Effect of interaction between cementite and pearlite on two-body abrasive wear behaviors in white cast iron

摘要

The wear interaction of cementite and pearlite in the white cast iron (WCI) was investigated using the two-body abrasive wear test under contact loads of 20, 35, and 50 N. The wear behavior, wear surface morphology, sub-surface structure, and wear resistance were evaluated using X-ray diffraction, microhardness testing, and nano-indentation. The results indicated that when the Cr content was increased from 0 to 4 wt%, there was a significant increase in the microhardness ( H ) and elasticity modulus ( E ) of the cementite. This yielded a 15.91%- and 23.6%-reduction in the degree of wear resistance and surface roughness, respectively. Moreover, no spalling and breaking of cementite was observed with increasing Cr content during the wear process, indicating improved wear resistance of the bulk cementite. In addition, the hard phase (cementite) and tough matrix (pearlite) composite structure exhibited a good protective and supporting effect. Thus, it was concluded that the interaction mechanism of the wear phase contributed to the reduction of the wear weight loss of the composite during the wear process. The contribution of the interaction between the hard wear-resistant phase and the tough phase in WCI to the wear resistance decreased with increasing hardness of the pearlite matrix.