Gas Nitriding Process & Services

Yes, nitrided cookware is generally considered safe for food use. The nitriding process creates a stable iron nitride layer that is chemically inert and does not leach harmful substances into food. However, industrial gas nitriding as performed by VaporKote is designed for metal components in manufacturing, aerospace, and industrial applications rather than consumer cookware production.

Nitriding produces a permanent metallurgical change in the steel. Because nitrogen atoms diffuse into and bond with the base metal structure to form iron nitrides, the hardened case cannot be wiped off or delaminate. The nitrided layer remains integral to the component throughout its service life, though extreme abrasion over time can gradually reduce case depth.

Both are diffusion case-hardening processes, but nitriding introduces nitrogen into the steel surface while carburizing introduces carbon. Nitriding is performed at lower temperatures, causes minimal distortion, and produces a harder surface case with better corrosion resistance. Carburizing typically allows for deeper case depths and requires quenching after treatment, which can cause more dimensional change.

Gas nitriding can achieve surface hardness values ranging from approximately 600 to over 1,100 HV (Vickers) depending on the steel alloy. Alloy steels containing nitride-forming elements like chromium, molybdenum, aluminum, or vanadium respond best, reaching the highest hardness values. VaporKote's IonPlasma Nitriding process is engineered to maximize achievable hardness for each specific material.

1018 is a low-carbon, low-alloy steel with minimal nitride-forming elements, which means it responds poorly to gas nitriding and produces only modest surface hardness improvements. For applications requiring significant wear resistance, alloy steels such as 4140, 4340, H13, or nitralloy grades are strongly recommended. VaporKote's engineers can advise on the best material and process for your specific component needs.

Yes, D2 tool steel can be successfully gas nitrided. D2's high chromium content makes it highly responsive to nitriding, producing an exceptionally hard, wear-resistant surface case. However, the process must be carefully controlled to avoid over-nitriding, which can cause surface brittleness. VaporKote's metallurgical expertise ensures D2 and other tool steel components are treated with precise atmosphere and temperature management.

Gas nitriding involves placing steel components in a sealed furnace filled with an ammonia (NH₃) atmosphere at temperatures typically between 950°F and 1,050°F. Ammonia dissociates on the steel surface, releasing active nitrogen atoms that diffuse into the metal, forming a hard iron nitride case. The process requires no quenching, resulting in minimal distortion and tight dimensional control of finished components.

Steels with significant amounts of nitride-forming alloying elements respond best to gas nitriding. Top choices include nitralloy grades (135M, N), 4140, 4340, H13 tool steel, 17-4PH stainless, and D2. These alloys contain chromium, molybdenum, aluminum, or vanadium that react with nitrogen to form very hard, stable nitrides. VaporKote can evaluate your specific component material and recommend the optimal nitriding approach.