stresses induced by quenching

[19Delta]

I'm new to FEA but i am doing an analysis on stresses induced during heat treat quenching. I have been using a load on the entire volume of the part and have a temperature constraint on all the surfaces of the part. I adjust the load until i get the correct delta T. I'm not sure the temperature gradient is correct but the results seem to mirror reality. Is there a better way to apply heat to the part? I am using ProMechanica.

 

[ESPcomposites]

Curious, how would account for the relaxation that occurs in the days/weeks following? The difference is usually dramatic.

Brian

http://www.espcomposites.com

 

[19Delta]

sorry, i need to clarify. We are getting cracks from the quenching itself. From the thermal expansion and contraction of the quenching process. Delta T is 1650F.

 

[ESPcomposites]

Well that is interesting. Aside from the FEA, why not just test at different temperatures? Wouldn't that be easier than FEA?

The cracking is related to fracture mechanics. Do you have internal voids or something to determine its effect? A simple stress result may not be meaningful. In other words, you could have two same residual stresses and one material would crack while another would not. How would you tell the difference in your model? A simple yield criterion is not going to cut it. I am asking this because if you are new to FEA, you may not be sure of the difference.

From a practical side, if you are getting cracks, why not change the material/alloy?

Brian

http://www.espcomposites.com

 

[mechfeeney]

This problem is quite difficult FEA/CFD problem. I've been doing FEA for a while, but have no experience with this. I did a little reading... take a look

http://www.scribd.com/doc/40243285/CFD-and-FEA-Used-to-Improve-the-Quenching-Process-2008