Effect of Preheating in Air on Gas Nitriding of SUS304 Stainless Steel

Autor: Yoshihisa Ohzono, Shigeru Kadomatsu, Hidekazu Sueyoshi, Kazuto Hamaishi, Takayuki Shiomizu
Rok vydání: 1997
Předmět:
Zdroj: Materials Transactions, JIM. 38:148-154
ISSN: 2432-471X
0916-1821
DOI: 10.2320/matertrans1989.38.148
Popis: In order to develop a method for gas nitriding of austenitic stainless steel SUS304 without chemical treatments, the steel was preheated in air in a temperature range of 473 to 1273 K, followed by nitriding in NH3 gas with a flow rate of 2.8 m 3 /h at 843 K for 72 ks. The influence of atmospheric preheating on nitriding behavior was examined in connection with microstructures of the surface film. Atmospheric preheating in a temperature range of 673 to 1023 K results in the formation of a uniformly nitrided layer with the Vickers hardness of 1000 and the depth of 100 to 150 μm. X-ray photoelectron spectroscopy analysis suggests that the surface film of the specimen preheated in a temperature range of 673 to 1023 K is inferior in protective quality to that of the non-preheated specimen. It is confirmed from the present results that gas nitriding of SUS304 is practicable without chemical treatments when atmospheric preheating is carried out in a temperature range of 673 to 1023 K.
Databáze: OpenAIRE