Effects of chromium addition on microstructure and abrasion resistance of Fe-B cast alloy

This research work studies the effects of chromium on microstructure and abrasion resistance of Fe-B cast alloy. The results show that eutectic boride changes from continuous network to less continuous and matrix changes from pearlite to martensite with the increase in chromium content in the alloy. Meanwhile, an increase in chromium addition in the alloy leads to an increase in the chromium content in M ₂B-type boride because chromium can enter boride by substituting for iron in Fe ₂B. Under two-body wear, Fe-B cast alloy exhibits excellent wear resistance. When alloys are tested against soft abrasive, chromium can markedly improve the wear resistance of Fe-B cast alloy, whereas excessive chromium can reduce the wear resistance. The wear resistance of Fe-B cast alloy increases first and then decreases with the increase in chromium. But when tested against hard abrasive, since the hardness of SiC is much higher than that of M ₂B boride, an increase in chromium content marginally increases the wear resistance. Weight losses of Fe-B cast alloy increase with the increase in the load and exhibit the linear relationship.