不同焊接工艺对P92钢焊接接头组织性能的影响

Effect of different welding process on microstructure and properties of P92 steel welded joint

P92钢长期被用于电站机组中的高温部件,不同的焊接工艺对其接头的组织和性能有着重要的影响。研究了自动焊和手工焊焊接工艺对P92焊接接头组织和性能的影响,并采用扫描电镜,透射电镜和力学性能测试等方法对不同焊接工艺下的P92钢焊接接头的显微组织和力学性能进行检测,结果表明:不同焊接工艺下焊缝组织均为回火马氏体组织,自动焊焊接工艺下焊缝金属组织较为细小;且由于自动焊焊接热输入较小,P92钢的热影响区的宽度仅为1.0~1.5 mm,而在手工焊焊接接头热影响区可见块状铁素体组织,热影响区宽度在3~4 mm。与手工焊焊接工艺相比,自动焊焊接接头抗拉强度也较高,尤其是冲击韧性,P92自动焊焊接接头的焊缝金属的冲击韧性相比手工焊提高了100%,热影响区冲击韧性提高了58%。因此采用自动焊焊接方法可显著提高P92钢焊接接头性能,并有助于提高接头的高温抗蠕变性能。

P92 steel has been used for a long time in the high-temperature components of power station,and the different welding process has an important effect on the microstructure and properties of the joint.The influence of automatic and manual welding processes on the microstructure and properties of P92 welded joints was studied,and the microstructure and mechanical properties of P92 steel welded joints under different welding processes were tested by means of scanning electron microscopy,transmission electron microscopy and mechanical property testing.The results show that the weld microstructure under different welding processes is tempered martensite microstructure,and the weld metal microstructure under automatic welding process is finer.Due to the small heat input of automatic welding,the width of the heat affected zone of P92 steel is only 1.0-1.5 mm,while the massive ferrite structure can be seen in the heat affected zone of manual welding joints,and the width of the heat affected zone is 3-4 mm.Compared with the manual welding process,the tensile strength of the joint welded by automatic welding is also higher,especially the impact toughness.Compared with the manual welding,the impact toughness of the weld metal of P92 automatic welding is increased by 100%,and the impact toughness of the heat affected zone is increased by 58%.Therefore,the automatic welding method can significantly improve the performance of P92 steel welded joints,and help to improve the high temperature creep resistance of joints.