Academic literature on the topic 'Dual Phase steel - DP'
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Journal articles on the topic "Dual Phase steel - DP"
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Punyamueang, Suttirat, and Vitoon Uthaisangsuk. "Determination of Stress-Strain Curve of Dual Phase Steel by Nanoindentation Technique." Key Engineering Materials 658 (July 2015): 195–201. http://dx.doi.org/10.4028/www.scientific.net/kem.658.195.
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The advanced high strength (AHS) steels, for example, dual phase (DP) steels, transformation induced plasticity (TRIP) steels and complex (CP) steels principally exhibit multiphase microstructure features. Thus, mechanical behavior of the constituent phases significantly affects the resulting overall properties of such AHS steels. Novel material characterization techniques on micro- and nano-scale have become greatly more important. In this work, stress-strain response of the DP steel grade 1000 was determined by using the Nanoindentation testing. The DP steel showed the microstructure containing finely distributed martensite islands of about 50% phase fraction in the ferritic matrix. The nano-hardness measurements were firstly performed on each individual phase of the examined steel. In parallel, finite element (FE) simulations of the corresponding nano-indentation tests were carried out. Flow curves of the single ferritic and martensitic phases were defined according to a dislocation based theory. Afterwards, the load and penetration depth curves resulted from the experiments and simulations were compared. By this manner, the proper stress-strain responses of both phases were identified and verified. Finally, the effective stress-strain curve of the investigated DP steel could be determined by using 2D representative volume element (RVE) model.
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Mohrbacher, Hardy, Jer-Ren Yang, Yu-Wen Chen, Johannes Rehrl, and Thomas Hebesberger. "Metallurgical Effects of Niobium in Dual Phase Steel." Metals 10, no. 4 (April 12, 2020): 504. http://dx.doi.org/10.3390/met10040504.
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Dual phase (DP) steels are widely applied in today’s automotive body design. The favorable combination of strength and ductility in such steels is in first place related to the share of ferrite and martensite. The pronounced work hardening behavior prevents localized thinning and allows excellent stretch forming. Niobium microalloying was originally introduced to dual phase steel for improving bendability by refining the microstructure. More recently developed “high ductility” (HD) DP steel variants provide increased drawability aided by a small share of austenite retained in the microstructure. In this variant niobium microalloying produces grain refinement and produces a dispersion of nanometer-sized carbide precipitates in the steel matrix which additionally contributes to strength. This study investigates the microstructural evolution and progress of niobium precipitation during industrial processing of high-ductility DP 980. The observations are interpreted considering the solubility and precipitation kinetics of niobium. The influences of niobium on microstructural characteristics and its contributions to strength and formability are discussed.
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Rasouli, Azam, and Mohammad Mazinani. "The Assessment of Work Hardening Behaviour of Dual Phase Steels with Coarse Martensite Islands." Advanced Materials Research 476-478 (February 2012): 311–15. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.311.
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In this paper, the tensile properties of dual phase (DP) steels with different martensite contents have been studied. Two steels with 0.09 and 0.15% carbon were used for the production of DP steel samples via intercritical annealing treatment, and the deformation behaviour of DP steel samples were examined during tensile loading. Although DP steels usually show two-stage work hardening behaviour, DP steels in this study with relatively high martensite content and coarse islands size exhibit a three-stage work hardening behaviour. This unusual behaviour was attributed, with the help of SEM micrographs, to decohesion of martensite-ferrite interface and martensite cracking.
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Abdo, Hany S., Asiful H. Seikh, Biplab Baran Mandal, Jabair A. Mohammed, Sameh A. Ragab, and Mohamed S. Abdo. "Microstructural Characterization and Corrosion-Resistance Behavior of Dual-Phase Steels Compared to Conventional Rebar." Crystals 10, no. 11 (November 23, 2020): 1068. http://dx.doi.org/10.3390/cryst10111068.
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Dual-phase (DP) steels consist of a ferritic matrix dispersed with some percentage of martensite, which gives the material a good combination of strength and ductility, along with the capacity to absorb energy and enhanced corrosion protection properties. The purpose of this work was to study the microstructural and corrosion behavior (mainly pitting and galvanic corrosion) of DP steel compared with that of conventional rebar. To obtain DP steel, low-carbon steels were heat-treated at 950 °C for 1 h and then intercritically annealed at 771 °C for 75 min, followed by quenching in ice-brine water. The corrosion rates of DP steel and standard rebar were then measured in different pore solutions. Macro- and microhardness tests were performed for both steels. It was found that DP steels exhibited a superior corrosion resistance and strength compared to standard rebar. The reported results show that DP steels are a good candidate for concrete reinforcement, especially in aggressive and corrosive environments.
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Pan, Zhiyi, Bo Gao, Qingquan Lai, Xuefei Chen, Yang Cao, Manping Liu, and Hao Zhou. "Microstructure and Mechanical Properties of a Cold-Rolled Ultrafine-Grained Dual-Phase Steel." Materials 11, no. 8 (August 10, 2018): 1399. http://dx.doi.org/10.3390/ma11081399.
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A new processing route to produce Ultrafine-Grained Dual-Phase steel has been proposed, involving cold-rolling and subsequent intercritical annealing of a fibrous ferrite–martensite starting structure. Ultrafine-grained DP (UFG-DP) steel with an average ferrite grain size of about ~2.7 μm and an average martensite island size of ~2.9 μm was achieved. Tensile testing revealed superior mechanical properties (the ultimate tensile strength of 1267 MPa and uniform elongation of 8.2%) for the new DP steel in comparison with the fibrous DP steels. The superior mechanical properties are attributed to the influence of microstructure refinement on the work-hardening and fracture behavior.
