共查询到19条相似文献,搜索用时 109 毫秒
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《锻压技术》2015,(7)
以宝钢生产的低合金高强度钢HC500LA为研究对象,对其成形特性进行了研究,通过单向拉伸实验,获得材料的基本力学性能,通过成形极限实验,研究了其在不同应变状态下的成形特性。结果表明,HC500LA材料的伸长率在20%左右,同时其成形极限的FLD0接近20%,具有良好的成形性能。通过U弯和V弯回弹实验,分析了该材料的回弹规律。V弯试验表明,材料的回弹量与弯曲角度、凸模圆角半径有关,且存在正、负回弹,可通过调整弯曲角度或弯曲模具圆角大小来合理控制零件回弹。U弯试验表明,材料的回弹量与施加的压边力有关,可通过调整压边力来减小零件的回弹。最终将该材料进行汽车座椅滑轨的试制,滑轨零件的成形效果较好。 相似文献
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双曲度覆盖件拉延回弹研究 总被引:2,自引:1,他引:1
研究了双曲扁壳覆盖件的成形机理及回弹特点,分析了双曲度拉延回弹机理。回弹与曲面部分的变形量有关,拉伸变形量增大,回弹量降低。同时,讨论分析了压边力、板材性能参数等因素对双曲度回弹的影响。 相似文献
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为了评估DP980高强钢材料的成形与回弹特性,通过加载-卸载实验与单向拉伸-压缩循环加载实验,获得了考虑包申格效应的吉田-上森硬化模型参数,并对DP980高强钢的U形弯曲实验进行了研究。实验结果表明,DP980高强钢U形件在凹模圆角处易开裂,在成形过程中需减小压边力并增大凹模圆角。由于材料的回弹量与施加的压边力有关,可通过增大压边力来减小U形件的回弹,但压边力过大又可能导致开裂,因此,需合理选择压边力。同时,对U形件成形后的回弹进行仿真分析,仿真中分别采用等向硬化模型与吉田-上森硬化模型,通过将实验数据与模拟的回弹结果进行对比分析发现,采用吉田-上森硬化模型的仿真结果与实验结果吻合良好,证明了吉田-上森硬化模型模拟回弹的准确度较高,可以应用于回弹仿真中。 相似文献
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《锻压技术》2019,(12)
基于自行设计制造的回弹实验模具,针对帽形件进行了大量的实验研究与分析,比较了HC420LA、HC420/780DP和QP980这3种不同性能的高强度钢板在不同U形弯曲成形的冲压工艺及不同成形状态下的回弹规律,为实际生产和设计提供理论指导。结果表明:任一冲压工艺下,HC420LA钢的回弹都远小于HC420/780DP钢与QP980钢;帽形件侧壁回弹在自由弯曲成形工艺下最小,法兰边回弹在中间预压料弯曲成形工艺下最小,而带压边力弯曲工艺下的回弹始终最大;随料厚的增加,3种高强度钢板的回弹不断减小,但料厚为1.4 mm的QP980钢进行中间预压料弯曲成形时,回弹呈反向增大的趋势;3种高强钢板的回弹随凸凹模间隙的增大而增大,180~280 kN压边力区间对HC420/780DP钢和QP980钢影响较小,而板料法兰边回弹随弯曲角度的增大而增大。 相似文献
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Third-generation advanced automotive medium-Mn steel, which can replace 22MnB5 steel, was newly developed to improve the lightweight and crashworthiness of automobile. Studies on the formability and simulation method of medium-Mn steel have just been initiated. In this study, finite element simulation models of square-cup deep drawing were established based on various material property experiments and validated by experiments. The effects of blank holder force (BHF), fillet radii of tools (die and punch) on the maximum drawing depth (MDD), thickness distribution of the formed products, and the microstructure before and after forming were investigated and compared with those on 22MnB5 steel. Results show that the MDD of the two steels decreased with increased BHF but increased with the fillet radius of punch; however, the fillet radius of die showed no significant effect on the MDD for both steels. Compared with hot-formed 22MnB5 steel, the martensitic transformation of the hot-formed medium-Mn steel is rarely influenced by the process parameters; thus, it holds the complete, fine-grained, and uniform martensitic microstructure. Moreover, the medium-Mn has better formability, lower initial blank temperature, and smaller impact of BHF and fillet radius of tools on the hot-formed product. Thus, a theoretical basis for the replacement of 22MnB5 steel by medium-Mn steel in hot forming process is provided. 相似文献
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E. Iriondo M.A. GutiérrezB. González J.L. AlcarazG.S. Daehn 《Journal of Materials Processing Technology》2011,211(5):909-915
This study focused on using electromagnetically generated impulses to correct dimensional errors resulting from springback on two different geometric features. Modification or correction of a corner feature is considered first. A simple linear actuator is used to correct springback on a simply bent high strength aluminum alloy (AA 5754) and a high strength steel alloy (DP 600). It is shown to be possible to fully correct for springback using a net-shape die with both materials with higher electromagnetic discharge energies being required for the steel. The second geometric feature considered is a sidewall curl ‘defect’ that is the result of bending and unbending U-Channel drawing. A serpentine actuator and net-shape die were shown effective at correcting for this defect in both DP 600 and TRIP 700 high strength steels. A somewhat higher forming energy is required for effective shape correction in the higher strength TRIP 700 alloy. A detailed mechanistic understanding of springback correction remains elusive, but these results are consistent with several other studies in the literature that show this is an effective means to control springback. 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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研究具有纵向焊缝的拼焊板在不同压边力作用下的回弹与焊缝移动及其相互关系,为拼焊板的回弹控制找到切入点.基于厚/薄侧变形均匀的思想,采用拼焊板两侧的截面应力相等的方法,理论推导了控制焊缝移动的公式,以此计算控制焊缝移动和拼焊板回弹所需要的拼焊板两侧压边力分布值.研究表明,总压边力的增大,带来双重效应:一方面随总压边力的增大拼焊板回弹降低;另一方面随总压边力的增大拼焊板焊缝移动增加,焊缝移动增加回弹增加.维持总压边力不变,通过调整压边力分布,消除焊缝移动,同时回弹也达到最小值.采用足够高的压边力的同时,对拼焊板厚/薄侧施加不均匀压边力,降低焊缝移动,这为拼焊板回弹控制提出了新的理论和方法. 相似文献
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高强度钢后保险杠成形工艺优化及回弹控制 总被引:2,自引:1,他引:1
采用高强度钢板制造的保险杠能大大提高乘员安全性,但高强度钢板成形困难。采用有限元分析软件Dynaform对某轿车高强度钢后保险杠成形过程进行模拟仿真,并使用结果优化成形工艺。主要研究了工艺补充面对零件冲压成形以及回弹的影响。通过模拟结果和实际样件对比,对工艺补充部分进行了调整,并设置凸顶得到了优化的工艺型面及坯料尺寸,为同类相关高强度钢零件的生产起到了指导作用。 相似文献