Thermal conductance in Steel .vs. Powdered Metal

[KirbyT]

I am using induction heating to heat a ring gear. I know the dimensions of the ring gear, and the temperature that I want to achieve throughout the ring gear to expand it a certain amount. Is there a formula that will tell me how long to heat the ring gear to achieve this temperature throughout the gear?

 

[johnp]

There are no instant answers.

Basically you can start at the definition of a British Thermal Unit - and see how much heat you need to raise the steel mass by so many degrees.

But you also have to look at any heat leakage paths, which may reduce the efficiency of the operation.

What is the heat transfer rate into the metal. You may get a hot surface, but it will take some time to get it into the core.

One way to address the problem is to take a sample to a laboratory to give you some basic heat transfer data.

Johnp.Rz

http://www.mets.net.au

 

[chicopee]

you are better off to use these temperature sensitive "wax" sticks that welders and fabrication shop use when an elevated temperature is sought out for pre heating and welding purposes instead of relying on formulae.