Microstructure and properties of Fe– Cr–B alloy with different WC addition

Abstract In this work, the microstructure and properties of Fe–Cr–B alloys with different WC additions were studied. The results indicate that the microstructure of Fe–Cr–B alloys with different WC additions is mainly composed of M7(C,B)3, M23(C,B)6 boron-carbides and metallic matrices. As the amount of WC added increases, the volume fraction of boron-carbides increases. Noodle-like metallic matrices can be observed in B and C samples. The wear resistance increases with the increase of WC addition, C sample reaches a good balance between wear resistance and impact toughness. Alloys with a high volume fraction of boron-carbides were prepared innovatively: when WC reached 1.858 at.% and 2.647 at.%, the volume fraction was as high as 85.662% and 87.698%. The weight loss and impact toughness of the C sample is 0.2087g and 10 J/cm2, respectively, and the average Rockwell hardness is 58 HRC. Heat treatments further improved the comprehensive mechanical properties of the C sample. After heat treatment, the weight loss, Rockwell hardness and impact toughness of QT400 are 0.0600 g, 63.5 HRC and 5.5 J/cm2, respectively. The secondary boron-carbides further improve the wear resistance and Rockwell hardness but reduce the impact toughness to a certain extent. The sintered samples of C and D have excellent wear resistance and good toughness and can be used directly as wear-resistant materials.