Evolution of the micro/nanostructureof high nitrogen stainless steels, related to the deformation mechanisms on the cavitation erosion resistance of stainless steels

• Grant number: 11/16211-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2012
• End date: August 31, 2013
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Transformation Metallurgy
• Principal Investigator: Andre Paulo Tschiptschin
• Grantee: Luis Bernardo Varela Jiménez
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The aim of this project is to establish relationships between the micro and nanostructure, and the cavitation erosion resistance of stainless steels in two different stainless steels: an austenitic stainless steel and a high nitrogen, medium alloyed duplex stainless steel. These relationships will be determined through the study of the degradation and plastic strain mechanisms observed at the surface, in the micro and nano levels, during vibrational cavitation tests.The high nitrogen contents of the tested steels will be supplied by a high temperature gas nitriding treatment. Part of the gas-nitrided samples will be submitted to plastic strain by rolling to determine if there is a synergic between nitrogen content and work hardening, before and during cavitation erosion, and its relationship with the micro and nanostructure in each case.The microstructural characterization will be done using Transmission Electronic Microscopy TEM, Scanning Electron Microscopy SEM, Electron Backscatter Diffraction EBSD, Light Optical Microscopy LOM and X Ray Diffraction XRD. TEM analysis will be used to characterize dislocationarrays and to assess the Stacking-Fault Energy of the studied alloys, trying to establish relationships between crystal structure, chemical composition and operative deformation modes in the high nitrogen steels.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PINEDO, CARLOS EDUARDO; VARELA, LUIS BERNARDO; TSCHIPTSCHIN, ANDRE PAULO. Low-temperature plasma nitriding of AISI F51 duplex stainless steel. SURFACE & COATINGS TECHNOLOGY, v. 232, p. 839-843, OCT 2013. (11/16211-5, 12/50890-0)

ESPITIA, L. A.; VARELA, L.; PINEDO, C. E.; TSCHIPTSCHIN, A. P.. Cavitation erosion resistance of low temperature plasma nitrided martensitic stainless steel. WEAR, v. 301, n. 1-2, p. 8-pg., 2013-04-01. (11/16211-5)

ESPITIA, L. A.; VARELA, L.; PINEDO, C. E.; TSCHIPTSCHIN, A. P.. Cavitation erosion resistance of low temperature plasma nitrided martensitic stainless steel. WEAR, v. 301, n. 1-2, SI, p. 449-456, APR-MAY 2013. (11/16211-5)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

JIMÉNEZ, Luis Bernardo Varela. Study of micromechanics of cavitation damage in UNS S 31803 high nitrogen stainless steel with and without work hardening.. 2013. Master's Dissertation - Universidade de São Paulo (USP). Escola Politécnica (EP/BC) São Paulo.