钇基重稀土蠕墨铸铁的高温性能研究

利用钇基重稀土资源熔炼蠕墨铸铁,探讨高温条件下灰铸铁和蠕墨铸铁的抗拉强度、氧化增重值、伸长百分率、耐热疲劳性和线性膨胀系数等性能,同时用数理统计的方法推导出两种铸件线性膨胀系数的回归方程.结果表明:高温下蠕墨铸铁的断裂性质为韧窝断裂,其高温抗拉强度明显比灰铸铁高;蠕墨铸铁的抗氧化性和抗生长性均比灰铸铁好而导热系数与灰铸铁相近;灰铸铁和蠕墨铸铁的线性膨胀系数相近,但灰铸铁的相变收缩要比蠕墨铸铁强烈得多.

Study of yttrium-based heavy rare earth compacted graphite cast iron high temperature properties

Compacted graphite cast iron was prepared by using of local rich resources of yttrium-based heavy rare earth.Several properties,such as tensile strength of gray cast iron and compacted graphite cast iron under condition of high temperature,oxidation weight increase value,percentage elongation,heat fatigue resistance and linear expansion coefficient were discussed.Two kinds of castings linear regression equation for expansion coefficient were proposed.The results showed that fracturing properties of compacted graphite cast iron was dimple fracture in high temperature,and tensile strength of compacted graphite cast iron is mush stronger than that of gray cast iron in high temperature.In addition,compacted graphite cast iron behaved better in anti-oxidizing and anti-weight increasing than gray cast iron and the former thermal expansion coefficient is close to the latter.Moreover,they have similar linear expansion coefficient and phase change of grey cast iron shrinked much more severe than that compacted graphite cast iron.