316 with Cu content? material identification help
316 with Cu content? material identification help
(OP)
We recently received parts with a 316 spec that had the following composition:
Element
C 0.03
Mn 0.91
Si 0.30
P 0.018
S 0.001
Cr 17.0
Ni 10.9
Mo 2.09
Cu 3.22
They were supposed to be 316 - anyone have an idea if this is a similar grade (parts from China) or what we can expect from this material. Seawater corrosion is our main concern (continual submersion - not sealing surfaces)
thanks
Ron
Element
C 0.03
Mn 0.91
Si 0.30
P 0.018
S 0.001
Cr 17.0
Ni 10.9
Mo 2.09
Cu 3.22
They were supposed to be 316 - anyone have an idea if this is a similar grade (parts from China) or what we can expect from this material. Seawater corrosion is our main concern (continual submersion - not sealing surfaces)
thanks
Ron





RE: 316 with Cu content? material identification help
This looks like a bad heat of steel. The high copper could be from a heat that was intended to be 17-4 PH stainless steel. Either way, I would reject it, period.
RE: 316 with Cu content? material identification help
Chocolates,men,coffee: are somethings liked better rich!!
(noticed in a coffee shop)
RE: 316 with Cu content? material identification help
RE: 316 with Cu content? material identification help
Probably if it is a casting,then my guess is that the lining of the melting furnace must have contributed to copper pickup from a previous campaign of copper casting!
Chocolates,men,coffee: are somethings liked better rich!!
(noticed in a coffee shop)
RE: 316 with Cu content? material identification help
RE: 316 with Cu content? material identification help
I couldn't cross this composition with any grade either.
Ron
RE: 316 with Cu content? material identification help
I can't see why a copper addition would decrease the pitting resistance (which is why I think you want 316 in a seawater environment?) of the 316, but can't find any data to prove it, either.
RE: 316 with Cu content? material identification help
The manufacturer is saying they are meeting an ISO 3506-1979 which stipulates that the material can deviate from the chemical composition as long as the manufacture can guarantee "the required physical and mechanical properties" and "an equivalent corrosion resistance"
Defining the first item is fairly straight-forward, the second is almost per application so its much harder to define. Does anyone have any insight on this standard or its acceptance in industry?
RE: 316 with Cu content? material identification help
Grade A2 allows up to 4 % Cu. It doesn't specify a Mo concentration, but it allows Mo at the descretion of the manufacturer.
Regards,
Cory
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: 316 with Cu content? material identification help
I would ask the supplier for specific corrosion test information to support with this level of copper content in lieu of any guarantee before I would accept for use.
RE: 316 with Cu content? material identification help
The print specified the grade of material (316) but no particular standard was on the print (ie - it was not listed as ASTM or AISI 316). The ISO standard cross references to the AISI or ANSI standard but via breaking them down as grade A1, A2, A4 much more generically. We did not specify a ISO grade A4 material as the shop delivered (and are claiming is equivalent)
RE: 316 with Cu content? material identification help
I've not typically found that crossing standards is acceptable unless its stated specifically on the print. I'm not an expert in the field of metallurgy so I'm wondering if we should expect that specifying 316 will open us up to comparable grades without our prior consent. To me thats poor practice but that may be the recognized standard in other disciplines. thoughts?
again - thanks for the help!
RE: 316 with Cu content? material identification help
Perhaps time for you to have a rethink on the supply source .
Chocolates,men,coffee: are somethings liked better rich!!
(noticed in a coffee shop)
RE: 316 with Cu content? material identification help