Analysis of a Failed Main Drive Gear from a Metals Rolling Mill

During routine operations, the gearbox of a reversing rolling mill suffered a critical failure. A multidisciplinary team was rapidly mobilized and identified broken teeth on the double helix main drive gears as the direct cause. Limited information about the failed gear’s design and service history was available at the time of failure. Metallurgical testing was requested to assist in determining the root cause. This presentation will discuss the fractographic, microstructural, and mechanical analyses performed. These provided insight into gear’s unique manufacturing method which contributed to the mode of failure.