Abstract: Through a lot of basic research on heat treatment process parameters,equipment,loading method and so on,it has been confirmed by many tests that suspension carburizing and quenching is the best method of furnace loading;Using φ3m large well carburizing furnace to suspend carburizing hardening,after carburizing,do not come out of the furnace and cool to 620℃ and then reheat,fractional quenching with nitrate at 170℃;This process method can effectively control the heat treatment deformation,obtain the best performance,and effectively improve the production efficiency.The research results of this process technology have important significance for the improvement of product performance.