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Kuang, Shuang, Xiu Mei Qi, and Yun Han. "Analysis of Microstructures and Mechanical Properties of Two Hot Dip Galvanized Dual-Phase Steels with Different Alloy Systems." Applied Mechanics and Materials 624 (August 2014): 198–201. http://dx.doi.org/10.4028/www.scientific.net/amm.624.198.
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The microstructures and mechanical properties of a high carbon DP steel and a low carbon Nb microalloying DP steel were investigated. The two types of DP steels have both qualified to meet European standard performance. But the high carbon content DP steel exhibits relatively low elongation and low hole expansion rate as well as poor bending performance. The martensite island in high carbon DP steel appears obvious band structure, and the size of martensite islands is big. Contrary, the matensite islands in low carbon and Nb microalloying DP steel are dispersed and fine, which lead to perfect comprehensive performance.
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Wang, Zhi Gang, Zheng Zhi Zhao, Ai Min Zhao, and Jie Yun Ye. "Microstructure and Recrystallization Texture Characterization of Cold-Rolled Dual-Phase Steel." Advanced Materials Research 430-432 (January 2012): 1223–26. http://dx.doi.org/10.4028/www.scientific.net/amr.430-432.1223.
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Deep drawing dual phase steel was designed and trial-produced in the laboratory. The microstructure and recrystallization texture was studied using OM,TEM and XRD techniques. The results show that texture components typically in DP steels are γ (<111>//ND) and α (<110>//RD) fibers, which is partly attributed to the precipitation of Mo-based carbides in hot-rolled plate. Besides, {554}<225> and {332}<113> texture components are also founded in deep drawing DP steels, which are beneficial to improvement of drawability. With the increasing of annealing temperature, the tensile strength and elongation of DP steels are increased and decreased, respectively, and the r value is reduced slightly.
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Hafez, Khalid M., M. Ramadan, N. Fathy, and Mona Ismail. "Microstructure and Mechanical Properties of Laser Welded Dual Phase and Mild Steel Joints for Automotive Applications." Applied Mechanics and Materials 865 (June 2017): 81–87. http://dx.doi.org/10.4028/www.scientific.net/amm.865.81.
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Recently, the laser welding technology of carbon steel is being widely used compared with arc welding technology for its better welding characteristics. In the present study, the influence of welding conditions of both laser beam welding (LBW) and gas metal arc welding (GMAW) as a comparative study on the weld joint microstructures, hardness distribution and fatigue properties crosses the butt-welded joints of dual phase (DP) steel and mild steel are investigated. The results show that LBW produced narrow welds with complete penetration while GMAW produces wide fusion and heat affected zones. The microstructure of the fusion zone of laser welded DP steels contains mainly bainite, martensite, and a few amount of acicular ferrite phases. Hardness values of the heat-affected zone (HAZ) for dual-phase (DP) steels showing lower values for both LBW and GMAW processes due to the tempering action of the martensite phase. A narrow softening region was clearly observed in the HAZ welded for LBW compared with GMAW. In general, the fatigue life of the welded joints is improved by using laser welding technique.
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Hashimoto, Shunichi. "Effect of Niobium on Zn-Coated Dual Phase Steel Sheet." Materials Science Forum 539-543 (March 2007): 4411–16. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4411.
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Dual Phase (DP) steel sheets, mainly 590 MPa TS grade steel, have been applied to structural parts of automobile because of their good formability, large bake hardenability and high crash worthiness. Although the concept of DP steel was established as early as the mid-1970th, the literature contains little discussion of Zn-coated DP steel, which has been the main application in recent years. In manufacturing Zn-coated DP steel, chemical composition which secures adequate Zn coatability and appropriate heat cycles, including galvannealing, must be considered. In this paper, the effect of Nb on the tensile properties, stretch flange formability and bake hardenability of 590 MPa TS grade DP steel is discussed. The base chemical composition was 0.05%C-2%Mn-0.5%Cr steel. The effect of Nb on the above-mentioned properties was studied using 0.05%Nb added steel and found that the addition of 0.05%Nb results in improved elongation, stretch flangeability and bake hardenability with higher tensile strength under both simulated GA and GI heat cycles. These improved properties by the addition of Nb are brought about by the grain refinement of ferrite matrix and finer dispersion of martensite.
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Kang, Jun-Yun, Seong-Jun Park, and Man-Been Moon. "Phase Analysis on Dual-Phase Steel Using Band Slope of Electron Backscatter Diffraction Pattern." Microscopy and Microanalysis 19, S5 (August 2013): 13–16. http://dx.doi.org/10.1017/s1431927613012233.
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AbstractA quantitative and automated phase analysis of dual-phase (DP) steel using electron backscatter diffraction (EBSD) was attempted. A ferrite–martensite DP microstructure was produced by intercritical annealing and quenching. An EBSD map of the microstructure was obtained and post-processed for phase discrimination. Band slope (BS), which was a measure of pattern quality, exhibited much stronger phase contrast than another conventional one, band contrast. Owing to high sensitivity to lattice defect and little orientation dependence, BS provided handiness in finding a threshold for phase discrimination. Its grain average gave a superior result on the discrimination and volume fraction measurement of the constituent phases in the DP steel.
Dissertations / Theses on the topic "Dual Phase steel - DP"
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Falk, Johannes. "Fracture prediction of stretched shear cut edges in sheets made of Dual-Phase steel." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-13956.
