Abstract
The fraction and form of retained austenite could have an effective effect on mechanical properties of a Fe-0.38 C-2.03 Mn-1.66 Si-0.65 Cr (wt%) bainitic steel. Based on the method of altering microstructure of low alloy steel by Alternately timed quenching (ATQ), the relationship between quenching time and the change rule of retained austenite was discussed. The microstructure was investigated and observed through TEM, SEM and XRD. The performance was determined by tensile and impact test. The results showed that the microstructure composed of bainite, martensite and retained austenite, and the values of the tensile strength, impact toughness and elongation were about 1100 MPa, 74 J cm−2 and 4.8%, respectively. Compared with quenching and partitioning (Q and P) process, with prolonging of water cooling time, the strength gradually increased and reached the maximum value of 1184 MPa at 25 s, while the elongation and toughness enhance first and then decrease, and reached the excellent values of 5.90% and 97 J cm−2 at 20 s respectively. In addition, the maximum product of strength and elongation (PSE, 6.77 GPa%) at 20 s of water quenching time could be obtained during ATQ processes. Due to the formation of film-like retained austenite under different cooling time, the ATQ process could dramatically elevate the combination mechanical properties of steel.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
