Premium
Isochronal Phase Transformations of Low‐Carbon High Strength Low Alloy Steel upon Continuous Cooling
Author(s) -
Huo Jie,
Liu Yongchang,
Zhang Dantian,
Yan Zesheng,
Gao Zhiming
Publication year - 2013
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.201100277
Subject(s) - materials science , acicular ferrite , microstructure , austenite , pearlite , ferrite (magnet) , continuous cooling transformation , metallurgy , alloy , high strength low alloy steel , transmission electron microscopy , martensite , bainite , scanning electron microscope , acicular , composite material , nanotechnology
Aimed to acquire optimum comprehensive properties for the oil and gas pipeline steels, thermal treatment should be controlled to achieve ideal microstructures. Effects of cooling rates on transformation kinetics and microstructures of the low‐carbon high strength low alloy (HSLA) steel were investigated to obtain an optimized thermal treatment technology. Dilatometric measurements, light microscopy, scanning electron microscopy, and transmission electron microscopy were employed in present work. The transformed microstructures contained polygonal ferrite + pearlite, acicular ferrite (AF), and bainitic ferrite (BF) due to the cooling rates increasing from 5 to 3000°C min −1 , in present investigated HSLA steel. The result shows that, the increase of cooling rate accelerates AF transformation and refines the steel's matrix. The morphology of martensite/austenite structures transformed from islands in AF to films in BF with the increase of cooling rate.