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Need the formula

Need the formula

Need the formula


I think/hope this is the right forum for this question.

I need the formula to calculate: Time(minutes) to melt 1 pound steel (power in joules).

Thank you

RE: Need the formula

Joules is energy, not power. Watts is power. Not sure how many Joules are required to melt steel on a per-pound basis, but once you decide how rapidly you want to melt the steel then the Joules divided by the time in seconds gives the Watts.

Joules and Watts are always capitalized as they are named for the people sharing those names. This is true of many SI units.

You'll likely need two numbers. One is the amount of energy to heat the steel from room temperature to the melting point and the second for how much energy is required to change the phase from solid to liquid.

RE: Need the formula


Time(minutes) to melt 1 pound steel (power in joules)

The specific heat and heat capacity for various types of steel are searchable on the web. Then a brute force total heat divided by the amount of heat you can provide will give you a start, after which you'll need to account for various heat losses, thermal conductivity/diffusivity of the steel, etc.

Is this for school?

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RE: Need the formula

Are you actually going to just be melting 1 lb?
Smaller furnaces will tend to be less efficient (more heat loss).

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: Need the formula

Quote (EdStainless)

Are you actually going to just be melting 1 lb?
Smaller furnaces will tend to be less efficient (more heat loss).

And not to forget extra metal in the crucible that needs to be melted but cannot be poured into product. I forget the term but there is waste metal in every melt.

RE: Need the formula

Usually called the 'heel'.
There is also some metal lost to slag (oxidation).
If a 1T furnace uses 625kWh to melt a ton of steel then a 1kg furnace would not need 625Wh, but more likely 750-800Wh.
We had a small lab induction furnace. We charged almost 6lb and made 5lb pours.
It was on a 5kW power supply and melts took us about 20 min (it wasn't steel, we needed more power).

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

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