Achievement of ultra-high strength in 45Si2MnCr2Mo steel via efficient and low-energy tempering

Abstract In this study, 45Si2MnCr2Mo steel was fabricated by casting, hot rolling, and normalizing, followed tempering at different temperatures from 180 to 520 °C for 2 h. Special attention paid the effects of on microstructure mechanical properties steel. The results indicate that tempered consists bainite, martensite, retained austenite (RA), it is not sensitive below 320 °C. However, after 420 °C, bainitic ferrite plates merged their lath boundaries became vague. turn, RA decomposed, whereas carbide particles appeared then coarsened. With increasing temperature, volume fraction achieved its peak value carbon concentration within attained optimal balance ultimate tensile strength 2306 MPa total elongation 8.24% in were being normalized 950 0.5 h subsequent 220 These values are found exceed those air-cooled isothermal steels. Finally, correlation between under consideration discussed.