Stainless 2205

By js55

Date 05-21-2014 15:33

For ASME Section IX it is P-10H.

By Lawrence (*****)

Date 05-21-2014 15:43

http://content.rolledalloys.com/technical-resources/databooks/2205_DB_US_EN.pdf

SPECIFICATIONS
UNS S31803/UNS S32205 W.Nr./EN 1.4462
ASTM/ASME
Flanges, Fittings and Valves A 182/SA 182
Plate, Sheet, Strip A 240/SA 240
Bars and Shapes A 276/SA 479
Seamless and Welded Tube A 789/SA 789
Seamless and Welded Pipe A 790/SA 790
Wrought Pipe Fittings A 815/SA 815
Fusion Welded Pipe A 938
Detection of Intermetallic A 923
Phases
Section VIII Division 2 Code Case 2067-2
ASME Code Case 2186 (Plates in Dimpled or
Embossed Assemblies)

ASME Section IX P No. 10H, Group 1

ASME B31.1 Code Case 153
NACE MR0175
FEATURES
• High resistance to chloride stress corrosion
cracking
• Chloride pitting and crevice corrosion resistance
superior to 317L stainless
• Good general corrosion resistance
• High strength
• Good sulfide stress corrosion resistance
2

By BIGBOB

Date 05-22-2014 11:11

Thanks for the response. As far as AWS D1.6 is concerned does it fall under a specific base metal group? In clause 4, table 4.1, 1.1 "a change in the base metal group or in the base metal type" I have a qualified weld procedure for GMAW-S that was qualified with a PQR with 304L, group A, UNS30403 base metal and 308LSi filler. I wanted to use the 2205 base metal, sheet A240, on a project but do not know if it would fall under the same base metal type so that it would be covered under my existing WPS. We would be using the same process, cover gases and using a 2209, F6 filler metal. Would the 2205 base metal be considered acceptable under this weld procedure? I appreciate the help as I am trying to better understand the codes.

Bob

By 803056

Date 05-22-2014 19:27

I believe it is a Duplex Stainless Steel. As such, it is not prequalified under AWS D1.6.

2205 is listed in AWS D1.6-2007, Table F.1, page 204 (8th column from the right margin). It is not prequalified, so it must be qualified by testing. If you are welding fillet welds, they must be qualified by welding a grooved test assembly to establish the mechanical properties. Once the grooved assembly is welded, fillets are qualified using Figure 4.5.

Best regards - Al

By qcrobert (***)

Date 05-28-2014 16:16 Edited 05-28-2014 16:22

Al is correct that it is not prequalified and you must qualify with both grooved test and fillet test.

I work with 2205 and use ASTM A923 which details three testing methods. Method A is a screening test. If a sample does not pass using this method, then B or C must be used to determine acceptability. It doesn't make much sense to run Method A in my case.

Our contract calls for ASME and Sec IX requires macrosection exams on a T-joint, no fracture test for procedure qualifications. ASTM, Method B cannot be performed on a T-joint because a charpy cannot be excised from the joint. Method C can be performed. With regard to the butt-weld plate, ASME Sec !X requires two tensiles and four bends. Method B & C can be perform on these procedures.

Ferrit content per ASTM E562. In production welding we use a Fischer Feritiscope.

Approx lab cost of T-fillet welds:
$475 5ea macroexams
$100 1ea Method C
$150 1ea Ferrite Count

Approx cost lab of butt welded plates:
$525 2ea tensiles/4 bends
$100 1ea Method C
$210 1ea Method B
$150 1ea Ferrite Count

As previously mentioned by others, 2205 duplex SS is very different from 330 series SS and is dependent of heat input and cooling rate to obtain desireable FE %. A feritescope is necessary to assure FE % and I found it difficult to rent so we bought one ($5000).

Hope this helps,
QCRobert

By 803056

Date 05-28-2014 16:36

Are you looking for the percentage of ferrite or the ferrite number? I was under the impression percentage had gone the way of the Doo-Doo bird because of the variability from one lab to the next.

Best regards - Al

By qcrobert (***)

Date 05-28-2014 17:19 Edited 05-28-2014 17:24

Our 2014 client engineering specifications state:
4.5.2 The Phase Balance test shall be performed on the weld metal in the qualification coupon. The test shall be performed on each weld pass, except if there are four or more passes, only the root, cap and mid thickness shall be checked. Testing shall be performed according to the manual point counting method as described in ASTM Specification E-562, or by the automatic computer evaluation method. The volume fraction of ferrite shall be within the following limits: GTAW=35-60%; GMAW=35-60%; SMAW=24-60%; SAW=25-60%. Fisch Ferrite scope to be used to measure ferrite content of the weld metal in production welding.

