solution annealing of 304 Stainless Steel
solution annealing of 304 Stainless Steel
(OP)
Our vendor is planning to use liquid Nitrogen (in lieu of water) as the cooling method for the solution annealing of ASTM A240-304 Stainless steel cold formed head (2 heads). The head thicknesses are 49mm and 85mm.
Can we use liquid nitrogen as the cooling media?
Can we use liquid nitrogen as the cooling media?





RE: solution annealing of 304 Stainless Steel
What diameter are the stainless heads? There is nothing to prohibit you from using liquid nitrogen as a cooling medium. This seems a little drastic to me, and I would be concerned about safety.
Why wasn't a water quench considered?
RE: solution annealing of 304 Stainless Steel
The vendor originally proposed to use water. I do no know the reason for the change.
the diameters are 2400mm (49 mm thick) and 4200mm (85 mm).
Do you mean it is techinically ok to use liquid nitrogen? is it possible to induce cracksof the 304 head during the cooling?
RE: solution annealing of 304 Stainless Steel
RE: solution annealing of 304 Stainless Steel
Small componnts,finish machined etc where value addition is very high one can consider exotic quenching methods,else stick to the basic practices.
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RE: solution annealing of 304 Stainless Steel
Thanks.
What kind of saty issues? Could you give me some examples?
RE: solution annealing of 304 Stainless Steel
Another safety issue is evaporation of LN2 can cause low oxygen conditions. The room will need to be appropriate for air flow, etc.
Regards,
Cory
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RE: solution annealing of 304 Stainless Steel
LN is a very poor quench. The cooling rates would be significantly slower than in water. The LN boils on the surface of the part and you end up with the part blanketed in nitrogen gas.
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Plymouth Tube
RE: solution annealing of 304 Stainless Steel
It would be much more likely that they are considering using a furnace that does not have water quenching capability (as in a vacuum furance) and are trying to back-flush with gaseous nitrogen for a quench. If so, you need to inquire about the cooling rates. I'm not sure what cooling rate is needed (some others may have better knowledge), but if they can meet the needed cooling rate, there is no reason it would not work. If they can't, you won't get a good solution anneal.
rp
RE: solution annealing of 304 Stainless Steel
RE: solution annealing of 304 Stainless Steel
rmw
RE: solution annealing of 304 Stainless Steel