773-774 (November 2013): 312–18. http://dx.doi.org/10.4028/www.scientific.net/msf.773-774.312.

Full text

Abstract:

A 1000MPa grade steel plate for coal mining machinery equipment was studied in this paper. The ultra-high strength steel plate is processed by direct quenching after hot rolling plus tempering (DQ-T) to obtain high toughness and ductility. It has found that the tempering temperature has an important influence on the steel microstructure, precipitation behavior and the plate mechanical properties. At the lower tempering temperatures from 400 °C to 450 °C, the steel plate has a low toughness. When the tempering temperature is higher than 450 °C, the higher mechanical properties can be obtained due to the carbides precipitation, dislocation dissolution and carbide decomposition from residual austenite after quenching. The steel microstructure is comprised of tempered sorbite and bainite, in which sorbite plays an important role in obtaining premium microstructure.

APA, Harvard, Vancouver, ISO, and other styles

48

Chiu, Liu Ho, Yu Jen Chen, Chang Hui Wu, and Heng Chang. "Vacuum Carburizing of AISI S7 Tool Steel." Solid State Phenomena 118 (December 2006): 91–96. http://dx.doi.org/10.4028/www.scientific.net/ssp.118.91.

Full text

Abstract:

The effects of vacuum carburizing under an acetylene atmosphere at 950 and 1000, followed by gas quenching and tempering at various temperatures on the properties of AISI S7 shock-resistant tool steel were studied. As carburized specimens undergo low temperature tempering, the surface hardness of the quenched specimens carburized at 1000 is lower than those of the specimens carburized at 950, due to the large amount of retained austenite in specimens carburized at 1000. Under high temperature tempering, specimens carburized at 1000 have higher surface hardness than specimens carburized at 950. As specimens are tempered in the range between 450 to 550, the surface hardness of carburized specimens show a modest increase due to the secondary hardening effects. According to the fracture toughness data, the toughness of carburized specimens peaked at tempering at 600.

APA, Harvard, Vancouver, ISO, and other styles

49

Jo, Haeju, Moonseok Kang, Geon-Woo Park, Byung-Jun Kim, Chang Yong Choi, Hee Sang Park, Sunmi Shin, Wookjin Lee, Yong-Sik Ahn, and Jong Bae Jeon. "Effects of Cooling Rate during Quenching and Tempering Conditions on Microstructures and Mechanical Properties of Carbon Steel Flange." Materials 13, no. 18 (September 21, 2020): 4186. http://dx.doi.org/10.3390/ma13184186.

Full text

Abstract:

This study investigated the mechanical properties of steel in flanges, with the goal of obtaining high strength and high toughness. Quenching was applied alone or in combination with tempering at one of nine combinations of three temperatures TTEM and durations tTEM. Cooling rates at various flange locations during quenching were first estimated using finite element method simulation, and the three locations were selected for mechanical testing in terms of cooling rate. Microstructures of specimens were observed at each condition. Tensile test and hardness test were performed at room temperature, and a Charpy impact test was performed at −46 °C. All specimens had a multiphase microstructure composed of matrix and secondary phases, which decomposed under the various tempering conditions. Decrease in cooling rate (CR) during quenching caused reduction in hardness and strength but did not affect low-temperature toughness significantly. After tempering, hardness and strength were reduced and low-temperature toughness was increased. Microstructures and mechanical properties under the various tempering conditions and CRs during quenching were discussed. This work was based on the properties directly obtained from flanges under industrial processes and is thus expected to be useful for practical applications.

APA, Harvard, Vancouver, ISO, and other styles

50

Lu, Feng, Chao Wang, Yuan Yuan Li, Long Lu, Zhao Dong Wang, and Guo Dong Wang. "Study of Direct Quenching and Tempering Process of a Low Carbon Equivalent 960 MPa Grade Steel." Advanced Materials Research 744 (August 2013): 329–33. http://dx.doi.org/10.4028/www.scientific.net/amr.744.329.

Full text

Abstract:

The chemical composition of a 960 Mpa grade high strength steel with low carbon equivalent was designed. Effect of direct quenching and tempering process on the microstructure and mechanical properties of the experimental steel was studied. Results showed that fine lath martensite was obtained after controlled rolling and direct quenching. With tempering temperature increasing, the mechanical properties showed different trends for different tempering stages. And this had a direct relationship with the microstructure evolution. The matrix recovery softening, carbon desolution and precipitation of nanomicroalloy carbides influenced the strength change. With increase of tempering time, the strength decreased and toughness improved. Experimental steel tempered at 450 °C for 40min could obtain the best mechanical properties, which meet the requirement with a large impact energy margin.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Low-temperature tempering'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles