2205双相不锈钢焊接力学性能和腐蚀性能研究

The Welding Mechanical Properties and Corrosion Properties of 2205 Duplex Stainless Steel

双相不锈钢2205是拥有良好的耐腐蚀性、物理与力学性能等多种特点的低碳型不锈钢,适用于腐蚀条件或力学强度高的工作环境中.在国内外被广泛应用在化工石油管道、造船建筑等行业中.但在焊接过程中,焊接接头会发生复杂的相转变问题,焊缝处易形成夹杂、气孔和微裂纹等缺陷,直接影响焊接接头性能.因此研究双相不锈钢2205焊接接头性能具有重要工程意义.本实验以双相不锈钢2205为研究主体,采用钨极氩弧焊(GTAW)与焊条电弧焊(SMAW)两种焊接方式,钨极氩弧焊选用ER2209、ER309、ER309Mo三种导电电极金属焊丝,手工电弧焊选用E2209-16、E309-16、E309Mo-16三种涂有药皮的金属焊条.焊接完成后对焊接接头进行X射线衍射分析(XRD)、光学显微镜(OP)显微组织观察来研究焊接接头相成分转变与析出合金元素,根据拉伸实验、冲击性能实验,硬度实验和电化学腐蚀实验分析焊接接头力学性能和耐腐蚀性能.实验结果表明,在综合力学性能与耐腐蚀性能上,GTAW焊接的三种焊接接头性能均好于SMAW焊接的三种焊接接头.GTAW焊接选用的ER309焊丝焊接接头的综合力学性能最佳,适合在对强度要求较高且耐腐蚀性不高的环境下.GTAW焊接选用的ER2209焊丝焊接接头耐腐蚀性最好,适合在要求较高耐腐蚀强度且综合力学性能要求不高的工程环境.

Duplex Stainless Steel 2205 is a low-carbon stainless steel with excellent corrosion resistance,physical and mechanical properties,and is suitable for working environments with high corrosion or mechanical strength.It is widely used in chemical oil pipelines,shipbuilding and construction industries at home and abroad.However,in the welding process,the welding joints will undergo complex phase transformation problems,and defects such as inclusions,pores and micro cracks will be formed at the weld joints,which will directly affect the performance of the welded joints.Therefore,it is of great engineering significance to study the properties of welded joints of duplex stainless steel 2205.In this experiment,the duplex stainless steel 2205 was taken as the main subject of the research,both Gas Tungsten Arc Welding and Shielded Metal Arc Welding are used.Gas Tungsten Arc Welding uses ER2209,ER309,and ER309 Mo as three kinds of conductive electrode metal wire,and Shielded Metal Arc Welding chooses E2209-16,E309-16,E309 Mo-16 as three kinds of coated metal electrode.After welding,X-ray diffraction analysis and optical microscopy microstructures were performed on the welded joints to study the phase transition and precipitation of alloy elements in the welded joints.According to tensile test,impact test,hardness test and electrochemical corrosion test,the mechanical properties and corrosion resistance of welded joints were analyzed.The experimental results show that the three welded joints of Gas Tungsten Arc Welding are better than those of Shielded Metal Arc Welding in terms of comprehensive mechanical properties and corrosion resistance.Welding joints of ER309 welding wire in Gas Tungsten Arc Welding have the best overall mechanical properties,suitable for the environment with high strength and low corrosion resistance.The corrosion resistance of ER2209 wire welding joints used in Gas Tungsten Arc Welding is the best,and it is suitable for engineering environments where high corrosion resistance and low mechanical strength are required.