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在304不锈钢薄壁管的生产过程中,对温度和残余应力进行了数值计算和实测。采用FDM法分析所得的温度与采用热电偶和温度仪所测得的温度完全一致,这说明用计算所得的温度分布来进行应力分析是可行的。对钨极惰性气体保护(TIG)电弧焊接和空气冷却后的残余应力计算,轴向单元FEM应力简化分析法也是行之有效的。X射线衍射法所测得的应力也同计算值基本一致。这就清楚地表明,甚至在定径后,仍然存在有超过300 MPa的残余拉应力。文中提出的两种消除应力的方法,即采用轴向延伸和周向压力变形,能使轴向和周向残余应力大幅度减少到100MPa以下。
In the production of 304 stainless steel thin-walled tube, the temperature and residual stress were calculated and measured. The temperature obtained by FDM analysis is in good agreement with the temperature measured by thermocouple and thermometer, which shows that it is feasible to use the calculated temperature distribution for stress analysis. For TIG arc welding and residual stress calculation after air cooling, stress reduction analysis of the axial element FEM is also effective. X-ray diffraction measured stress with the calculated value is basically the same. This clearly shows that there is still residual tensile stress in excess of 300 MPa even after sizing. Two stress relieving methods proposed in this paper, namely axial extension and circumferential pressure deformation, can greatly reduce axial and circumferential residual stress below 100MPa.