Open AccessMicrostructure evolution and fire-resistant properties of 690 MPa anti-seismic fire-resistant steel plate
Author(s) -
Chunxiang Lü,
Tianzi Lin,
Jian Cao,
Shubiao Yin,
Peng Gao,
Xing Liu,
Fang Zhan
Publication year - 2021
Publication title -
materials research express
Language(s) - English
Resource type - Journals
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ac0a03
Subject(s) - lath , microstructure , bainite , tempering , materials science , martensite , metallurgy , ferrite (magnet) , austenite , quenching (fluorescence) , acicular ferrite , carbide , acicular , composite material , physics , quantum mechanics , fluorescence
In this precent study, microstructure evolution of a newly developed 690 MPa composite microalloyed anti-seismic fire-resistant steel plate after quenching at 740 °C , quenching at 740 °C + tempering at 400 °C were studied and the fire resistance mechanism was analyzed. Experimental results show that the microstructure of hot rolled state of the tested steel is lath martensite, acicular ferrite, bainite and M/A island. After quenching at 740 °C, the microstructure of steel was composed of lath martensite, polygonal ferrite and retained austenite. The mixed microstructure of tempered troostite + bainite + a small amount of M/A island was obtained after quenching at 740 °C + tempering at 400 °C , it transforms into tempered sorbite + bainite after holding at 600 °C for 3h. A great number of fine carbides containing Mo, Nb, V and Ti precipitate at 600 °C of the quenched + tempered state of tested steel. The mixed microstructure and fine composite carbides make the quenched +tempered steel have excellent fire resistance.