Can anyone identify this material?

[nash0427]

hi Folks,

I'm trying to identify this stainless steel alloy. It's extremely tough to machine:
The spectroscope says so:

Fe: 73.10
Cr: 13.19
Ni: 9.79
Mn: 1.93
Mo: 0.88
V : 0.36
Si: 0.28
Cu: 0.27
Co: 0.10

Any help will be highly appreciated!

Thanks,
N

 

[Maui]

What is the spec for the carbon content supposed to be?

 

[EdStainless]

Is it difficult to machine because it is hard, or because it is soft and is smearing instead of cutting?
I could either be an austenitic stainless (soft and gummy) or a PH stainless (hard).
Sounds like you need to call your tooling supplier.

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P.E. Metallurgy, Plymouth Tube

 

[nash0427]

About carbon content, I'm just guessing, it cannot be higher than 0.1% since if you add all the contents it sums to 99.9

Machinability, it has broken the inserts which are specially made for 304 at just 80m/min Vc. Those inserts go at 200m/min in 304. Its gummy but extremely tough. The inserts get chewed up as if they were a grain of dried terracotta, not tungsten carbide! I've had visits from seco, jongen and emuge-franken, no one could figure it out. The machine and fixturing is extremely rigid. It gets cut cleanly at 38m/min Vc.

The work is over but I want to identify the commercial name of this alloy. It is not listed in the database of the spectroscopic gun which gave it's composition above.

Bstrgds,
N

Ph.D., Aerospace Engineering.

 

[metengr]

Send a sample of the material to a metallurgical lab for a complete chemical analysis. It should cost less than $200.

 

[EdStainless]

What is the hardness?
The alloy is only half of the issue, you need to know condition also.

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P.E. Metallurgy, Plymouth Tube

 

[nash0427]

@metengr the spectroscopic gun is extremely accurate (and is calibrated) in identifying the chemical composition which I've listed in the first post. If you know the commercial name, feel free to chime in with your gems of knowledge. Thank you!

@EdStainless
I don't have the hardness of the material and no more material remaining, other than chips from machining. At this moment the hardness does not interest me much since the 20 or so parts have been made and are in the hands of the customer. If this job comes to us again, we'll do a hardness test. But I'm more interested in the type of steel it is, so that we don't break expensive inserts and tools. Someone told me that this could be 17-4PH, but this has Vanadium as well as a generous amount of Ni, which is not in 17-4PH. The issue is that all aerospace parts come with a detailed spec sheet of each raw block, this one was not an aerospace part and the paperwork didn't have any details of the material except: X5CrNi18-10 (aust. 304) written on the drawing. It is clearly not 304 from both the spectroscopic analysis as well as the way it ate up the 304 specific inserts. If you have an idea of the material, that's great but if not, I've got the message around my networks and someone should chime in.

 

[arunmrao]

nash0427

I presume the spectroscopic gun you are referring to is PMI using XRF principle . It certainly has certain limitations in identifying carbon, phosphorous,silicon, nitrogen and sulphur.

On a first step basis I regularly use it but follow with OES results.

As suggested please submit your sample for complete analysis using OES. This would clear several ambiguities.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[EdStainless]

Sorry, but I don't trust your gun numbers.
How did you prep the surface? The same as your standards? Do your standards contain all of those elements, in those amounts roughly?
Was this a 3-4 minute analysis?
No, guns are for type verification, not analysis of unknown alloys.
Is there any Al or Ti or B?
Get a real analysis.
There are some PH variants that are similar to this, but if they had been aged they would have been over RC40 and not sticky.
This looks like a modified 300 alloy, until we know more.


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P.E. Metallurgy, Plymouth Tube

 

[Chumpes]

what are the mechanical properties ?