Effect of Triple Treatment on the Surface Structure and Hardness of 304 Austenitic Stainless Steel

Authors

Mohammed H. Fawey, Physics Department, Faculty of Science, Sohag University, 82524 Sohag, EgyptFollow
A. M. Abd El-Rahman, Physics Department, Faculty of Science, Sohag University, 82524 Sohag, Egypt\\ Physics Department, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi ArabiaFollow
F. M. El-Hossary, Physics Department, Faculty of Science, Sohag University, 82524 Sohag, EgyptFollow
Tawheed Hashem, Institute of Functional Interfaces (IFG), KIT-Innovation HUB, Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz- Platz 1, 76344 Eggenstein-Leopoldshafen, GermanyFollow

Abstract

Nitriding, annealing, and carbonitriding processes are conducted to modify the surface of AISI 304 austenitic stainless steel via radio frequency plasma. A ~20 μm thick nitride layer is obtained in ten minutes at a plasma power of 450 W. Hence, all nitrided samples are annealed under vacuum for one hour at 400 ̊C. The nitrided-annealed samples are carbonitrided via the identical technique at various C2H2/N2 gas pressure ratios. Numerous analytical techniques, including X-ray diffractometry, glow discharge optical spectroscopy (GDOS), Talysurf Intra Profilemeter, optical microscopy (OM), scanning electron microscopy (SEM), and Vickers microhardness tester, were employed to investigate the triple-treated specimens. Microstructure analysis of the triple-treated samples reveals the formation of N2 expanded austenite phase (γN), γʹ-Fe4N, CrN, Fe3C, and Fe7C3. The results indicate that the elemental composition, microhardness, and thickness of the triple-treated layers are all depending on the gas composition. After carbonitriding, the total thickness of the compound layer grew from ~20 to ~34.5 μm. The surface microhardness of the triple-treated samples increased as the C2H2/N2 gas composition ratio increased up to 70%, reaching 1,497±33.5 HV0.1, which is ~6.8 and ~1.42 folds higher than the untreated and prenitrided samples, respectively.

Recommended Citation

H. Fawey, Mohammed; M. Abd El-Rahman, A.; M. El-Hossary, F.; and Hashem, Tawheed (2023) "Effect of Triple Treatment on the Surface Structure and Hardness of 304 Austenitic Stainless Steel," Information Sciences Letters: Vol. 12 : Iss. 1 , PP -.
Available at: https://digitalcommons.aaru.edu.jo/isl/vol12/iss1/10