Does the Stainless Steel E316 resist seawater and Temp?? 5

[finder01]

My name is Bassam, i am an industrial engineering student, meanwhile i am in a research about Stainless Steel.<br>the main subject of this project is how many years could the Stainless Steel live in seawater, particulary the Stainless Steel E316.<br>i will be so glad if you let me know whether this kind of material could resist seawater, and humidity??? could the properties of this material remain the same under temp. 50 c<br>???<br>if this isnt the proper material to use under seawater, could you please recommend me of the best material???<br><br><br>Awaiting forward to your kind reply.<br><br>BAssAM

 

[Ron]

Type 316 Stainless Steel is commonly used for marine applications and severe corrosion service.&nbsp;&nbsp;Has better corrosion resistance than Type 304, particularly in chlorine/chloride environment.<br><br>If you are considering a welded application, use Type 316L which has a lower carbon content.<br><br>Either should be able to handle the 50C temperature without detriment.<br>

 

[finder01]

what if we need to form the satainless steel E316 by heating it above&nbsp;&nbsp;or equal to 500 c ???? does this temp. affect the properties of the E316&nbsp;&nbsp;in the future??<br>i mean will not the E316 resist the Oxidization and rust forming?????<br><br><br>&nbsp;

 

[Ron]

Since 316 is weldable and 316L even more so, you will get an increase in corrosion resistance over 304 or 304L.&nbsp;&nbsp;Is it possible to get rust with 316? Yes, though reasonably light.&nbsp;&nbsp;The long term properties should not be so adversely affected as to cause great concern as 316 is successfully used for bouys, boat parts, dock parts, fasteners, and other marine applications.

 

[netti]

Do you have information regarding a simple test to identify 316 and 304 stainless steel.

 

[spartacus]

Hi guys,
I'm an applications engineer for a sealing systems company and i would agree with Ron on the fact that 316 is used in marine applications but it is not ideal.
It is used because its relatively inexppensive for large applications like hulls, but for this it is usually coated.
In typical applications where i would want the anticorrosion properties to be good i would use ST.ST 420 or even higher, but it really depends on what you want to use it for.
Regards,
Sparky

 

could you give me some illustrationon how to create under water structure its materials used and others the computaTION ALSO.

 

[myteoh]

i'm an applications engineer for a pump trading company. Generally, I would use bronze or Ni-Resist Material instead of stainless steel for sea water application.

 

[MikeONeill]

In the few-dozen seawater piping systems I've done, the following alloys are far superior to 316(L):

Monel 400
Copper-Nickel alloy 706 or 715
AL6XN
254SMO

Regards,

Mike

 

I am an Ocean Engineer. I would not recommend any stainless for long term subsea applications- period. Potential crevice corrosion problems are not worth the headache. For near surface and splashzone use, type 316 is very good, and if you are welding, use type 316L to avoid carbon precipitation near the heat zone. There are some very good reference materials available free from the Nickel Institute in Canada.

 

[dwfry]

I was a marine engineer in the navy and currently a chemical engineer working in SoCal. We are next to the ocean, and as a water conservation measure installed 316L SS piping to supply our scrubbers with sea water. The piping lasted about 2 years before springing leaks. 90/10 Copper Nickel, which was used onboard Navy ships for the sea water/firemain will last 20-40 years, and is much better for piping. (Straight copper tubing lasts 1-2 years in service!).
The problem with 316L is stress corrosion cracking, that propagates through the granular structure of steel, causing pin hole leaks. For deck and hull fittings stainless is very strong and corrosion resistant. I would not recommend for piping material with seawater!!!!

 

[MURZ]

The metals Handbook from ASM gives some information on stainless steels in seawater applications. This information can be found on pp. 15.15 – 15.16. One interesting thing that I read from this section was the fact that in stagnant seawater or when the velocity is less than 1.5 m/sec (5 ft/ sec), 316 may be completely unsatisfactory. They suggest alloy 254 SMO, AL6X, and five others. There is also a table (Table 13 pg. 15.16) that shows Crevice corrosion of Ferritic SS in low-velocity seawater. If you do not have access to this handbook, I would be glad to fax or e-mail you a copy of the pages.

Hope this helps.

 

[jemclau]

In the Biopharmaceutical business we have had to go to AL6XN for tanks and piping when handling guanidine HCL because the quanidine HCL has early and very obvious effects on 316L.

 

[mcguire]

I'm a PhD in metallurgy-stainless specialist. 316 is marginally resistant to seawater. The next better choice would be a duplex such as 2205. You could as suggested above go to a super-austenitic such as AL6xN, or any other proprietary 6% molybdenum grade.
Mechanical properties do not vary significantly with temperature in the range you mention, but corrosion depends exponentially on environmental temperature.

 

Do you have information regarding a simple test to identify 316 and 304 stainless steel?
Please help.

 

[rkg]

1. Titanium is also widely used for sea water applications, in particular for tubes of Shell and Tube heat exchanger using sea water as a cooling medium. Cupro-nickel, both 70-30 and 90-10 are highly suitable. SS316 should not be used for sea water applications.

2.It is not a good idea to carry out forming operations at 500 deg. C as this would cause &quot;sensitizing&quot;, which means onset of precipitation of chromium carbides at grain boundaries. This, in turn, impairs corrosion resistance of the Stainless Steel. Using &quot;L&quot; grade helps to a large extent by limimting carbon available for combining with chromium. If hot forming in this temp. range is unavoidable, please carry out solution annealing the formed part at 1050 deg. C followed by quenching in DM Water.

3.To distinguish 316 from 304, people use a simple &quot;Moly test&quot;. This involves applying a chemical which changes colour if Molybdenum is present. This kit is called a &quot;Moly Tester&quot; and readily available in the market.

 

[mgp]

In the North Sea offshore industry it is quite common to use 6MO stainless steels for piping systems for Seawater service (wet firewater systems and water injection), e.g.

Sandvik 254 SMO (= UNS 31254)
Also Sandvik SAF 2205 (= duplex 2205 = UNS31803) or Titanium is used, but SS316 or SS304 is normally never accepted.

Try the site

http://www.steel.sandvik.com/

or

http://www.avestasheffield.com/steel_grades.asp

They have specs for SMO254 and SAF2205

If it is for submerging into seawater, other rules apply.

The NORSOK standards homepage have a standard for material selection, which includes some considerations for both piping for seawater service and for subsea installations.
Try the material selection standard at

http://www.nts.no/norsok/m/m00102/m00102.htm

Also there's a site

http://www.corrosionsource.com/technicallibrary/corrdoctors/Modules/Seawater/Seawater.htm

which may have some info


Regards
Mogens

 

What effect would 12000 PPM of wet chlorine have on 304 SS with some residual welding and rotating stress running at 180 degress f? We are currently running this unit at 120 F and would like to raise the temp to 170-180.

 

[loeb]

On recreational boats, 316 is commonly used for high corrosion areas. It's affordable. More serious builders with slighly bigger budgets use Monel.

 

[quark]

Netti!

I think it is too late to answer. But there is a test kit which we generally use to check whether a steel is 304 or 316. (I presume these are the only two samples infront of you) The kit consists of a torch with graphite tip and an electrolyte. Put a drop of electrolyte on the steel, dip the graphite tip in the sloution and switch on the torch. If the steel consists of molybdinum the color of electrolyte turns to reddish pink.

Regards,