High-intensity stainless steel powder metallurgical material and preparation method thereof

The invention relates to a high-intensity stainless steel powder metallurgical material and a preparation method thereof. The high-intensity stainless steel powder metallurgical material is prepared from the following substances in percentage by mass: 14 to 18 percent of Cr, 10 to 14 percent of Ni, 1 to 4 percent of Mo, 0 to 10 percent of Si3N4, 0 to 3 percent of Al and the balance of Fe. The preparation method comprises the following steps: weighing the raw materials according to the ratios, and then performing raw material mixing, ball grinding, pressing molding, sintering and subsequent machining, thus preparing a high-intensity 316L stainless steel material. According to the stainless steel powder metallurgical material prepared through the preparation method disclosed by the invention, the pitting corrosion resistance and the crevice corrosion resistance of stainless are enhanced; meanwhile, the chloride erosion resistance and the high-temperature sulfidation resistance are improved, and the high-intensity stainless steel powder metallurgical material is high in radiation resistance; the silicon nitride enhances the intensity of the stainless steel; by adding of an aluminum element, an Al2O3 protection film which is more stable than Cr2O3 and grows slower is formed on the surface of an alloy body; and the corrosion resistance of the stainless steel is further enhanced.