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Dual-Phase (DP) steels, part of the group of Advanced High Strength Steels (AHSS), are used by car manufactures due to its large strength to weight ratio. The high strength of the DP steel does have a negative impact on the formability during sheet metal forming and stretch forming, e.g. fractures often appear in shear cut edges during forming of blanks made of DP steel. The main objective with this thesis is to develop a new punch for Volvo Cars that concentrates the strain to the sheared edges of a test specimen made from different types of DP steel. This is done to be able to measure and obtain maximum fracture strain during stretch forming tests in a press. The newly developed test method is called CTEST (Concentrated Trim Edge Strain Test). The tests are performed with DP steel specimens with three different qualities of the shear cut edges; fine cut, medium cut and worn cut. DP steels tested are DP600GI, DP600UC and DP800GI from three different suppliers. 10 different types of DP steels are tested in this study with different thickness. Thickness of specimens tested are 1 mm, 1.1 mm, 1.5 mm and 2 mm and all specimens tested have a lengthwise (RD) rolling direction. The quality of the sheared cut edge has a great impact to the formability and maximum fracture strain of the specimen. A specimen with a fine cut endures higher fracture strain than medium cut and a worn cut for all types of DP steel with different thickness. A 1 mm thick specimen endures a lower fracture strain than 1.5 mm and 2 mm specimen for all cut qualities. Further, the impact of the orientation of the burr zone of a shear cut edge is studied. With the burr zone facing upwards from the CTEST punch the formability of the specimens is decreased compared to a burr zone facing downwards, especially for a worn cut specimen with micro cracks and imperfections in the edge surface. ARAMIS Digital Image Correlation (DIC) system is used to analyze the specimen edges during press experiments. The ARAMIS results unveil that several small fractures appear in the sheared edges of a specimen just before the specimens split into two pieces. This phenomenon was seen for specimen with worn and medium shear cut qualities. Finite Element (FE) simulations of the CTEST is performed in AutoForm to determine maximum values of the true strain for the three different cut qualities. The simulation in AutoForm does show a slightly higher value of the force and press depth than the value from the press test before maximum fracture strain in reached. The small fractures seen in ARAMIS just before the specimen split into two pieces cannot be seen in the simulation in AutoForm.
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Zanluchi, Jeferson Jorge Dallagnol. "Avaliação de retorno elástico para processos de estampagem à frio dos aços bifásicos DP 600 e DP 800." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/127900.
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Este trabalho procura avaliar o retorno elástico em aços avançados de alta resistência utilizados em processo de dobramento. Para isso, foram usadas chapas de aço bifásico DP 600 e DP 800, ambas revestidas. Foram empregados dois métodos de medição a fim de abordar e avaliar o retorno elástico. O primeiro método abordado foi à conformação de tiras em U e o segundo método foi à realização do ensaio Dobramento Sob Tensão, aos quais possibilitaram a coleta de dados para aplicação em cálculo de coeficiente de atrito no processo de dobramento. Em ambas as avaliações foram utilizadas duas diferentes condições de lubrificação para o processo de dobramento, visando variar a condição de atrito no processo. A primeira foi à aplicação de um lubrificante em forma de pasta, de nome comercial Clarus Desmoldax DCP 35 e a segunda foi à aplicação em forma líquida, denominado Clarus Desmoldax DCP 35X. Para analisar o retorno elástico, foram utilizadas como critério de avaliação as medições de abertura da parede da tira conformada, permitindo desta forma considerar o atrito por intermédio da variação do tipo lubrificante. As análises realizadas nos corpos de prova conformados em formato U evidenciaram um retorno elástico menor para as amostras do aço DP 600, se comparadas com as amostras do aço DP 800. Não existiu relevância na variação dos lubrificantes quanto ao retorno elástico nas amostras de um mesmo tipo de aço. As análises realizadas nos corpos de prova submetidos ao ensaio de dobramento sob tensão, também evidenciaram um retorno elástico menor para as amostras do aço DP 600 se comparadas com as amostras do aço DP 800. Comparando as amostras com base nos dados coletados e aplicados ao cálculo de coeficiente de atrito, percebeu-se que as amostras que tiveram um retorno elástico menor, também possuíam coeficientes de atrito menor, constatando assim que quanto menor o coeficiente de atrito, menor é o retorno elástico.This piece of work seeks to evaluate the springback effect on advanced high strength steel used in the bending process. For this, biphasic steel plates DP 600 and DP 800, both coated, were used. Two methods of measurement were used to approach and asses the springback effect. The first method approached was the conformation of strips in U and the second method was the preformance of the Bending Under Tension test, which enabled the data collect for the application in calculation of the friction coefficient in the bending process. In both assessments two different lubricant conditions for the bending process were used with the aim of varying the condition of friction in the process. The first one was the application of a paste lubricant, with the brand name Clarus Desmoldax DCP 35 and the second one was the application of a liquid lubricant, called Clarus Desmoldax DCP 35X. To analyze the springback effect the measurements of the opening of the wall of the conformed strip were used, thus allowing to consider the friction through the variation of the type of lubricant. The assessments carried out in the specimens in U shape showed a smaller springback effect for the steel samples DP 600 in comparison with the DP 800 ones. There was no relevance in the range of lubricants as the springback effect in the samples of the same type of steel. The analyzes carried out in the specimens subjected to bending under pressure test also showed a smaller springback effect for the steel samples DP 600 compared with the DP 800 ones. Comparing the samples based on the data collected and applied to the calculation of the friction coefficient, it was noticed that the samples that had a smaller springback effect also had lower friction coefficients, therefore verifying that the lower the friction coefficient is, the lower the springback effect.
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Hou, Yuliang. "Modelling of plasticity and fracture behaviors of dual-phase steel." Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2302/document.
