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I. S. Song D. J. Yoo J. W. Yoon D. Y. Yang H. Huh J. H. Lee 《Journal of Materials Engineering and Performance》1995,4(5):593-598
The forming of automobile sheet metal parts in a draw die consists of clamping a blank by binders to form a binder wrap and
drawing the blank into the final part. This paper proposes a numerical method to calculate the binder wrap. A blank is composed
of two regions: the contact region with the die face and the noncontact region of the die cavity. In this study, surface boundary
condition is suggested for calculating the configuration of the binder wrap. Surface boundary condition means that the three-dimensional
geometric data of the die face are used as the base for the displacement boundary condition of the finite-element analysis.
To verify the validity of the proposed method, the binder wraps of complicated automobile parts, including a front fender
and a trunk lid, are analyzed. 相似文献
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采用脉冲钨极氩弧钎焊使用CuSi3钎料对镀锌钢板进行了连接.主要研究脉冲频率变化对接头界面组织和力学性能的影响.结果表明,当电弧脉冲频率由100 Hz增加到2 000 Hz时,电弧钎焊熔池的搅拌和冲刷作用效果逐渐增强,促进了界面须状金属间化合物的破碎行为和熔池成分过冷区域的增加,使得钎料区域内部Fe5Si3(Cu)强化相数量不断增多,弥散宽度变宽,由40 μm增加到120 μm,接头显微硬度最大值也相应增加,由175 MPa增加到204 MPa. 相似文献
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U-channel forming tests were performed to investigate the surface topography evolvement of hot-dip galvanized(GI) and galvannealed(GA) steels and the effects of die hardness on sheet metal forming(SMF). Experimental results indicate that the surface roughness values of the two galvanized steels increase with the number of forming, i.e., the surface topographies of galvanized steels are roughened in SMF. Moreover, GI steel has a better ability of damage-resistance than GA steel. The mechanisms of topography evolvement are different in the forming of GI and GA steels. Scratch is the main form of surface damage in the forming of GI steels. The severity of scratch can be decreased by increasing die hardness. GA steel results in exfoliating of the coating firstly and then severe scratching. The surface topography of galvannealed steels can be improved by increasing die hardness. However, the hardness should not be too high. 相似文献
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退火工艺对SPCC-SD冷轧板组织和性能的影响 总被引:2,自引:0,他引:2
在实验室条件下,研究了罩式退火工艺对SPCC-SD冷轧板组织和性能的影响。试验结果表明.在再结晶的低温区(580~620℃)退火和采用双台阶退火,SPCC-SD冷轧板均具有较细的铁索体品粒、较高的屈服强度和抗拉强度。 相似文献
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Mechanical properties of galvannealed (GA) steel sheet used for automotive exposed panel and predicted failure phenomenon of its coating layer were evaluated using finite element method. V-bending test was performed to understand better the fracture of coating layer of GA steel sheet during plastic deformation. Yield strength of the coating layer was calculated by using a relative difference between hardness of coating layer measured from the nano-indentation test and that of substrate. To measure shearing strength at the interface between substrate and coating layer, shearing test with two specimens attached by an adhesive was carried out. Using the mechanical properties measured, a series of finite element analyses coupled with a failure model was performed. Results reveal that the fracture of coating layer occurs in an irregular manner at the region where compressive deformation is dominant. Meanwhile, a series of vertical cracks perpendicular to material surface are observed at the tensile stressed-region. It is found that 0.26-0.28 of local equivalent plastic strain exists at the coating and substrate at the beginning of failure. The fracture of coating layer depends on ductility of the coating layer considerably as well. 相似文献
