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testing for 303 ss 1

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berkshire

New member
Jun 8, 2005
4,429
I am looking for a quick test for 303 SS.
I know about sulphuric acid and photo paper.
I wondered if there was anything more convenient than that.
I bought a piece of "304" round bar. I am just getting a little suspicious ( or paranoid.) because of the way it is turning on the lathe.
B.E.
 
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A lab test we used for many years was to immerse the suspected piece in warm HCl for a few minutes. If the material was 303 it would be coated with a heavy black smut while a known piece of 304 would not be covered with smut. You will also get whiff of rotten eggs.
Do not try to smell the container the HCl is in.

I'm trying to remember whether the HCl was concentrated or a 50/50 mixture with water. We should get some help from some others on this.

This has to done in fume hood or outside.

There are some materials like Project 70 that machine very well in a lathe. Even though 303 is listed the other materials machine quite well.

 
unclesyd (Materials)
I will try the HCI test on Monday when I go back to work.
The thing that is driving my suspicion, is that this material is turning a lot better than I thought 304 or 304L should.
B.E.
 
If you've finish machined the part, use 25-45 vol% nitric acid (passivation Type VI per QQ-P-35C; Nitric 2 per ASTM A967). This won't etch 304 as HCl will, and on 303 will produce bubbles & H2S smell.
Be sure to degrease the SS before putting into nitric.
 
kenvlach (Materials)
I have not finish turned the part yet. I took a roughing cut, and as I mentioned to Unclesyd It was turning far better than I am used to seeing on 304.
I do not have Nitric in house. I have Phosphoric, Hydrochloric and Sulphuric.
The other thing that is driving this paranoia is that the finished part has to be welded to another 304 part.
 
Does anyone know if the Te or Se versions of 303 will respond to the sulfur print test? If not, you could come to an erroneous conclusion about 303 vs 304. If this is a critical application, I think I would just pay the $50 or $60 and get a spectro run.
 
Swall it is tested for 4$ in India. I can be in very good business if I could get this price.

I was actually wondering if berkshire has 202 in his hands for a long time. Hence I posted a general discussion on 200 series stainless steel.
 
Berkshire, There is also the Outokumpu Prodec. This material meets standard chemistries and machines very well. You might have just gotten some good material.
If it were me, I would check chemistry also.

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Thanks for the help guys,
I will do a sulphur check today, I guess the other thing I can do is take a sample and weld it and see if I get hot shortening.
If I do not get a clear answer I will go back and buy more material with certs The first piece came without certs.
B.E.
 
Well guys,
I did unclesyd's Acid test today, no smutting, no rotten egg smell. The only unusual thing I noticed was that the Hcl turned pale green. I also did the Sulphuric acid/ photo paper test, no indication of sulphur.
I also cut off a small piece and welded it to a piece of 304L then folded the piece 90 degrees one way then back to straight with no cracking at the weld joint.
Whatever this is I like it. Again thank you for the help.

Arunmrao
Isn't type 202 17-4 type stainless?
B.E.
 
202 or 17/4 PH are certainly stainless steels. But today we observe a lot of mixing (deliberate) by traders dealing in 304 .

 
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