... elements.high chrome casting steel ball:c:2.0-2.8,si:<1.0,mn:0.5- ... 5,cr:22-30,mo:0-1.0,cu:0-2.0,ni:0-1.5,p:<0. ... 06middle chrome casting steel ball:c:2.1-3.2,si:0.5-2.2,mn:0.5-1.5, ... cr:7-15,mo:0-1.0,cu: ... 0-0.8,ni:0-1.5,p:<0.10,s<0.06low chrome casting steel ball:c:2.2 ... -3.6,si:<1.2,mn:0.5-1.5,cr ... :1.5-3.0,mo:0-1.0,cu:0 ...