铸铁材质标准 Gray lron 灰铸铁 Standard-Spec.No.&Class 标 准 T.S. σb≥ N/mm 2 Hardness HB≤ Note:(1)Test Bar θ=30mm(2)Chemieal composition and other requirement can be established upon written agreement between manufacturer and purchaser.(3)The hardness values are for castings of 15~30mm thickness. 注: (1)试棒直径 =30mm;(2) 化学成分和其它要求可与 客户商定; (3)硬度值适用于 15-30mm 壁厚铸件 GB China/ISO JIS JAPAN ASTM U.S.A. HT20