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L’acier à double phase (DP) a été développé par l'industrie automobile pour le but de réduire le poids, l'amélioration de la performance de la sécurité et l'efficacité énergétique. Habituellement, l'acier DP contient des îlots de martensite dure noyée dans une matrice de ferrite doux. La synergie entre ces deux phases avec la microstructure inhomogène présente d'excellentes propriétés mécaniques. Les propriétés mécaniques (comportements de plasticité et de dégâts) d'acier DP sont principalement dérivés de sa microstructure, par exemple, la fraction de volume, la taille, la distribution et la morphologie de chaque phase constituante. Les approches micromécaniques sont largement appliquées pour prédire la plasticité et d'autres propriétés mécaniques de l'acier DP selon divers scénarios de chargement. Dans ce travail, la modélisation micromécanique de l'acier DP a été réalisée en utilisant des microstructures réelles ou artificielles. Une véritable microstructure est obtenue à partir de l'image métallographique, tandis qu'un générateur de microstructure artificielle à l'aide d'un algorithme d'affectation de phase améliorée basée sur l'optimisation de la topologie matériau est proposé d'étudier les propriétés mécaniques. Dans ce générateur artificiel, un processus d'affectation de phase est réalisé sur une mosaïque de Voronoï modifié pour obtenir une mesure représentative de l'élément de volume (VER) avec une bonne convergence. La méthode proposée comprend également une réduction appropriée décomposition orthogonale (POD) des courbes de débit (instantanés), qui sont calculés en utilisant le schéma asymptotique homogénéisation d'extension (AEH), pour identifier le contrôle des paramètres optimaux pour l'acier DP. Cette méthode numérique est vérifiée en utilisant DP590 et DP980 aciers qui indiquent un bon accord avec la contrainte d'écoulement à partir de mesures et prédiction de RVE basés sur de vraies microstructures. Les prédictions des modèles de déformation plastique, y compris des bandes de cisaillement en utilisant la microstructure artificielle ressemblent étroitement le comportement mécanique réel dans des conditions de chargement similaires. En outre, une interpolation a été adoptée pour obtenir une corrélation entre ces paramètres de contrôles basés sur l'identification des différents aciers DP. En outre, un modèle de substitution bi-niveau réduit est élaboré et présenté pour identifier les paramètres matériels du critère de rupture de Mohr-Coulomb (MMC). En utilisant cette méthode, le processus d'identification devient possible avec un nombre limité de tests Expérimentaux. La méthode combine des éléments critiques locaux associés à des modèles globaux. Le modèle de substitution de la souche de fracture construit en utilisant l'approximation diffuse et les éléments locaux, réduit le coût de calcul pour la recherche des paramètres matériels. Des simulations de fracturation sont effectuées globales pour mettre à jour la déformation à la rupture de la cible et pour calculer le déplacement de l'apparition de la panne correspondante. Des résultats probants sont obtenus par application successive de la conception de l'expérience (DOE) et l'amélioration des algorithmes de transformation de l'espace de conception. Le protocole d'identification proposée est validé avec de l'acier DP590. Robustesse de la méthode est confirmée par des valeurs initiales différentes. Ces investigations numériques fournissent nouvelle direction pour les simulations multi-échelles de la plasticité et de dégâts des comportements d'acier DP. De plus, ils contribuent efficacement à combler le fossé entre la recherche scientifique et à l'application de l'ingénierie des matériaux hétérogènesDual-phase (DP) steel has been developed by automotive industry for the purpose of weight reduction, improvement in safety performance and fuel efficiency. Usually, DP steel contains hard martensite islands embedded in a soft ferrite matrix. Synergy between these two phases with the inhomogeneous microstructure exhibits excellent mechanical properties. The mechanical properties (plasticity and damage behaviors) of DP steel are mostly derived from its microstructure, e.g., volume fraction, size, distribution and morphology of each constituent phase. Micromechanical approaches are vastly applied to predict plasticity and other mechanical properties of DP steel under various loading scenarios. In this work, micromechanical modelling of DP steel has been performed using real or artificial microstructures. A real microstructure is obtained from metallographic image, while an artificial microstructure generator with an enhanced phase assignment algorithm based on material topology optimization is proposed to investigate the mechanical properties. In this artificial generator, phase assignment process is performed on a modified Voronoï tessellation to achieve the tailored representative volume element (RVE) with a good convergence. The proposed method also includes a proper orthogonal decomposition (POD) reduction of flow curves (snapshots), which are computed using the asymptotic extension homogenization (AEH) scheme, to identify the optimal controlling parameters for DP steel. This numerical method is verified using DP590 and DP980 steels that indicate a good agreement with the flow stress from measurements and RVE prediction based on real microstructures. Predictions of plastic strain patterns including shear bands using the artificial microstructure closely resemble the actual mechanical behavior under similar loading conditions. Moreover, an interpolation has been adopted to obtain a correlation between these controlling parameters based on the identification for various DP steels. Additionally, a bi-level reduced surrogate model is developed and presented to identify the material parameters of the Mohr-Coulomb (MMC) fracture criterion. Using this method, the identification process becomes feasible with a limited number of experimental tests. The method combines local critical elements associated with global models. The surrogate model of fracture strain constructed using the diffuse approximation and the local elements, reduced the computational cost for searching material parameters. Global fracture simulations are performed to update the target fracture strain and to compute the corresponding failure onset displacement. Convincing results are obtained via successive application of design of experiment (DOE) and enhanced design space transformation algorithms. The proposed identification protocol is validated with DP590 steel. Robustness of the method is confirmed with different initial values. These numerical investigations provide new direction for multiscale simulations of the plasticity and damage behaviors of DP steel. Moreover, they efficiently contribute to bridge the gap between scientific research and engineering application of heterogeneous materials
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Sung, Ji-Hyun. "The Causes of “Shear Fracture” of Dual-Phase Steels." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1268039436.
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Olsen, Eric Michael. "Friction Stir Welding of High-Strength Automotive Steel." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/951.
