Mechanical Properties of Type 304 Austenitic Stainless Steel Coated with Titanium Nitride after Ion-Nitriding

• Published in: Materials Transactions, JIM Vol. 34; no. 8; pp. 696 - 702
• Main Authors: Yasumaru, Naoki, Tsuchida, Kouzou, Saji, Eiji, Ibe, Toshio
• Format: Journal Article
• Language: English
• Published: Sendai The Japan Institute of Metals 1993; Japan Institute of Metals
• Subjects: Applied sciences; austenitic stainless steel; corrosion; Exact sciences and technology; fatigue; ion-nitriding; ion-plating; Metals. Metallurgy; Nonmetallic coatings; Production techniques; Surface treatment; TiN-coating; wear; Austenitic stainless steel; Mechanical properties; Titanium nitride; Fatigue limit; Hardness; Surface treatment; Sulfuric acid; Corrosion resistance; Stainless steel-304; Ion plating; Wear resistance; Microstructure; Ion nitriding
• ISSN: 0916-1821; 2432-471X
• DOI: 10.2320/matertrans1989.34.696

Austenitic type 304 stainless steel was ion-nitrided at 823∼853K, using a N2–H2 d.c. glow discharge plasma. After ion-nitriding, the top thin compound layer mainly composed of γ′-Fe4N was removed by emery paper. A thin layer of Ti with a thickness of 0.1 μm was deposited on this nitrided specimen and, subsequently, TiN of 1.7 μm was deposited at about 623 K, using an ion-plating technique. By this combined treatment of ion-nitriding and subsequent ion-plating, surface hardened layers were formed, which were composed of (i) a thin outermost coating layer of TiN with the hardness of about Hv 2200 and (ii) a thick inner diffusion layer of about Hv 1100. The mechanical properties of the specimens TiN-coated after ion-nitriding were examined and compared with the untreated or only ion-nitrided or only TiN-coated specimens. The duplex treated specimens showed an improved resistance to wear, the largest wear resistance among them. As for the corrosion resistance, the specimens were a little inferior to the only TiN-coated specimens, but showed an improved resistance compared with the untreated specimens. The fatigue limit of the specimens was lowered slightly compared with the only ion-nitrided specimens, but showed a considerable improvement compared with the untreated specimens.