材料期刊网

借助光学显微镜、扫描电镜和X射线衍射分析等手段, 研究了硼(B)含量>2.0%和碳(C)含量<0.2%的铸造Fe-B-C合金的凝固组织及热处理后的组织和性能. 铸造Fe-B-C合金的凝固组织由Fe2B、铁素体和珠光体组成, 硼化物呈网状沿晶界分布. Fe-B-C合金经950℃正火处理后, 局部出现断网现象, 基体组织全部转变为板条马氏体,硬度大幅度提高, HRC接近 60, 冲击韧度大于10 J/cm2, 动态断裂韧度大于30 MPa•m1/2.在干滑动磨损条件下, Fe-B-C合金的耐磨性优于镍硬白口铸铁和GCr15、Cr12MoV等合金钢, 与高铬白口铸铁相当.Fe-B-C合金熔炼简便、铸造性能好, 且不含Ni和Mo等昂贵合金元素, 具有较低的生产成本.

The solidification structures of cast Fe-B-C alloy containing more than 2.0%B and lower than 0.2%C and the structures and properties of alloy after heat treatment were researched by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), hardness measurements, impact tester and pin abrasion tester. The results show that the solidification structures of cast Fe-B-C alloy are made up of boride (Fe2B), pearlite and ferrite, and boride distributes along grain boundary in network form. After normalizing at 950oC, the part broken network of boride of cast Fe-B-C alloy appears, the matrix all transforms into lath martensite. The hardness of cast Fe-B-C alloy increases obviously and nears to60HRC, its impact toughness and dynamic fracture toughness excel 10J/cm2 and 30MPa.m1/2 respectively. In the condition of dry skimming wear, cast Fe-B-C alloy has excellent abrasion resistance. Its abrasion resistance is more excellent than that of Ni-hard white cast iron, GCr15 and Cr12MoV, nears to that of high chromium white cast iron. Cast Fe-B-C alloy has simple melting process and good casting property, there are no costly nickel and molybdenum elements and low production cost.