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The following thesis is a study on the ability to create acceptable welds in thin-plate, ultra-high-strength steels (UHSS) by way of friction stir welding (FSW). Steels are welded together to create tailor-welded blanks (TWB) for use in the automotive industry. Dual Phase (DP) 590, 780, and 980 steel as well as Transformation-Induced Plasticity (TRIP) 590 steel with thicknesses ranging from 1.2 mm to 1.8 mm were welded using friction stir welding under a variety of processing conditions, including experiments with dissimilar thicknesses. Samples were tested under tensile loads for initial determination if an acceptable weld had been created. Acceptable welds were created in both TRIP 590 and DP 590 at speeds up to 102 centimeters-per-minute. No acceptable welds were created in the DP 780 and DP 980 materials. A series of microhardness measurements were taken across weld samples to gain understanding as to the causes of failure. These data indicate that softening, caused by both excessive heat and insufficient heat can result in weld failure. Not enough heat causes the high concentration of martensite in these materials to temper while too much heat can cause excessive hardening in the weld, through the formation of even more martensite, which tends to promote failure mode during forming operations. Laser welding is one of the leading methods for creating tailor-welded blank. Therefore, laser welded samples of each material were tested and compared to Friction Stir Welded samples. Lower strength and elongation are measured in weld failure while the failure location itself determines the success of a weld. In short, an acceptable weld is one that breaks outside the weld nugget and Heat Affected Zone (HAZ) and where the tensile strength (both yield and ultimate) along with the elongation are comparable to the base material. In unacceptable welds, the sample broke in the weld nugget or HAZ while strength and elongations were well below those of the base material samples.
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Rosado, Diego Belato. "Comparação do efeito da fragilização por hidrogênio em aços com resistência à tração acima de 1000 MPa." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/37374.
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Este trabalho tem por objetivo avaliar os efeitos do hidrogênio em três diferentes tipos de aços de alta resistência mecânica. São descritos os fenômenos de introdução, difusão e aprisionamento de hidrogênio (H) dentro dos metais, em conjunto com os diferentes tipos de danos provocados devido à presença do hidrogênio. Os materiais de estudo são aços da família Advanced High Strength Steels (AHSS): aços Dual Phase (DP 1000 e DP 1200) e aço Martensítico (M 190). A introdução de hidrogênio nos materiais foi realizada através de carregamento catódico, o qual é representativo para as condições industriais a que se destinam. De modo a avaliar a influência do H nas propriedades mecânicas dos aços, os seguintes ensaios foram propostos: ensaio de carregamento com H, para determinar o conteúdo total de H (saturação) e conteúdo de H difusível (suscetibilidade a fragilização); ensaio de tração ao ar, para determinar a tensão no final da região elástica e resistência à tração na região do entalhe e ensaio de tração com carga constante em ambiente hidrogenado, para avaliar os efeitos provocados pela presença do H e determinar o patamar abaixo do qual o H não apresenta efeito crítico sobre o material. Os efeitos provocados pela aplicação de diferentes densidades de correntes (0,2 – 1,0 mA/cm²) foram avaliados nos ensaios de quantificação de H difusível. Conforme os resultados obtidos todos os aços apresentaram perdas na resistência mecânica à tração quando em ambiente hidrogenado, ou seja, sofreram fragilização por H. Os aços DP 1200 e M 190 (de microestrutura predominantemente martensítica) foram fortemente afetados, conforme evidenciado pela notável queda nos valores de tensão necessários para provocar a falha. Por outro lado, o aço DP 1000, de menor resistência mecânica, demonstrou menor suscetibilidade à fragilização, o que é atribuído a menor permeabilidade do H na microestrutura austenítica.This work aims to evaluate the effects of hydrogen in three high- strength steel grades. The phenomena of hydrogen (H) entry, transport and trapping inside the metals, together with the different types of damages due to the presence of hydrogen are presented. The study materials are a range of AHSS steel grades: Dual Phase Steel (DP 1000 and DP 1200) and Martensitic Steel (M 190). The hydrogen entry was performed by cathodic charging, which is suitable for industrial applications. In order to evaluate the influence of H on the steel mechanical properties, the following tests were done: H charging, to measure total H content (saturation point) and diffusible H content (embrittlement susceptibility); uniaxial tensile test of uncharged samples to determine notched tensile strength values and the strength levels at the end of elastic region and constant load tensile testing carried out in hydrogen environment, to determine the threshold values where hydrogen has an effect on the material. DP 1200 and M 190 were strongly affected by H pre-charging, as shown by the significant drop in stress required to break them. On the other hand, DP 1000 showed a lower embrittlement susceptibility, which is attributed to its lower mechanical strength. The current densities effects (0.2 up to 1.0 mA/cm²) were evaluated during H charging to measure diffusible H content. All steels showed a drop in the tensile strength i.e. experienced hydrogen embrittlement. Steels with higher tensile strength, as DP 1200 and M 190, showed a much bigger drop that is related to the favorable characteristics of martensitic microstructure regarding to the hydrogen permeability and diffusivity.
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Piao, Kun. "An Elevated-Temperature Tension-Compression Test and Its Application to Mg AZ31B." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1316096630.
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Mallick, Dwaipayan. "Hydrogen behavior in first and second generation of advanced high strength steels." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI052.
