Investigation on the weldability of a Zr-Ti microalloyed X120 linepipe  

作　　者：雷玄威 王红鸿 吴开明 尹雨群 李丽 赵晋斌 

机构地区：[1]International Research Institute for Steel Technology, Wuhan University of Science and Technology, Wuhan, 430081. [2]Nanjing Iron & Steel Group Co. , Ltd. , Nanjing, 210035.

出　　处：《China Welding》2015年第4期46-50,共5页中国焊接（英文版）

基　　金：Acknowledgements The authors greatly acknowledge the support from National Natural Science Foundation of China （ under Grant No. 50734004） and Shanghai Baosteel Group Corporation.

摘　　要：Three-wire submerged arc welding was utilized to weld a newly developed Zr-Ti microalloyed X120 linepipe with heat input of 21 kJ/cm. The microstructure in the heat-affected zone （HAZ）, predominantly consisted of bainite, was examined by means of optical and scanning electron microscope. The average Vickers hardness of grain coarsening heat-affected zone （GCHAZ） is about 290 HV0. 2. The lowest Vickers hardness in HAZ is about 265 HV0. 2. No obvious softening occurred in HAZ. The average impact toughness at -30 ℃ in HAZ was 186 -191 J. The tested results indicated that HAZ of newly developed Zr-Ti microalloyed X120 linepipe steel had high strength and excellent low temperature toughness which met the requirements of API 5L standard.Three-wire submerged arc welding was utilized to weld a newly developed Zr-Ti microalloyed X120 linepipe with heat input of 21 kJ/cm. The microstructure in the heat-affected zone （HAZ）, predominantly consisted of bainite, was examined by means of optical and scanning electron microscope. The average Vickers hardness of grain coarsening heat-affected zone （GCHAZ） is about 290 HV0. 2. The lowest Vickers hardness in HAZ is about 265 HV0. 2. No obvious softening occurred in HAZ. The average impact toughness at -30 ℃ in HAZ was 186 -191 J. The tested results indicated that HAZ of newly developed Zr-Ti microalloyed X120 linepipe steel had high strength and excellent low temperature toughness which met the requirements of API 5L standard.

关 键 词：X120 submerged arc welding heat-affected zone BAINITE WELDABILITY 

分 类 号：TG457.11[金属学及工艺—焊接] U463.34[机械工程—车辆工程]