Untitled in english

Author(s)

María Cristina Moré Farias

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola Politécnica (EP/BC)
• Defense date: 1999-07-08

Examining board members

Amilton Sinatora; Helio Goldenstein; Deniol Katsuki Tanaka

• Advisor: Amilton Sinatora

Abstract

One of the reasons for the high efforts dedicated to study the sliding wear is its complexity, due to the multiple mechanisms involved. Mechanisms such as adhesion, abrasion, tribochemical effects and fatigue are present in sliding wear. Also transitions in the wear rate due to effects like loading, sliding speed or phase transformation, among other factors can occur. In austenitic stainless steels strain-induced martensitic transformation during sliding wear occurs. The explanation of the influence of that transformation is still a point of attention for researches. To study the austenitic stainless steels wear behavior as well as the influence of strain-induced martensitic transformation, sliding wear tests were performed with various normal loads and sliding distances. The materials studied were stainless steels AISI 304 and AISI 316. The wear tests were performed on pin-on-disk equipment. The wear surfaces and wear debris were characterized by means of optical microscopy, scanning eléctron microscopy and X-ray diffraction. For the characterization of the sub-superficial áreas microhardness measurements were performed. In the sliding wear of austenitic stainless steels the microstructure and sub-surface hardness are affected by the presence of strain-induced martensite. The hardness of sub-superficial areas influences the wear magnitude. The material will suffer a larger wear if the less hardened base region cannot support a strongly hardened sub-superficial area due to plastic deformation and/or martensite presence. (AU)