摘要
以5种不同强度级别的先进高强钢板(DP590、 DP780、 DP980-A、 DP980-B和MS1180)及1种6061铝合金板为实验材料,通过面内、面外剪切实验对比研究了不同微观组织形貌对金属板材不同方向上剪切断裂强度的影响。结果表明,对于两种具有相同马氏体体积分数和抗拉强度的DP980板材, DP980-A在板厚中间形成了一层较宽的中心马氏体带,其面外剪切断裂强度比面内剪切断裂强度低12.1%,而DP980-B中的马氏体主要以等轴状均匀地分布在板平面内和板厚方向上,其面内面外剪切断裂强度基本一致(相差2.2%),表明马氏体带状分布对先进高强钢板面外剪切断裂强度具有一定弱化作用。对于3种不同强度级别的先进高强钢板(DP590、 DP780和DP980-A),随着抗拉强度的提高,马氏体带的宽度和数量增加,对材料面外剪切断裂强度的弱化作用也越显著。MS1180在厚度方向上出现了组织分层现象,导致其面外剪切断裂强度显著低于其面内剪切强度(相差13.1%)。不同于先进高强钢板, 6061铝合金中的细小强化相Mg_(2)Si均匀分布在基体中,在厚向上未表现出分层现象,因此其面内和面外剪切断裂强度基本一致(相差2.4%)。
The materials interest in this work were five different advanced high-strength steel sheets(namely DP590,DP780,DP980-A,DP980-B and MS1180)and a 6061 aluminium alloy sheet.The in-plane shear test and out-of-plane shear test were carried out to investigate the effect of microstructure on the shear fracture strengths along different loading directions for sheet metals.The results show that the DP980-A and DP980-B steel sheets have the same martensite volume fraction and tensile strength.A central line of martensite parallel to the rolling plane is observed in the DP980-A steel sheet.As a result,the out-of-plane shear fracture strength of DP980-A steel sheet is 12.1%lower than its in-plane shear fracture strength.The martensite in DP980-B steel sheet is distributed uniformly along the rolling direction and thickness direction.As a result,the out-of-plane shear fracture strength is almost the same as the in-plane shear fracture strength for the DP980-B steel sheet(defference of 2.2%).The results indicate that the existence of martensitic bands may weaken the out-of-plane shear fracture strength of advanced high-strength steel sheet.For the three different strength levels of advanced high-strength steel plates DP590,DP780 and DP980-A,with the increase of tensile strength,the width and quantity of martensitic bands increase,and the weakening effect on the out-of-plane shear fracture strength becomes more significant.The out-of-plane shear fracture strength of the MS1180 steel sheet is 13.1%lower than its in-plane shear strength,because the microstructure of MS1180 is stratified in the thickness direction. Unlike the advanced high-strength steel plates, the Mg_(2)Si is the main strengthening phase of 6061 aluminum alloy sheet and is uniformlydistributed in the Al matrix. Besides, no stratification phenomenon is observed in the thickness direction. As a result, the inplaneand out-of-plane shear fracture strength of AA6061 aluminum alloy sheet are basically the same.
作者
顾彬
李淑慧
何霁
戚宇彤
GU Bin;LI Shu-hui;HE Ji;QI Yu-tong(State Key Laboratory of Mechanical System and Vibration,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《塑性工程学报》
北大核心
2025年第10期184-193,共10页
Journal of Plasticity Engineering
基金
国家重点研发计划(2019YFA0708803)
国家自然科学基金资助项目(52005330,52475377,U23B20100)
上海交通大学“新进青年教师启动计划”。
关键词
金属板材
各向异性断裂
面内剪切
面外剪切
剪切断裂强度
sheet metal
anisotropic fracture
in-plane shear
out-of-plane shear
shear fracture strength
