The invention relates to a manufacturing process of ultralow-temperature XM16
precipitation type
martensitic stainless steel. The manufacturing process comprises the following steps that S1, raw materials are prepared, wherein C is smaller than or equal to 0.03%; less than or equal to 0.50% of Si; 0.50% or less of Mn; less than or equal to 0.015% of P; less than or equal to 0.015% of S; the
alloy comprises the following components in percentage by weight: 8.0 to 9.5 percent of Ni, 11.5 to 12.5 percent of Cr, 2.0 to 2.5 percent of Cu, 1.0 to 1.4 percent of Ti and 0.15 to 0.50 percent of Mo; step S2,
forging deformation: step 1, heating a blank to 550 + / -20 DEG C; 2, the blank is heated to 850 + / -20 DEG C; 3, the blank is heated to 1170 + / -10 DEG C; 4, deformation is conducted, and the finish
forging temperature of the
forge piece is controlled to be 830 + / -15 DEG C; step S3,
solid solution: step 1, first-stage
solid solution is carried out, and the
solid solution temperature range is 880 + / -10 DEG C; 2, second-stage
solid solution, wherein the
solid solution temperature range is 880 + / -10 DEG C; and S4, aging is conducted, and the aging temperature range is 460-560 DEG C. The method has the beneficial effects that
forging defects are eliminated, coarse grains and mixed grains in the structure are reduced, the
impact toughness index of the
precipitation type
martensitic stainless steel at the ultralow temperature is improved through
fine grain strengthening, and the forging quality is improved.