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Tribological and microstructural characteristics of ion-nitrided steelsThree steels AISI 4140, AISI 4340 and AISI 304 stainless steel were ion nitrided in a plasma consisting of a 75:25 mixture of H2:N2, sometimes with a trace of CH4. Their surface topography was characterized by SEM and two distinct compound phases were identified: the gamma and the epsilon. The core-case hardness profiles were also established. The low Cr alloy steels have an extended diffusion zone in contrast to the 3034 stainless steels which have a sharp interface. The depth of ion-nitriding is increased as the Cr content is decreased. Friction tests reveal that the gamma surface phase has a lower coefficient of friction than the epsilon phase. The lowest coefficient of friction is achieved when both the rider and the specimen surface are ion nitrided. Previously announced in STAR as N83-24635
Document ID
19840036438
Document Type
Reprint (Version printed in journal)
Authors
Spalvins, T. (NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 12, 2013
Publication Date
January 1, 1983
Publication Information
Publication: Thin Solid Films
Volume: 108
ISSN: 0040-6090
Subject Category
METALLIC MATERIALS
Distribution Limits
Public
Copyright
Other