Analysis of wear life and mechanical stability for wear steel

Abstract: This thesis work is carried out in collaboration with Olofsfors AB. They manufacture steel products such as tracks and chains for forest machines and wear steel for plows and graders. The focus of this project is on wear steel. The aim with this project is to obtain a better understanding of mechanical stability and wear on different types of wear steel. This knowledge can then be used to prolong the life cycle in future products. This project was divided into two parts where the  first one concerns wear steel for plows. In this part a comparison between six different steels was conducted using mechanical tests. The steel type will not be specifed in this report but will instead be denoted with the letters A to F. The tests used were rubberwheel abrasion tests to investigate wear resistance, Charpy-V impact tests in cold temperatures to  find crack resistance and tensile tests in order to analyze tensile properties. Steel F was not a part of the rubber wheel abrasion test since a specimen with correct dimensions could not be manufactured from the product due to its special geometry. The second part of the project was for Olofsfors Bruxite grader edges. The objective with this part was to build a model to predict wear on edges using Numerical modeling. The multiphysics program LS-DYNA was used. The environment for the grader is a mining site giving a very rough gravel road. Discrete element method was used for computation of the granular material of the road and the  fnite element method was used on the grader. The wear calculations were made with Archard's wear law. The road was built up in two different ways, in the first model loose discrete element spheres were used. In the second model one layer of bonded discrete element spheres was used with a top layer of loose spheres.Different meshes and loads were also tested.