焊接热输入对ULCB钢焊接接头组织性能的影响  

Effects of Welding Heat Input on Microstructure and Properties of Ultra-low Carbon Bainitic Steel Welded Joints

作　　者：李继红[1] 陈阳阳[1] 邢奎 刘明志[1] 张敏[1] 

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048

出　　处：《热加工工艺》2015年第7期60-63,共4页Hot Working Technology

基　　金：陕西省自然科学基金资助项目(2012JM6003);国家自然科学基金(51274162);国家高技术研究发展计划(2013AA031303)

摘　　要：采用自动埋弧焊机对超低碳贝氏体钢(ULCB钢)进行直缝双面焊双面成型焊接试验,分析了焊接热输入对其焊接接头组织及性能的影响。结果表明:焊缝显微组织主要是针状铁素体和粒状贝氏体,这两种相组成和相比例,极大地影响了接头的强韧性。随着焊接热输入增大,焊缝区针状铁素体含量先减少后增加,粒状贝氏体含量先增大后减少,热影响区晶粒变得粗大,ULCB钢接头强韧性呈现一定规律的变化。在较小的焊接线能量(24.81 k J/cm)下,焊接接头具有优良的强韧性,抗拉强度达到803.63 MPa,为母材抗拉强度的94.3%,焊缝和热影响区冲击韧性分别为193、232 J。The effect of welding heat input on the microstructure and properties of ultra-low carbon bainitic steel was studied by using automatic submerged arc welding machine. The results show that the microstructure of weld zone is acicular ferrite and granular bainitic. The ratio of two microstructure closely ties with the strength and toughness of the welded joint. The content of acicular ferrite decreases with the heat input increasing, then increases. The content of granular bainitic increases with the heat input increasing, then decreases. The grain becomes coarse in heat affected zone. The toughness of the welded joint follows certain rules. Under the energy of 24.81 kJ/cm, the welded joints show excellent strength and toughness, with its tensile strength to 803.63MPa, which is 94.3% of the base metal. The weld and HAZ impact toughness is 193 J, 232J, respectively.

关 键 词：超低碳贝氏体钢(ULCB钢) 焊接热输入 埋弧焊 微观组织 力学性能 

分 类 号：TG445[金属学及工艺—焊接]