A study of the quenching structures of Fe-B-C alloy

The effect of quenching temperature and cooling rate on the structures of cast Fe-B-C alloy containing 1.0wt.%B and 0.2wt.%C was researched. The results showed that, under the same quenching temperature, the microstructures of the metallic matrix are transformed from the mixture of the pearlite, ferrite and martensite to the martensite along with the increase of quenching cooling rate. Under the water cooling condition, excessively low or excessively high quenching temperature did not favor to obtain the single martensite matrix. In the Fe-B-C alloy, the stability of Fe2B was good. It still had not been dissolved while heating up to 1050 degrees C. The dissolution of boride appeared heating at the high temperature. The higher the quenching temperature was, the more the boride dissolved obviously. Along with the dissolution of boride, the boride morphology changed from network to broken-network and isolated shape. When the heating temperature was 1050 degrees C, the boride transformed the isolated shape completely. Quenching at 950 similar to 1000 degrees C, cast Fe-B-C alloy transformed into the compound structures of fine lath martensite and boride in the water cooling condition.