压痕对不锈钢材料表面残余应力的影响

为研究自动球压痕过程残留压痕残余应力分布情况,以压力容器常用的奥氏体不锈钢板材S30408、S32168、 S31603 和 S30403为对象,通过常规拉伸试验获得材料的本构关系及自动球压痕试验获得压痕过程的载荷-位移曲线,采用有限元软件ABAQUS进行模拟。试验结果表明:压头卸载后,压痕凹坑底部材料承受的残余压应力达到最大,Mises应力状态下最大残余应力约为700 MPa左右,压痕残余应力影响范围在受压面上大约占球形压头半径的1.3%。同时,对材料施加一定大小的外载荷拉应力,研究残余应力和外载荷共同作用下压痕周围材料的应力分布状况,结果显示最大叠加应力出现在压痕材料堆积区域,但是应力影响区域很小,影响深度为所受影响平面半径的6%以内。

The influence of indentation on the surface residual stress of stainless steel

In order to obtain the residual stress distribution around the residual indentation, the austenitic stainless steel sheets of S30408, S32168, S31603 and S30403 were chosen as the research materials. The constitutive relations of the materials were acquired by the tensile tests, and the force-depth curves were obtained by the ABI tests. The ABI process was simulated by finite element software ABAQUS; The results showed that the maximum value of the residual stress under Mises stress state is about 700 MPa, and the residual stress exists within the area of 1.3% of the ball radius. In addition, the stress concentration around the indentation under the action of external tensile load was studied. The results showed that the maximum superposition stress appears in the indentation materials accumulating area, and the influence range in the thickness direction was limited within 6% of the influence radius.