Effects Of Heat Treatment And Vanadium-titanium Alloy On Carbide Morphology And Mechanical Properties Of High Chromium Cast Iron

High chromium cast iron as wear-resistant materials has been widely used inmetallurgy mine, machinery industry, building materials industry, nationaldefense industry, and other fields. It has been widely praised due to the betterperformance in the matrix and dispersion distribution of M7C3with the hardness1200~1800Hv. Comparing with white cast iron, the high chromium cast has agood wear-resisting ability. Because as-cast high chromium cast iron does notreach the requirements of practical application, it has to mostly be treated toachieve the required wear-resisting ability. In order to better improveperformance and reasonable use of resources, that reducing the content ofprecious alloy, choosing cheaper alloy is necessary, and the function of alloyelements in high chromium cast iron needs to research deeply. In this paper, byadding various contents of vanadium and titanium elements, and through thechange of heat treatment process, the effects of vanadium, titanium and heattreatment process on carbide morphology and the mechanics properties of highchromium cast iron were studied.In this paper, Analysis methods such as the metallographic microscope，X-ray diffraction (XRD), scanning electron microscope (SEM), Rockwell hardness tester and pendulum impact testing machine. The test results show that the rightamounts of V, Ti in high chromium cast iron can change the carbide morphology,such as net morphology changing into broken and block distribution. Whenadding content4%V, then the hardness increases nearly5HRC, but the impacttoughness is not improved. When0.75%Ti, hardness and impact toughness havebeen significantly improved, and the carbides is uniformly distributed.The heat treatment of quenching and tempering of high chromium cast ironwith0.75%of Ti were studied. The test results show that, with the increasing ofquenching temperature, the block and direction carbides were been developed.The carbides got a very good refined at900℃quenching. With the increasing oftempering temperature, carbides tend to be the pellets, appeared the finedispersed carbides could received at400℃tempering, and the hardness andimpact toughness have a good combination, hardness value58HRC, impacttoughness6.1J/cm2.