Technology Parameter:l CASTING SIGN: HT250. 2 CHEMICAL COMPOSITION (%) :C:3.1~3.4 Si:1.9~2.3 Mn: 0.6~0.93 METALIC-PHOTOGRAPHE: PEARLITE >95%; CEMENTITE<1%; A GRAPHIT >85% 4 MECHNICAL PROPERTY: TENSILE STRENGTH>210N/mm2. 5 HARDNESS: 187~241