heating 1080 steel
heating 1080 steel
(OP)
We are arc welding the entire inside of a 1080 steel cyclinder, 9 1/2" ID 3/4" wall thickness by about 9". We are worried about deforming the outside of this wall as this will be used as a mold and don't want failure at high pressures. Hooking a thermocouple to the outside of this mold, what temperature should I be worried about the 1080 steel's physical properties?





RE: heating 1080 steel
To what degree - I don't know or whether that will affect your final mold.
You might have to re-machine the OD to get the accuracy you want or need.
Try one.
RE: heating 1080 steel
RE: heating 1080 steel
Since you haven't mentioned how the part was previously heat treated it seems likely that you don't know.
But after you weld the entire ID, certainly it will have very different properties than it did before you started welding.
RE: heating 1080 steel
It is highly unlikely that you will get any membrane distortion, we're talking about a 3/4 inch wall! What is highly important is to have the proper pre-heat, in order to get the proper weld penetration into the alloy sub matrix, followed by a controlled post heat back to ambient. So you slow down the cooling rate in order to mitigate thermal residual stressing.
Note that by the code, 3/4 inch wall and greater need to be HTSR. I believe this also applies to weld repair. Memory is foggy, but I'm pretty sure that applies.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: heating 1080 steel
I agree with MintJulep on the issue. Even if you have a good procedure you may still experience cracks during/after welding.
If you are trying to put a thin deposit layer, sometimes metal spraying under controlled atmosphere is cheaper and better.
Sometimes, it is better to make a new one instead of repairing for certain type materials, or replace the welding with a liner suitable for the operation.
These may not be the answers what you are looking for, but it is better to mention.
RE: heating 1080 steel