第42卷第4期 Vol. 42No. 4
材料与成形性能
假压技术
FORGING & STAMPING TECHNOLOGY
QP980和DP980高强钢板的抗延迟断裂性能
濮振谦"2，林建平1,2，叶又3，赵强1,2
2017年4月 Apr.2017
（1.同济大学上海市地面交通工具空气动力与热环境模拟重点实验室，上海201804；2.同济大学机械与能源工程学院，
上海201804；3.泛亚汽车技术中心有限公司，上海201201）
摘要：高强钢零件的延退断裂现象是汽车使用安全性的严重威胁。针对QP980和DP980两种高强度汽车用钢板，基于单向拉伸实验和电化学充氢，分析了预变形对高强钢充氢后的伸长率及强度的损失规律，对比了DP980和QP980的抗延退断裂性能。研究发现，预应变从0至7%变化时，QP980和DP980均发生严重的塑性损失，但在同一预应变下，QP980的各项塑性损失儿乎均大于DP980，得出QP980的抗延退断裂性能较DP980差。通过断口形貌分析，发现QP980相比DP980更易受到氢的
侵入从而脆化，从而验证了实验结果的准确性和科学性。关键词：预应变：高强钢：延退断裂；DP980；QP980 DOI: 10. 13330/j. issn. 1000-3940. 2017. 04. 027
中图分类号：TG142.1*2
文献标识码：A
文章编号：1000-3940（2017）04-0153-06
Delayedfractureresistanceperformanceforhighstrengthsteelsheet
QP980andDP980
Pu Zhenqian'.2, Lin Jianping'-2, Ye You', Zhao Qiang'.2
(1. Shanghai Key Laboratory of Vehicle Aerodynamics and Vehicle Thermal Management Systems , Tongji University ,
Shanghai 201804, China; 2. School of Mechanical and Energy Engineering College, Tongji University, Shanghai 201804, China :
3. Pan Asia Technical Automotive Center, Shanghai 201201, China)
Abstract: Delayed fracture phenomenon of high strength steel parts is a serious threat to the safety of automobile use. For high strength steel sheet DP980 and QP980 used in the vehicle, based on the uniaxial tension test and electrochemical hydrogen charging, the loxs regu-larities of pre-deformation on elongation after high strength steel sheet hydrogen charging and strength change were studied, and the de-layed fracture resistance performances for high strength steel sheet DP98O and QP98O were compared. The result shows that when the pre-strain changes from 0 to 7% , both materials of DP980 and QP980 have great ductility losses, but with the same pre-strain, the ductility loss of QP980 is always greater than that of DP980. So, it is concluded that the delayed fracture resistance performance of QP980 is wea ker than that of DP980. By the analysis of fracture surface morphology , it is found that QP980 is more permeable by hydrogen than DP980, and the experiment results are of accuracy and scientificity.
Key words: pre-strain; high strength steel; delayed fracture; DP980; QP980
QP钢（Quenchingand Partitioning Steel）作为第3代的高强钢，相比DP钢（DualPhaseSteel），在强度、延展性、冲压成形性能方面表现更加优异，用作汽车钢板除可减轻车身自重、降低油耗外，同时还其有较强的能量吸收能力，因而在汽车轻量化
收稿日期：20161213；修订日期：20170216 基金项目：国家自然科学基金资助项目（51375346）
作者简介：溉振谦（1991-），男，硕士研究生 E-mail: lofty_ thill@ 163. com
通讯作者：林建平（1958-），男，教授，博士生导师
E-mail : jplin58@ tongji. edu. cn 万方数据
领域得到越来越多的应用，逐渐取代后者的地位[1-4]。然而，当钢暴露于氢环境时常会发生塑性和强度损失，产生氢致延迟断裂（氢脆）现象。氢致延迟断裂如在高强钢中发生，可导致突然的脆断。一般来说，高强钢的强度等级越高，其对氢致延迟断裂的敏感性也就越大[5-8]
高强钢板料在成形过程中产生的变形大小会直接影响其抗延迟断裂性能。关于预变形对于高强钢抗延迟断裂性能的影响，目前学者们已经做了一些研究。学奇等*通过纯净钢SM490B的双电解池氢渗透实验，证明变形过程中增加的位错和晶界等