摘要
从焊接方法及材料的选用、焊接保护气体及热输入控制、组对和预热要求及工艺参数、冬季施工焊前预热4个方面分析了25Cr-7N-4Mo型双相不锈钢的焊接性及注意事项。从焊接环境温度、二次回火及GTAW和GTAW+SMAW的热输入3个方面介绍了25Cr-7Ni-4Mo型双相不锈钢焊接接头组织的控制。结果表明,在北方冬季施工时,GTAW+SMAW的焊接效果优于GTAW;如果在夏季或者南方地区施工,应采取积极的降温措施,来保证焊缝铁素体和奥氏体的占比。正面保护气体宜采用98%Ar+2%N_(2),背面保护宜采用100%N_(2)来弥补焊接过程N元素流失,更有利于增加焊缝的稳定性;极端寒冷条件建议采取预热措施,避免管道焊接时产生裂纹。
The weldability and precautions of 25Cr-7Ni-4Mo duplex stainless steel were analyzed fromfour aspects of selection of welding method and material,control of welding protection gas and heat input,group pair and preheating requirements and process parameters,preheating before welding in winter construction.The microstructure control of 25Cr-7Ni-4Mo duplex stainless steel welded joint was introduced from three aspects of welding ambient temperature,secondary tempering and heat input of GTAW and GTAW+SMAW.The results showed that the welding effect of GTAW+SMAW was better than that of GTAW in winter construction in north China.However,if the construction was in summer or in the south China,positive cooling measures should be taken to ensure the proportion of weld ferrite and austenite.98%Ar+2%N_(2)should be used for the front protection gas,and 100%N_(2)should be used for the back protection gas to compensate for the loss of N element in the welding process,which was more conducive to increasing the stability of the weld.It was recommended to take preheating measures in extreme cold conditions to avoid cracks in pipeline welding.
作者
武建朝
左世飞
刘思玲
延雨龙
Wu Jianchao;Zuo Shifei;Liu Siling;Yan Yulong(SHCCIG YuLin Chemical Co.,Ltd.,YuLin 719000,Shaanxi,China)
出处
《机械制造文摘（焊接分册）》
2021年第4期17-21,33,共6页
Welding Digest of Machinery Manufacturing
