engleski

Utjecaj povišenog sadržaja silicija na svojstva odljevaka od nodularnog lijeva

This paper investigates the influence of silicon content of 3.5 wt. % on the microstructure and mechanical properties of ductile cast iron at different cooling rates. The cast geometry consists of samples with different thickness ; cone block with diameter 300 mm and height 350 mm and standard Y2 and Y3 keel-blocks. Microstructure analysis and tensile test were performed on the as-cast materials. Based on the metallographic observations of the present work, it could be concluded that silicon content of 3.5 wt. % has negative effect on spheroidal graphite morphology for this melt and solidification conditions. Tensile test showed that silicon strengthens the ferrite, resulting in an increase in yield and tensile strength, while the elongation decreases. Also, based on the metallographic observations in this investigation, the risk of chunky graphite formation increases with increase in wall thickness, i.e., lowering of the cooling rate. Chunky graphite formation negatively effects on mechanical properties, especially elongation, in cast irons with silicon content higher than 3.5 wt. %.

ductile cast iron ; high silicon ; cooling rate ; microstructure ; mechanical properties

nije evidentirano