The effect of alloying element Cr on the chilled property and metallographic microstructure of the chilled cast iron roller

摘要

This study investigated the effect of alloy contents (0.3％Cr、 0.6％Cr、 1.2％Cr) with different chiller materials (S45C、 FC200、 SKD61 )and dimensions ( Φ87.5 、Φ105 、Φ140 、Φ210)on the chilled property and metallographic microstructure of chilled cast iron roller (Φ70mm×L120mm) The measured hardness varies with the different metallographic microstructure of the chilled cast iron roller. The hardness near roller center is increased with increasing Cr％ and chiller size. The order of the hardness for various chiller materials is that FC200＞SKD61＞S45C. We use XRD to analyze roller in Cr content. Result reveals that (Cr,Fe){sub}7C{sub}3、 Cr{sub}7C{sub}3 、Cr{sub}23C{sub}6 exist in the microstructure of the roller. The microstructure near the center of chilled gray cast iron roller with S45C indicates that chiller (87.Smm in diameter) consists of 4％ferrite 15％pearlite and 81％graphite. The microstructure near the surface of chilled gray cast iron roller consists of 13％Cementite, 9％Graphite, 60％Pearlite, 18％ transformed Ledeburite. The measured hardness of roller surface can reach H{sub}RC42.