A method for manufacturing a lightweight piston pin includes preparing a mixture of a base metal powder comprising chromium, carbon and iron, a TiC powder and a binder, metal powder injection molding (MIM) the mixture into a piston pin shape, degreasing the molded body to remove the binder from the mixture, sintering the binder-deprived, molded body, forming an intermediate layer composed of chromium carbide that surrounds the TiC powder in the sintered body, and transforming a matrix structure of the sintered body into a martensitic structure.

A compressor of an embodiment includes a compression mechanism part that compresses a refrigerant in a sealed container. The compression mechanism part includes Cr and includes a first member and a second member which slidingly move relative to each other. The first member has a chromium layer and a nitride layer formed on a base member surface in this order. The nitride layer includes CrN and TiN. Carbide is deposited on a surface of the second member.

A compressor of an embodiment includes a sealed container and a compression mechanism part configured to compress a refrigerant within the sealed container. The refrigerant is an unsaturated refrigerant or a mixed refrigerant containing an unsaturated refrigerant. The compression mechanism part contains chromium. The compression mechanism part includes a first member and a second member. The first member and the second member slide relative to each other. A blend layer containing chromium nitride and titanium nitride is formed on a surface of the first member. The titanium nitride in the blend layer is distributed such that a concentration of the titanium nitride increases and decreases regularly in a thickness direction of the blend layer. Carbide is precipitated on a surface of the second member.