Mechanical properties of 0. 40 Pct C-Ni-Cr-Mo high strength steel having a mixed structure of martensite and bainite

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02656714· OSTI ID:6490053

Tomita, Y; Okabayashi, K

A study has been systematically made of the effect of bainite on the mechanical properties of commercial Japanese 0.40 pct C-Ni-Cr-Mo high strength steel (AISI 4340 type having a mixed structure of martensite and bainite. Isothermal transformation of lower bainite at 593 K, which appeared in acicular form and partitioned prior austenite grains, in association with tempered mar tensite, provided a better combination of strength and fracture ductility, improving true notch tensile strength (TNTS) and fracture appearance transition temperature (FATT) in Charpy impact tests. From the results, it is assumed that the mechanical properties of high strength steels having mixed structure of martensite and bainite are affected more strongly by the size, shape, and distribution of bainite within martensite than by the difference in strength between martensite and bainite or by the type of mixed bainite present. The remarkable effects of the size, shape, and distribution of bainite within martensite on the mechanical properties of the steel are briefly discussed in terms of the modified law of mixtures, metallographic examinations, and the analyses of stress-strain diagrams.)

• Research Organization: University of Osaka
• OSTI ID: 6490053
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 16A:1; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
BAINITE
CARBON ADDITIONS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
HIGH TEMPERATURE
IRON ALLOYS
IRON BASE ALLOYS
MARTENSITE
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NICKEL ALLOYS
PHASE TRANSFORMATIONS
STEELS
TEMPERATURE EFFECTS