某回转窑托轮在热装后产生裂纹。采用宏观观察、化学成分分析、力学性能测试、金相检验、扫描电镜分析等方法,分析了该托轮裂纹产生的原因。结果表明:裂纹是由补焊形成的缺陷引起的,托轮与托轮轴的装配过盈量大、托轮的热处理工艺不当及屈服强度不符合要求促进了裂纹的形成与扩展。

Cracks were found on the supporting roller of a rotary kiln after hot installation. By means of macroscopic observation, chemical composition analysis, mechanical property test, metallographic examination and scanning electron microscope analysis, the causes of cracks on the supporting roller were analyzed. The results show that the cracks were caused by the defects formed by repair welding, and the formation and expansion of cracks were promoted by the large interference between the supporting roller and the supporting roller shaft, improper heat treatment process of the supporting roller, and unqualified yield strength.