Development of 500MPa grade environmental friendly automobile structural steel

2nd International Workshop on Materials Science and Mechanical Engineering

机械制造;材料科学

Hui, Y.J.^1^2 ; Wu, K.M.^3 ; Xu, K.H.^3 ; Xiao, B.L.^1^2 ; Pan, H.^1^2 ; Du, Q.^1^2 ; Lv, L.G.^1^2

Technology Institute of Shougang Group Co.Ltd., Beijing

100043, China^1

Beijing Key Laboratory of Green Recyclable Process for Ironand Production, Shougang Group Co. Ltd., Beijing

100043, China^2

Qian'An Iron and Steel Company of Shougang Group Co. Ltd., Manufacturing Department, Hebei

064404, China^3

关键词: Black ashes;    Coiling temperature;    Environmental-friendly;    Finish rolling temperature;    High temperature;    Lower temperatures;    Optical microscopes;    Structural steels;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/504/1/012003/pdf
DOI  :  10.1088/1757-899X/504/1/012003

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The microstructure, properties and oxide scale of the 500MPa grade environmentalfriendly automobile structural steel were investigated by utilizing optical microscope (OM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that the "black ash" was consisted of massive oxide scale and a s mall amount of powdered o xide scale, the phase proportion of Feo, Fe3O4, and Fe2O3 were 41.9%, 55.6% and 2.5%, especially. By reasonable controlling of the proportion and morphology of FeO and Fe3O4 in the structure of o xide layer can prevent o xide scale peeling. The process of "fast rolling at high temperature" combined with lower-temperature coiling could obtain the optimal oxide scale structure, which is thin and consisted of lamellar Fe3O4/Fe eutectoid transformat ion product, and with a small amount of FeO distributed uniformly and island-like in Fe3O4. The mechanical properties and the surface quality can meet the user's requirements when the finish rolling temperature and coiling temperature were 900C and 570C, the thickness of the oxide scale was less than 7.5μm, the proportion of Feo, Fe3O4 and Fe2O3 were 7.0%, 86.2% and 6.8%, especially.