铸造Fe-B-G合金组织和性能的基础研究

借助光学显微镜、扫描电镜、电子探针显微分析仪和X衍射分析等手段,研究了含1.5%～2.0%B、0.4%～0.7%C的铸造Fe-B-C合金的凝固组织及合金元素的分布规律,并测试了铸造Fe-B-C合金的力学性能.结果显示铸造Fe-B-C合金的凝固组织主要由珠光体、马氏体、铁素体和高硬度的Fe2B组成,硼元素主要分布在硼化物中,基体中分布甚微.铸造Fe-B-C合金正火处理后可以获得马氏体加Fe2B组成的双相组织,硬度大于60HRC,冲击韧性大于8 J/cm2.

A Study on the Microstructures and Properties of Cast Fe-B-C Alloy

The solidification structures of cast Fe-B-C alloy containing 1.5%~2.0%B and 0.4%~0.7%C and the distribution characteristics of alloy elements were researched by means of optical microscopy,scanning electron microscopy(SEM),electron probe microanalyzer(EPMA) and X-ray diffraction(XRD).The mechanical properties of cast Fe-B-C alloy were tested by impact tester and hardmeter.The results showed that the solidification structures of cast Fe-B-C alloy were made up of pearlite,martensite,ferrite and Fe2B having high hardness.Boron element mainly distributed in the boride and there was little distribution in the matrix.After normalizing treatment the structures of cast Fe-B-C alloy became a mixture of martensite and Fe2B boride,which presented a better performance in hardness and impact toughness.The hardness of cast Fe-B-C alloy exceeded 60 HRC and its impact toughness was larger than 8 J/cm2.