But to comment on variability, yes I have found descrepancies in results from different labs.

QCRobert

By js55

Date 05-22-2014 20:33

Just curious. Why are you using the duplex?

By BIGBOB

Date 05-23-2014 13:27

It was an engineering decision. It is stronger tensil and better corrosion resistance than a standard weldable 300 series stainless.

By js55

Date 05-23-2014 14:28

Keep in mind you do not weld this stuff like a 300 series stainless steel. If you do not achieve a duplex balance you will not get the properties it intends.

By ssbn727 (*****)

Date 05-23-2014 17:59

YES INDEED!!! Phase balance is crucial with duplex...

Another question... What is the intended application? Do you have to confirm adequate corrosion resistance that certain standards require such as passing a ASTM G 48 test?

And finally to follow up on your reply to js55's 1st question, How many other types & grades of Stainless steel did you look @ to match the tensile & corrosion resistance requirements for your application?

Respectfully,
Henry

By js55

Date 05-23-2014 18:10

Henry,
Those are important questions.
First of all duplex is not more corrosive resistant in all media.
Secondly, G48 is the wooly booger. People fail this all of the time.
Duplex solidifies first as ferrite like most 300 series SS's. However, if you keep the heat input down and interpass too low, as is often done with 300 series SS's the duplex will cool too fast which will cause the phase balance to favor ferrite. And you will lose corrosion resistance. It you cool it too slow you will favor austenite and lose strength, SCC resistance and perhaps cause segregation of elements.
It is not a difficult alloy to weld but you need to really know what you are doing. Same with alloys like titanium or CSEF's.

By ssbn727 (*****)

Date 05-23-2014 19:14

"G48 is the wooly booger. People fail this all of the time."

I wholeheartedly agree with you J! Have you read this article yet?

http://www.corrosionlab.com/papers/astmg48/problems-in-utilizing-astm-g-48.htm

Respectfully,
Henry

By js55

Date 05-23-2014 19:31

Got it now. Good one. Thanks

By mechan

Date 05-24-2014 01:48

Duplex is fairly common in pulp mill applications now days ... For what it's worth, I would rent a ferrite tester depending on the scope of the project.

By js55

Date 05-28-2014 17:18

Its common offshore as well, and other applications where chloride SCC is a primary concern.
I would agree a ferrite tester is critical to success.

By nantong (**)

Date 05-29-2014 00:32

I wonder too why you are using Duplex for a structural application. It is so expensive, why not use a high strength carbon steel and paint it? In my experience Duplex is used mainly in the Offshore Oil and Gas Industry where it is necessary to save space and weight on an Offshore Platform and for the increased corrosion resistance for the aggressive product it conveys.
G48 tests are only a quality control tool and really tell you nothing about fitness for a specific purpose. On phase balance heat input and interpass temperatures do have an effect, especially on thinner sections however phase balance is predominantly controlled by the chemistry. With regard to measuring the phase balance I think the E562 point counting method is still the best. It can be done on the cross section of the test piece and measure balance in weld/haz/parent material. Ferritscopes can be used in production but generally can only be used on the weld cap whereas I am interested in the weld root where the corrosive product is carried. How to equate % ferrite and FN numbers for duplex for production monitoring? I think Lincoln came up with something. I have had an Owner specifying the same value for acceptance criteria.

By mechan

Date 05-29-2014 02:45

It really all depends on his application, but it is not uncommon to use duplex outside of the wetted environment. Painted steel outside the wetted environment always ends up being a pain at some point because the process never stays inside its happy home. Not to mention over time the gases themselves that escape the higher metallurgy environment have a chance to corrode the steel.

It sort of depends on the design and application to whether or not one is able to use a ferrite tester on the root of a weld. To say it generally can only be used on the cap is a stretch.

