双向拉伸试样测试区域尺寸对DH780屈服行为的影响  

Influence of biaxial tensile specimen gauge area size on yield behavior of DH780

作　　者：胡钊 连昌伟 何睿 陈博 侯泽然 林建平[1] 李亚 HU Zhao;LIAN Chang-wei;HE Rui;CHEN Bo;HOU Ze-ran;LIN Jian-ping;LI Ya(School of Mechanical Engineering,Tongji University,Shanghai 201804,China;Research Institute,Baoshan Iron&Steel Co.,Ltd.,Shanghai 201900,China;State Key Laboratory of Development and Application Technology of Automotive Steels(BAOSTEEL),Shanghai 201900,China)

机构地区：[1]同济大学机械与能源工程学院,上海201804 [2]宝山钢铁股份有限公司研究院,上海201900 [3]汽车用钢开发与应用技术国家重点实验室(宝钢),上海201900

出　　处：《塑性工程学报》2024年第8期179-188,共10页Journal of Plasticity Engineering

摘　　要：为了探究十字双向拉伸试样测试区域尺寸对高强钢屈服行为的影响,以DH780双相钢为研究对象,参考ISO标准十字试样,开展了不同测试区域尺寸试样的双向拉伸实验对比研究;为了使小型十字试样获得的实验结果与ISO标准试样相同,通过正交实验优化了十字试样的几何尺寸。结果表明,在等双拉加载条件下,随着测试区域尺寸的减小,实验获得的双轴各向异性r值基本相同。而双轴等效屈服应力先减小后增大,其核心原因是不同尺寸试样中心测试区域的变形程度不同;对于测试区域尺寸为8 mm×8 mm的小型十字试样,其主要几何参数对实验结果的影响程度排序为:狭缝数量>臂间圆角半径>狭缝长度;优化后的8 mm×8 mm新试样与ISO标准30 mm×30 mm试样的实验屈服轨迹点相对差值相较于原始试样的6.90%减小到2.36%。To explore the influence of cruciform biaxial tensile specimen gauge area size on the yield behavior of high strength steel,taking DH780 dual phase steel as the research object,the comparative study of biaxial tensile experiments of specimens with different gauge area sizes was carried out with the reference of ISO standard cruciform specimens.To obtain the same experimental results as the ISO standard specimen,the geometric size of cruciform specimen was optimized by orthogonal experiments.The results show that under equi-biaxial tension condition,the biaxial anisotropy r values obtained by experiments are basically the same as the gauge area size decreases.The biaxial equivalent yield stress decreases first and then increases,the core reason is that the deformation degree of the gauge area of specimens with different sizes is different.For the small cruciform specimen with the gauge area size of 8 mm×8 mm,the influence of the main geometric parameters on the experimental results is ranked as follows:number of slits>radius of fillet between arms>length of slits.The relative difference between the experimental yield loci points of the optimized 8 mm×8 mm new specimen and the 30 mm×30 mm specimen in ISO standard decreases to 2.36%compared with 6.90%of the original specimen.

关 键 词：DH780钢 屈服强度 双向拉伸实验 测试区域尺寸 

分 类 号：TG142[一般工业技术—材料科学与工程]