铝含量对Fe-12Cr-1.5B-Al合金凝固组织和硬度的影响  

Effect of aluminum content on solidification structure and hardness of Fe-12Cr-1.5B-Al alloy

作　　者：鞠江[1] 符寒光[1] 程美洁[2] 符定梅[2] 雷永平[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]中冶建筑研究总院有限公司,北京100088

出　　处：《材料热处理学报》2016年第9期133-138,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51274016);北京市自然科学基金(2142009)

摘　　要：用真空感应炉熔炼含0-8.0%Al的Fe-12Cr-1.5B-Al合金。采用光学显微镜、扫描电镜、XRD、洛氏、维氏硬度计,研究了铝含量对Fe-12Cr-1.5B-Al合金凝固组织和硬度的变化规律。结果表明:无铝Fe-Cr-B合金凝固组织由基体和硬质相组成。基体主要是马氏体和少量奥氏体组织。硬质相有M2(B,C)、M7(C,B)3和M23(C,B)6。铝的加入使Fe-12Cr-1.5B-Al合金基体转变为珠光体和铁素体组织,而对硬质相类型无明显影响。当铝含量超过6.0%时,部分铝元素与铁结合形成铁铝金属间化合物。Cr元素主要存在于硬质相中,基体中也含有一定量的Cr元素。Al元素主要存在于基体和铁铝金属间化合物中。B元素主要存在于M2(B,C)相中。无铝Fe-Cr-B合金洛氏硬度达到61.1 HRC,随着铝含量的增加,Fe-12Cr-1.5B-Al合金的洛氏硬度以及维氏硬度呈现先急剧下降后缓慢升高的趋势。An Fe-12Cr-1.5B-Al alloy containing different amount of Al was melted in a vacuum induction furnace.Effects of aluminum addition on solidification structure and hardness of the Fe-12Cr-1.5B-Al alloy were studied by means of optical microscope（OM）,scanning electron microscopy（SEM）,X-ray diffraction（XRD）,energy dispersive spectrometer（EDS） analysis and hardness test.The results show that the as-cast microstructure of the aluminum-free Fe-Cr-B alloy consists of matrix and hard phases.The matrix is mainly composed of martensite and a small amount of austenite.The hard phases are M2（B,C）,M7（C,B）3and M23（C,B）6types.The addition of aluminum element changes the matrix into pearlite and ferrite and has no obvious effect on the hard phases.When the content of aluminum is more than 6%,a part of Al and Fe are combined to form iron and aluminum intermetallic compound.Cr element is mainly observed in the hard phase,and the matrix also contains an amount of Cr element.B element is mainly found in the M2（B,C） phase.Al element is mainly detected in the matrix and iron and aluminum intermetallic compounds.The Rockwell hardness of the aluminum-free FeCr-B alloy is 61.1 HRC.The Rockwell hardness and Vickers hardness of the Fe-12Cr-1.5B-Al alloy shows a trend of slow increase after sharp decrease with the inereasing of the aluminum content.

关 键 词：铝合金化 Fe-12Cr-1.5B-Al合金 凝固组织 硬度 

分 类 号：TG143.7[一般工业技术—材料科学与工程]