Effect of Titanium Element on Microstructure and Mechanical Properties of Fe-Ni-C-W powder hardfacing coating

In this paper, the effect of titanium element on microstructure and mechanical properties of Fe-Ni-C-W powder hardfacing coating was investigated. Electrode coatings were made by a combination of iron, ferro-boron, nickel, ferro-titanium, tungsten and graphite powders. The electrode core was obtained from the E6013 electrode. The results of microstructural analysis showed that the microstructure of the weld metal of specimen 1 included the matrix of needle-like martensitic, residual austenite regions and carbides, while the microstructure of the weld metal of sample 2 consisted of austenite matrix with martensitic and residual austenite regions as well as carbides. The results of the EDS analysis indicated that the carbides consist of titanium carbides and tungsten carbides. There are also some tungsten carbides around titanium carbides. The results of XRD analysis showed that the phases present in the weld metal of samples 1 and 2 were austenite, martensite, titanium carbide, tungsten carbide and titanium oxide. The results of the Vickers microhardness test showed that in the weld metal of sample 1, the average hardness of the austenitic regions is 714 HV and the average hardness of the martensite regions is 804 HV. Also in the weld metal of sample 2, the average hardness of austenite regions is 334 HV and the average hardness of the martensite regions is 565 HV. The results of the Rockwell C hardness test showed that the average hardness of sample 1 weld metal is 42 RC and the average hardness of sample 2 weld metal is 49 RC.