管线钢在役焊接热影响区显微组织的热模拟研究  

Microstructure of heat-affected zone of in-service welding onto pipeline steel by welding thermal simulation

作　　者：陈玉华[1] 王勇[2] 

机构地区：[1]南昌航空工业学院材料科学与工程学院,江西南昌330063 [2]中国石油大学(华东)机电工程学院,山东东营257061

出　　处：《材料科学与工艺》2009年第2期178-180,185,共4页Materials Science and Technology

基　　金：中国石油大学(华东)博士创新基金资助项目(B2005-3);博士科研基金资助项目(Y040312)

摘　　要：为探讨在役焊接这种严酷的焊接条件下管线钢焊接热影响区显微组织的变化,采用焊接热模拟技术、金相分析及透射电镜对比研究了X70管线钢在役焊接热影响区和常规焊接热影响区的金相组织和精细结构.结果表明,在役焊接的快速冷却只对粗晶区的金相组织产生了较大影响,而对过渡区、细晶区和类母材区的金相组织几乎没有影响.金相显微镜下两者粗晶区的组织均为贝氏体铁素体和粒状贝氏体,但各组织的形态和数量不同.在透射电镜下观察,两者粗晶区的精细结构有较大差异,在役焊接粗晶区生成了少量细小的横穿贝氏体铁素体板条的板条马氏体,常规焊接粗晶区生成了少量的块状铁素体组织.To understand the microstructure alteration in heat - affected zone （HAZ） of in - service welding onto pipeline steel, welding thermal simulation, metallographic analysis and transmission electron microscope （TEM） were used to study the metallurgical structure and sub structure in HAZ of in - service welding and routine welding. The results show that a higher cooling speed of in - service welding joint only affects the microstructure of coarse grain heat - affected zone （CGHAZ） and almost doesn＇ t affect the microstructure in transition zone, fine grain zone and similar base metal zone. Metallurgical microstruetures in both HAZ of in - service welding and HAZ of routine welding are granular bainitic and bainitie ferrite, but the shape and a- mount of the two kinds of mierostruetures are different in each HAZ. Much more difference between the sub structure in CGHAZ of in - service welding sample and routine welding sample were observed by TEM. There are a small amount of fine lath martensite crossing the lath of bainitie ferrite in CGHAZ of in - service welding and a small amount of massive ferrite in CGHAZ of routine welding.

关 键 词：在役焊接 X70管线钢 热影响区 显微组织 精细结构 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG406[金属学及工艺—金属材料]