屈服强度对压痕应变法测量焊接应力中应变增量的影响  

EFFECT OF YIELD STRENGTH ON STRAIN INCREMENTS IN MEASURING WELDING STRESSES BY AN INDENTATION STRAIN METHOD

作　　者：曲鹏程[1] 陈怀宁[1] 林泉洪[1] 孟宪陆[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《机械强度》2007年第6期904-907,共4页Journal of Mechanical Strength

摘　　要：压痕应变法测量焊缝残余应力时采用母材的标定系数,常常由于焊缝和母材屈服强度的较大差异而带来严重误差。文中首先针对焊缝应力的计算方法提出改进,然后采用有限元数值模拟,针对直径2.0mm球形压头和0.2mm的压入深度,分析距离压痕中心4mm～6mm范围内不同屈服强度材料的塑性区变化特征,以及不同屈服强度材料的压痕叠加应变增量和有效应力(外加应力和屈服强度之比)之间的关系,获得一系列有价值的结果,基本解决了压痕应变法测量焊缝残余应力中用母材标定结果计算焊缝应力存在的误差问题。The coefficients resulting from the experimental calibration of base metal were usually applied to the stress calculation during the measurement of welding residual stresses by an indentation strain method. But the difference of yield strength between the base metal and the weld may cause great error. Firstly a modified calculating formula based on the previous study was put out, then for the system with 2.0 mm diameter indenter and 0.2 mm penetration depth, a finite element analysis on the materials with different yield strengths was conducted for the plastic zone size arotmd an indentation and overlap strain increments in the range of 4 rmn- 6 mm away from the indentation center. The beneficial results were obtained for solving the error problem using the calibration coefficients of base metal while measuring the residual stresses in the weld.

关 键 词：压痕应变法 焊缝应力 屈服强度 应变增量 

分 类 号：TB302.5[一般工业技术—材料科学与工程] TG113.251[金属学及工艺—物理冶金]