Study On Preheat Treatment Of Carbonization And Property Of Wheel Gear

In this paper, the effects of pre-heat treatment in different technology conditions (normalizing, normalizing and thermal refining, thermal refining with cooling) on the structure-core structures and carburizing layer structures, performance-core hardness and surface hardness, the depth of carburizing layer of carburizing gears were studied. The deformation regularity, impact toughness and riction-wear properties of samples of carburizing with three different pre-heat treatment were analyzed. Analysis by synthesis, the pre-heat treatment of thermal refining with cooling was determined.The following conclusions were obtained:(1) There was no significant difference between the core structures and carburizing layer structures of samples of carburizing with three different pre-heat treatment. They are conform to the technical requirements.(2) There was no significant difference between the core hardness and surface hardness of samples of carburizing with three different pre-heat treatment. They are conform to the technical requirements.(3) The samples of carburizing pre-heat treatment of thermal refining with cooling show best impact toughness and friction-wear properties. They have good combination property and smaller deformation.Analysis on the above educe that the pre-heat treatment can be simplified to short production period, the heat distortion can be decreased and the service condition can be improved with thermal refining with cooling to use for wind carburized gears. The pre-heat treatment of thermal refining with cooling can achieve better economy with reducing the production cost, improving the utilization efficiency of the furnace, and reducing energy consumption.