EFFECT OF COBALT ON THE TRANSFORMATION CHARACTERISTICS OF 5NI-CR-MO STEELS.
Abstract
Studies were initiated to determine (1) whether the addition of cobalt to raise the M sub s temperature would increase self tempering in a 5Ni-Cr-Mo steel without deleteriously reducing hardenability and (2) whether cobalt additions would reduce the susceptibility of a 5Ni-Cr-Mo steel to heat-affected-zone cracking. The results of high-speed dilatometric measurements on specimens heat treated to simulate the cooling of 1/2- through 4-1/2-in.-thick water-quenched plates indicated that the addition of cobalt raised the M sub s temperature of the 5Ni-Cr-Mo steel about 17 F per 1.0% cobalt in the range 0 to 5% cobalt, and also increased self tempering of the martensite. However, the addition of 8% cobalt reduced the hardenability so that an undesirable amount of coarse bainite was formed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 02, 1964
- Accession Number
- AD0429139
Entities
People
- D. S. Dabkowski
- L. P. Connor
Organizations
- U.S. Steel