Simulation increases quality of rolls
Residual stresses occur when rolls are cast. Swerim has simulated this and demonstrated that residual stresses can be checked. By adapting the process, cracking risks can be decreased and roll quality increased.
Rolls for rolling mills can be manufactured through casting. The molten metal is poured into a casting mould that rotates at high speed. With this solution, the roll’s surface is cast first and it is then filled inwards.
Casting is performed in several steps with different materials in the roll’s core and surface. These materials solidify in different ways, which leads to residual stresses in the roll. If the residual stresses are too high they can cause cracks, and in the worst case, roll failure, with associated costs for roll change and production loss.
Increased rolls quality and less waste
In a joint project conducted by Swerim and the roll manufacturer Åkers, Swerim has simulated residual stresses and demonstrated that they can be analysed. Thanks to improved analysis, the quality of the rolls increases, which in turn leads to a reduction in rejects and fewer complaints.
The simulation models are used to study the residual stresses in detail. The models give answers to questions about stress magnitudes, their locations in the rolls and how they change during the process. For Åkers, these results have been very important.
“The project has given us deeper insight into the casting and cooling process, and even brought up a number of issues that we need to address,” says Mats Söder, R&D manager, Åkers Sweden AB.