Accession Number : AD0429139


Title :   EFFECT OF COBALT ON THE TRANSFORMATION CHARACTERISTICS OF 5NI-CR-MO STEELS.


Descriptive Note : Progress rept.,


Corporate Author : UNITED STATES STEEL CORP MONROEVILLE PA


Personal Author(s) : Connor,L P ; Dabkowski,D S


Report Date : 02 Jan 1964


Pagination or Media Count : 11


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)


Descriptors :   *SUBMARINE HULLS , *STEEL , METAL PLATES , WELDS , NICKEL ALLOYS , CHROMIUM ALLOYS , MOLYBDENUM ALLOYS , COBALT , TRANSFORMATIONS , FRACTURE(MECHANICS) , HARDENING , MARTENSITE , BAINITE , MICROSTRUCTURE


Distribution Statement : APPROVED FOR PUBLIC RELEASE