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Join Date: Dec 2008
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Making Stainless Steel Chemically-Neutral

12/11/2008 11:44 PM

Which process we can do on the Stainless Steel to make it chemically neutral for boi medical purpose?

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Guru
Hobbies - DIY Welding - New Member

Join Date: Sep 2007
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#1

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 7:34 AM

Carpenter Steel makes some stainless steel alloys that are claimed to be bio-compatible in some applications. The materials that are commonly used in implant applications are Titanium, Platinum, and perhaps Gold. However, although rare, certain pepole can have allergic reactions to even the most bio-compatible metals.

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Join Date: Dec 2006
Location: Germany 49° 26' N, 7° 46' O
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#2

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 8:29 AM

Hi,

what is "inert" ?

There are Fe, Ni and Cr on the surface, Cr oxidised, Fe, Ni leached?

If you have to stay with stainless steel you have to test if your process is suiting the material or reverse.

Electropolishing and then anodising will make it better but not ideal-

Why not stay with plastics (PE, PP, PFE,...), glass, quartz-glass, sapphire, Ti?

RHABE

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#3

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 9:52 AM

Check out electropolishing and passivating.

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#4

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 10:07 AM

Why not make it Kosher while your at it?

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#5

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 5:14 PM

It depends what you mean by bio {boi???} medical purpose.

If you mean for surgical tools, passivation and or electropolishing should suffice. I don't mind sharing that.

If you mean for human implantable devices, there is no way that you should be consulting "engineers of record" over the internet on an open forum.

Nor would any qualified professionals give you a prescription by such means.

You should do your own research and clinical trials on this.

Since research to you seems to be internet, please google, "ASTM Implantables." ASTM F1813,2129 and 2180 come to mind. If your budget actually permits the purchase of books, you should have this:

http://measurementmedia.com/index.php?name=News&file=article&sid=881

In the interest of protecting people, I would urge my fellow CR4 members to not provide freelance consulting of a prescriptive nature on medical practices where the advice may actually be responsible for some critical aspect of the care. Especially when the questions are vague about actual application, Or materials- 303 is stainless. Should this ever be used for a bio medical application? Unless its your field.

My opinion. I'll take the flame. Its better than some kid dying because somebody decided to use UNS 30300 for a surgical staple, catheter tip, bone screw or orthopedic device. Cause it machines well. And the nice engineers on the internet at CR4 told them its ok as long as they just passivate it.

milo

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#6
In reply to #5

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 5:33 PM

Well spoken, Milo!

What makes the situation worse than imaginable:

any metal is containing more than enough wanted and unwanted other alloying elements or impurities.

These may or may not corrode and/or trigger allergies.

This will differ from one person to the next.

Allergic reactions are amplified 106 to above 109-fold from ordinary toxicity.

RHABE

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#7
In reply to #6

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 5:51 PM

Yep, and variation between suppliers, and suppliers processes...

milo

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#8
In reply to #5

Re: Making Stainless Steel Chemically-Neutral

12/13/2008 8:35 PM

...and another GA to you! I must confess I didn't really think about the possible ramifications before I put my 2ยข in...

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Users who posted comments:

Anonymous Poster (1); dkwarner (2); Milo (2); RHABE (2); welderman (1)

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