热轧工作辊失效原因分析及其预防

Analysis and Prevention of Failure Behaviors of Hot Rolling Work Rolls

通过对首钢迁钢2 250mm热连轧机组发生的工作辊失效原因进行了系统总结,发现轧辊本身存在的制造缺陷和辊间应力集中是导致轧辊失效的主要问题根源。根据分析结果,提出并应用了预防措施。对轧辊材质提出更高的标准要求,避免轧辊材质本身存在的工作层残余奥氏体比例超标、芯部石墨球化不良、结合层与芯部严重渗铬等制造缺陷,有效降低了由于轧辊材质本身问题导致的剥落和断辊失效事故。为了预防使用不当发生的轧辊失效,加强了轧辊的探伤检测,严禁不合格轧辊上机工作,通过加强轧辊的使用管理,有效避免了轧辊的失效行为。应用辊形技术解决了轧辊边部应力集中导致轧辊剥落的问题。

Through systematical summaries on the work roll failures occurred in 2 250 mm hot strip mill of Shougang Qian^an Iron and Steel Company, the roll material defects generated during the manufacturing processes and the contact pressure concentration between rolls are the main reasons. According to the analytical results, preventing measures are given and applied. Higher requirements on roll material was put up forward to avoid the manufacture defects such as excessive retained austenite in work layer, bad spheroidization of graphite in roll core, Cr permeating in binder layer and the core and so on. Roll spalling and breaking failures resulted by roll material defects were elimi nated thoroughly. For preventing the roll failures from incorrect using, the works of defect detection and inspection were enhanced to avoid using unqualified roll on mill. Roll failure behaviors were avoided effectively after the using management of rolls was strengthened. Roll spalling problems resulted by roll edge contact stress concentration were solved through applying the roll contour technology.