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高强度板热冲压成形模具设计 总被引:2,自引:0,他引:2
通过对高强度22MnB5硼镁合金板材热冲压成形工艺和关键技术分析、热冲压成形模具热平衡分析,建立了高强度板材热冲压成形热平衡模拟方程,提出高强度板材热冲压成形模具设计方法,对热冲压成形模具冷却系统作了详细的设计. 相似文献
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热成形技术因结合热锻和冲压的技术优势,已经在汽车零部件制造工艺中获得了广泛的关注和应用。在热成形生产中,产品在高温下成形伴随非等温淬火过程容易出现起皱、破裂等成形质量缺陷。本文围绕高强度热成形钢板22MnB5材料相变过程、机械性能进行了相关研究,基于深冲盒试验进行热成形工艺改进优化,在热成形生产工艺过程中增加相应的转运冷却环节,使完全奥氏体化后的板料在冲压淬火前降低至优化冲压温度。实验表明:改进后的热成形工艺对冲压产品的成形性有明显改善,可有效降低和消除起皱、破裂等缺陷,材料微观马氏体转化更加细致充分,可获得抗拉强度达到1500MPa以上,硬度达到450HV以上的热成形产品,满足连续热冲压成形自动化生产过程工艺改进要求。 相似文献
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热冲压成形22MnB5钢板的组织和性能 总被引:6,自引:0,他引:6
采用扫描及透射电镜观察和力学性能实验研究了22MnB5钢板热冲压成形件的组织形貌和力学性能。结果表明,加热温度930℃,保温4.5 min,初始成形温度850℃,冲压速度75 mm/s条件下,22MnB5钢板热冲压成形完成完全马氏体转变,得到均匀板条马氏体组织,组织内产生高密度位错,强度大幅提升,抗拉强度达到1550 MPa。形变有助于动态再结晶并获得更为细小的马氏体组织,促进细晶强化。硼元素在晶界发生偏聚,延长奥氏体转变孕育期,提高了22MnB5钢的淬透性,同时引起点阵畸变,促进相变强化。 相似文献
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以22MnB5高强钢板力学及热物理性能的实验数据为基础,运用PAMSTAMP软件对22MnB5高强钢板U形梁的热冲压成形过程、成形后的淬火冷却工艺以及回弹分析的全部过程进行了有限元模拟,并根据模拟参数进行了物理实验验证,找出了22MnB5钢板U形梁热冲压成形后的淬火时间对回弹影响的基本规律.实验分析结果表明:在特定时间内,随着淬火时间的增加,板料回弹量有所降低;当淬火时间继续延长时,板料回弹值不再发生显著变化,最佳淬火时间为20 s.实验分析结果为高强钢板热冲压工艺的实际生产运用提供了良好的实验依据. 相似文献
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以22MnB5高强钢板力学及热物理性能的实验数据为基础,运用PAMSTAMP软件对22MnB5高强钢板U形梁的热冲压成形过程、成形后的淬火冷却工艺以及回弹分析的全部过程进行了有限元模拟,并根据模拟参数进行了物理实验验证,找出了22MnB5钢板U形梁热冲压成形后的淬火时间对回弹影响的基本规律。实验分析结果表明:在特定时间内,随着淬火时间的增加,板料回弹量有所降低;当淬火时间继续延长时,板料回弹值不再发生显著变化,最佳淬火时间为20s。实验分析结果为高强钢板热冲压工艺的实际生产运用提供了良好的实验依据。 相似文献
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由于资源和环境等原因.近年来汽车界在减轻整车重量、节约油耗方面投入了大量精力。汽车既要求轻量化,同时又要求保证车身结构的强度和安全性,因而高强度钢板在现代汽车领域得到越来越广泛的应用。随着材料强度的提高.钢板成形性能总体呈下降趋势.成形难度加大。高强板零件拉延开裂.扭曲回弹尤其难以解决.特别是变截面类和窄长梁类零件。扭曲回弹、开裂是一个长期困扰;中压领域的难题。 相似文献
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利用Gleeble-3500热模拟试验机,在温度为700℃~950℃、应变速率为0.01/s~0.4/s的条件下,对高强度硼钢22MnB5的热变形行为进行研究。结果表明,随着变形温度的升高,硼钢的延伸率升高,变形抗力降低;随着应变速率的提高,硼钢22MnB5的变形抗力和延伸率增大。根据高温拉伸实验得出的数据,构建硼钢22MnB5的稳态流变应力模型和热变形方程,并将试验结果和构建的本构方程输入ABAQUS软件进行U型件热弯曲成形的回弹模拟,数值模拟结果与实验结果吻合较好,验证了模型的可靠性和正确性,为成形所需的最大载荷及设备选择提供依据。 相似文献
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在高强度钢板冲压成形过程中,常常因为显著的回弹和面畸变导致形状和尺寸精度出现问题.利用数值模拟方法分析了超高强度钢门槛板的成形,根据模拟结果提出了利用设置拉延筋控制高强度板冲压回弹的方法,制定了合理的门槛板冲压模具的拉延筋设置方案.实际生产验证了该方法对回弹控制的有效性. 相似文献
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Numerical and Experimental Investigation into Hot Forming of Ultra High Strength Steel Sheet 总被引:3,自引:0,他引:3
Hongsheng Liu Wei Liu Jun Bao Zhongwen Xing Baoyu Song Chengxi Lei 《Journal of Materials Engineering and Performance》2011,20(1):1-10
Hot forming of ultra high strength steel (UHSS) sheet metal grade 22MnB5 boron for channel components using water cooling
is studied on a laboratory scale. After hot forming, the different microstructures such as martensite, bainite, and pearlite
in formed component are produced, which are closely related with mechanical properties of formed component. The effect of
forming start temperature and the contact state between blank and die on the microstructure evolution is investigated. In
addition, the effect of processing parameters, such as forming start temperature and blank holder force (BHF), on the final
