Method for increasing proportion of special grain boundaries in precipitation strengthened austenitic heat-resistance steel

The invention belongs to the field of precipitation strengthened austenitic heat-resistance steel and relates to a method for increasing the proportion of special grain boundaries in the precipitation strengthened austenitic heat-resistance steel. An optimization treatment process includes solid solution, cold rolling and annealing. The method is characterized in that solution treatment is performed at the temperature from 1150 DEG C to 1300 DEG C for 20 min to 60 min; indoor temperature rolling with the deformation ranging from 20% to 60% is then performed, the single pass reduction is not lower than 15%, and then at the temperature from 1100 DEG C to 1250 DEG C, periodical short-time annealing and water cooling are performed. After optimization treatment is performed, the special grain boundaries in a microscopic structure of the precipitation strengthened austenitic heat-resistance steel are evenly distributed, and the proportion is higher than 80%. By the adoption of the method, the strain storage energy is improved by increasing the indoor temperature deformation, recrystallization is promoted to occur in precipitation strengthened austenitic steel, the proportion of the special grain boundaries in the precipitation strengthened high-Cr and high-Ni austenitic heat-resistance steel is increased, the performance of the steel related to the grain boundaries is optimized, and corrosion resistance and irradiation swelling resistance are particularly optimized.