SLIDING MEMBER, METHOD FOR GAS-SULFURIZING AND NITRIDING THE SAME, AND DEVICE THEREFOR

摘要

PURPOSE:To obtain a sliding member having an FeS2 layer on its outermost surface by heating a steel member to a specified temp. in the gaseous atmosphere having specified contents of hydrogen sulfide and ammonia, then stopping the supply of ammonia gas and secondarily heat-treating the member. CONSTITUTION:A nitriding gas (ammonia gas) contg. 20-70vol.% ammonia and a sulfurizing gas (hydrogen sulfide) contg. 10-500ppm hydrogen sulfide are introduced into a reaction furnace contg. a steel member, and the gases are heated to 480-600 deg.C to dissociate nitrogen and sulfur. The dissociated nascent nitrogen and sulfur are allowed to react with the Fe in the surface layer of the steel member to form FeS2. The supply of the nitriding gas is then stopped, the temp. is lowered to 200-350 deg.C, and the member is heat-treated at this temp. An FeS2 layer 63 combined with Fe in the base material 69 is formed on the outermost surface, and an FeS layer 65 and a gamma-Fe4N layer 67 are formed thereunder in this order.