A study of microstructure and performance of cast Fe-8Cr-2B alloy

作者：Yue M; Han guang F^*; Shang lin M; Yong ping L

来源：Materialwissenschaft und Werkstofftechnik, 2014, 45(10): 912-919.

DOI：10.1002/mawe.201400252

• Cast Fe-8Cr-2B alloy
• quenching temperature
• boride
• microstructure
• mechanical performance
• crusher hammer

The effects of quenching temperature on microstructure and hardness of cast Fe-8Cr-2B alloy containing 0.3 wt% C, 2.0 wt% B, 8.0 wt% Cr, 0.6 wt% Si, and 0.8 wt% Mn were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Rockwell hardness and Vickers microhardness testers. The experimental results indicate that the as-cast microstructure of cast Fe-8Cr-2B alloy consists of M2B (M = Fe, Cr), M-7(C, B)(3), alpha-Fe, and gamma-Fe. The dendritic matrix composed of lath martensite mixed with a small amount of retained austenite, and the netlike boride M2B distribute in the grain boundary. After quenching between 950 degrees C and 1100 degrees C, the netlike eutectic boride are broken up and a new phase-M-23(C, B)(6) which is distributed in the shape of sphere or short rod-like are precipitated from the matrix. Both the macrohardness and microhardness of specimens increase with the increasing quenching temperature. At about 1050 degrees C, the hardness reaches the maximum value. However, when the temperature exceeds 1050 degrees C, the hardness will decrease slightly. With the increase of tempering temperature, the hardness of cast Fe-8Cr-2B alloy quenching from 1050 degrees C decreases gradually and its impact toughness increases slightly. Crusher hammer made of cast Fe-8Cr-2B alloy quenching from 1050 degrees C and tempering from 300 degrees C has good application effect, and its service life improves by 150-180% than that of high manganese steel hammer.

• 出版日期2014-10
• 单位北京工业大学; 沈阳铸造研究所