高强度灰铸铁缸体铁液处理工艺研究

Research on Iron Melt Treating Process Used for High Strength Gray Iron Cylinder Block Production

介绍了6DL、道依茨(Deutz)、6DM、6DN系列灰铸铁缸体铸件的力学性能要求。对材料性能不稳定的原因进行了分析,提出了稳定材料性能的试验研究内容,最后采取了以下改进措施:采用预处理剂,提高铁液形核、抗衰退、受孕育能力;选用优质增C剂,增加石墨核心数量;改变铁液充型的进液位置;适当降低原铁液w(C)、w(Si)及w(Mn)量,提高w(S)量;降低GF300合金加入量,并将GF300合金改成随流变质处理剂,与随流孕育剂一同在浇注时加入到铁液中。结果显示:上述各系列缸体的本体抗拉强度已稳步提高,达到了技术要求。

The mechanical properties requirements of gray iron cylinder blocks used for 6DL,Deutz,6DM,6DN series diesel engines were introduced.The reason causing mechanical properties of block material instable was analyzed,and the research items to stabilize material properties were proposed.Finally,the following improvements were adopted：using pre-modifying agent to increase nucleation ability,anti-degeneration ability and inoculation sensitivity of the iron melt;choosing high quality carburizer to increase graphite nucleus amount;changing the ingating location from where the iron melt entering and filling the mold;decreasing properly carbon content,silicon content,manganese content,increasing sulphur content; reducing adding amount of GF300 alloy,using it as stream inoculant and adding it into iron melt in the pouring process together with other stream inoculant.As the result of adopting above measures,the casting body tensile strength of above-mentioned series blocks have enhanced steadily and met the technical requirements.