焊接热输入对X70级管线钢埋弧焊接头组织的影响  

Effect of Heat Input on Microstructure of Submerged Arc Welding Joint of X70 Pipeline Steel

作　　者：杨津瑜 

机构地区：[1]中油管道机械制造有限公司,河北廊坊065000

出　　处：《热加工工艺》2015年第1期221-223,共3页Hot Working Technology

摘　　要：采用埋弧焊的方法,研究了热输入对X70钢接头组织的影响。采用OLYMPUS分析软件分析了焊接接头的宏观结构尺寸。采用OLYMPUS-PMG3金相显微镜对埋弧焊接头显微组织进行了观察。结果表明,由于X70级管线钢为采用控扎控冷工艺获得的细晶粒钢,焊接热影响区晶粒长大倾向严重。随着热输入的增加,热影响区宽度明显增加、母材和焊丝熔化量增加、焊缝深宽比减小;在单道焊的情况下,随着热输入的增加,侧板条铁素体含量增加,针状铁素体含量减小,不利于焊接接头性能的提高。X70 pipeline steel is used widely in recent years. The effects of heat input on the microstructure of submerged arc welded joint of X70 pipeline steel were studied. The macrostructure of welded joint was analyzed by OLYMPUS software, and the microstructure of welded joint was investigated by OLYMPUS-PMG3 optical microscope. The results show that because the X70 pipeline steel is obtained by rolling-control and cooling-control technology, it has seriously coarsening tendency. With increasing heat input, the width of heat affected zone becomes broad, the fusion amount of base metal and filler metal increases, the D/W ratio decreases. In the condition of single pass weld, with heat input increasing, the content of ferrite side plate increases and the content of acicular ferrite decreases, which can decrease the mechanical properties of welded ioints.

关 键 词：X70级管线钢 埋弧焊 热输入 显微组织 

分 类 号：TG454[金属学及工艺—焊接]