热输入对3Cr耐候钢MAG焊缝金属组织和性能的影响

发布时间：2018-05-25 00:20

本文选题：热输入 + 焊缝金属　；参考：《焊接学报》2017年06期

【摘要】：采用三种热输入进行3Cr耐候钢MAG焊,借助金相显微镜、扫描电子显微镜及透射电子显微镜分析了热输入对焊缝金属组织和性能的影响.结果表明,三种热输入焊缝金属组织主要由板条贝氏体、粒状贝氏体和M-A组元组成.随着焊接热输入的增加,焊缝组织中粒状贝氏体含量增加;M-A组元含量增加且尺寸增大.随着热输入的增加,焊缝金属冲击韧性降低.组织粗化、M-A组元含量增加尺寸增大是导致其韧性降低的主要原因.接头不同区域耐蚀性能相当,腐蚀产物主要由α-Fe OOH组成.热输入为8~12 k J,采用所选焊丝焊接高强耐候钢能够获得强韧性、耐蚀性匹配良好的焊接接头.热输入为8 k J,接头综合性能最佳.
[Abstract]:MAG welding of 3Cr weathering steel was carried out by three kinds of heat input. The effect of heat input on the microstructure and properties of weld metal was analyzed by means of metallographic microscope, scanning electron microscope and transmission electron microscope. The results show that the microstructure of the three heat input weld metals is mainly composed of lath bainite, granular bainite and M-A component. With the increase of welding heat input, the content of granular bainite in weld microstructure increases and the content of M-A component increases and the size increases. With the increase of heat input, the impact toughness of weld metal decreases. The increase of the content of M-A component in tissue coarsening is the main reason for the decrease of toughness. The corrosion resistance of the joints is similar in different regions, and the corrosion products are mainly composed of 伪 -Fe OOH. The heat input is 8 ~ 12kJ. The welding joint with high strength and good corrosion resistance can be obtained by welding high strength weathering steel with selected welding wire. The heat input is 8 kJ, and the joint has the best comprehensive performance.
【作者单位】：钢铁研究总院先进钢铁流程及材料国家重点实验室;
【分类号】：TG457.11

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