High Silicon Moly Iron

[Jamesa]

What Carbon percentage gives the most favorable results as far as shrinkage goes, and at what temperature should the metal be poured to minimise shrinkage. How significant is the difference in melting point between an iron of 3.2%C compared with 3.8%C?

 

[metman]

JamesA

The iron-iron carbide diagram shows about 180 F difference in melting point from 3.2-3.8%C. The higher temperature is at 3.2%C. This of course will be somewhat different with Si and Mo additions. Jesus is the WAY

 

[Jamesa]

Thanks Metman,
You touched on the point of Si having an influence on the melting point.
With ~3.5 to 4.0% Si and 0.8% Mo, I believe this throws us to the other side of the Eutectic. Does this sound correct?

 

[arunmrao]

The formula for Total Carbon is given as %Carbon+1/3%Si+1/3%P. Now for an eutectic alloy C.E will be 4.3%. With the chemistry suggested by you the carbon should be brought down suitably to be near eutectic,whilst maintaining the high silicon percentage.

This will control your feed metal requirement and also control shrinkage defects.