高铬白口铸铁中碳当量对抗磨性能的影响

高铬白口铸铁的共晶显微组织与普通白口铸铁的共晶组织不同,其中不连续的条块状共晶铁、铬碳化物M7C3占25%左右,与富铬的二次碳化物位于金属基体奥氏体或其转变产物中,而后者的M3C碳化物能占到48%,可看作渗硫体基体或海锦状渗碳体,里面镶嵌奥氏体转变产物,所以共晶型高铬白口铸铁的韧性比普通共晶型白口铸铁好,共晶组织中碳化物的短小空间对共晶奥氏体基体起到良好的保护作用,在高应力磨料磨损条件下,过共晶高铬白口铸铁中的大块状初生M7C3碳化物能很好地抵抗磨粒对抗磨件施加的法向压力和切向剪切力,不易断裂,故而抗磨性能较好.

Influence of Carbon Equivalent for High Cr White Cast Iron on Abrasion Resistant

The eutectic microstructure of the high-Cr white cast iron differs from ordinary white cast iron without alloys, the former contains 25% M7C3 carbides, the later has 48% M3C carbides. So the eutectic high-Cr white cast iron is tougher than the ordinary eutectic white cast iron because of minimizing the inter-carbide spacing to protect austenitic matrix well. In a high-stress abrasion environment, the large pro-eutectic carbides in the hypereutectic high-Cr white cast iron are more resistant to fracture under the tangential and tending force exerted by the abrasive particle.