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Les aciers AHSS sont largement utilisés pour les caisses des véhicules, en raison de leurs bonnes propriétés mécaniques et de leurs capacités à réduire l'empreinte carbone. Toutefois, leur utilisation est limitée par leur sensibilité à la fragilisation par l'hydrogène (HE). La présente étude vise à comprendre l'influence de l'hydrogène sur quatre aciers AHSS : deux biphasés (DP), un phase complexe (CP) et un à plasticité induite (TWIP). Les résultats montrent une forte susceptibilité à l’HE pour les aciers DP et TWIP par rapport aux aciers CP. Le comportement de CP est attribuée à une microstructure plus homogène, une densité de piège plus petite (mais à énergie élevé) et une concentration en H plus faible. Dans les aciers DP, la forte densité de pièges à faible énergie et la forte absorption de H augmentent la susceptibilité à l’HE. Les dislocations et les joints de grains sont les principaux sites de piégeage pour tous ces aciers, ainsi que la cémentite dans les aciers CP et les particules AlN et l’austénite pour les aciers TWIP. Sous chargement mécanique, la désorption de l'hydrogène s’accélère avec l'expansion du réseau cristallin et les mouvements des dislocations (jusqu'à la limite d'élasticité), alors qu'elle diminue en raison de la génération de défauts dans la domaine plastique. Pour l'acier CP, l'hydrogène piégé fortement désorbe à l'UTS alors que dans l'acier TWIP, la génération de défauts libère l'hydrogène. Pour l’acier DP galvanisés, la couche de Zn se comporte une couche barrière à l’hydrogène sous polarisation fortement cathodiques, tandis qu'à potentiels cathodique plus faible, elle favorise la perméation de l'hydrogène en raison de sa dissolutionAdvanced High Strength Steels (AHSS) are increasingly used as fabrication material for vehicle Body In White (BIW), owing to their superior properties and ability to reduce carbon footprint. However, its susceptibility to hydrogen embrittlement (HE) restricts the use of AHSS. The present study aims to understand the H influence on four commercial-grade AHSS steels, two Dual Phase (DP), one Complex Phase (CP), and one Twinning Induced Plasticity (TWIP) steel. Results show high HE susceptibility for DP and TWIP steel compared to CP steel. The superior HE resistance in CP steel was attributed to a more homogeneous microstructure, smaller yet stronger trap density, and lower H concentration. In DP steels, a high density of weak traps and high H uptake increased HE susceptibility. During charging, H preferentially adsorbed along the grain boundaries and interfaces for all steels along with grain interior in TWIP steels. Dislocations and grain boundaries were the main trap sites for all steels, along with cementite particles in CP steels and AlN particles and austenitic grain interior in TWIP steels. For all steels under stress, hydrogen desorption increased up to yield point due to lattice expansion and dislocation movement, whereas decreased in the plastic region due to defect generation. For CP steel, strongly trapped hydrogen desorbed at UTS whereas in TWIP steel, generation of deformation twinning released hydrogen. The study of the galvanized layer showed that at higher cathodic overpotential, the Zn layer behaved as a barrier layer protecting the steel, while at a lower potential, it increased the HE susceptibility due to Zn layer dissolution. Overall, CP steel was the most resistant steel to HE, followed by TWIP and DP steels
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Sun, Shoujin. "Directionally structured dual phase steel composites." Thesis, University of Canterbury. Mechanical Engineering, 1998. http://hdl.handle.net/10092/8134.
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Manganese partitioning and mechanical properties of dual phase steels have been examined. The manganese partitioning coefficient increases to a limit with increasing isothermal holding time, and the final equilibrium partitioning coefficient decreases with increasing annealing temperature. The combination of diffusion equations in austenite and ferrite plus mass balance and austenite growth can give the manganese distribution in austenite and ferrite respectively, and the manganese partitioning coefficient at any isothermal holding time.
The introduction of rolling during annealing or at the end of annealing can strengthen dual phase steels by elongating austenite and introducing internal stresses and dislocations, the magnitude of which depends on finishing rolling temperature and the timing of rolling during annealing. The tensile properties of as-rolled dual phase steels are strongly influenced by finishing rolling temperature and martensite volume fraction because of internal stresses and dislocation density, whereas those of post-rolling annealed steels depend on only martensite volume percentage.
To model the heat-treatment for producing dual phase steels (“in-situ” dual phase steel), a steel-steel composite is produced by incorporating high strength steel-wires into ductile steel sheets through hot-rolling (“artificial” dual phase steel). The properties of the reinforcing wire, matrix steels, interfacial strength between wire and matrix steels and steel-steel composite are affected by the surface condition of wire, finishing rolling temperature, preform holding time at rolling temperature before rolling, and heat-treatment after fabrication of composites.
Mileiko’s theory can predict the relationship between the steel-steel composite strength and the volume fraction of wire. But for dual phase steels, Mileiko’s theory can be applied only when martensite volume fraction is over 30% because the residual stress, high dislocation density and carbide are produced at low temperature, at which low martensite volume fraction is obtained.
Continuous wire composites can simulate the as-rolled dual phase steel when the reinforcement content is over 30%, but discontinuous wire composites can not simulate the post-rolling annealed dual phase steel.
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Cochrane, Hal. "Formable dual-phase steels." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329964.
Full textBooks on the topic "Dual Phase steel - DP"
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Hamzah, E. Strength and ductility of alloyed dual-phase steel. Manchester: UMIST, 1993.
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Saleh, M. Husin Bin. Retained austenite in dual phase steel and its effect on mechanical properties. Manchester: UMIST, 1998.
Find full textBook chapters on the topic "Dual Phase steel - DP"
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Moussy, F. "Deformation Mechanisms in a Dual Phase Steel." In Advanced Technology of Plasticity 1987, 1165–69. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-662-11046-1_61.
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Liu, Dong Sheng, Matthias Militzer, and Warren J. Poole. "Microstructure Model for a Dual-Phase Steel." In THERMEC 2006, 4391–96. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-428-6.4391.
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Traint, Sandra, Ewald Werner, Andreas Pichler, and Peter Stiaszny. "Low Alloyed Dual-Phase and Multiphase Steel Strip." In Steels and Materials for Power Plants, 71–76. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/3527606181.ch13.
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Liu, Yan Dong, Q. W. Jiang, Tong He, Yan Dong Wang, and L. Zuo. "The Texture Evolution of Dual Phase Steel Sheets." In Advanced Materials Research, 51–54. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-463-4.51.
