Abstract from my 2004 presentation to the Society of Tribologists and Lubrication Engineers….. Probably one of the best papers I have ever given, and winner of the Deutsch award for practical tribology research. That was a big day for me!
Predictive testing of Steel Rolling oils using the Elastohydrodynamic Lubrication Rig
The rolling of steel sheet from continuously cast slabs and coils or ingots to sheet and tin products is a fundamental step in the manufacture of goods worldwide. Slab and sheet reduction is accomplished by plastic deformation of the slab using large metal rolls to apply a force normal to the slab. The contact area between the roll and the slab/sheet must be lubricated to provide proper sheet finish and good tool life. Rolling operations are very large, and it is difficult to test the performance of rolling oils on the mill due to the volume of lubricant and the set-up times required. Development of reliable predictive testing methods is critical for the design of good rolling lubricants.
Rolling oils are typically formulated from fat and mineral oil basestocks with appropriate additive packages and provide hydrodynamic and boundary lubrication to the roll contact. The rolling contact is formed by the plastically deformed sheet and the roll and has three specific zones – the backward slip zone, the neutral point, and the forward slip zone. In both of the slip zones, fresh metal surface is exposed and the process operates in a slip condition. At the neutral point, the contact operates in a true rolling condition. This suggests that a test method with variable slip is for testing and evaluation of rolling lubricant performance.