17-4 Welding recommendations 1

[DVWE]

I have a piece of tubing in which a solid clevis shaft will slip fit into. The wall thickness of the tubing is 1.5", and I require a full penetration weld to connect the clevis to. I believe that both pieces are in the annealed condition. The finished part requires the properties of H1150 - 135 ksi minimum tensile and 105 minimum yield.

My question is, since the finished part is long, heat treating it may not be an option, so what are the properties of this material in the annealed condition? I have found some literature that suggests it may be close to that of the H1150 condition, is this correct? I'm not having much luck finding information as far as mechanical properties on the 630 filler metal that I would like to use, so any information would be helpful. Are there any other concerns leaving this material in the as welded condition? Service temperatures should not exceed 400 F.

Thanks in advance.

 

[Neubaten]

PH steels should not be used in the annealed condition.

 

[metengr]

DVWE
You need to know the actual heat treatment condition of the 17-4 PH, assuming it is annealed is not good enough. Go to this web site for information regarding 17-4 pH material and heat treatments;

http://www.aksteel.com/markets_products/stainless.aspx

Re;Welding
The 17-4 PH filler metal responds similar to the BM composition. The weld deposit can be left in the as-welded condition or subject to thermal treatment.

 

[DABwilldo]

Carpenter has some good reference info on 17-4PH. see here.

http://www.cartech.com/techcenter.aspx?id=1692

Neubaten makes a good point. 17-4PH should not be placed in service in the annealed condition. The annealed microstructure is vunerable to stress corrosion cracking.

Here is some data on mechanical properties for the annealed state:

http://www.matweb.com/search/DataSheet.aspx?MatGUID=d3029183533b4e5fa7df551ae4015394

I can't speak for how accurate it is.

 

[DVWE]

All -

Thank you for your input. I have the MTRs of the materials in my hands now, and both are in the H1150 condition.

If I leave this part in the as welded condition, what are the concerns? The weld is not truly solution annealed, and it is not aged. I have been told if absolutely necessary, the part could be re-aged at 1150 F, but the solution anneal at 1900+ is out of the question.

My plan at this point is to prepare two test coupons, one aged and one not. Would impact testing of the HAZ be in order here? I have concerns about loss of toughness for the as welded coupon.

 

[metengr]

DVWE;
I would perform a second H1150 treatment of the BM and weld to improve the ductility of the as-deposited weld metal. I also agree with impact testing.

 

[DVWE]

metengr -

Thank you very much for your input. My coupon thicknesses will be 1.5" to try to match as close as possible to what we're doing in production. I believe the re-aged coupon should be done at 1150 F for 4 hours. Is that correct?

 

[metengr]

Yes, based on literature that I have reviewed.

 

[MikeMet]

Maybe late to the discussion, but we have been welding 17-4PH sst in your thickness for years and have done both the 1150 heat treatment for 4 hrs on the welded structure and done a full solution anneal and aging treatent after welding. Both have worked. It should be noted that ASME requires a full solution anneal and aging treatment after welding. This is due to non-homogeneous properties that can be present due to thermal gradient away from the area heat treated. You need to take this into consideration.

 

[DVWE]

MikeMet,

How much distortion did you experience with the full solution anneal and aging treatent after welding?

 

[MikeMet]

DVWE
Sorry have not looked at the post in a while. We get some minor movement if we do a full solution anneal and aging heat treatment. However, it is not so much that we can not move back into place with a little cold work.