Cemented carbides, also known as hard metals (HM), are composite materials that are widely used in many technological applications requiring favourable mechanical properties, specifically a high wear resistance. In the steelmaking industry, these materials have been effectively used to produce rollers for both hot and cold rolling operations.

In this study, failure analysis of a roller used for cold rolling was performed, starting from a detailed material investigation to a fracture surface characterisation using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM + EDXS). A finite element (FE) analysis of the roller was performed to determine the Hertzian-type stress distribution in the contact area. To identify the most critical zone, the Crossland multiaxial criterion was applied, and the results were then compared with measurements obtained from a component failure analysis. An additional investigation of the possible causes of failure was performed by adopting a material model (the Murakami–Endo equation) to distinguish the actual causes of failure more clearly, mainly at the crack nucleation site.

The failure analysis results showed that the roller failed primarily because of rolling fatigue, which started from an internal pore acting as a source of local stress concentration. The component reached the fatigue limit of the material in proximity to the pore, which behaved as a crack nucleation site.

硬质合金，也称为硬质合金（HM），是复合材料，广泛用于许多需要良好机械性能（特别是高耐磨性）的技术应用中。在炼钢工业中，这些材料已被有效地用于生产热轧和冷轧作业的轧辊。

在这项研究中，对冷轧用辊进行了失效分析，从详细的材料研究到使用具有能量色散X射线光谱（SEM + EDXS）的扫描电子显微镜对断裂表面进行表征。对辊进行了有限元（FE）分析，以确定接触区域的赫兹型应力分布。为了确定最关键的区域，使用了Crossland多轴判据，然后将结果与从组件故障分析获得的测量结果进行比较。通过采用材料模型（Murakami–Endo方程）对可能的失效原因进行了进一步研究，以便更清楚地区分出实际的失效原因，主要是在裂纹成核部位。

失效分析结果表明，辊的失效主要是由于滚动疲劳，滚动疲劳始于内部孔，该内部孔是局部应力集中的来源。该组分达到了接近孔的材料的疲劳极限，该疲劳表现为裂纹成核位置。