Specific heat of cast iron at very high temperatures

[Soderdahl]

Hello,

 

I have trouble finding data of specific heat and thermal conductivity of cast iron at temperatures around 300-1000c.

Anyone here that could help out?

[Enthalpy]

Hi Soderdahl, nice to see you again!

 

You can take the heat capacity of pure iron for its alloys containing a few % other elements.

A polynom here http://webbook.nist.gov/cgi/cbook.cgi?ID=C7439896&Mask=2

A monography there http://www.nist.gov/data/PDFfiles/jpcrd298.pdf

For accuracy, distinguish between alpha and gamma iron and the transitions between them.

 

The heat conductivity differs a lot between pure elements and their alloys. I'll check if I have data.

[John Cuthber]

As far as I can see, the heat capacity of most metals shouldn't change much with temperature

https://en.wikipedia.org/wiki/Dulong%E2%80%93Petit_law

 

Th big problem there will be energy absorbed during phase transitions.

 

Thermal conductivity of metals typically correlates strongly with electrical conductivity.

You can probably find measurements of the electrical conductivity as a function of temperature- though to a fair approximation you can says that the resistivity is proportional to the absolute temperature.

 

Why do you wan to know?

[TransientResponse]

It could be useful if you knew "how do they response to temperature".

Moreover, you could make interpolations yourself: by using at least one value of low temperature, and one value of high temperature, for each material property.

However since phase changes are "singular" changes, if you want more correct values, you may need to make few interpolations for one property for different phase ranges. There should be few functions relating to different phases, for each property..

Edited May 8, 2016 by TransientResponse

[Enthalpy]

Found some data, but not at 1000°C up to now.

 

Metals Handbook. Properties and selection :
iron, steels and high performance alloys.
Vol. 1, ASM International, 10th ed 1990.

 

Depending on the C contents and the kind of cast iron, the heat conductivity drops like:

33 to 31W/m/K from 400K to 700K

39 to 37W/m/K from 400K to 700K

50 to 40W/m/K from 400K to 700K

more carbon conducts heat better, I didn't expect that.

 

Some more data, limited to 500°C more or less:

 

nvlpubs.nist.gov/nistpubs/jres/12/jresv12n4p441_A2b.pdf

 

Googlebook "ASM specialty handbook: cast irons" by Joseph R. Davis

 

Depending on the needed accuracy, you could take a good fraction of the thermal conductivity of elemental iron for cast iron at real heat. At room and cryo the alloying elements change everything, but at 1000°C they influence less.

[studiot]

Here you go, some data above 300C it rises dramatically.

 

If you are still interested I will look further.

 

 

 

[studiot]

Here is a graph of heat capacity up to 1600C, perhaps this is enough?