leometwu的部落格

200X     產生白口的灰鑄鐵: 白色部位為白共晶(white), 冶金學上稱之為"粒滴斑鐵";  暗色部份為"灰共晶(grey)+初晶(P)".  粒滴斑鐵為半陶瓷半金屬, 很傷刀具. 出現此物時, 加工者會拒絕加工; 如果鑄造廠自己有加工廠, 使用特殊刀具還是可加工的. 試片取自厚60 mm之油壓閥鑄件, 鉻添加過量(0.80%)而生白口.

Hydraulic valve casting, 60 mm in thickness. White areas: white eutectic, aslo called  Ledeburite. It is caused by adding too much Cr in the melt. Ledeburite is like semi-ceramic and very harmful to cutting tools. In most cases, we try our best to produce FC castings with 100% pearlite, and 0% Ledeburite.