摘要
目的研究热成形钢热浸镀铝硅镀层的微观组织与物相组成。方法利用扫描电镜(SEM)和能谱仪(EDS)分析铝硅镀层表面与截面的微观组织形貌与成分,利用X射线衍射(XRD)和电子背散射衍射技术(EBSD)分析铝硅镀层的物相组成与比例。结果热浸镀铝硅镀层表面由富Al相、少量的富Fe相以及树枝晶网状分布的高Si相构成,截面是由内外两层组成,其靠近铁基体的内层为Fe-Al-Si合金层,外层为Al-Si层。进一步的研究显示,Al-Si层由富Al相、少量的富Fe相以及柱状分布的高Si相构成,高Si相主要存在于合金层与铝硅层界面以及Al-Si层中。结论热浸镀铝硅镀层中富Al相、富Fe相、高Si相和Fe-Al-Si三元合金层的物相分别为Al、Al_(13)Fe_(4)、Si和Al_(8)Fe_(2)Si。对热浸镀铝硅镀层中高Si相的研究显示,分布于合金层与铝硅层界面处的高Si相,可以有效阻碍镀层的生长,而分布于铝硅层中的高Si相在空间中以立体网状骨架的结构形式存在,这种立体网状结构形式作为镀层的主体框架,可以有效地提高镀层的强韧性和成形性能。
This paper aims to study the microstructure and phase composition of hot-dip Al-Si coating on hot-formed steel.Scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDS)were used to analyze the microstructure and composition of the surface and cross-section of the Al-Si coating;X-ray diffraction(XRD)and electron backscatter diffraction(EBSD)were used to analyze the phase composition and ratio of the Al-Si coating.The surface of the hot-dip Al-Si coating is composed of Al-rich phase,a small amount of Fe-rich phase,and high Si phase with dendritic network distribution;the cross-section of the hot-dip Al-Si coating is composed of inner and outer layers,the inner layer close to the iron matrix is an Fe-Al-Si alloy layer,and the outer layer is an Al-Si layer.Further research shows that the Al-Si layer is composed of Al-rich phase,a small amount of Fe-rich phase,and columnar distributed high Si phase;the high Si phase mainly exists at the interface between the alloy layer and the Al-Si layer and in the Al-Si layer.The phases of Al-rich phase,Fe-rich phase,high Si phase and Fe-Al-Si ternary alloy layer in the hot-dip Al-Si coating are Al,Al_(13)Fe_(4),Si and Al_(8)Fe_(2)Si respectively.The study of high Si phase in hot-dip Al-Si coating has shown that the high-Si phase distributed at the interface between the alloy layer and the Al-Si layer can effectively hinder the growth of the coating,while the high-Si phase distributed in the Al-Si layer exists in the form of a three-dimensional network framework in space.This three-dimensional network structure as the main frame of the coating can effectively improve the strength and toughness and formability of the coating.
作者
崔桂彬
鞠新华
尹立新
严春莲
CUI Gui-bin;JU Xin-hua;YIN Li-xin;YAN Chun-lian(Shougang Group Company Limited Research Institute of Technology,Beijing 100043,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2021年第8期375-381,共7页
Surface Technology