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Jong Hyun Suh To Hoon Kim Byung Kil Yu Kyoung Don Lee 《Metals and Materials International》1998,4(2):157-163
Research was conducted on tailored blank welding between mild steel sheet and Zn-coated steel sheet using CO2 laser beam. The materials used in this study were low carbon steel sheets with a thickness of 1.2 mm and Zn-coated steel
sheet with the same thickness and 6.3 μm Zn coating. Experiments were conducted by applying the Taguchi method to obtain optimum
conditions for the application of this tailored blank laser welding method in practical manufacturing processes. Optical microscopy,
XRD, SEM and TEM analysis were performed to observe the microstructures and to determine the structures of welded zone. In
addition, mechanical properties were measured by the microhardness test, tensile test and Erichsen test to evaluate the formability
of the welded specimen. There was no trapped Zn in the fusion zone, and the phases of this region consisted of polygonal ferrite,
quasi-polygonal ferrite, banitic ferrite and martensite. The elongation value of welded specimen was more than 80% of the
value in substrate metal, and the LDH value was more than 90% of the value in substrate metal. 相似文献
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研究车体用2 mm不锈钢材料X2Cr Ni N18-7及其焊接薄板通过火焰调修后的力学性能。采用低温、中温和高温三种温度分别对不锈钢母材、焊接钢板的焊缝进行火焰调修,获得了调修温度对母材、焊缝以及调修后焊缝的屈服强度、抗拉强度、延伸率和硬度的影响规律。结果表明:采用较高温度火焰调修能够获得焊缝区域屈服强度524 MPa、抗拉强度760 MPa和延伸率22.0%,性能良好。火焰调修能够提高焊缝及熔合区的硬度,但调修温度在450℃~850℃之间时,调修温度对硬度的影响并不显著。 相似文献
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The material structure of laminated vibration damping steel sheet(LVDSS) was introduced in detail. An interface cohesive model between the skin sheets was developed by using a contact/interface approach, and the model was applied to simulate "T"-peel and lap-shear processes of LVDSS. The interface contact stress distribution during the "T"-peel and lap-shear processes is obtained, and the finite element analysis(FEA) results agree satisfactorily with the corresponding experimental results. As a result, the model is suitable to simulate the cohesive of LVDSS 相似文献
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对冷轧1100 MPa和1500 MPa级超高强马氏体钢板进行了不同温度(200~400 ℃)和时间(120~360 s)的过时效处理,采用光学显微镜、扫描电镜、透射电镜和拉伸试验机等手段分析了过时效处理对马氏体钢板组织与性能的影响。结果表明,随着过时效温度的升高和时间的延长,抗拉强度下降,断后伸长率逐渐升高;屈服强度在250 ℃时先升高,250~300 ℃相对稳定,而后呈逐渐降低趋势。对两种以马氏体相为主的超高强钢经250 ℃´240 s过时效处理后,均可得到强塑性结合良好的综合性能,当过时效温度高于300 ℃,保温时间为360 s时,马氏体大量分解,抗拉强度和屈服强度显著下降。 相似文献
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The forming of coated sheet steel products is performed for a wide range of processing conditions. This article examines the
effects of die history on the frictional nature of the sheet-die interface. It has been found that as successive tests are
performed on a die from the as-lapped condition to the “run-in” condition, the die surface morphology changes significantly
and the coefficient of friction, μ, decreases. Changes in surface roughness as well as scratch formation on the die are believed
to affect the nature of the die-workpiece, lubricant interaction. The findings in this study suggest that the extensive polishing
procedures used in the manufacture of new stamping dies should be carefully reevaluated. 相似文献
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高强度钢板具有高屈服强度、高韧性及较高的能量吸收率和疲劳强度,以及优良的成型性能和高烘烤硬化性能、防撞凹性能等优点,广泛应用于汽车外壳及车体结构件的制造。高强度钢板工业生产线的批量生产及汽车组装过程多采用电阻焊,随着钢板强度化的提高,焊接难度加大,限制了高强度钢板的大范围应用。从薄板连续退火及连续镀锌生产线中的头-尾连接、汽车用同种钢板焊接、汽车用异种材质焊接三种不同工艺形式方面阐述了高强度钢板电阻点焊、缝焊的研究进展,指出异种材质的电阻焊研究及电阻缝焊数值模拟研究还有待加强,同时展望了未来高强度钢板电阻焊的发展方向。 相似文献
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以硫磺回收装置液硫池顶板内侧防腐用不锈钢薄板焊接为例,采取必要的工艺措施和控制方法,可以有效防止不锈钢薄板产生焊接变形,确保整个池顶板安装及浇筑的质量。 相似文献