A method for heat treating a steel component, the method comprising steps of: (a) carbonitriding the steel component and (b) ferritically nitrocarburizing the steel component.

A method for heat treating a steel component, the method comprising steps of: (a) carbonitriding the steel component and (b) ferritically nitrocarburizing the steel component.

An aluminum alloy material is provided. The aluminum alloy material has excellent bonding durability and is not susceptible to decrease in the bonding strength even if exposed to a high-temperature humid environment. A bonded body, a member for automobiles, and a method for producing the aluminum alloy material are also provided. In the method for producing the aluminum alloy material, the etching amount is controlled to be less than 700 nm when a first film composed of an oxide film is formed on the surface of an aluminum alloy base; and after the formation of the first film by a treatment using an aqueous solution containing a silicate salt, which is the final stage of the substantial film formation, a second film having a siloxane bond is formed by performing a silane coupling treatment.

A piston ring may include a stainless steel base having between 8% and 15% by weight of chromium, together with other elements and impurities, and having a hardness between 350 HV and 420 HV. The piston ring may also include a superficial nitrided layer having a depth of no more than 60 μm and an average hardness measured upon the surface exceeding 800 HV. The nitrided layer may include a plurality of nitride particles, which may have a maximum size of 5 μm and may be distributed over between 4% and 8% of an area of the nitrided layer.

A piston ring may include a stainless steel base having between 8% and 15% by weight of chromium, together with other elements and impurities, and having a hardness between 350 HV and 420 HV. The piston ring may also include a superficial nitrided layer having a depth of no more than 60 μm and an average hardness measured upon the surface exceeding 800 HV. The nitrided layer may include a plurality of nitride particles, which may have a maximum size of 5 μm and may be distributed over between 4% and 8% of an area of the nitrided layer.

A composition and medical implant made therefrom, the composition including a thick diffusion hardened zone, and preferably further including a ceramic layer. Also provided are orthopedic implants made from the composition, methods of making the composition, and methods of making orthopedic implants from the composition.

The present disclosure relates to a titanium or titanium alloy member and to a surface hardening method for the titanium or titanium alloy member. The titanium or titanium alloy member includes a base material of titanium or titanium alloy, and at a surface of the base material, a hardened layer formed by diffusion of oxygen into the surface.

A method of manufacturing a roller cone for a drill bit includes: selectively carburizing a land of the roller cone between a plurality of spots on the land for protection against erosion; after carburization, forming sockets in the roller cone at the spots; and mounting cermet inserts in the sockets.

A method of manufacturing a roller cone for a drill bit includes: selectively carburizing a land of the roller cone between a plurality of spots on the land for protection against erosion; after carburization, forming sockets in the roller cone at the spots; and mounting cermet inserts in the sockets.

An embodiment of the invention describes a method of treating an article to improve its corrosion resistance. The method includes the step of nitriding the article in a cyanide-free nitriding bath to obtain a nitrided article, heating the nitrided article in an atmosphere having nitrogen and carbon-carburizing to obtain a nitrided oxidised article. Further, in certain embodiments, the oxidised nitrided article may be coated with a metallic layer. The oxidised nitrided article with the metallic coating has improved corrosion resistance.