Heat-treated steels, alloy steels, and automatic steels. Part 5: Nitrided steels

This technical document establishes specific requirements for nitriding steels, which represent a specialized subset of heat-treated steels, alloy steels, and automatic machining steels. Focused on the fifth section of a comprehensive series, it addresses materials engineered to undergo nitriding processes to enhance surface hardness and wear resistance while maintaining a tough core. The scope covers the chemical composition limits, mechanical property ranges, and metallurgical characteristics essential for these grades. It serves as a reference for manufacturers, foundries, and engineers involved in the production and application of components requiring high surface durability under demanding conditions. The specification outlines classification criteria and testing methodologies to ensure consistency and reliability across the supply chain. By adhering to the outlined parameters, industries can achieve uniform quality in parts utilized for gears, shafts, and other critical machine elements where deep case hardness is paramount. This framework aligns with international practices for material specification, facilitating trade and technical interoperability. The content provides a definitive guide for selecting appropriate grades based on intended service environments, ensuring that the final products meet rigorous performance expectations without compromising structural integrity.