The invention relates to an isothermal die
forging technique of a large-sized
magnesium alloy component and belongs to the technical field of
magnesium alloy materialmachining. According to the implementation scheme of the invention, the isothermal die
forging technique comprises the following steps of heating to 380-430 DEG C after a large-sized
magnesium alloy forged disc is machined to be a blank according to a designed blank size; carrying out once isothermal die
forging formation at 380-430 DEG C after preserving the temperature for 3-6h to obtain a forged piece; taking out the forged piece and
cooling down to obtain a finished-product, wherein the average
crystal size of the large-sized
magnesium alloy forged disc is smaller than or equal to 15 microns, and the ratio of equiaxed
grain number to total
crystal grain number of the large-sized
magnesium alloy forged disc is equal to or larger than 0.95; in the isothermal die forging process, the downstream speed when the die is fed is 0.05-0.2mm / s, the downstream time when the die is fed is 10-30min, the pressure is 35,000-80,000kN, and the pressure preservation time after the die is formed is 30-40min. According to the isothermal die forging technique of the large-sized
magnesium alloy component, which is disclosed by the invention, the magnesium alloy die forged piece with the
diameter of 680-1,000mm, the wall thickness of 30-100mm and the maximum horizontal
projected area of equal to or larger than 0.4m<2> can be prepared; the preparation technique is simple, the production period is short and the precision and the performance of the obtained forged piece are higher than the precision and the performance of a common die forged piece.