Please identify this material. 2

[BRMW]

The chemistry is as follows:
Carbon 0.05
Sulfur 0.004
Silicon 0.08
Manganese 0.10
Iron 19.3
Chromium 21.5
Molybdenum 2.79
Copper 0.01
Aluminum 0.25
Titanium 3.53
Cobalt 12.7
Nickel Matrix

The chemistry is of a 1.5" stud from a large turbine case.

Any help would be greatly appreciated.

 

[EdStainless]

How did you get this chemistry?
A couple of things look very odd.
It looks like a maraging alloy, but the ratios don't fit allys that I know off hand.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[metengr]

If this stud was removed from a high pressure steam turbine or gas turbine inner shell it could be one of the Udimet alloys (nickel base)710 or 720.

 

[BRMW]

We obtained the chemistry by performing a spark emission spectroscopy on the stud. Also a hardness survey was done and came out a 31 HRC. The stud was removed onsite and sent in by the customer. They need 100 manufactured but don't have any material specs on the stud.

 

[BRMW]

One more thing, when the testing laboratory ran the spectroscopy, their database came back with a "close" match of waspaloy. Now the chemistry on waspaloy looks very close to this except the iron. Waspaloy has 2% max iron and as you can see my unknown has 19.3.

Again any help is appreciated.

 

[metengr]

What is the turbine casing - steam or gas? What is the operating temperature?

 

[EdStainless]

Yes, there is an entire family of Ni based alloys that are close, but....
The Fe, Al and Ti are out of wack. (I don't trust the Co either)
What about W, Ta and Nb?
Only 31RC? That sounds low for an aged Ni based alloy.

You need to have some one with better ref standards run another chemistry.
When was this manufactured? By whom? Where?

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[BRMW]

It is a steam turbine but I don't know the operating temperature. But I would assume 1,000°F to 1,200°F.

 

[BRMW]

Yes I agree that some of the numbers don't seem right, however, this stud has been in operation for some 10 - 15 years. Now I'm not sure if that many years of operation at that temp. could change the chemistry or the harness. Yall would know better than me.

But if we knew when, who, and where this stud was manufactured...I wouldn't be here asking for help.

 

[SMF1964]

Nickel alloy 925?

 

[BRMW]

If you are referring to incoloy 925, the cobalt content rules the incoloy out. Incoloy was my first guess also until the I saw the cobalt at 12.7%.

 

[SMF1964]

Have you contacted the turbine manufacturer? They generally have 'proprietary grades' that they use. I've got a GE alloy B50A445, 19Cr-10Mo-10Co-1Al-2.5Ti that is 'closer' (it's got the cobalt but now doesn't have nickel), but my listing is many decades old and there may be 'improvements'.

 

[btrueblood]

Looks more like Rene 41, except the iron, as unclesyd said, is a bit high among other things.

As far as the cobalt content, a lot of older alloys specify (or may have once specified?) a combined Co+Ni content (Inconel 600 and 625 for instance; and my circa 1980's Huntington alloys reference card shows this for all of the inconel/Huntington alloys), since these metals were/are difficult to seperate. If the cobalt content was ignored, would you be able to identify the alloy?

 

[BRMW]

If not for the cobalt I would identify it as a incoloy 925 as SMF1964 said or incoloy 825. Also some of the inconel alloys come very close, but lack the iron.

But as this project is getting close to start we are leaning towards the waspaloy, the only problem with the waspaloy is the lack of iron. Waspaloy is a 2% max iron while ours has 19.3%.

As stated above we are definitely thinking this is the turbine manufacturer's properitary alloy and will be unable to duplicate and will end up paying the $45/# of waspaloy .. ouch!

 

[metengr]

Why use this current bolting material? If this is a steam turbine, the operating temperature would probably be between 1000-1070 deg F for HP steam. GE or W would have typically specified an AISI Type 422 stainless steel stud, A 286 material or Refractaloy 26. I have seen GE recommend 19-9 DL however for temperature at or above 1050 deg F, this material was replaced with A 286.

 

[BRMW]

Well the client asked for the exact material if possible so thats what we're trying for. I mean its held up for 15 yrs., why go and change it now.

But I think your right on track with the refractaloy. I had forgot we use to drill out the studs on turbine decks and the material of the studs then was refractaloy. After pulling an old job and finding the chemistry on those studs..see below

Carbon 0.02
Sulfur 0.002
Silicon 0.10
Manganese 0.11
Iron 27.1
Chromium 20.0
Moly 3.62
Copper 0.01
Aluminum 0.06
Titanium 2.90
Cobalt 13.2
Nickel Matrix

I think this is it.

Thank yall so much for the help!

 

[TVP]

I am not familiar with Refractaloy 26. Anyone care to provide a brief summary for the uninitiated?

 

[metengr]

TVP;
Refractaloy 26 is a superalloy developed and used by Westinghouse (W) for gas and steam turbine bolting. It was commonly used thru the 1960’s and 1970's by W. The typical operating temperature range for this alloy is 1050 deg F up to 1250 deg F. It is a nickel-base alloy that is solution treated at 1950 deg F, oil quenched and aged at 1500 deg F for 4 hours.

 

[TVP]

metengr,

Thanks for the 411.

 

[49078]

It may be too late to help, but I know matweb has a search where you enter alloying compositions, and it supposedly gives you the alloys that are closest to this criteria. I have never used it, but ran across it the day.

Cheers