摘要
目的确定Q355B厚板埋弧焊的最佳热输入参数,分析热输入对其焊接接头组织和性能的影响规律。方法选取32 mm厚Q355B钢板,选用H10Mn2焊丝和SJ101焊剂,匹配27.43、30.17、34.97、39.00 kJ/cm 4种热输入进行焊接。采用光学显微镜、洛氏显微硬度计、液压万能试验机和摆锤冲击试验机分别对接头组织、硬度、拉伸性能和冲击性能进行测试。结果当热输入为27.43 kJ/cm时,焊缝和粗晶区组织以铁素体为主,存在少量的珠光体和贝氏体,接头硬度为83HRB~90.5HRB,抗拉强度为524.5 MPa,冲击功为112.7 J和121.3 J;当热输入增加到30.17 kJ/cm时,焊缝组织基本无变化,粗晶区铁素体和珠光体增多,粒状贝氏体减少,接头硬度为82.7HRB~88.7HRB,抗拉强度为518 MPa,冲击功为121 J和132 J;继续增加热输入到34.97 kJ/cm,焊缝和粗晶区块状铁素体增多,粒状贝氏体和珠光体减少,晶粒变粗大且出现魏氏组织,接头硬度为83.5HRB~88.1HRB,抗拉强度为522 MPa,冲击功为106.7 J和118 J;当热输入达到39 kJ/cm时,焊缝以块状铁素体为主,同时存在少量的先共析铁素体和珠光体,与34.97 kJ时相比,粗晶区组织基本无变化,接头硬度为83.1HRB~85.8HRB,抗拉强度为516 MPa,冲击功为92.3 J和91.7 J。结论随热输入的增加,焊缝和热影响区组织变粗大,热影响区会出现魏氏组织;同时焊接接头的强度和硬度呈下降趋势,冲击性能呈先增大后减小的趋势;当热输入为30.17 kJ/cm时,焊接接头的组织和综合力学性能最好。
The work aims to find the optimal heat input parameters of submerged arc welding of Q355B thick plates,and analyze the influence of heat input on the micro-structure and performance of welded joints.A 32 mm thick Q355B steel plate was selected,a H10Mn2 welding wire and SJ101 flux were used to match four kinds of low,medium and high heat inputs(27.43,30.17,34.97 and 39.00 kJ/cm)for welding.Optical microscope,Rockwell micro-hardness tester,hydraulic universal testing machine and pendulum impact testing machine were used to test micro-structure,hardness,tensile and impact performance of the joint.When heat input was 27.43 kJ/cm,weld and coarse crystal structure were mainly ferrite,with a small amount of pear-lite and bainite,joint hardness was 83HRB-90.5HRB,tensile strength was 524.5 MPa,and impact power was 112.7 J and 121.3 J;When heat input was increased to 30.17 kJ/cm,weld structure was basically unchanged,ferrite and pearlite in coarse crystal structure increased,granular bainite decreased,joint hardness was 82.7HRB-88.7HRB,tensile strength was 518 MPa,and im-pact power was 121 J and 132 J;When heat input was increased to 34.97 kJ/cm,weld and coarse crystal structure were mainly massive ferrite,granular bainite and pearlite decreased,grains became coarse and Weishi structure appeared,joint hardness was 83.5HRB-88.1HRB,tensile strength was 522 MPa,and impact power was 106.7 J and 118 J;When heat input was 39 kJ/cm,weld was mainly massive ferrite,with a small amount of eutectic ferrite and pearlite,coarse crystal structure was basically un-changed with 34.97 kJ,joint hardness was 83.1HRB-85.8HRB,tensile strength was 516 MPa,and impact power was 92.3 J.In conclusion,with the increase of heat input,micro-structure of weld and heat affected zone becomes thicker,and Widmanstatten micro-structure appears in the heat affected zone.At the same time,strength and hardness properties of the welded joint show a downward trend,and impact performance shows a trend of first increasing and then decreasing.When heat input is 30.17 kJ/cm,micro-structure and comprehensive mechanical properties of the welded joint are the best.
作者
孙艳芬
朱天一
田松亚
SUN Yanfen;ZHU Tianyi;TIAN Songya(College of Mechanical Engineering,Changzhou Vocational Institute of Mechatronic Technology,Jiangsu Changzhou 213164,China;School of Mechanical and Electrical Engineering,Hehai University,Jiangsu Changzhou 213164,China)
出处
《精密成形工程》
北大核心
2025年第2期122-129,共8页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52175223)
江苏省产学研合作项目(BY2021589)。
关键词
Q355B厚板
埋弧焊工艺
低中高热输入
焊缝和热影响区组织
焊接接头力学性能
Q355B thick plate
submerged arc welding process
low,medium and high heat input
micro-structure of weld and heat affected zone
mechanical properties of welded joint
