The Character of Observed Porosity and Its Possible Effects on Rolling Contact Fatigue Life of M-50 Steel.
Abstract
This thesis studied a warm-rolling of AISI M-50 steel at 750 C (1382 F). Samples of both warm-rolled and as-received (spheroidized annealed) M-50 were austenitized at 1036 C (1897 F) for various times and subsequently tempered. The heat treated samples were subjected to rolling contact fatigue (RCF) testing. In all cases prior warm-rolling degraded the RCF life at both the L(10) and L(50) levels. Scanning electron microscopy was used to examine the microstructure of the as-received and warm-rolled material between 4000X and 10,000X magnification. It is thought that the increase in the void diameters accounts for the decrease in RCF performance of warm-rolled M-50. The degraded RCF performance is due to both the increase in mean void diameter and the increase in larger sized voids that accompany warm rolling. A qualitative model was developed to account for the origin of voids in as-received material and for the increase in void diameter in warm-rolled material. Keywords: Thermomechanical processing, Residual carbides, Porosity, Void Size Distribution, Bearings, Void Origin Model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1985
- Accession Number
- ADA155930
Entities
People
- Jillian L. Perry
Organizations
- Naval Postgraduate School