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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。
In order to study the residual stress distribution of residual indentation during the auto-ball indentation, the constitutive relations of the materials and the automatic ball-pressing pressure were obtained by conventional tensile tests using S30408, S32168, S31603 and S30403 austenitic stainless steel plates commonly used in pressure vessels The load-displacement curve of the indentation process was obtained by the indentation test, and the simulation was carried out by the finite element software ABAQUS. The results show that the residual compressive stress on the bottom of indentation pits reaches the maximum after unloading of the indenter, and the maximum residual stress in Mises stress state is about 700 MPa. The influence range of indentation residual stress on compressive surface accounts for about 1.3% of the ball indenter radius. At the same time, a certain amount of external tensile stress is applied to the material to study the stress distribution of the material around the indentation under the combined effect of residual stress and external load. The results show that the maximum superimposed stress appears in the indentation material accumulation area, but the stress-affected area is small , The influence depth is within 6% of the affected plane radius.