5%Ni低温钢MAG焊接工艺研究  

Study on the MAG welding process of 5%Ni low‑temperature steel

作　　者：曾志伟 金旭 姜冬雪 黄贺楠 张露云 孙家禄 张峻巍[1] ZENG Zhiwei;JIN Xu;JIANG Dongxue;HUANG Henan;ZHANG Luyun;SUN Jialu;ZHANG Junwei(School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,China;General Heavy Steel Rolling Plant,Angang Steel Co.,Ltd.,Anshan 114009,China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051 [2]鞍钢股份有限公司大型总厂,辽宁鞍山114009

出　　处：《压力容器》2025年第1期26-33,共8页Pressure Vessel Technology

摘　　要：针对5%Ni低温钢,采用熔化极活性气体保护焊进行焊接试验,对接头微观组织和断口形貌进行观察,分析接头硬度、拉伸性能、低温冲击韧性和弯曲性能。结果表明:焊接接头成型良好,焊缝组织为奥氏体树枝晶。母材受焊接热循环形成热影响区,其组织以粒状贝氏体、M-A组元和回火索氏体为主。接头硬度在197~258 HV10之间,未出现明显的硬化现象。接头平均抗拉强度为685 MPa,拉伸断裂在硬度最低点附近且抗拉强度低于母材,印证了接头存在强度下降现象。熔合线微区的低温冲击韧性最低,平均值为36 J,为混合断裂模式,这与熔合区附近粗大的组织和第二相粒子有关。各项弯曲性能均合格,表明接头有良好的塑形。本文研究对于MAG焊接工艺在5%Ni钢低温压力容器焊接领域的推广应用具有积极意义。For 5%Ni low-temperature steel,welding experiments were carried out by means of gas metal arc welding with active gas shielding.The microstructure and fracture morphology of the joints were observed,and the hardness,tensile properties,low-temperature impact toughness and bending properties of the joints were analyzed.The results show that the welded joints are well formed,and the microstructure of the weld is austenitic dendritic crystal.The base metal is affected by the welding heat cycle to form a heat affected zone,and its microstructure is mainly composed of granular bainite,M-A components and tempered sorbite.The hardness values of the joints are ranged from 197~258 HV10 without significant hardening.The average tensile strength of the joint is 685 MPa,and the tensile fracture is near the lowest hardness point and the tensile strength is lower than that of the base material,which confirms the strength decline of the joint.The low-temperature impact toughness of the micro-region of the fusion line is the lowest,with an average value of 36 J,which is a mixed fracture mode.This is related to the coarse microstructure and the second phase particles near the fusion zone.All bending properties are qualified,indicating that the joints have good plasticity.This research in this paper has positive significance for the popularization and application of MAG welding process in the field of 5%Ni steel low temperature pressure vessel welding.

关 键 词：5%Ni钢 MAG焊接 微观组织 低温韧性 

分 类 号：TH142[一般工业技术—材料科学与工程] TG146.15[机械工程—机械制造及自动化] TG44[金属学及工艺—金属材料]