Relationship between Austenite‐stabilizing Elements and Austenite Fraction in Near‐rapidly Solidified Fe‐Mn‐Al‐C Lightweight Steel

A peritectic reaction (liquid+ δ-ferrite→ γ-austenite) and eutectoid reaction (γ-austenite→ α-ferrite+ κ carbide) occur in the Fe-Mn-Al-C light weight steel. Experimental results show that the main constituent phase of the near-rapidly solidified Fe-Mn-Al-C lightweight steel is γ-austenite and/or δ-ferrite in this work, and the eutectoid reaction is restrained by the rapid cooling rate. With the increase of C content, the γ-austenite fraction of near-rapidly solidified medium-Mn and high-Mn Fe-Mn-Al-C lightweight steels increases significantly. However, the increased Mn content had little effect on the γ-austenite fraction of the near-rapidly solidified Fe-(8/12/16)Mn-9Al-0.8C steel strips in our early work. This work attempts to reveal the reasons for the different effects of Mn and C on Fe-Mn-Al-C lightweight steel strip under near-rapid solidification. It is found that the γ-austenite fraction of the near-rapidly solidified Fe-Mn-Al-C steel strip is closely related to γ-austenite fraction at the end of equilibrium solidification. This suggests that the main constituent phase of light weight steel strip depends on its liquid-solid phase transformation under near-rapid solidification, and is seldom affected by solid phase transformation. This article is protected by copyright. All rights reserved.