×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

316l stress corrosion cracking elevated temperature

316l stress corrosion cracking elevated temperature

316l stress corrosion cracking elevated temperature

(OP)
Can someone please recommend a reference for 316L corrosion resistance at elevated temperature.

We have a system with 316L water pumps operating at 110C and would like pump same fluid at 207C @18bar. What is the change in SCC resistance over this temperature range? Water cl- ~ 2140 mg/l.

Note the water is oxygen free and all the piping and valves are carbon steel.

I have done research and found

"temperature should be seen as a key indicator for susceptibility to
CLSCC"
"If free from oxygen, solutions will not cause CLSCC"
"The 316L stainless steel did not exhibit any evidence of IGSCC in 500°C deaerated supercritical water"

RE: 316l stress corrosion cracking elevated temperature

You do need to be careful because 'oxygen free' mean sub-ppb levels, something that in above ground systems is almost impossible to achieve without using oxygen scavengers.
The supercritical water that you refer to has a total impurity load (all anions and cations and particulate) of <2ppm. No iron in that system.
If there is active corrosion then there is a risk of SCC. I would consider pitting in 316L at 207C and 2000ppm Cl to be rapid. In fact I cannot imagine 316L surviving 2000ppm Cl at room temperature for long.
I don't think that SCC should be your first concern here.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: 316l stress corrosion cracking elevated temperature

(OP)
Thanks EdStainless

The water source is from underground. We have no problems with this fluid and 316L and 110C.

RE: 316l stress corrosion cracking elevated temperature

Reference from Figure A8-2 "Material Selection for hydrocarbon and chemical plant, David Hansen" (Note that it is a guideline of Cl SCC.)

1. Time to failure at 2,200 ppm of chloride at 250 C - 20 hours

2. Time to failure at 2,200 ppm of chloride at 150 C - 15,000 hours

3. Time to failure at "4,000 ppm" of chloride at 100 C - above 100,000 hours (more than 10 years)






SiHyoung Lee,


RE: 316l stress corrosion cracking elevated temperature

(OP)
Thanks for your input.
Our client when with super duplex for this duty. One reason was the quote from the corrosion consultant to report on 316L was more the cost of the super duplex option.

RE: 316l stress corrosion cracking elevated temperature

Just curious, did they have a thorough specifications with corrosion or impact testing required on all raw materials and as part of the weld qualification?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: 316l stress corrosion cracking elevated temperature

Kev, i wouldn't use 316L to handle 200 'C chloride-laden fluids.
ClSCC is the possible threat, alongside with other damage mechanisms, e.g. pitting, crevice.

SDSS would certainly a better option, with a much higher chrome content, hence the higher PREN, CPT and CCT. The mechanical properties are also more superior that that of 316L. I am not sure why your client claimed that 316L costs more though?

CH. Lee, PhD P.E
Lead Materials and Corrosion Engineer
Intecorr Consultancy
www.intecorr.com
twitter.com/intecorr

RE: 316l stress corrosion cracking elevated temperature

A superduplex (>25% Cr) will cost a lot more than 316L, but 2205 should be very close as you will reduce the wall thickness by at least 40%.
The real problem in this application is that if there is a leak, even a microscopic one you will have saturated brine at 200C and oxygen. Both pitting and CSCC will take off rapidly in 316L, and only a bit slower in 2205.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: 316l stress corrosion cracking elevated temperature

On google image search, enter the terms 'venn diagram' and 'stress corrosion cracking' and it will yield the results of 100,000 undergraduate engineering reports.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Engineering as It Should Be - Chapter 2: Document Security
This ebook covers basic tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Chapter 2 covers cybersecurity and answers the question: How do you secure your files and documents? Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close