Corrosion resistance of 316L SS vs 304 SS 1

[RonHRob]

I am working on a pharmaceutical project involving some machined and some formed and welded parts. I am wondering if I need to bear the expense of the 316L or can I manage with the 304. The environment is mostly dry, but is exposed to cleaners (isopropyl alcohol, and mild bleach solutions).

Any thoughts or comments would be appreciated.

Thanks, Ron.

 

[mcguire]

The agressiveness of the environment you cite depends largely on whether the bleach is chlorinated. But you also have some other aggravating factors, welding, residual stress, sulfur(for welding and machining). I think you question defies a simple answer and you would be well advised to get some expert advice if the application is significant.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[unclesyd]

I though this was posted yesterday must have been another senior moment.

You should go with 316 SS preferably the L grade. You should get the best finish that you can. The smoother the better. Shinny is even better.

You need to design the equipment with the very minimum of nooks and crannies as you probably know.

 

[mcguire]

Following unclesyd's suggestion, consider electropolishing for optimal surface finish.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[greg87]

I agree with previous to use 316L. The cost difference is minor, overall. Not clear from your question if these parts are in contact with product/process, or external. If in contact, product quality drives material and finish, and may require some degree of polish. Electropolish would only be used for demanding applications. If external, only a minor amount of polish is used.

 

[mthakur]

i agree with Gerg87 to use 316L as the cost difference is small. Besides being better corrosion resistant, 316L is also better protected against intergrannular corrosion due to cabide precipitation, as you have welded parts too.

 

[EdStainless]

There is a lot of 304L used in dry gas/air lines. Is this a waste/drain line? If so then 304L isn't a good idea. It may have various mixtures of stuff sitting in it. Without a rinse and dry system in place 304L is risky.
Use the 316L with a mechanical polish. It wil linstall fine and be easy to keep clean.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

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