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Singh, Abhishek K., S. K. Nath, M. Bhardwaj, V. Pancholi, and G. P. Chaudhari. "Microstructural Studies on Thermomechanically Processed Plain Carbon Dual Phase Steel." In Supplemental Proceedings, 659–65. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118357002.ch82.
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Hashimoto, Shunichi. "Effect of Niobium on Zn-Coated Dual Phase Steel Sheet." In THERMEC 2006, 4411–16. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-428-6.4411.
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Thiessen, Richard G., Jilt Sietsma, and I. M. Richardson. "A Phase Transformation Model for the Austenitisation of Martensite in Dual-Phase Steel." In THERMEC 2006, 4608–13. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-428-6.4608.
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Jaber, Hassanen, and Tunde Kovacs. "Dissimilar Resistance Spot Welding of Ferrite-Martensite Dual Phase Steel/Low Carbon Steel: Phase Transformations and Mechanical Properties." In Lecture Notes in Mechanical Engineering, 709–18. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-75677-6_60.
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Micheletti, Alessandra, Junichi Nakagawa, Alessio A. Alessi, Vincenzo Capasso, Davide Grimaldi, Daniela Morale, and Elena Villa. "Mathematical Morphology Applied to the Study of Dual Phase Steel Formation." In Mathematics in Industry, 759–68. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-23413-7_105.
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Mazinani, M., and Warren J. Poole. "Deformation Behaviour of Martensite in a Low-Carbon Dual-Phase Steel." In THERMEC 2006 Supplement, 774–79. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-429-4.774.
Full textConference papers on the topic "Dual Phase steel - DP"
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Tüzemen, Mehmet Çağrı, and Elmas Salamci. "Effect of Microstructure on Mechanical Properties and Abrasive Wear Behavior of Low Carbon Dual-Phase Steels." In ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/esda2014-20231.
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The mechanical properties and wear behavior of Dual Phase (DP) steels have been investigated and compared with those observed in normalized (N) steel that has the same chemical composition. The DP steels having different content and morphology of martensite were produced by varying intercritical annealing temperature and initial microstructures. Mechanical properties of four different DP steels and N steel have been investigated by carrying out tensile and macrohardness tests. Dry sliding wear tests have been conducted on four different the DP steels and the N steel using pin-on-plate to investigate their wear characteristics. It has been found that the yield and tensile strengths and macrohardness increase with increasing martensite content and decreasing martensite size. The yield and tensile strengths and macrohardness of the N steel were significantly lower than the DP steels whereas percentage of total elongation was higher. Wear properties are improved by increasing martensite volume fraction and size in the DP steels. The N steel specimen showed the highest wear rate.
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Lou, Ming, Yunwu Ma, and Yongbing Li. "Study on Formation and Performance of Electric-Aided Self-Piercing Riveted Aluminum Alloy and Dual-Phase Steels With Different Strength Grades." In ASME 2019 14th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/msec2019-2984.
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Abstract To improve the joint quality by reducing the deformation resistance of dual-phase (DP) steels, electric-aided self-piercing riveting (EA-SPR) was conducted in this paper. The effect of current density on the joint forming process, geometry characteristics and mechanical properties of EA-SPR for both combinations of aluminum to steel and steel to aluminum were investigated and compared with the traditional SPR joints. It was found that the riveting force decreased for all the DP steels with different strength grades. The increase amplitude of undercut increased with the elevated strength grades of DP steels. When riveting from aluminum to steel, the tensile-shear and cross-tension strengths of EA-SPR joints could improve up to 13.3% and 15.7% respectively, compared with the traditional SPR joints. For joints riveted from steel to aluminum, the current showed less effect on the tensile-shear strength due to the rivet shank fracture. Nevertheless, the cross-tension strength could still improve by 13.04%.
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Koganti, Ramakrishna, Sergio Angotti, Armando Joaquin, Cindy Jiang, and Chris Karas. "Gas Metal Arc Welding (GMAW) Process Optimization for Uncoated Dual Phase 600 Material Combination With Aluminized Coated and Uncoated Boron Steels for Automotive Body Structural Applications." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-43419.
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With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years as new safety and fuel economy regulations are enacted. These new steels pose significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures, especially when durability of the welded structures is required. In this paper, Gas Metal Arc Welding (GMAW) of uncoated DP 600 and boron (coated and uncoated boron) steels were investigated. In the first study, 2.0 mm DP 600 and 2.0 mm uncoated boron lap joints (Joint #1 and #2) were investigated. In the second study, 1.00 mm DP 600 and 2.0 mm USIBOR (aluminized coated boron) lap joints (Joint # 3 and #4) were investigated. Static and fatigue tests were conducted on the four joint configurations. The effects of steel stack-ups and microhardness distribution along the tensile stress flow direction of the joints on fatigue performance defined by fatigue life as well as crack initiation site and propagation path were analyzed. Metallurgical properties of the dissimilar metal lap joints were evaluated using optical microscopy. The boron steel shows a significant drop in hardness at the heat affected zone (HAZ) as compared to the DP600 steel side. It was found that for the 2.0 mm DP600 and 2.0 mm boron steel dissimilar joint, fatigue life of the joint is better when boron steel was on the top of the joint (Joint #2). However, in the case of 1.0 mm DP 600 and 2.0 mm USIBOR lap joint, the fatigue life of the joint is better when 1.0 mm DP 600 was on the top of the joint (Joint # 3). Ductility of boron steel and significant HAZ softening in boron steel are believed to be the key factors for the fatigue failure at the boron steel side (in all four joint configurations).
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Mahagaonkar, N. S., K. N. Kulkarni, V. V. Shinde, M. R. Saraf, and Lothar Issler. "Evaluation of Fatigue Properties and Effect of Stress Concentration on Fatigue Life of Dual Phase Steel Grade DP 800." In SIAT 2011. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2011. http://dx.doi.org/10.4271/2011-26-0120.
