The invention relates to a method of providing a metallic surface with a protective diffusion layer, wherein a chromium-containing slip is applied to the surface and is then subjected to a heat treatment in order to produce the protective diffusion layer. In addition to the chromium powder, the slip contains silicon powder in order to shorten the hold time required in the heat treatment.

The invention relates to a method of providing a metallic surface with a protective diffusion layer, wherein a chromium-containing slip is applied to the surface and is then subjected to a heat treatment in order to produce the protective diffusion layer. In addition to the chromium powder, the slip contains silicon powder in order to shorten the hold time required in the heat treatment.

For providing a structural material having improved fatigue strength and abrasion resistance, provided is a structural material containing iron and carbon, including: a first layer formed of pearlite; a second layer formed of a mixed phase of martensite and a carbide; and a third layer formed of a carbide, in order from a center to a surface of the structural material. The carbide of the third layer is represented by MC (where M is one element among Ti, V, Nb, Mo, Ta, and W), and the structural material has a concentration gradient in which an M element concentration is decreased from the surface to the center of the structural material.

This electric current transmission cable includes a non-anodized bare conductor based on aluminum or an aluminum alloy having a hydrophilic external specific surface intended to be in contact with the atmospheric environment, and an inside volume intended to conduct an electric current. The external specific surface of the bare conductor has a first roughness parameter, defined as the arithmetic mean deviation, measurable by profilometry, of peaks and valleys in comparison to a predetermined average profile over a reference length or surface, equal to or greater than 1.9 m. In addition, the inside volume of the bare conductor has oxygen doping of its aluminum-based or aluminum alloy-based components at a ratio equal to or greater than 20%, to a depth of at least 300 nm with respect to the external specific surface.

This electric current transmission cable includes a non-anodized bare conductor based on aluminum or an aluminum alloy having a hydrophilic external specific surface intended to be in contact with the atmospheric environment, and an inside volume intended to conduct an electric current. The external specific surface of the bare conductor has a first roughness parameter, defined as the arithmetic mean deviation, measurable by profilometry, of peaks and valleys in comparison to a predetermined average profile over a reference length or surface, equal to or greater than 1.9 m. In addition, the inside volume of the bare conductor has oxygen doping of its aluminum-based or aluminum alloy-based components at a ratio equal to or greater than 20%, to a depth of at least 300 nm with respect to the external specific surface.

Provided are a chain component that has a simple surface treatment structure and can maintain good wear resistance over a long time, and a chain that includes the chain component and maintains good wear elongation resistance. The chain component of a power transmission chain for industrial use includes a chromium nitride layer formed on an outer side of a steel base material and containing more than 0 mass % but not more than 55 mass % iron. At least a surface of the chromium nitride layer that slides against other components is a rough surface with peaks and valleys.

A process for producing an ordered martensitic iron nitride powder that is suitable for use as a permanent magnetic material is provided. The process includes fabricating an iron alloy powder having a desired composition and uniformity; nitriding the iron alloy powder by contacting the material with a nitrogen source in a fluidized bed reactor to produce a nitride iron powder; transforming the nitride iron powder to a disordered martensitic phase; annealing the disordered martensitic phase to an ordered martensitic phase; and separating the ordered martensitic phase from the iron nitride powder to yield an ordered martensitic iron nitride powder.

A process for producing an ordered martensitic iron nitride powder that is suitable for use as a permanent magnetic material is provided. The process includes fabricating an iron alloy powder having a desired composition and uniformity; nitriding the iron alloy powder by contacting the material with a nitrogen source in a fluidized bed reactor to produce a nitride iron powder; transforming the nitride iron powder to a disordered martensitic phase; annealing the disordered martensitic phase to an ordered martensitic phase; and separating the ordered martensitic phase from the iron nitride powder to yield an ordered martensitic iron nitride powder.

Provided are a chain component that has a simple surface treatment structure and can maintain favorable wear resistance over a long time, and a chain that includes this chain component and maintains favorable wear elongation resistance. The chain component of a power transmission chain for industrial use includes a chromium nitride layer containing more than 0 mass % but not more than 55 mass % iron and formed on an outer side of a steel base material.

Provided are a chain component that has a simple surface treatment structure and can maintain good wear resistance over a long time, and a chain that includes the chain component and maintains good wear elongation resistance. The chain component of a power transmission chain for industrial use includes a chromium nitride layer formed on an outer side of a steel base material and containing more than 0 mass % but not more than 55 mass % iron. At least a surface of the chromium nitride layer that slides against other components is a rough surface with peaks and valleys.