Analysis of Micro-Porosity Defect and Remedial Measures in Crankshaft (Ductile Iron) – A Case Study

摘要

This paper presents some analysis of micro-porosity defect in a Crankshaft - Ductile cast iron (FCD 700/2) product, carried out at an automotive foundry manufacturer in Malaysia. Systematic analyses on the cause-effect and defect diagnostic study were carried out to understand the root causes of the micro-porosity. Two significant factors were identified that affect the formation of micro-porosity, mould factor and metal factor. Four remedial countermeasures were proposed to prevent micro-porosity including increasing squeeze pressure at the moulding machine, controlling sand moisture, increasing radius at edge of mould, and reducing magnesium content. Results of the trials showed substantial reduction of micro-porosity defect in crankshaft (casting). The manufacturer has accepted the countermeasures and incorporated them in their standard operating procedure.