Development of silicon - enriched bearing steel

• Grant number: 13/18801-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2014
• End date: July 31, 2016
• Field of knowledge: Engineering - Mechanical Engineering - Manufacturing Processes
• Principal Investigator: José Benedito Marcomini
• Grantee: José Benedito Marcomini
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil
• City of the host institution: Lorena
• Associated researchers: Carlos Antonio Reis Pereira Baptista ; Durval Rodrigues Junior ; Miguel Justino Ribeiro Barboza

Abstract

The purpose of this work is the preparation of high carbon Bearing steels, based on chemical composition of AISI52100/DIN 100Cr6, containing 0,8 - 1,0 % Si. This proposal is based on the same idea of silicon enrichment of SAE 4340 steel leading to the developmento of 300M steel for aerospace application, reaching better toghness and increasing the Tempered Martensite Embrittlement (TME) temperature. After the preparatin of the new alloy, the samples will be quenched from the intercritical gamma+carbide region and tempered in order to obtain a martensite matrix, carbides and a few of retained austenite. The aim of this mixed structure is to obtain high hardness combined to a better impact toghness and good contact fatigue resistance. The samples softening during the tempering and the tempered martensite embrittlement (TME) phenomena will be studied. The mechanical characterization of the new alloy will be held by means of tensile tests, impact tests and contact fatigue tests. In a second step of the present work, the detection of transition carbides precipitation in this alloy will be performed by means of transmission electron microscopy (TEM) technics or scanning electron microscopy using a field effect gun scanning electron microscope (FEG-SEM). This second step makes this work a dual research combining technological research to purely scientific research. (AU)