Quenching of CF* Casting
Quenching of CF* Casting
(OP)
I have a 1000lb CF8 casting that is fairly complex in shape with sections ranging from 0.3" up to about 3". It has undergone weld repair so solution annealing is called for by ASTM A351.
The question is whether to 'rapid air quench' the part rather than water quench. I am wary of this suggestion, due to too slow and non-symmetrical cooling, leading to other types of distortion. Also because of the wide range in sections thickness. It is a pressure part that will see chlorides in service.
Any thoughts/experiences on this?
The question is whether to 'rapid air quench' the part rather than water quench. I am wary of this suggestion, due to too slow and non-symmetrical cooling, leading to other types of distortion. Also because of the wide range in sections thickness. It is a pressure part that will see chlorides in service.
Any thoughts/experiences on this?





RE: Quenching of CF* Casting
RE: Quenching of CF* Casting
RE: Quenching of CF* Casting
It just seems like an air fan, even a high powered one, won't do the job adequately for this part.
RE: Quenching of CF* Casting
Good,then you can take the splash! No issues.
RE: Quenching of CF* Casting
I will recommend the customer $pend$ a little more :)
Thanks to all.
RE: Quenching of CF* Casting
Why??? You have up to 3" in thickness in some locations. I would re-think this position very carefully for cast austenitic stainless steel.
RE: Quenching of CF* Casting
RE: Quenching of CF* Casting
Well said, from an expert on castings.
RE: Quenching of CF* Casting
See picture attached - the outer ring is more massive than I recalled, while the middle cone gets fairly thin.
This kind of heat treatment is outside my normal range as a welding engineer, and I don't want to make this piece an expensive data point in my experience ;)
RE: Quenching of CF* Casting
Finally,as you mentioned that you do not desire to make this an expensive experience. You are right in expressing your concern. Request you to take assistance of an independent consultant,.
RE: Quenching of CF* Casting
The flanged nozzles are probably the least of my concerns, as they are free to move. The flange face location is not critical, as the feed piping is somewhat flexible (I would assume).
I have already decide to defer to the specialist's expertise. As it turns out, nobody here in town does anything other than stress relief of welds and are not even equipped for simple water quenching.
RE: Quenching of CF* Casting
RE: Quenching of CF* Casting
I would be a hesitant to reheat treat a machined part.
RE: Quenching of CF* Casting
One way to get better cooling rates with air is to use a low thermal mass furnace similar to these at Pinson Valley Heat Treatment. Look at he two pdfs and in the standard pdf you can see something similar to a pump casing being cooled and there is no background radiation. The stress relief pdf shows one way to do this build the furnace around the part.
http://www.pvht.com/home.asp
http://www.pvht.com/flyers/Standard.pdf
http://www.pvht.com/flyers/StressRelief.pdf
RE: Quenching of CF* Casting
If you are below 0.045% then you can use rapid air cooling.
Higher than that then you need to water quench.
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Plymouth Tube
RE: Quenching of CF* Casting
From the tone of your posts, I would guess that you are the material manufacturer/foundry. Is that correct? I am just guessing here, but if you were, you would probably be solution annealing/water quenching daily. If you are not the foundry, you are not responsible to manufacture the part to ASTM A351. There are no rules that require solution annealing by fabricators or repairers of castings once the material has already been certified to ASTM A351 by the original foundry.
Also, from the pictures, it appears that the part has welded on flanges in addition to any repairs you may have made. In this case, if solution annealing is required, you have to make sure all welding procedures used, including repair, fabrication, or possibly repair at the original foundry are qualified for this sort of heat treatment.