中文摘要：

根据等温条件下的铁索体晶粒长大公式,推导出了焊接热影响区（HAZ）铁索体晶粒长大的动力学方程,并结合焊接热循环的数值分析结果对TCS不锈钢热影响区晶粒长大进行了预测.在此基础上,对复合焊新型焊接工艺条件下TCS不锈钢HAZ的晶粒长大情况进行了数值计算,得到了3种工艺参数下TCS不锈钢复合焊HAZ内的晶粒尺寸.基于TCS不锈钢复合焊接接头的金相图片,测量了HAZ内的平均晶粒尺寸,对数值模拟结果进行了验证.初步讨论了晶粒尺寸随热循环温度的长大情况和热循环温度差异对晶粒长大的影响规律.

英文摘要：

According to the formula of grain growth under isothermal condition,the kinetics equation of ferritic grain growth in heat affected zone（HAZ） was obtained,which was combined with the calculated thermal cycles to predict the grain growth in HAZ of TCS stainless steel under the new-type welding procedure-hybrid welding.The grain sizes in HAZ of TCS stainless steel have been calculated for three welding conditions.Simulation results are validated by the average grain sizes measured on the metallographic images of the welding joint of TCS stainless steel.Preliminary discussion has been made on correlation of the grain growth with the thermal cycles and the effect of local variation in thermal cycles on the grain growth.