摘要2205 双相不锈钢是由铁素体和奥氏体组成，其内部铁素体相与奥氏体相两 相比例接近，再加入不同的元素成分进而得出的复式不锈钢。由于双相不锈钢金 相组织有奥氏体相与铁素体相组成，因此具有奥氏体不锈钢和铁素体不锈钢两者 特点。2205 双相不锈钢具有奥氏体不锈钢的优异韧性与焊接性的同时也拥有铁 素体高强度与耐腐蚀性能。81512

本文采用激光 MIG 复合焊对 2205 双相不锈钢进行焊接，通过对焊接接头两 相比例的测定，与焊缝电化学测试结果相比对，分析两相比例对焊接接头耐蚀性 能的影响。首先在不同焊接参数下对双相不锈钢进行焊接，之后对焊后试样进行 处理，通过光学显微镜、扫描电镜、超景深等仪器观察其微观组织，然后根据金 相照片测定两相比例；其次对焊接接头进行拉伸强度、硬度进行测试，并对试样 进行极化曲线测试分析。

结果表明，各试样焊接接头宏观形貌及微观组织基本符合工艺要求；其力学 性能完好；根据试样两相比例测定与极化曲线测试分析得出两相比例偏差越小其 耐蚀性能越好。

毕业论文关键词：2205 双相不锈钢；激光复合焊；两相比例；焊接接头耐蚀性

Abstract 2205 duplex stainless steel is composed of ferrite and austenite，and the dual phase scale in the DSS is similar。 Because the duplex stainless steel microstructure consists of austenite and ferrite, it both has the characteristics of the ferritic stainless steel and the austenitic stainless steel。 Duplex stainless steel 2205 has excellent toughness and weld ability of austenitic stainless steel and also has high strength and corrosion resistance of ferritic stainless steel。

This article uses laser-MIG hybrid welding to the welding of 2205 duplex stainless steel。 The dual phase scale in the welded joint is measured, comparing with the result of electrochemical testing on the weld and correlation of the dual phase scale with the properties of welded joints corrosion resistance。 Firstly, the duplex stainless steel is welded by different welding parameters。 Then optical microscope, scanning electron microscopy (SEM), super depth of field instruments are used to observe the microstructure of test samples which are under simple treatment。 Then measure the dual phase scale according to the metallograph。 Secondly, we study on the tensile strength and hardness of welded joint, beside that, electrochemical test is applied。

Results show that the macro and micro organization in the sample of welded joints are largely in line with technological requirements; its mechanical properties are in good condition; according to the measurement of the dual phase scale and polarization curve test sample analysis , the less deviation of the dual phase scale , the better its corrosion resistance。

Keywords: 2205 duplex stainless steel；laser hybrid welding；the dual phase scale； corrosion resistance of welded joint

目录

第一章绪论 1

1。1 前言 1

1。1。1 双相不锈钢概述 1

1。1。2 双相不锈钢分类 1

1。1。3双相不锈钢性能特点 1

1。1。4 双相不锈钢焊接性 2

1。1。5 双相不锈钢焊接工艺进展 3

1。2 SAF2205 双相不锈钢 3

1。2。1 2205 双相不锈钢概述 3

1。2。2 2205 双相不锈钢的性能特点 4

1。3 激光焊接 5