成分及第二相组织对球墨铸钢热疲劳性能的影响

利用正交试验、定量金相、热疲劳试验及回归分析等方法，研究了碳、硅、铜、铬及石墨与碳化物体积分数对球墨铸钢热疲劳性能的影响规律，并得到了其相应的定量关系式－回归方程，从而为热循环条件下工作的球墨铸钢的成分选择及组织控制提供了依据。研究表明，球状石墨及促进石墨化元素有利于其热疲劳性能的提高，而碳化物及反石墨化元素则削弱其疲劳性能。中还对这些影响因素进行了必要的分析讨论。

Effect of Chemical Compositions and Second Phases on Thermal Fatigue Property of Cast Steel with Spheroidal Graphites

In this paper, using orthogonal experiment, quantitative metallographical technology, thermal fatigue test and regression analysis, the author studied the regular pattern about the effect of C, Si, Cu, Cr and quantities of graphite and carbide on the thermal fatigue property of cast steel with spheroidal graphites, and obtained some regression equations, thus provided the necessary basis for selecting chemical compositions and controlling structures in the material. The results showed that spheroidal graphites and graphitizing elements improve the thermal fatigue property obviously, while carbides and its promoting elements weaken the property. The reasons for the patterns were also analysed theoretically.