Optimisation of long product rolling through improved understanding of roll wear and lubrication

The principal aim of this project was to improve knowledge on wear processes occurring during long product rolling. In addition, improved means for lubrication application, lubrication removal from water systems and recycling were determined and quantified in terms of economic benefits. The main activities included collecting wear data for a number of roll materials, rolling mills and types of rolling stand. The input data were based on a wear parameter derived from the ratio of measured to predicted results and were surprisingly constant for all the conditions considered. The predictions were calculated using an algorithm able to deliver similar wear profiles to those derived from wear measurements. In some cases, the wear predictions had to be made from models using worn rolls to generate more accurately the factors of relative slip and surface pressure that contribute to the modified Archard equation. Repeating the model with worn rolls was found, in all cases, to remedy inadequate predictions. The project was successful as far as measuring wear profiles and comparing these with the modified Archard algorithm to predict wear is concerned. Each partner contributed towards these wear measurements and looked at means of avoiding the deleterious effects of wear and whether excess wear caused loss of shape, lapping or surface roughness. Roll lubrication was studied, in terms of different types of lubricants and their effectiveness in reducing roll wear, as well as how best to treat the resulting cooling water/lubricant mix. The results showed the difficulties associated with the successful application of lubrication in long product rolling, where the type of application is key and is dependent on the avoidance of being affected by cooling water.