合金元素对中硅耐热铸铁性能影响研究及在铸铝模具上的应用

Effect of the Alloy Element on Medium Silicon Heat-proof Cast-iron and the Application in Al-casting Mould

通过在中硅耐热铸铁中添加不同组合的合金元素稀土、铜、钛使其合金化,经过孕育和球化处理,得到铁素体+珠光体+球状石墨的金相组织。研究发现,铜的加入增加了中硅耐热铸铁的导热性提高了抗氧化生长能力;稀土的加入细化了晶粒,改善了氧化膜的粘附性,提高了热疲劳性;钛的加入恶化了石墨分布,增加了石墨和铁素体总量,导致了耐热铸铁强度下降。稀土、铜共同加入得到了比较规整的球状石墨,综合性能表现良好。该方案成功解决了某铸铝厂铸铝模具在高温作业中寿命不足的问题。

Adding different alloy combination of RE, copper and titanium, then through gestation and nodulizing disposal, we got the fine texture of ferrite pearlite and spheroidal graphite. It was fond that adding the single copper can increase the thermal conductivity of the medium silicon heat-proof cast iron and increase the oxidation resistance; while adding the RE can refined the grain and improve the adhesion of the oxide film, and increase the heat-fatigue resistance. Adding the Ti can＇t form spheroidal graphite easily, which worsen the distribution of the graphite while increase the total of the graphite and ferrite, that lead to decline the strenth of heat-proof cast iron. While adding the copper and RE together, we got the regular graphite, and it behaves well, Finally it solved the problem that the AI casting mould worked under a high temperaturewhich couldn＇t serve for a long time successfully.