Hot Cracking of Laser and Electron Beam Welds in X20CrMoV121 Heat-Resisting Steel

摘要

X20CrMoV12 1 heat-resisting steels are normally welded by shielded metal-arc welding or gas metal -arc welding using very strict pre- and post-weld heating sequences. With thick materials this means quite a long work. In this paper laser and electron beam welding were applied to find out their possibilities for joining of these materials. It was found that hot cracking is a problem when welding them without any pre-heat treatment. With a careful control of welding parameters the hot cracking could be controlled but not totally eliminated. The use of pre-heat treatment could further decrease the hot cracking and in some cases totally avoid it. With sound laser or electron beam welds better creep properties, compared to conventional welds, can be suspected.