【摘要】 使用焊接热模拟技术研究了SA508—3钢回火焊道实现的热循环条件,试验结果表明,粗晶区和临界粗晶区在经历峰值温度650℃的二次焊接热循环后均可以形成以回火索氏体为主的显微组织,显微硬度低于350HV,冲击吸收能量高于100 J,均满足标准要求。粗晶区和临界粗晶区在经历峰值温度950℃的焊接热循环基础上再经历峰值温度650℃的焊接热循环时,均可得到晶界附近细小的回火索氏体和晶粒内部的回火索氏体组织,显微硬度330 HV左右,冲击吸收能量达到190 J。基于热模拟试验结果,找到了两种回火焊道实现的焊接热循环条件。更多还原

【Abstract】 The conditions to realize the welding thermal cycle of the temper bead for SA508-3 steel were studied by welding thennal simulation.The results shows that the microstructure in CGHAZ and IC-CGHAZ can be mainly tempered to form sorbite after experiencing a welding thermal cycle with peak temperature of 650℃,the micro-hardness is less than 350 HV and impact toughness is more than 100 J.After experiencing welding thermal cycle with peak temperature of 950 ℃which follows the experiencing the welding thermal cycle with peak temperature of 650 °C,the microstructures in the CGHAZ and IC-CGHAZ are mainly fine tempered sorbite,the micro-hardness is less than 330 HV and the impact toughness is more than 190 J.Based on the results of thermal simulation experiment,two welding thermal cycle conditions of temper bead welding were obtained.更多还原