Cast Iron Alloy Suggestion 1

[dshore]

We are casting a variety of brass and bronze alloys into ingot form, in a cast iron 30 class double cavity mold. Typical casting temperature of most of the alloys is 2200 F. After the metal is poured into the mold, it travels thru a water spray in order for the metal to solidify in time so that it will drop out of the mold at the end of a 30 foot conveyor. Once the ingot is released from the mold, the hold gets re-filled again about a minute later. Most of the alloys typically have over 80% copper with tin, lead, zinc and bismuth being some of the other major elements.

The thermal shock is causes the molds to crack, as per the attached photo. I have more photo's available which could be emailed. Any suggestions in alloy selection would be appreciated.

On another note, can anything be done to fill in the cracked molds so that they could be kept in production, rather than scrapped ?

Thanks
David

 

[arunmrao]

It is the rapid cooling, when they pass through water spray. You can try Ductile Iron moulds , which can withstand cracking. Compacted Graphite irons will also do well.

You an try using cast iron welding rods for filling the cracks.

I'm just one step away from being rich, all I need now is money.
( read somewhere on the internet)

 

[EdStainless]

DI might help, though the molds on pig iron casters are grey iron, not CG or DI.
They also use an alloy that is roughly 0.75% Mo and 0.25% Cr.
Can you make the molds lighter? Heavy cross sections will be worse.
Also lessen the spray. It should be light enough that in the first portion all of the water flashes off.
Making the cooling slightly less aggressive will help a lot.

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Plymouth Tube

 

[arunmrao]

DI certainly helps. There were 2 casting lines , one was fitted with cast iron moulds and the other with DI . The former had several failures, ultimately resulting in serious replacements , While there was not a single failure in D.I moulds.
I learnt my lesson, not to trust the sales, who booked the order.

I'm just one step away from being rich, all I need now is money.
( read somewhere on the internet)