Preparation method of novel large-specification special-shaped thin-wall front case of engine

The invention belongs to a processing and manufacturing technology of a novel large-size stainless steel engine front casing, and relates to a preparation method of a novel large-size special-shaped thin-wall front casing of an engine. A homogenized large-specification bar without delta ferrite control and with the diameter phi of 350 mm is manufactured through vacuum induction and electroslag remelting, a front casing forge piece is manufactured through a die forging forming process for the first time, and firstly, the optimal heat treatment process with the casing performance index meeting the design index requirement is obtained; 2, a shot blasting process for remarkably prolonging the fatigue life of the cartridge receiver; and 3, a surface protection process for further improving the corrosion resistance of the material. Various sizes and performances of the 1Cr12Ni3Mo2VN steel front casing prepared by the method meet design index requirements, and the 1Cr12Ni3Mo2VN steel front casing can be installed an