quality of component, i.e., springback, that happens after hot forming of UHSS is investigated. It can be concluded that the
forming start temperature has a significant effect on the final mechanical properties of formed components. The effect of
forming start temperature on springback is examined in detail under a wide range of operating conditions. The higher the BHF
and the forming start temperature, the lower is the springback after hot forming. Furthermore, thermo-mechanically coupled
finite element analysis model encompassing heating of sheet blank, forming and quenching are developed for hot forming process.
The stress distributions on sheet blank under different conditions during hot forming are compared to gain a fundamental understanding
of the mechanism of springback. Comparisons show that numerical simulation results have good agreement with experimental results. 相似文献
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A. Andersson 《Journal of Materials Engineering and Performance》2007,16(3):301-307
The automotive industry is using more and more of Advanced High Strength Steel in order to reduce the weight of the car. Since
this will generate more springback, it is of vital importance to be able to predict the amount of springback in the parts.
Otherwise, many late changes have to be made in order to fit the parts in their position. In order to increase the ability
to understand and test the behavior of the springback in sheet-metal parts, a new semi-industrial experimental tool, the flex-rail,
has been developed. This is a very flexible tool, which can be used for various kinds of materials, from mild steel and aluminum
to advanced high strength steel such as TRIP-steel and CP-steel by using different insert. The tool is designed for experimental
analysis of 3D-springback, which is the case in the more complicated automotive parts, such as b-pillars and side members.
The scope of this work is to analyze the springback behavior and prediction for Advanced High Strength Steel both numerically
and experimentally. Sheet-metal-forming simulations were made in LS-DYNA. The results proved that the new geometry, flex-rail,
gave a complex springback behavior for all tested materials. Furthermore, the prediction of springback showed good correlation
in sections with small amounts of twist but that LS-DYNA under-predicts the springback for sections with large amounts of
twist for all materials except DP600.
This article was presented at Materials Science & Technology 2006, Innovations in Metal Forming symposium held October 15-19,
2006 in Cincinnati, OH. 相似文献
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用A.Thomas的试验方法,在相同的工况条件下,对比了6种热作模具钢的热塑性摩擦系数,以及润滑对摩擦系数的影响。同时还研究了模具钢的高温强度、延伸率、抗氧化性能与摩擦系数的关系。用失重法研究5种热作模具钢的热磨损次数与磨损量的对应关系。用金相、扫描电镜等手段,分析了经热磨损试样的端面硬度变化,磨损表面形貌和次表层组织的变化。 相似文献
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35CrMo钢热变形机制的模拟研究 总被引:1,自引:0,他引:1
以弯曲镦锻 3 5 Cr Mo钢火车曲轴为例 ,通过将该钢以 90 0℃~ 1 2 5 0℃变形温度 ;0 .0 5 s-1、0 .5s-1、1 .0 s-1的应变速率 ;在 Greeble-1 5 0 0试验机上进行压缩 1 5 %~ 80 %的热变形实验 ,和随后进行的微观组织分析得出了 :材料热变形屈服应力变化模型 ;材料热变形本构关系 ;动态与静态再结晶模型和热加工参数与微观组织变化的相关性资料。描绘了在 1 2 5 0℃ ,应变速率为 1 .0 s-1时 ,3 5 Cr Mo钢热变形应力应变曲线和相应的再结晶组织。通过对 3 5 Cr Mo钢在高温大变形条件下 ,试件内部各区域晶粒尺寸的回归计算 ,验证了该钢热变形晶粒计算模型。所得出的实验结果和计算模型为热成形工艺分析和质量控制提供了科学的依据 相似文献