C、Cr、Si、Mn对低铬白口铸铁组织和力学性能的影响

The low chromium white cast irons were casted in the green mould and the effect of C, Cr, Si and Mn on the structure and mechanical properties of low chromium white cast iron was studied by orthogonal test. The results show that the carbides are basically distributed in a netlike form with 2.4wt%C and 2.7wt%C and the divorced eutectic carbide with netlike structure is formed. When the carbon content is 3.0wt%, the divorced eutectic netlike carbides disappear. The results also reveal that high carbon, low silicon, high chromium and low manganese are beneficial for increasing hardness, and low carbon, low silicon, medium chromium and high manganese contribute to improving impacting toughness, whereas high carbon, low silicon, low chromium and high manganese contribute to increasing wear resistance. The new developed low chromium white cast iron has better hardness, impacting toughness and wear resistance than those of the materials used in overflowing components of scouring diving pump, and the operating life can be improved by around five times.