2205不锈钢双面埋弧焊熔合区组织与性能的关系  

Relationship Between Microstructure of Fusion Zone and Mechanical Properties of 2205 Duplex Stainless Steel Joint in Double-Sided Submerged Arc Welding

作　　者：罗键[1] 刘德佳[1] 赵国际[1] 王向杰[1] 冉汉权 

机构地区：[1]重庆大学机械传动国家重点实验室,重庆400030 [2]重庆川东造船厂,重庆408102

出　　处：《稀有金属材料与工程》2011年第S2期369-374,共6页Rare Metal Materials and Engineering

基　　金：教育部博士点基金资助项目(20070611030);教育部新世纪优秀人才支持计划(NCET-08-0607);教育部长江学者和创新团队发展计划(IRT0763);重庆市自然科学基金重点项目(CSTC2009BA3026);重庆市科技重大专项(CSTC2008AB3033)

摘　　要：采用光学显微镜、扫描电镜(SEM)、能谱分析(EDS)、X射线衍射分析(XRD)和显微硬度仪分析2205双相不锈钢双面埋弧焊接头组织成分与显微硬度以及–20℃冲击和常温拉伸断裂特征,重点研究双面埋弧焊接时,反面焊接对正面焊道的热处理作用对正面焊道熔合区σ相及其它第二相析出的影响机制。结果表明:由于该热处理作用,使得正面焊道熔合区内σ相数量增多,并且从单一的孤立块状分布变成连续分布状态;冲击试样缺口位于熔合区时,断裂为具有剪切唇和撕裂特征的混合断裂,而缺口位于焊缝区的冲击断裂为由2~10μm的非等轴韧窝组成的韧性断裂;拉伸断裂方式为韧性断裂,在熔合区断裂处出现较多的5~10μm的σ相粒子;由于正面焊道的熔合区内σ相数量较多,使其硬度值比反面焊道熔合区的显微硬度值要高;研究认为双面埋弧焊反面焊接对正面焊道的热处理作用对熔合区σ相的析出影响显著,有提高接头显微硬度和拉伸强度、降低接头韧性的趋势。The means of OM, SEM and XRD were used to analyze the microstructure and properties of 2205 duplex stainless steel joint in double-sided submerged arc welding. The microhardness and the microstructures of fusion zone of the welding joint were considered carefully. The influences on the heat treatment of the reversed welding procedure to advanced welding side were compared. The results show the heat treatment effect of the reverse welding procedure makes σ-phase on the fusion zone of advanced welding side increased, and the disperse distribution of σ-phase changes into a continuous feature on fusion zone of the advanced welding side. When the notch lies in the fusion zone near the fusion line, the impact fracture mode of welding joint is a mixed fracture with a shear lip and tear. While the notch lies in the center of welding seam zone, the impact fracture mode is a ductile fracture. The tensile fracture mode on fusion zone of the welding joint is of a plastic characterization, with a large number of 5-10 μm σ-phase particles. The microhardness in fusion zone of advanced welding side is higher than that of reverse welding side. It is shown that the reverse welding procedure promote the σ-phase precipitation in fusion zone of advanced welding side, and it tends to increase the microhardness and tensile strength of the welding joint, but decrease the ductility.

关 键 词：双相不锈钢 双面埋弧焊 熔合区 Σ相 机械性能 

分 类 号：TG457.11[金属学及工艺—焊接]