Chromite Sand 1

[evan_z]

Is anyone familiar with whether there are adverse effects of chromite sand getting back into molding sand in steel casting applications. This can be with either green sand or Airset molding?

 

[EdStainless]

How much would be in the system?
We used to cast in green sand and airset, some of our cores were Olivine (MgSiO).
It only made up about 3-5% of our sand by weight so we didn't see any effect.

Are there any chemical bonding issues with Chromite in either of your sand systems?
That would be my only worry.

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P.E. Metallurgy, Plymouth Tube

 

[arunmrao]

Chromite sands are used in heavy section steel castings. Such castings have good surface finish and lesser defects.
Chromite sands are preferred for following reasons:
. High thermal conductivity
• Low thermal expansion
• Wetability resistance to molten steel
• Basic to neutral pH
• High melting point
• Broad sieve distribution

Green sand molding using chromite sands, I am not familiar, but they are used in Airset resin sand moulds. I recently saw a 3D printed sand mould using Chromite sand and Furan resin as binder.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[evan_z]

At the moment, we are looking into using chromite to address hot tears in some of our castings. I know that Chromite has a good effect on hot tears. My concern is that we have no way to separate it after casting and an unknown amount will end return into the molding sand. I read in one paper that when it gets heated, it can react with silica sand and alter the stability of the mold. I was just trying to find out if anyone had any experiences with this.

 

[arunmrao]

Did you try Zircon sand for reducing your hot tear problem. I have no such knowledge about reduction in properties of moulding sand due to contamination. Please share the reference for our understanding. Thanks.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[EdStainless]

It would have be a significant fraction to have an impact.
I have never seen chromite in green sand either, but in airset and heat set it is not uncommon.

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P.E. Metallurgy, Plymouth Tube