The effects of microstructures on the tensile properties, high-cycle fatigue properties and corresponding damage mechanism of compacted graphite iron (CGI) were investigated. The results show that with the increase of pearlite content, both the tensile strength and fatigue strength show an upward trend. Fatigue cracks usually initiate at the graphite/ferrite interface and gradually propagate into the matrix under the high-frequency cyclic stress. The adjacent cracks bridge to form the main crack, leading to the final fracture. Based on the pearlite content and tensile strength, a new model for predicting the fatigue strength of CGI with high accuracy was proposed.

中文翻译：

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不同显微组织致密石墨铁的损伤机理及疲劳强度预测

研究了显微组织对致密石墨铁（CGI）的拉伸性能、高周疲劳性能及相应损伤机制的影响。结果表明，随着珠光体含量的增加，抗拉强度和疲劳强度均呈上升趋势。疲劳裂纹通常始于石墨/铁素体界面，并在高频循环应力作用下逐渐扩展至基体中。相邻的裂缝桥接形成主裂缝，导致最终断裂。基于珠光体含量和抗拉强度，提出了一种高精度预测CGI疲劳强度的新模型。