過共晶灰鑄鐵 hyper-eutectic grey iron－leometwu的部落格

片狀石墨就是基地(鉄)上既存的裂縫, 有初晶石墨出現時, 鑄鐵幾乎無強度可言. 所以要加入很多低碳鋼將C%, Si% 稀釋到這些巨大石墨片不見得 FC 150 . 或利用球化處理將石墨轉變成球狀, 得 FCD 450 以上.下面這組照片是"生鉄塊"的金相照片. Micrographs of a pig iron. Pig iron is usually hyper-eutectic and has "primary graphite flakes in the microstructure. Primary graphite flakes are "large cracks" that reduce tensile strength to a low low level. So, scrap steel is used to "dilute" carbon content to the degree that these primary graphite flakes are gone.下面是生鉄丸(4%C, 2.40%Si, CE=4.8%)直接切片所攝金相照片. 紅色箭頭所指為粗大的初晶石墨其他較細小的石墨為共晶石墨.