A method for evaluation of weld overlays exposed to combined wear and very high cycle fatigue conditions

摘要

Key machinery components used for diminishing, transporting or processing massive volumes of material in heavy industries are severely exposed to combinations of different wear mechanisms, like abrasion and surface fatigue. The microstructure and wear properties of state of the art iron based welding alloys used as surface protection do not only depend on the nominal chemical composition of the welding consumables and their manufacturing route, but also on the base material, variations in process technology and applied welding parameters. Commonly used wear and hardness and test or micro structural investigations are either cost and time consuming or do not provide a complete understanding about the material behavior of surface coatings exposed to combined wear including fatigue. Thus the aim of this study was to prove the concept of using ultrasonic fatigue testing as new method to understand and predict the behavior of welded surface coatings in a fast and reproducible way. Two flux cored wires from different manufacturing lines, but of the same nominal chemical composition were compared applying identical welding parameters. As a result, the two wires could be distinguished clearly by applying the ultrasonic fatigue test method.