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Ben-Yahia, Faycal, James A. Nemes, and Farid Hassani. "Investigation of Structural and Material Effects on Crashworthiness of Advanced High Strength Steel Columns." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-55106.
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An experimental and numerical study was performed to evaluate the crashworthiness of several advanced high strength steels. The behavior of two Dual Phase (DP) steels and an HSLA steel are compared by examining the crush response of longeron column specimens, experimentally and computationally. The closed section columns, fabricated by spot welding formed channel sections, in both single hat and double hat configurations were exposed to 182 kg and 454 kg axial impacts at different velocities. Final column height and impact force history were recorded and compared with results of finite element simulation of the columns. Good agreement was found between experiments and computations.
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Pérez, Iñaki, Maribel Arribas, Iñigo Aranguren, Ángela Mangas, Radhakanta Rana, Chris Lahaije, and Daniele De Caro. "Processing of new dual-phase (DP) and complex-phase (CP) steels for automotive applications by tailored hot forming routes." In PROCEEDINGS OF THE 22ND INTERNATIONAL ESAFORM CONFERENCE ON MATERIAL FORMING: ESAFORM 2019. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5112724.
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Shih, Hua-Chu, Changqing Du, and Dajun Zhou. "Die Wear and Galling in Stamping DP980 Steel." In ASME 2013 International Manufacturing Science and Engineering Conference collocated with the 41st North American Manufacturing Research Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/msec2013-1142.
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Stamping of dual phase (DP) 980 steel creates higher deformation heat, contact pressure and friction force between the tooling and sheet steel. These, in turn, cause higher die wear and galling. Although various countermeasures have been adopted in production to prevent excessive wear associated with forming DP980 steel, the stamping die tryout process has not been revised accordingly to ensure that the die surfaces in contact with sheet metal have been hardened and coated. The effects of die hardness and lubrication conditions on die wear and galling in stamping DP980 steel during the die tryout process were evaluated at different contact pressures using the bending under tension (BUT) tester. A reciprocal cyclic bend test system (CBTS) of modifying bending under tension test was used to investigate wear and galling between a die in the tryout phase and in a production condition. The results indicate that the hardness of the die material dominates the galling and wear behavior in the die tryout phase. A better surface treated die material and an anti-galling strategy was also identified to decrease galling and wear in both die tryout and production.
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Xu, Chun, and Shuhui Li. "Correlation Between Strain and Exfoliating Performance of Galvannealed DP Steels." In ASME 2006 International Manufacturing Science and Engineering Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/msec2006-21021.
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The galvannealed dual-phase steels are used in automotive applications. However, galvannealed coating is often exfoliated when it is in the pressing process. Galvannealed exfoliation is examined as a function of strain state using double reserve Olsen test to simulate forming process. Distances of punch in first and second reverse Olsen tests are changed to used to generate other strain state. The circle grids are etched on sheet to measure strain. Significant exfoliating is encountered in biaxial compress strain zone while no exfoliating occurred in biaxial tensile strain zone. Exfoliating is measured at specific locations and correlated with strains in those locations. An exfoliating map is generated in strain space.
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Shih, Hua-Chu. "Evaluation of Zinc Coating Adhesion in Stamping Advanced High Strength Steel." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-37977.
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Advanced high strength steels (AHSS) have been widely used in vehicle structural components due to their high strength properties balanced with good formability. In many applications, a zinc coating is often applied to AHSS for the corrosion protection. Due to the high strength properties of AHSS, higher forming forces and binder pressures are also required in stamping AHSS, which often results in coating powdering/flaking or galling around the draw bead and die radius areas. The degree of coating powdering/flaking depends upon forming process variables such as draw bead force, forming speed, lubrication, and die temperatures. This study was designed to develop a lab-based coating adhesion test to quickly characterize the coating adhesion behavior of AHSS. In this study, both the bending under tension test and the modified draw bead test were used. A typical substrate of AHSS is coated with either a hot-dip Galvannealed (GA) or a Galvanized (GI) coating. In this study, dual phase (DP) steels with tensile strength levels of 600, 780 and 980 MPa were investigated at two different thicknesses and with two different coating types, GI and GA. The results reveal that GA tends to have worse coating adhesion than GI coatings under normal forming conditions. However, GI coatings are more sensitive to the lubrication condition and have worse coating adhesion than GA coatings under a larger draw bead penetration and smaller draw bead corner radius condition.
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Shih, Hua-Chu, and Ming F. Shi. "Die Wear and Coating Galling in Stamping Advanced High Strength Steels." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62668.
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Advanced high strength steels (AHSS) have been widely used in vehicle structural components due to their high strength nature with balanced formability. In a typical application, a zinc coating is often required and applied to AHSS for the purpose of corrosion protection. Due to the high strength nature of AHSS, higher forming forces and binder pressures are also required in stamping AHSS, which often results in coating galling and die wear. The degree of coating galling and die wear depends upon forming process variables such as contact pressure, forming speed, lubrication and die temperatures. In this study, the Bending Under Tension (BUT) tester was used to evaluate the effects of these process variables on coating galling and die wear. Dual phase (DP) 590 and 780 steels with galvanized (GI) and galvannealed (GA) coatings were investigated in the study. The results indicate that GI coatings tend to have better wear resistance than GA coatings. A better surface treated (Thermo-Reactive Diffusion Vanadium Carbide) die material was also identified to decrease coating galling and die wear in stamping AHSS.
Reports on the topic "Dual Phase steel - DP"
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Miyasato, S. The mechanical properties of drawn dual phase steel wire. Office of Scientific and Technical Information (OSTI), December 1987. http://dx.doi.org/10.2172/6902128.
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