Quick search
Go!

THE INFLUENCE OF CRYOGENIC AND ULTRASONIC TREATMENTS ON THE QUANTITY OF RESIDUAL AUSTENITE IN STEELS FOR BEARINGS


GHEORGHIAN MIRELA, CIUCESCU DORU
UNIVERSITY OF BACĂU

Issue:

MOCM, Number 13, Volume I

Section:

Issue No. 13 - Volume I (2007)

Abstract:

After quenching and tempering the bearing steel, being a hypoeutectoid one, presents a structure containing martensite, residual austenite and carbides. The rotation precision and the functional role of the bearings impose a good dimensional stability and high mechanical properties. These properties depend on the nature of the natural constituents, their size and distribution and, also, on the degree of structural homogeneity. The technological parameters (temperature and maintaining time) influence the quantity of transformed austenite and the kinetics of this transformation. In this paper is presented the variation of quantity of residual austenite with the cooling temperature under 0oC for the variants of classic treatment: 5 variants of cryogenic treatments and 2 variants of treatment with cooling in ultrasonic field for the 100Cr6 and 100CrMnSi6-4 steels. For these variants of treatments were realized measurements of the quantity of residual austenite by diffraction with X-rays.

Keywords:

residual austenite, cryogenic cooling, heat treatment, bearings.

Code [ID]:

MOCM200713V01S01A0025 [0001463]


Copyright (c) 1995-2007 University of Bacău