The influence of austenitization time and temperature on the austenite grain growth in high Ti-V HSLA steels

  • S R J Rezaei University of Pretoria
  • C W Siyasiya University of Pretoria
  • Z Tang Sichuan University
  • J Moema Mintek
Keywords: Austenitization time, Precipitation, Austenite grain growth, HSLA steels

Abstract

Generally, in high titanium-containing high strength low alloy (HSLA) steels, the challenge is to ensure that an adequate amount of Ti dissolves during soaking for precipitate strengthening during cooling or hot working. Therefore, this work focused on the effect of soaking time and temperature on the austenite grain growth kinetics of HSLA steels, of the three alloys containing 0.1 %Ti, and 0 to 0.12 %V. The samples were austenitized at 1150 and 1280 °C for 1, 2 and 3 hrs and quenched in a 10% NaCl brine. Thereafter, the samples were tempered at 490 °C for 72 hrs in order to reveal the prior austenite grain boundaries. The grain size was analysed by the linear intercept method. The precipitation behaviour was predicted by Thermo-Calc software and confirmed by SEM-EDS. At 1150 °C austenitizing temperature, all three steel grades exhibited the Ti (C, N) (Type 1), (Mn-Ti) (C, S) (Type 2), MnS (Type 3 (Ti4C2S2) (Type 4) and TiC (Type 5) precipitates. After escalating the temperature to 1280 °C, only the TiC dissolved. Type 4 and 5 precipitates were the finest and possibly responsible for the grain size refinement. Consequently, alloy 1 with the highest S content of 140 ppm exhibited the finest grain size at both temperatures.

Author Biographies

S R J Rezaei, University of Pretoria

Department of Materials Science & Metallurgical Engineering, University of Pretoria, Hatfield, Pretoria, South Africa

C W Siyasiya, University of Pretoria

Department of Materials Science & Metallurgical Engineering, University of Pretoria, Hatfield, Pretoria, South Africa

Z Tang, Sichuan University

Department of Materials Science and Engineering, Sichuan University, Chengdu 610000, China

J Moema, Mintek

Advanced Materials Division (AMD), Mintek, 200 Malibongwe Drive, Randburg, 2125, South Africa

Published
2022-01-25
How to Cite
Rezaei, S., Siyasiya, C., Tang, Z., & Moema, J. (2022). The influence of austenitization time and temperature on the austenite grain growth in high Ti-V HSLA steels. Suid-Afrikaans Tydskrif Vir Natuurwetenskap En Tegnologie / <i>South African Journal of Science and Technology</I&gt;, 40(1), 142-149. Retrieved from http://satnt.co.za/index.php/satnt/article/view/895
Section
Conference of the South African Advanced Materials Initiative

Most read articles by the same author(s)