Analysis on Microstructure and Properties of 45 Steel Welded Joints

The microstructure and properties of the welded joint of 42CrMo steel was analyzed at different levels of welding current. The impact of t8/5 on the microstructure and properties of the welded joint was also studied. The results show that the microhardness of the weld metals is much higher than that of welded joint. With t8/5 decreasing, more brittle martensite is produced in the quenching zone of 45 steel, resulting in the increase of the hardness of welded joints. It is possible to reduce or avoid the generation of the quenched structure by increasing t8/5, thus improving the properties of the steel.