Home /
Search 🔍
the Site

Chime right in! (no registration req'd)


"Stainless Steel - 316 vs. 317"


Q. On Galvanic Series charts I always see stainless steels 316 and 317 listed next to each other (in both the passive and active forms). Does this imply that SS 316 and SS 317 would experience zero galvanic corrosion if placed together? For instance, if I have a plate heat exchanger with a SS 316 frame, could I use SS 317 plates without experiencing galvanic corrosion between the plates and the frame?

Bibiana Agostini
- Tarrytown, New York


A. Yes, indeed! Any of the austenitic stainless steels can be placed in contact, with seawater as the electrolyte, and the design would be acceptable per Mil-STD-889 [affil. link to spec at Techstreet], the standard the aerospace industry uses.

lee gearhart
Lee Gearhart
metallurgist - E. Aurora, New York

317L/316L vs. 304L


Q. Would 316L or 317L grade stainless be a good option instead of 304L for resistance to chloride solutions (pH<5) at room temperature to prevent pinhole corrosion?

Susan Lloyd
- Raleigh, North Carolina


A. In general, 316L will always offer better pitting/crevice corrosion resistance than 304L. This is due to the addition of 2-3% molybdenum. Chromium, Nickel and Molybdenum contents are slightly higher in the 317L in comparison to 316L and as a result will provide significantly higher resistance to pitting and crevice corrosion at ambient temperatures.

In answer to your question, yes 316L/317L will provide better pitting (pinhole) corrosion resistance but at an increased cost.

M Hogan
- Australia

Is SS-317 much harder than SS-316?


Q. Hi,
I am a young instrument engineer in a pulp & paper plant in China.
We are now at the stage of selecting some analyzers for measuring consistency of the medium consistency pulp.
There are options for the material used, i.e., SS-316 and SS-317. Shall I choose 317 instead of 316 due to the hardness of 317 which is higher than 316?
I would be very happy of any feedback I receive and some guidance from my seniors at this field.
Thanking you guys in advance.

Eddy YS
Engineer - Guangxi, Qinzhou, China

316L isn't resisting sea water. Will 317L?

July 28, 2008

Q. I am using SS316 L pipes for sea water application which is at elevated temp of 40 degree. I face lot of problems of pipe puncture, whether SS317L will solve this problem?

Salinity of sea water is more than 20000 ppm, chloride contain is also more. Kindly suggest whether SS317L can give corrosion resistance properties.

Girish Bidikar
- Dahanu, Maharashtra & India

July 31, 2008

A. The best that 317L will do, is to take a little longer before it fails the same way that 316L fails.

You need to use 2205 stainless for such an application.

Bill Reynolds
Bill Reynolds [dec.]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.


August 1, 2008

A. There is a new Duplex Steel called YST 130N by Yokota. It has much higher chromium content of about 26% than regular S.S 316L which should take care of your problem. This steel is made specifically for uses like yours.

Kiran Patel
- Mumbai, INDIA

February 8, 2009

Q. Dear Sirs,
Seasons greeting!
I would like to know 316L stainless plate (about thickness 0.6mm) or pipe be used for water which contains 530 ppm chloride, is any temp. and corrosion rate property to reference?

Best Regards,

Linda Wang
importer, international trading company - Taipei, Taiwan

Is 317 more corrosion resistant than 316?


Q. In our plant, we deal with a corrosive fatty acid liquid. In the early days of the plant, the pipe specs for this material called for 316 stainless steel but now it calls for 317 stainless steel. However, 317 SS is found to be quite a bit more expensive for some reason. My question is, can it be proven that 316 SS is just as corrosion resistant as 317 SS or is the premium price paid for 317 SS for a good reason.

Rick Wanner
Akzo Nobel - Saskatoon, Saskatchewan, Canada

February 20, 2013

A. By calculating the PREN number (Pitting Equivalent Number with Nitrogen) you can see that 317 is something around 20% more resistant to pitting corrosion (24 for 316 versus 29 for 317).

Yes, it is valuable.

Nico Leve
- Montreal, Quebec, Canada

Substitute 316 for 317 in gasoil refinery?

August 9, 2014

Q. In a refinery process, it's requested to use 317 for gasoil with H2S and coke particulate (about 150 ppm of 3000 um).

Can I use 316 in lieu of the 317 for this oil?

Alcimar Monteiro
process management - Sorocaba, SP, Brazil

finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

Q, A, or Comment on THIS thread SEARCH for Threads about ... My Topic Not Found: Start NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
Consult'g, Train'g
& Software

About/Contact    -    Privacy Policy    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA