辅热搅拌摩擦焊X80钢接头组织演变与韧性  

Microstructure evolution and toughness of X80 high strength pipeline steel joint by auxiliary heating and friction stir welding

作　　者：王铮 陶庭芳 虎雅雯 聂志坚 崔洪波 Wang Zheng;Tao Tingfang;Hu Yawen;Nie Zhijian;Cui Hongbo(Guilin University of Technology,Guilin 541000,Guangxi,China)

机构地区：[1]桂林理工大学,广西桂林541000

出　　处：《焊接》2024年第8期52-60,共9页Welding & Joining

基　　金：广西自然科学基金-青年科学基金资助项目(2021GXNSFBA196061);广西科技基地和人才专项资助项目(2018AD19173)。

摘　　要：【目的】利用搅拌摩擦焊接技术可高质量完成钢铁材料的焊接,但昂贵的搅拌头磨损严重,焊前辅助加热是减轻搅拌头磨损的有效方式。【方法】文中利用控温辅热垫板将X80管线钢焊缝预热至150℃和270℃后采用搅拌摩擦焊接技术进行焊接,并对辅热搅拌摩擦焊接X80管线钢的接头温度变化、组织特征和冲击韧性展开详细研究。【结果】常温和150℃辅热下焊接接头组织相近,主要为板条贝氏体和少量粒状贝氏体,冲击韧性略微升高,270℃辅热下接头组织主要为粗大的粒状贝氏体,冲击韧性下降。在较低的辅热温度下,辅热软化材料使焊接主要热输入搅拌头摩擦产热降低,环境温度升高带来的影响较小,峰值温度降低进而晶粒细化;在较高的辅热温度下,环境温度升高的影响大于搅拌头产热减小的影响,所以峰值温度升高进而晶粒粗化。【结论】焊接时采用较低的辅热温度可获得良好的焊接效果。[Objective]Using friction stir welding technology can complete the welding of steel materials with high quality,but the expensive stir tool is seriously worn,and auxiliary heating before welding is an effective way to reduce the wear of stir tool.[Methods]This paper uses the temperature control auxiliary heat pad to preheat the weld of X80 pipeline steel to 150℃and 270℃,and then uses the friction stir welding technology to weld,and carries out a detailed study on the temperature change,microstructure characteristics and impact toughness of the auxiliary heat friction stir welding X80 pipeline steel.[Results]The results show that the microstructure of welded joints at room temperature and 150℃is similar,mainly lath bainite and a small amount of granular bainite,and the impact toughness increases slightly.The microstructure of welded joints at 270℃is mainly coarse granular bainite,and the impact toughness decreases.At a lower auxiliary heat temperature,the auxiliary heat softening material reduces the friction heat production of the main heat input stir tool of welding,and the impact of the increase of ambient temperature is small.The peak temperature decreases and then the grain is refined.At a higher auxiliary heating temperature,the influence of the increase of the ambient temperature is greater than that of the decrease of the heat generation of the stirring tool,so the peak temperature rises and the grain coarsens.[Conclusion]Therefore,good welding effect can be obtained by using a lower auxiliary heat temperature during welding.

关 键 词：辅助加热搅拌摩擦焊 X80管线钢 峰值温度 微观组织 冲击韧性 

分 类 号：TG453.9[金属学及工艺—焊接]