Where theworld gathers for metal finishing
Q&As since 1989
-----
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, the standard the aerospace industry uses.
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
2003
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
2003
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.
Engineer - Guangxi, Qinzhou, China
2007
316L isn't resisting sea water. Will 317L?
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.
- Dahanu, Maharashtra & India
July 28, 2008
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 [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
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
August 1, 2008
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,
importer, international trading company - Taipei, Taiwan
February 8, 2009
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 WannerAkzo Nobel - Saskatoon, Saskatchewan, Canada
2006
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.
- Montreal, Quebec, Canada
February 20, 2013
Substitute 316 for 317 in gasoil refinery?
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?
process management - Sorocaba, SP, Brazil
August 9, 2014
Q, A, or Comment on THIS thread -or- Start a NEW Thread