应变速率对Q460钢及其埋弧焊接头拉伸行为的影响  

Effect of Strain Rate on Tensile Behavior of Q460 Steel and Submerged Arc Weld Joint

作　　者：赵卓 贺玉伟 王磊 刘杨 ZHAO Zhuo;HE Yuwei;WANG Lei;LIU Yang(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学材料科学与工程学院,沈阳110819

出　　处：《机械工程材料》2023年第12期12-18,共7页Materials For Mechanical Engineering

基　　金：东北大学实验技术研究重点项目(202203)。

摘　　要：利用埋弧焊技术对Q460钢进行焊接,研究了应变速率(0.001~100 s^(-1))对母材及焊接接头拉伸性能和断口形貌的影响。结果表明:焊接接头的室温准静态(应变速率为0.001 s^(-1))屈服强度、抗拉强度与母材均接近,但断后伸长率明显减小;随应变速率增大,母材屈服强度和抗拉强度的增大,对应变速率敏感;当应变速率在0.01~0.1 s^(-1)时,焊接接头的屈服强度和抗拉强度与准静态相当,当应变速率在1~100 s^(-1)时,强度明显提高,即强度对高应变速率敏感;母材、焊接接头的断后伸长率均先降低后增大,最小值分别出现在应变速率为0.01,0.1 s^(-1),焊接接头变化幅度很小;应变速率的增加使焊接接头拉伸断口中的韧窝先变小变浅随后变大变深,但未改变微观断裂机制,接头均为韧性断裂。Q460 steel was welded by submerged arc welding technology, the effect of strain rate(0.001-100 s^(-1)) on tensile properties and fracture morphology of base material and weld joint was studied. The results show that the room temperature quasi-static(strain rate was 0.001 s^(-1)) yield strength and tensile strength of the weld joint were close to those of the base material, but the percentage elongation after fracture decreased obviously. The yield strength and tensile strength of the base material increased with the increase of the strain rate, and was sensitive to strain rate. When the strain rate was 0.01-0.1 s^(-1), the yield strength and tensile strength of the weld joint were equivalent to the quasi-static strength. When the strain rate was 1-100 s^(-1), the strength increased obviously, that is, the strength was sensitive to high strain rate. The percentage elongation after fracture of the base material and the weld joint decreased first and then increased, and the minimum values appeared at the strain rate of 0.01, 0.1 s^(-1), respectively;the rate of increase of the weld joint was small. The increase of strain rate made the dimples in tensile fracture of the weld joint became smaller and shallower first and then larger and deeper, but did not change the micro-fracture mechanism. The joint fractured in ductile mode.

关 键 词：低合金高强度钢 焊接接头 拉伸强度 应变速率 

分 类 号：TG457.11[金属学及工艺—焊接]