基于逆焊接技术的T122/P122钢环焊缝残余应力消除工艺

Numerical analysis of eliminating residual stress by post welding cooling treatment for circumferential weld of TP122 steel

关键词:  逆焊接工艺  焊接残余应力  有限元模拟  压应力层

Key words:  inverse welding  welding residual stress  finite element method  compressive stress layer

摘要:

采用ABAQUS有限元软件生死单元技术针对逆焊接消除残余应力的工艺方法进行分析,模拟计算了T122/P122钢环焊缝的逆焊接消除焊接残余应力的工艺过程,分析了逆焊接消除残余应力的操作工艺中不同热处理温度、冷却速率、冷却范围、冷却时间对消残余应力效果的影响. 结果表明,经过逆焊接处理后,Mises残余应力及环向残余应力均明显降低,且热处理温度对残余应力的消除影响最为显著,其次是冷却时间和冷却速率. 当热处理温度为400 ℃,冷却时间为20 s时不仅可以消除焊接残余应力,还可以在处理表面形成1.3 mm厚的压应力层.

Abstract:

The inverse-welding method, post welding cooling treatment(PWCT) to eliminate residual stress, was analyzed by deactive element method using commercial finite element code ABAQUS. The residual stresses eliminated in post welding cooling treatment of P122 steel were quantitatively analysed with different heat treatment temperatures, the cooling media, the cooling rates and cooling times. Results show that both the Mises residual stress and transverse residual stress were reduced obviously after PWCT. And the effect of heat treatment temperature on PWCT method was the most remarkable. Then the effects of cooling time, cooling rate of cooling medium during the PWCT were reduced sequentially. When the heat treatment temperature is 400 ℃, the cooling time is 20 s, this method could not only eliminate the welding residual stress but also form compressive stress layer of 1.3 mm depth in the surface of the treatment.