对SA213-T92钢焊管在600～750 ℃进行了不同时间的退火处理, 对退火前后的残余应力进行了测定, 对应力的热松弛行为进行了分析, 根据高温松弛动力学曲线计算得到了松弛激活能。结果表明: 退火前焊管接头表面的纵向残余应力高于横向的, 两者分布规律相似, 离焊缝越远, 残余拉应力越小; 不同温度退火后焊管接头表面的残余应力比退火前均有降低, 随着退火温度的升高, 残余拉应力逐渐降低; 根据不同退火温度下焊缝残余应力的热松弛动力学曲线, 求得蠕变等效方程中的系数B为5.07×104, 应力指数n为4.4及应力松弛激活能Q为242 kJ·mol-1。

Welded SA213-T92 pipes were annealed at 600-750 ℃ for different times. The residual stresses in welded pipes before and after annealing were tested, and the thermal relaxation behaviors of residual stress were analyzed. The relaxation activation energy was obtained by calculation based on high temperature relaxation kinetic curves. The results show that the residual stress along longitudinal direction was higher than along the transverse direction before annealing. But both of them had similar distributions that tensile residual stress became smaller with increasing the distance from the welding line. The residual stress of the surface of welded pipe after annealing at different temperatures decreased compared with before annealing. With the increase of temperature, the tensile residual stress decreased. According to the relaxation kinetic curves at different annealing temperatures, the coefficient B in creep equivalent equation was 5.07×104, the stress exponent n was 4.4 and the relaxation activation energy was 242 kJ·mol-1 by calculation.