轧辊服役损伤行为及失效机制研究

轧辊是轧钢机上的重要零件，每年服役失效后的大修或维修大大影响生产效率、浪费资源乃至经济效益。通过对轧辊的服役损伤行为研究，探讨不同失效模式下的失效机制。结果表明:轧辊服役损伤失效行为主要有剥落、裂纹、断裂，各损伤失效机制均主要为制造、使用以及两者综合作用的结果。其中剥落是由于局部大应力和升温，微裂纹产生于次表面并扩展形成剥落坑；裂纹是热循环应力及塑性应变等因素作用的结果；断裂大多是承受较大外载荷作用，并在轴颈应力集中处或内部近表面缺陷处发生的失效。针对轧辊的不同失效机制分别进行工艺改进和制定合理的检修周期，采用科学有效的检测手段，为有效使用轧辊、提高轧辊使用寿命提供依据。

Study on Damage Behavior and Failure Mechanism of Rollers

Rollers are important parts of rolling mills. The annual overhaul or maintenance after failure greatly affects production efficiency, waste of resources, and even economic benefits. The failure modes were discussed by studying the damage behavior of rollers in service. The results show that the failure behavior of rollers is mainly fatigue flaking, crack and fracture, which result from manufacture, use and their co-effect. Fatigue flaking is due to local excessive stress and heating up. Micro cracks forms at the subsurface and expands, leading to flaking pits. Cracks result from the co-effect of thermal cycle stress and plastic strain. Fracture is mostly due to larger loads and often occurs that at the stress concentration region of the neck or at the subsurface with defects. According to different failure mechanisms of rollers, process improvement is carried out and proper repair cycle is established. Combined with scientific and effective detection methods, a solid foundation can be laid for effective use and life increase of rollers.