驱动辊断齿失效分析及改进

Failure Analysis and Countermeasures of Teeth-breaking of the Driving Rollers

从显微组织、热处理工艺等方面对二中间辊驱动辊齿部断裂原因进行了分析。分析结果表明:驱动辊淬火加热时齿部过热是造成驱动辊断齿的主要原因;轧辊存在严重的网状碳化物也是造成冲击性能偏低的原因之一;在工艺设计方面,驱动辊齿部强度有余,韧性不足,是驱动辊断齿的隐患,通过控制网状碳化物级别提高轧辊原材料质量和降低驱动辊齿部硬度强度,可以有效提高驱动辊齿部冲击性能。

From the perspectives of microstructure and heat treatment regime, this paper carries out careful analysis on the fracture of the second intermediate driving rollers. The results indicate that the teeth-breaking of driving rollers is mainly attributed to the teeth overheating during heating process of quenching. Besides, serious reticulate carbonides in the rollers are also one reason that leads to the poor impact performance. In terms of process design, the strength of driving roller teeth is high enough while the toughness is not adequate, which is a hidden danger of teeth-breaking of the driving rollers. By virtue of controlling reticulate carbonides, the quality of roller blank is improved and meanwhile the hardness and strength of the driving roller teeth are lowered, thus effectively enhancing the impact performance of the driving roller teeth.