STUDY ON NARROW GAP LASER WELDINGOF 42CrMo STEEL BEVEL GEAR SHAFT

摘要

The manufacture of heavy type bevel gear shafts isrngenerally machined separately, and then jointed by welding.rnAimed to the joining of quenched and tempered 42CrMornbevel gear shafts for heavy-duty machine, a 3500W SlabrnCO2 laser was applied and narrow gap laser weldingrnprocess was adopted with filler wire of TGS-2CM, at thernsame time, the performance and metallographic structure ofrnthe joint were studied. The experimental resultsrndemonstrate that there are no cracks in the joint evenrnwithout preheating and post-weld heat treatment when thernappropriate processing parameters are used. Thernmicrostructure of the weld bead and heat-affected zone isrnfine bainite. The micro-hardness of fusion area is aboutrnHV0.1 530, and no apparent softened zone exists in thernwelding joint. The average tensile strength value of the jointrnis 1020MPa, equivalent to that of the base material, whichrnis satisfied with the service demand. Currently, the actualrnwelding products were already used in industry.