摘要
针对厚板低合金耐热钢和奥氏体不锈钢异种钢焊接存在的难题,提出在耐热钢一侧预边堆焊2~3 mm厚的E309L、ENiCrFe⁃3、ENiCrMo⁃3三种不同过渡层,AA⁃TIG焊打底及埋弧焊填充的高效高质量的焊接方法。采用金相显微镜和扫描电镜观察界面微观组织形貌,采用电子探针分析界面合金元素分布,采用显微硬度和拉伸试验对接头力学性能进行测试。结果表明:12Cr2Mo1R母材/堆焊层界面处Cr、Ni、Fe元素存在大的浓度梯度,E309L堆焊层焊缝组织的铁素体含量大于ENiCrMo⁃3和ENiCrFe⁃3堆焊层。通过电子探针发现,碳原子在靠近融合线的晶界处有富集的现象,在ENiCrMo⁃3堆焊层中有M_(23) C_(6)碳化物析出相。E309L、ENiCrFe⁃3、ENiCrMo⁃3堆焊层与母材界面的最高硬度依次增加,且向中心方向逐渐降低。E309L、ENiCrFe⁃3、ENiCrMo⁃3三种过渡层的焊缝接头的拉伸强度分别为608.1 MPa、596.2 MPa、564.5 MPa,断后伸长率分别为21.7%、21.2%、18.2%,且断口形貌都呈韧窝状。
Aiming at the welding problem of thick plates for low⁃alloy heat⁃resistant steel and S30408 austenitic stainless steel,this work proposed a high efficiency and quality welding process,which adopted different transitions layer of E309L,ENiCrFe⁃3,ENiCrMo⁃3 with the thickness of 2-3 mm on the side of the heat⁃resistant steel,then used AA⁃TIG welding method to weld back side,and used finally submerged arc welding for filling.Metallographic microscope and scanning electron microscope were used to observe interfacial microstructure,and electro probe micro⁃analysis was performed to analysis alloy elements distribution at the interface.Microhardness and tensile tests were used to test the mechanical properties of the weld joint.The results show that there is a great concentration gradient of Cr,Ni and Fe elements at the interface of 12Cr2Mo1R base metal/transition layer.The ferrite content in the weld of the E309L transition layer is more than ENiCrMo⁃3 and ENiCrFe⁃3.The electro probe micro analysis(EPMA)results show that C atom is enriched at the grain boundaries,and the M_(23)C_(6) carbide⁃phases is formed in ENiCrMo⁃3 transition layer.The hardness of interface between base metals and the E309L,ENiCrFe⁃3 and ENiCrMo⁃3 transition layer,increases sequentially and gradually decreases toward the center.The tensile strengths of the weld joints of E309L,ENiCrFe⁃3 and ENiCrMo⁃3 are 608.1 MPa,596.2 MPa,564.5 MPa and the elongation are 21.7%,21.2%,18.2%,respectively.All fracture surfaces show the dimple⁃like morphology.
作者
刘光银
黄健康
于晓全
张建晓
樊丁
LIU Guangyin;HUANG Jiankang;YU Xiaoquan;ZHANG Jianxiao;FAN Ding(State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Lanzhou Lanshi Heavy Equipment Co.,Ltd.,Lanzhou 730314,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第12期145-149,共5页
Materials Reports
基金
国家自然科学基金(51775256)。
关键词
异种钢焊接
埋弧焊
过渡层
碳化物
dissimilar steel welding
submerged arc welding(SAW)
transition layer
carbide phases
