The chilled zone property and metallographic microstructure of chilled spheroidal graphite cast iron roller

摘要

The objective of this study is to investigate the effect of chiller design and material on the chilled zone property (chill depth, hardness) and metallographic microstructure of the chilled spheroidal graphite cast iron roller (Φ70 mm × L120 mm). At first, the chilled spheroidal graphite cast iron roller was made by the different chiller dimension (Φ 87.5 mm, Φ105 mm, Φ140 mm, Φ210 mm) and material (S45C, SKD61, FC200). Experimental results showed that chilled spheroidal graphite cast iron roller, which the hardness of center or surface was increase as chiller dimension rise. It was made by the same dimension (Φ 140 mm) and different material (S45C·FC200·SKD61), which hardness of center or surface was similar. Thus it can be seen the different chiller dimension was effect more than the different material chiller (thermal conductivity) to the hardness of chilled spheroidal graphite cast iron. The metallographic microstructure of chilled spheroidal graphite cast iron roller (made with S45C, Φ140 mm chiller), which center was the bull's eye structure, and surface were composed of the small spheroidal graphite, pearlite, and cementite.