焊接热输入对690 MPa级HSLA钢焊缝金属组织与力学性能的影响  

Effect of heat input on microstructure and mechanical properties of weld metal of 690 MPa grade HSLA steel

作　　者：汤忖江 安同邦[2] 彭云[2] 林纯丞 马成勇[2] 刘旭明 TANG Cunjiang;AN Tongbang;PENG Yun;LIN Chuncheng;MA Chengyong;LIU Xuming(Ansteel Beijing Research Institute Co.,Ltd.,Beijing,102209,China;Central Iron and Steel Research Institute,Beijing,100081,China;College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing,100029,China)

机构地区：[1]鞍钢集团北京研究院有限公司,北京102209 [2]钢铁研究总院,北京100081 [3]北京化工大学,机电工程学院,北京100029

出　　处：《焊接学报》2024年第9期110-119,共10页Transactions of The China Welding Institution

摘　　要：采用自研直径4.0 mm的焊条对厚度为27 mm的690 MPa级HSLA钢进行不预热焊接,研究了焊接热输入对焊缝金属组织和性能的影响及强韧化机理.结果表明,焊接热输入由13 kJ/cm提高至19 kJ/cm对焊缝金属组织结构及其强韧性产生了显著影响,对接接头抗拉强度、硬度呈现降低趋势,焊缝金属−50℃冲击吸收能量呈现先升高后降低趋势.16 kJ/cm热输入条件下获得了良好的强韧性,对接接头抗拉强度为828 MPa,焊缝中心−50℃冲击吸收能量为71~90 J,均值为80 J.13 kJ/cm及19 kJ/cm热输入条件下焊缝金属强韧性较低,前者与焊缝金属中板条贝氏体及侧板条铁素体形成有关,后者与其中粗大的M-A组元形成相关.热输入16 kJ/cm条件下,充分形成了塑性良好的针状铁素体组织,针状铁素体和贝氏体呈交织分布,同时,细小弥散分布的M-A组元并未对其韧性产生显著的负面作用,焊缝金属获得了良好的强韧性配合.690 MPa grade high strength low alloy(HSLA)steel of 27 mm in thickness was welded by self-developed electrode of 4.0 mm in diameter without preheating.The effects of heat input on microstructure and mechanical properties of weld metal were studied and the mechanism of strength-toughness was revealed.The results show that heat input had significant effect on microstructure and mechanical properties of weld metal,which increased from 13 kJ/cm to 19 kJ/cm.With the increasing of heat input,tensile strength and hardness of butt joint decreased,−50℃impact energy firstly increased and then decreased.Good strength-toughness was obtained under the heat input condition of 16 kJ/cm.The tensile strength of butt joint was 828 MPa,−50℃impact energy of weld metal was 71~90 J,the average value was 80 J.The lower strength-toughness properties of weld metal under 13 kJ/cm and 19 kJ/cm heat input conditions were related with the formation of lath bainite and ferrite side plates,the formation of coarse M-A,respectively.Under the 16 kJ/cm heat input condition,good plasticity acicular ferrite was sufficiently formed and acicular ferrite and bainite were distributed in an interwoven pattern.Meanwhile,small and dispersively distributed M-A had no obviously negative effect on toughness of weld metal.Therefore,weld metal with excellent strength-toughness had been obtained.

关 键 词：690 MPa级HSLA钢 焊接热输入 焊缝金属 强韧化机理 

分 类 号：TG442[金属学及工艺—焊接] TG457.11