Abstract
A new type of 0.2%C–1.5%Si–1.5%Mn ultra high-strength low alloy TRIP-aided steel consisting of lath martensite structure matrix and metastable retained austenite films, “TRIP-aided martensitic steel; TM steel”, was developed by means of quenching and partitioning process. In addition, effects of partitioning temperature and time on the microstructure and retained austenite characteristics were investigated. The matrix structure was composed of two kinds of lath martensite structures, or wide and narrow lath martensite structures. Most of the retained austenite of about 3 vol% was located along the narrow martensite lath boundary. On the other hand, a small amount of fine and needle-like carbides precipitated only in wider lath martensite structure. Partitioning at temperatures lower than 250°C for 1000 s after quenching in oil or ice brine considerably increased carbon concentration of the retained austenite phase to about 1.0 mass%, maintaining volume fractions of retained austenite and carbide. Also, the carbon-enrichment mechanism in the retained austenite was proposed through TEM observation, as well as the carbide precipitation and coarsening mechanisms.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.