Accession Number : AD0733068

Title :   Effects of Microstructure, Composition, and Strength on the Strength-Differential Phenomenon Observed in HY-80 Steel.

Descriptive Note : Final rept.,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD

Personal Author(s) : Salive,Marcel L. ; Willner,Abner R.

Report Date : OCT 1971

Pagination or Media Count : 51

Abstract : Steel from 22 heats of low-carbon Ni-Cr-Mo steel (MIL-S-16216G and ASTM A543-65) were heat treated to study the effects on the strength-differential effect and the difference between tensile and compressive yield strength of (1) commercial variation in composition and inclusion content, (2) variation in microstructure such as prior austenitic grain size and the relative amount of isothermally produced ferrite or bainite in a tempered martensitic matrix, and (3) the observed variation in strength obtained after a 1-hour 1150 F temper followed by a water quench to prevent embrittlement while cooling from the temperating temperature. The difference between the tensile and compressive yield strength, sometimes called the strength differential (S-D) effect, was observed in this study to be at least 5 percent of the tensile yield strength. Data are cited to show that in the low-carbon Ni-Cr-Mo steels studied here, the S-D effect observed was a relatively constant percent of the tensile yield strength, and was markedly structure-sensitive to prior austenitic grain size, microstructural constituents, tempering temperature, type and distribution of carbides formed during tempering, and tempering slightly above the lower critical temperature. (Author)

Descriptors :   (*STEEL, MECHANICAL PROPERTIES), MICROSTRUCTURE, NICKEL ALLOYS, CHROMIUM ALLOYS, MOLYBDENUM ALLOYS, TENSILE PROPERTIES, COMPRESSIVE PROPERTIES, HEAT TREATMENT, COMPUTER PROGRAMS

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE