PURPOSE: To reinforce the mechanical properties and prolong the life by heating a molded and sintered body composed of powder of a stainless steel and short fibers which are respectively specific in a nitrogen atmosphere.

CONSTITUTION: The molded and sintered body is produced from the mixture composed of the powder essentially consisting of the powder of the low-C- and low-N-content Cr stainless steel and the short fibers of the stainless steel having 20 to 100μm size in terms of diameter and 0.4 to 3.0 mm length. This molded and sintered body is heated in the nitrogen atmosphere and is nitrided, by which content of the nitrogen is specified to 1.0-1.5%; thereafter, the sintered body is rapidly cooled down to ≤250°C at a cooling rate of ≥0.5°C/min average cooling rate, by which the excessive precipitation of the nitride and the transformation of the austenite phase to a ferrite phase are prevented. The austenite phase is partly transformed stably to the martensite phase. The austenite phase remaining at room temp. is further reheated at 500 to 650°C and is transformed to the martensite phase, by which the workability is improved. The strength is also improved by the precipitation strengthening effect of the nitride.