Microstructural examinations of Fe-W-B base hard-faced steel

Abstract

It is now well established that considerable improvement in the mechanical/ chemical properties of near surface regions of materials can be achieved by the process of surface alloying. In the present study, surface alloying treatment with Tungsten and Boron on the surface of AISI 1020 steel was realized by the technique of TIG welding. Ferrous boron alloy and ferrous-tungsten were used for surface alloying treatment. Before the treatment, ferrous alloy was ground and sieved to be smaller than 45 μm. The powders were mixed to be composed of Fe 5 WB 4. Prepared powder was pressed on the steel substrate and melted by TIG welding for surface alloying. Coated layers formed on the steel substrate were investigated using by optical and scanning electron microscopy, X-ray diffraction analysis and Vickers micro-hardness tester. It was shown that surface alloyed layer has composite structure including eutectic matrix and blocky boride phase which is white color and well distributed. Borides formed in the coated layers have a sharp corner structure and distributed in the matrix. X-ray diffraction analyses showed that coated layers include Fe 2 B, FeB and FeW 2 B 2 phases. The hardness of blocky boride phases is 2095. HV 0.01.