Estudo de falha e comparação de linga de corrente atuando como elemento mecânico de laminadores de perfis estruturais reversíveis

This study aims to analyze the possible failures of chain slings, widely used in the industrial sector, especially in applications involving lifting loads with varying weights and shapes. Slings are also used as mechanical elements in several machines. In this study, the failure of a specific chain sling, used as a mechanical component in reversible rolling mills of X/H structural profiles, will be analyzed. This sling is responsible for supporting the upper horizontal cylinder, used in a steel mill, where it was subjected to adverse conditions, such as heat, humidity and constant stress cycles. The objective was to evaluate the feasibility of replacing the Grade 8 sling with a Grade 10 sling. The fracture surface of the Grade 8 sling was characterized. In addition, the Grade 8 and Grade 10 slings were compared, as well as their respective manufacturing standards. The analyses performed for comparison included: stresses through analytical calculations, visual inspection, optical microscopy, scanning electron microscopy – SEM/EDS (energy dispersive spectroscopy), chemical analysis via optical spectrometer and Vickers hardness – HV 100gf. These analyses were essential to determine the real cause of the sling failure and propose solutions to prevent recurrence or mitigate the problem. This mechanical component is extremely important for the stability of the continuous rolling process of structural profiles.