SkinDI - Influence of surface properties on the fatigue performance of ductile cast iron components

Purpose and goal

Cast iron grades of the type ductile (SGI) are used for many different parts. The fatigue strength is lower at the as cast surfaces than at machined surfaces, the reason are not yet fully understood. Improvement of the cast surface can be improved at the casting process or through post-processing such as shot-peening. The aim of the project is to allowing for lighter components with improved durability and lower environmental impact through enhanced knowledge of the influence of surface properties on fatigue strength.

Expected effects and result

Results: mechanisms behind poor properties of cast skin identified, methods for preventing decreased strength validated, 25% improved durability (life length or load), lifelength predictions witl 10% accuracy. Effects short term: decreased environmental impact through increased life length and fewer prototype versions. Effects longterm: development of better ductile iron grades that can replace more resource requiring solutions as for example welded steel sheet. Less resource demanding solutions contribute to a more circular flow of material.

Planned approach and implementation

Planmed work packages: WP1. Project administration - meetings, information distribution, reports to agency WP2. Material production - sand casting industrially respectivel laboratory scale WP3. Characterisation: micro structure and surfaces and Modification of surfaces through shot peening and machining WP4. Mechanical testing, static properties and fatigue properties WP5. Modelling the formation of cast skin and its mechanical properties WP6. Life Cycle Assessment WP7. Demonstrator - casting, modification of surfaces, testing and validation of models from WP6.