水平连铸铁索体球墨铸铁型材的断裂韧性

The Fracture Toughness of Shaped Ferritic Ductile Iron by Horizontal Continuous Cast

研究了不同硅含量的水平连铸铁素体球铁型材的断裂韧性,且与砂铸试样进行了对比.按照GB2038—30,测定了J积分及阻力曲线斜率dJ/da,并结合其拉伸性能、光学和电镜断口观察进行综合分析.试验表明,连铸型材有较好的断裂韧性,其在失稳断裂之前有较大的稳定扩展区,对预防突然断裂十分有利.

The fracture toughness of shaped ferritic ductile iron containing different silicon content by horizontal continuous cast has been studied,compared with sand mould cast samples. According to GB2038-80, the value of J-integral and slope of resistance curve dJ/da were examined,using the tensile properties,optical and scanning electron microscope the fracture shape of samples was analysed. The results have showed that the shaped ductile iron by continuous cast gives the good fracture toughness , before unsteady failure , a wider stable extended region occurs, which favours the prevention from sudden fracture. The satisfactory mechanical properties is due to the good metallurgical quality, smaller and regular graphite nodules and refined ferritic grain.