In view of the problems and deficiencies existing in the existing furan resin sand process, motor shell sand mold casting design process and molten steel smelting process in the actual production of motor shell steel castings, combined with the current situation and development trend of molding sand process, casting process and smelting pouring process at home and abroad, the causes and influencing factors of hot cracks and sand inclusion defects of motor shell steel castings are analyzed, and the process optimization scheme is put forward and put into practice, The expected effect has been achieved. The research results are as follows:
① Optimization of molding sand process: using alkaline phenolic resin sand process instead of furan resin sand process to produce motor shell steel castings will greatly reduce the number of crack defects of motor shell steel castings.
② Optimization of sand mold casting process: adopt bottom pouring system, equipped with ceramic pipe, ceramic flake and ceramic gate cup; Cold iron shall be placed in the hot spot and thick part of sand casting; Adopt high heating insulation riser; At the same time, the central 1# core and 2# core adopt chromite ore process; Optimizing pouring temperature, pouring speed and pouring time can greatly reduce the probability of cracks and sand inclusion defects.
③ Chemical composition optimization and smelting control of molten steel: controlling the main elements in the chemical composition within the range of large alloy crack resistance strength can reduce the crack defects of motor shell steel castings.