不同退火条件下304L不锈钢埋弧焊接头组织及性能分析

Microstructure and properties of 304L stainless steel submerged arc welding joint under different annealing conditions

关键词:  埋弧焊  304L不锈钢  退火  残余应力  韧性

Key words:  submerged arc welding  304L stainless steel  annealing  residual stress  toughness

摘要:

采用埋弧焊方法，进行了304L不锈钢厚板的对接试验研究.通过对焊接接头处的组织观察，并结合焊接接头的-196 ℃冲击韧性以及不同退火条件下残余应力测试，分析了埋弧焊304L不锈钢焊接接头组织和性能. 结果表明，热影响区组织为奥氏体，焊缝区则为奥氏体与少量的铁素体的复相组织；采用残余应力盲孔释放测量方法对焊接接头进行测试，随着退火温度的升高，焊缝及热影响区的残余应力得到进一步的释放；冲击试验中，热影响区-196 ℃冲击吸收能量随退火温度的升高急剧下降，焊缝区-196 ℃冲击吸收能量则呈平稳下降趋势.

Abstract:

The butt joint experiment of 304L stainless steel thick plate was carried out by submerged arc welding method. The microstructure and properties of 304L stainless steel welded joint were analyzed by observing the microstructure of welded joint, combining with the impact toughness of welded joint at -196℃ and the residual stress test under different annealing conditions. The results show that the microstructure of heat affected zone is austenite, and the weld zone is austenite + a small amount of austenite. The results show that the residual stresses in weld seam and heat affected zone change greatly after annealing, and the residual stresses are further released with the increase of annealing temperature. In impact test, the impact energy of heat-affected zone at -196℃ decreases sharply with the increase of annealing temperature, and the impact work in weld zone at -196℃ decreases sharply with the increase of annealing temperature. The impact work showed a steady downward trend.