铬对亚共晶Fe-C-B合金组织与力学性能的影响  

Effect of chromium content on microstructure and mechanical properties of Fe-C-B hypoeutectic alloys

作　　者：邓培凯[1,2] 黎振华[1,2] 岑启宏[1,2] 刘美红[3] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]云南省先进成形制造工程技术研究中心,云南昆明650093 [3]昆明理工大学机电工程学院,云南昆明650093

出　　处：《材料热处理学报》2013年第12期67-72,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(50701020;51171073);云南省中青年学术技术带头人后备人才培养项目(2008PY011;2009CI022);昆明理工大学金川集团预研项目(KKZ4201251003)

摘　　要：为了研究含量在低于3.80%范围内,Cr含量对亚共晶Fe-0.46C-1.48B合金的组织与力学性能的影响,采用光学显微镜、定量金相及X射线衍射研究了合金的微观组织,测试并分析了合金的硬度和冲击韧性。结果表明,Cr能促进亚共晶Fe-C-B合金凝固组织中初生奥氏体析出和珠光体转变,减少共晶莱氏体和共晶硬质相的析出,改善硬质相的形态分布。随Cr含量增加,铸态及热处理后合金的冲击韧性增加;硬度则先增加后下降,在Cr含量为3.23%时达到极大值。与不含Cr的试样相比,含Cr 3.80%的试样冲击韧性提高约50%。In order to investigate the effect of chromium content （Cr ≤3.80% ） on microstructure and properties of Fe-C-B hypoeutectic alloys, the microstrueture of the alloys was observed by optical microscopy（ OM ） , quantitative metallography analysis and X-ray diffraction （XRD） , their hardness and impact toughness were analyzed and tested. The results show that chromium can accelerate precipitation of primary austenite and pearlitic transformation of the alloy, decrease volume of eutectic ledeburite and eutectic hard-phase, and improve the distribution of hard-phases. The impact toughness of as-cast and heat-treated alloys improves with increasing of chromium content. However, the hardness of the alloys firstly increases and then decreases with the increasing chromium, and it reaches the maximum when Cr content is 3.23% in present experiment. The impact toughness of the sample containing 3.80% Cr increases by about 50% compared with that of the sample without chromium.

关 键 词：铬 亚共晶Fe—C—B合金 组织 力学性能 

分 类 号：TG113.12[金属学及工艺—物理冶金]