Effect of Ar Purification on Microstructure and Properties of High Strength Gray Cast Iron

Abstract

The effects of Ar purification on the impurity characteristic, graphite morphology and quality indexes of high strength gray cast iron were investigated by microstructures analysis and mechanical properties examination. The results show that there are a large amount of particles and floccule impurities in the specimens without Ar purification. The granular impurities usually have been incorrectly considered as “C-type” graphite observed by optical microscopy in the metallographic examination in the practical production of small and medium high strength gray cast iron castings. The amount of impurities is greatly decreased and the quality indexes of high strength gray cast iron with Ar purification are markedly improved.