大型支撑辊断裂原因分析及改进

Analysis and Improvement of Fracture Reason for Large Back-up Roll

从成分设计、组织形态以及强度校核等方面对大型支撑辊的断裂情况进行了分析,发现轧辊厂家在冶炼过程中采用了真空脱氧技术,成分设计与国内标准略有差异;辊颈与辊面交界处的硬度最低,低于通常设计范围;对辊颈部位进行全面校核,传统的理论校核已不能满足于轧辊的安全生产,需要通过有限元分析,验证轧辊的薄弱环节,并进行合理的设计。辊颈、辊面的交界处是轧辊的薄弱点,在交变应力作用下易产生疲劳裂纹。为了保证轧辊的安全使用,在不改变轧辊外形设计的基础上,适当提高了辊颈硬度,并完善了轧辊的检测、维护制度。

In this paper,the fracture of large back-up roll was analyzed from the aspects of composition design,structure form and strength check.It was found that the roller manufacturer used vacuum deoxidation technology in the smelting process,and the composition design was slightly different from the domestic standard.The boundary between the roller neck and the roller surface has the lowest hardness,which is below the normal design range.The neck position of the roll has been checked comprehensively,the traditional theoretical check has been unable to meet the safety of the roll production,the verification on the weak links of the roll through the finite element analysis and a reasonable design are needed.The junction of roll neck and roll surface is the weak point of roll and fatigue crack is easy to occur under the action of alternating stress.In order to ensure the safe use of the roll,the hardness of the roll neck is appropriately increased on the basis of no change in the design of the roll shape,and the system of testing and maintenance of the roll is perfected.