Unknown material

[bruv]

Can anybody tell me the alloy designation for the following composition? It came from the wear ring on an impeller.
C 0.05%
Si 0.4%
Mn 0.8%
Ni 5.2%
Cr 13.5%
Mo 1.4%
Nb 0.25%
Cu 1.7%
Fe balance

Thanks

 

[NickE]

How hard is this metal?

the chemistry you give is funny, I would like to say PH13-8Mo, but the Cr and Mn are high, while the Ni and Mo are low...

As mcguire explained to me a few years ago chem. analysis of SS is not quite as easy as carbon steels... Is this an arc&spark (OE spectro) analysis? You might want to try a few burns to see if the values for the elements move around much.

nick

 

[metengr]

I have seen pump impellers and impeller wear rings manufactured from CA 6NM material (410 NiMo). My guess is that the wear ring will be hardened for this application.

 

[NickE]

metengr-
I also thought a 4xx series SS, but the the carbon content and the Nickel are way off for any of the ones in my GEM.

I just looked into my ASM desk reference pg 15.3 and found:

s45000 Custom450 (xm-25)

C: 0.05
Mn: 1.00
Si: 1.00
Cr: 14.0-16.0
Ni: 5.0-7.0
Cu: 1.25-1.75
Mo: 0.5-1.0
Nb: 8x%Cmin

Not exactly what youve given but is rather close. The Cu, Ni and Cr are close.....

(this is A PH alloy also)

I do agree w/ metengr this is probably a hardened alloy for wear resistance.....

nick

 

[unclesyd]

Here is the analysis for Carpenter Custom 450. There are several alloys in this family Custom 630, 15-5Ni, Pyromet 350, and Pyromet 355.

http://www.cartech.com

Custom 450
Carbon (Maximum)
0.050%

Manganese (Maximum)
1.0 %

Phosphorus (Maximum)
0.0300%

Sulfur(Maximum)
0.0300%

Silicon (Maximum)
1.0%

Chromium
14.0 TO 16.0%

Nickel
5.00 to 7.00%

Molybdenum
0.50 to 1.0%

Copper
1.3 to1.8%

Columbium/Niobium
8 X C Minimum

Iron
Balance

 

[bruv]

Nick E

Analysis is consistent around the part, done wih OES. Hardness is 33-35HRC

 

[metengr]

bruv;
Based on information provided Nick E and unclesyd and your reported hardness, the alloy is probably a Custom 450 ss (UNS S4500), age-hardened (H1050).