A steel mill that produces rolled steel products from 100 percent recycled materials was experiencing bearing failures and turned to Graphalloy for help.
The mill used guide rolls to keep the metal bars centered on the conveyor.
The rolls are required to turn when the bar glances off them. The bearings for the guide rolls were grease lubricated and the temperature range of 170-180°C was baking out the grease and causing the bearings to seize. In some applications with the guide rolls, they could not use excessive grease, and those bearings seized even faster.
The steel mill’s plant engineer worked with Graphalloy’s engineering team to discuss technical considerations in designing a Graphalloy, graphite/metal alloy, self-lubricating bushing to replace the greased roller bearing. After several engineering discussions, the plant engineer purchased and installed four pieces of a Graphalloy bronze-grade bushing, with a stainless-steel housing, in the guide roll assembly. Graphalloy bushings require no external lubricating and work in temperatures up to 400°C (750°F).
After six months in service, the plant manager said that the Graphalloy bushings “are performing very well” and that they would replace all the roller bearings in these assemblies with the Graphalloy bushings. The Graphalloy upgrade has saved them maintenance time and money already, and should lead to more savings down the road.
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