Mr.. Herman and Mr Rana,
Attached are some documents which references Chloride SCC in CaCl2 solution.
ASTM G-36, is a very long established standard for chloride SCC. I have come across of some literatures reporting that MgCl2 test being aggressive on a number of stainless steels.Hence a more moderate one e.g CaCl2 test is followed by the industry.
Many manufacturers of duplex SS refers to SCC in CaCl2 media. However to the best of my knowledge no ASTM standard cross refers CaCl2 media for chloride SCC.
Mr. Herman,if you have more information through your association with various labs/testing facilities,may put up the updates.
Please see the extracts from G-36 on the pros and cons of MgCl2 test.
Thanks
Pradip Goswami,P.Eng.,IWE.
Welding & Metallurgical Specialist & Consultant
Email-pgoswami@sympatico.ca,
G-36 extracts:-
- This practice describes a procedure for conducting stress-corrosion cracking tests in a boiling magnesium chloride solution. Although this test may be performed using various concentrations of magnesium chloride, this procedure covers a test solution held at a constant boiling temperature of 155.deg°C (311.deg°F).
-
The boiling magnesium chloride test is applicable to wrought, cast, and welded stainless steels and related alloys. It's a method for detecting the effects of composition, heat treatment, surface finish, microstructure, and stress on the susceptibility of these materials to chloride stress corrosion cracking
- Boiling magnesium chloride may also cause pitting of many stainless alloys. This leads to the possibility of confusing stress-corrosion failures with mechanical failures induced by corrosion-reduced net cross sections. This danger is particularly great when small cross section samples, high applied stress levels, long exposure periods, stress-corrosion resistant alloys, or a combination thereof are being used. Careful examination is recommended for correct diagnosis of the cause of failure.
- For most applications, this environment provides an accelerated method of ranking the relative degree of stress corrosion cracking susceptibility for stainless steels and related alloys in aqueous chloride-containing environments. Materials that normally provide acceptable resistance in hot chloride service may crack in this test. The test may not be relevant to stress-corrosion cracking in polythionic acid or caustic environments.
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of jignesh.rana@Linde-LE.com
Sent: Thursday, December 30, 2010 7:48 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:9027] Re: Stress Corrosion Cracking Test
Sent: Thursday, December 30, 2010 7:48 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:9027] Re: Stress Corrosion Cracking Test
Dear Mr. Herman
Thanks for quick reply.
It is not mistake in specification. Specification categorically demands 40% CaCl2 solution (Ph -6.5, Testing time - 500 Hrs., 100 Deg Boiling, Acceptance criteria - Stress to cause rupture shall exceed 0.85 times UTS, as per ASTM G 46)
Further, specification calls for MgCl2 solution for Duplex grade as per G 36.
Since, aberrant solution is being asked for testing as per ASTM G 36, precisely the question was put in this forum.
Request all team members to share views of chloride stress corrosion test of super Duplex ( S 32750)
With Best Regards,
Jignesh R Rana
Manager - QA & QC
Linde Engineering India Pvt. Ltd.
38, Nutan Bharat Society, Alkapuri, Vadodara 390007, India
Tel.: +91 265 3056789, Fax: +91 265 2335213 , Mobil: +91 90999 86019
jignesh.rana@linde-le.com, www.linde-india.com
This e-mail is confidential. If you are not the intended recipient, please notify us immediately. You should not disclose its contents to any other person nor use it for any purposes.
| hpi001 <pieper-qsi@kpnmail.nl> Sent by: materials-welding@googlegroups.com 30/12/10 16:53
|
|
Why does anyone asking for ASTM G36 with an aberrant test solution?
Probably there will be no big difference between both solutions
because Chloride is the important part in this test but by choosing
for CaCl you won't have any reference or acceptance criteria or is
this also specified in the project specification? Can it be a mistake
in the specification as well?
Best Regards,
Herman Pieper
On 30 dec, 11:44, jignesh.r...@Linde-LE.com wrote:
> Dear Members,
>
> One of our project specification calls for Chloride Stress Corrosion
> Cracking as the ASTM G 36 with CaCl2 (40%) solution for super Duplex
> Stainless steel ( S 32750)
>
> ASTM G- 36 is based on MgCl2 solution.
>
> Does any one having experience with SCCT with CaCl2 solution ?
>
> With Best Regards,
>
> Jignesh R Rana
> Manager - QA & QC
>
> Linde Engineering India Pvt. Ltd.
> 38, Nutan Bharat Society, Alkapuri, Vadodara 390007, India
> Tel.: +91 265 3056789, Fax: +91 265 2335213 , Mobil: +91 90999 86019
> jignesh.r...@linde-le.com,www.linde-india.com
>
> This e-mail is confidential. If you are not the intended recipient, please
> notify us immediately. You should not disclose its contents to any other
> person nor use it for any purposes.
--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
No comments:
Post a Comment