980MPa级超高强Q&P钢的成形失效研究与改进  

RESEARCH AND IMPROVEMENT ON FORMING FAILURE OF 980 MPa ULTRA HIGH STRENGTHQ&PSTEEL

作　　者：连波 何方 吉伟 Lian Bo;He Fang;Ji Wei(Technical Center of HBIS Group Hansteel Company,Handan 056015,Hebei;Qinhuangdao Baigong Iron and Steel Co.,Ltd.,Qinhuangdao 063000,Bebei)

机构地区：[1]河钢集团邯钢公司技术中心,河北邯郸056015 [2]秦皇岛伯工钢铁有限公司,河北秦皇岛063000

出　　处：《河北冶金》2024年第4期6-11,共6页Hebei Metallurgy

基　　金：河北省科技计划项目(21341001D)。

摘　　要：随着汽车行业在车身安全性方面的要求不断提高,开发出具有更高强度、更高碰撞吸收能等优异成形失效特性的新一代汽车用先进钢铁材料是汽车制造领域快速发展的迫切需求。超高强冷轧淬火配分Q&P钢是具有高强度、高碰撞吸收能的新一代汽车用先进钢铁材料的代表,符合汽车等先进制造行业发展需求,但其冲压成形失效等问题,制约Q&P钢的进一步广泛应用。本文通过分析980MPa级超高强Q&P钢的成形失效现象,发现冲压失效现象主要发生在钢卷头尾部,失效部位取样的屈服强度及抗拉强度均明显高于正常部位,且总伸长率下降了三分之一以上;失效部位的显微组织特征是残余奥氏体含量下降。引起冲压失效的工艺因素主要是热轧卷取阶段的温度稳定性差,头尾部的卷取温度过低时,得到的热轧组织不利于后续淬火配分中获得大量稳定性良好的残余奥氏体。通过工艺优化改进,并经过成形极限评价,980MPa级超高强Q&P钢成品卷冲压成形性有了很大提高,用户反馈良好。With the continuous improvement of the automotive industry's requirements for body safety,the development of a new generation of advanced steel materials for automobiles with superior forming failure characteristics such as higher strength and collision absorption energy is an urgent need for the rapid development of the automotive manufacturing field.Ultra high strength cold rolled and quenched Q&P steel is a representative of the new generation of advanced steel materials for automobiles with high strength and collision absorption energy.It meets the development needs of advanced manufacturing industries such as automobiles,but its stamping forming failure and other problems restrict the further widespread application of Q&P steel.This article analyzes the forming failure phenomenon of 980 MPa ultra high strength Q&P steel and finds that the stamping failure phenomenon mainly occurs at the head and tail of the steel coil.The yield and tensile strength sampled from the failed part are significantly higher than those from the normal part,and the total elongation rate has decreased by more than one-third.The corresponding microstructure feature is a decrease in residual austenite content at the failure site.The process factor causing stamping failure of 980 MPa grade ultra-high strength Q&P steel is mainly the temperature stability during the hot rolling coiling stage.The hot rolling microstructure obtained when the coiling temperature at the head and tail is too low is not conducive to obtaining a large amount of stable residual austenite in subsequent quenching and blending.Through optimization and improvement of relevant processes and forming limit evaluation,the stamping formability of the tail end of the 980 MPa ultra high strength Q&P steel coil has been greatly improved,and userfeedbackis good.

关 键 词：Q&P钢 冲压成形失效 卷取温度 残余奥氏体 成形极限 

分 类 号：U466[机械工程—车辆工程]