Influence Of Original Position Autogeny Ceramic Composite On The Properties Of Iron Based Surfacing Layer

The topic of the task is influence of original position autogeny ceramic composite on the properties of iron based surfacing layer. Major study of the improvements of overlay by adding vanadium, boron and chromium in the iron based alloy. The iron-based composite materials of Fe-Cr-V-C and Fe-Cr-B-C hardfacing alloys were deposited on the surface using plasma arc welding (PAW) technology. Hard phase original position autogeny on the properties of iron based surfacing layer. By the reciprocity between hard phase and iron base, add overlay shows good wear resistance. We achieved the best mixture ratio through regulate the proportion of alloy, and contrast times without number.So the mechanical property of weld overlay got optimum value.A plasma arc welding(PAW) surfacing of Fe-Cr-V-C and Fe-Cr-B-C alloy system was designed.The disciplinarian of mechanical property was examined using Rockwell hardometer and wear testing machine respectively.A series of research, such as the X-ray diffraction (XRD) analysis of product,the metallographic observation and scanning electron microscope(SEM),have been taken to analze the phase form,organizational form and disposition of alloy.The results show that:(1) the wear resistance of the hardfacing alloy is excellent.When volume fraction of ceramic phases was high and microstructure of matrix surrounding it distributed uniformly, which can enhanced bond strength between borides and matrix,thus evidently improved the wear resistance of hardfacing alloys.(2) Because of the add of vanadium,carbide has formed. Vanadium carbide particles are small and distribute in the martensite base dispersely and form wear resistant structure with intermittent and netted (Fe, Cr,V)7C3 which distribute at grain boundary.So the welding deposited metal of weld overlay shows good wear resistance.(3)When the vanadium content is up to 26.2 percent,and the chromium content is 13.4 percent,the mechanical property of weld overlay has optimum value,the hardness is 64.9HRC and the rattler loss is 0.0784g.(4)The quantity of boride and carbide has increased with the increase of boron content.Wear resistant structure formed by this chemical compound. So the welding deposited metal of weld overlay shows good wear resistance.(5) The amount of borides significantly increased with B content increasing and the hardness and wear resistance of surfacing layer reached optimum value when B contents reached 5% and the chromium content is 13.4 percent.The hardness is 66.1HRC and the weight reduction is 0.1383g. The wear resistance of surfacing layer decreased with the amount of boron continually increasing.