压力管道在役焊接粗晶区组织与硬度研究  

Research on Microstructure and Hardness of Coarse Grain Heat-affected Zone by In-service Welding of Pressurized Pipelines

作　　者：黎超文[1] 王勇[1] 李立英[1] 韩涛[1] 韩彬[1] 

机构地区：[1]中国石油大学(华东)机电工程学院,山东东营257061

出　　处：《压力容器》2010年第4期9-12,38,46,共6页Pressure Vessel Technology

基　　金：中国石油大学(华东)博士创新基金资助项目(B2009-13);中国机械工程学会焊接学会创新思路预研经费资助项目(08-12-028)

摘　　要：采用自行研制的平板腔式带压焊接模拟试验装置,以水为介质,对X70管线钢在不同内部介质压力、不同壁厚和不同焊接线能量下粗晶区的组织与硬度进行了模拟研究。结果表明:内部介质的压力对粗晶区的组织和硬度影响不大,随着线能量或板厚的减小,焊缝平均硬度和焊接热影响区最大硬度值增大。水介质从焊件带走了大量的热量,加速了焊接接头的冷却速度,热影响区形成了贝氏体铁素体和粒状贝氏体组织,虽然改变板厚和线能量,但热影响区组织组成相基本不发生变化,只是组织形态和数量发生变化。适当增大焊接线能量,能减少高硬度不平衡相的形成,从而降低焊接热影响区氢致开裂敏感性。An in -service welding experiment, researching on the microstructure and hardness of coarse grain heat - affected zone （CGHAZ） by in - service welding X70 pipeline steel in different pressure, plate thickness and heat input, was carried out based on self- made pressurized bead -on -plate welding test equipment. The results show that internat water pressure has no effect on hardness and microstructure of CGHAZ. With the thickness or heat input decreasing, the hardness in the weld zone and maximum hardness in heat - affected zone （HAZ） increase. Due to water media took away most of the heat effects from welding and the cooling rate is accelerated, the main microstructure of CGHAZ is composed of banitic ferrite and granular banitic. The phase don＇t change as the thickness and heat input changing, while the amount and size of each microstructure change in the CGHAZ. The increase of heat input or thickness can reduce the formation of large hardness and unbalance microstructure, which can decrease the susceptibility of hydrogen cracking.

关 键 词：在役焊接 X70管线钢 显微组织 硬度 

分 类 号：TG973.3[金属学及工艺—钳工工艺]