Effect of Vanadium on The Mechanical Properties and Microstructure of Ni-Hard 2

摘要

Material Ni-Hard 2 which was used in this experiment has the composition 2.9 wt.% C; 3.3-4.8 wt.% Ni; and 1.5-2.6 wt.% Cr. Material Ni-Hard 2 has lower wear-resistant than the other Ni-Hard. Material Ni-Hard 2 was alloyed with the vanadium to improve the physical properties by melting them with the variation of composition vanadium (3 and 7 wt.%) in the induction furnace and was formed to the desired shape for each test. Phase structure after alloying is austenite, carbide, martensite, and ferrite according to XRD result and microstructure analysis. The optimum hardness is in the 7 wt.% of vanadium that is 43.6 HRC. For the impact was influenced by the changing of microstructure due to the variation of composition and the optimum impact is in the 3 wt.% vanadium that is 73.3 J/cm~2. Whereas the optimum wear rates of after alloying is in the 3 wt.% vanadium that is 50 x 10~(-8) mm~3/mm. The effect of composition variation of vanadium could reduce the grain size, impact, and wear-resistant due to the low content of ferrite is in the microstructure. On the other hand, the hardness could increase.