By js55

Date 05-29-2014 12:17

nantong,
"G48 tests are only a quality control tool and really tell you nothing about fitness for a specific purpose."
Ain't that the truth. Many an engineer has had an severe oops when reality hit. This is of course a issue with all standardized corrosion testing. At best it gives a rough ordering. When you are faced with a new environment, a slight change in chemistry, a slight change in temperature, a slight change in flow, a slight change in mechanical design, all bets are off and you cross your fingers.
I would agree on the point count method as well.
And your point about chemistry and phase balance is well taken in relation to ferritscopes on caps. The dilution from the base metal on root passes has the potential to vary the phase balance considerably from that which is experienced in the cap (reduction of nickel and therefore higher ferrite-though this may help SCC).
However, relating ferrite % to FN is, to my knowledge, as yet unresolved. I have not seen Lincolns resolution (been away from duplex awhile) but I suspect it may be close but still unsatisfactory, much like carbon equivalence equations where they just seem to proliferate based upon varying chemistries. In any case with 2205 types it isn't as critical as supers. With supers I think the best way to go is tightly controlling parameters related to point counting and other testing regimes. This also helps control nitrides and intermetallics which are far more of a critical issue with supers.
With 2205 the decision really has to sit with the design engineers as to how robust a testing regime he wishes to impose based upon how close to the viable threshold the chosen material is. If the material is really overkill for the application but a lesser material is not enough then a savings can be realized in testing. Though with the cost of the material itself its almost a who cares.

By ssbn727 (*****)

Date 05-30-2014 02:50 Edited 05-30-2014 09:03

I wonder if there has been wide scale acceptance or even adoption of this method below of using algorithms such as a Bayesian Neural Network in a computer program
(Linux based) to predict the ferrite number in austenitic as well as duplex stainless steels?

http://www.msm.cam.ac.uk/phase-trans/2001/Ferrite_number.pdf

This is a really good article regarding the microstructure of super duplex stainless steels and it does cover the inconsistencies one will experience regarding PRE tests and does emphasize the importance of maintaining good austenite/ferrite phase balances which depend greatly on the chemical compositions of both the parent/base alloy and the filler metals starting in chapter 3 on page 24 of the article (Not the .pdf page number)... So the article for me basically starts on page 24 but, start reading where you want to:

http://www.msm.cam.ac.uk/phase-trans/2007/Sharafi/Pt1.pdf

In case anyone is interested, here are some more programs from the Materials Algorithm Project - otherwise known as MAP developed @ Cambridge University's Metallurgy & Material Science Department... These are from our old friend Professor Harry Bhadeshia and his Grad students of the Phase Transformation Research Group...
Please read the disclaimer first before you proceed any further:

http://www.msm.cam.ac.uk/map/mapmain.html

MAP Program & Data Library Contents:

http://www.msm.cam.ac.uk/map/map.html

Enjoy the reading! :eek:

Respectfully,
Henry

By js55

Date 05-30-2014 12:44

Henry,
I didn't do a thorough study of the article however a cursory review indicates the same problem we have been dealing with for decades pertaining to delta ferrite in austenitic stainless steel welds. The influence of heat input and heat energy on the resulting microstructure. These models all seem to be chemistry heavy. Which is a defect.
And even though, as with delta ferrite, it can be reduced to cooling rate within a certain temperature range, the variables determining cooling rate are quite extensive, i.e., amps, volts, travel speed, thickness, conductivity, etc. I know that neural networks are very popular as a possible resolution but I am skeptical of mathematical solutions to practical applications and always remember an incident involving the great Harry Ebert at a conference in Detroit. A young man had just finished a very impressive presentation on some cutting edge ideas when Harry (who fully understood EXACTLY what the young man was trying to convey) stood up and staggered him with a very simple question. "How do I translate this to the field?"
The silence was deafening.
However, having said all this I will certainly defer to those who know much more about these things than I do. A list of which I suspect is very extensive. :smile:

By ssbn727 (*****)

Date 05-30-2014 23:36

I agree with you J...

When you get a chance to re-read the article, the author repeatedly claims whether it be directly or indirectly that the chemistry, values, algorithms ,etc., are neither precise or absolute... As far as Harry's question is concerned... Of course this couldn't be translated to be used in the field because there was no application back then! Or Bayesian Neural network algorithms, or portable computers with the necessary processing power to process the math in relatively short period of time as is capable with the tools available today.

Respectfully,
Henry

By mechan

Date 05-29-2014 02:47

It's critical to success or becomes one hell of a can opener for that can of worms! :evil:

By nantong (**)

Date 06-01-2014 00:53 Edited 06-01-2014 00:56

JS55 you hit the nail on the head. You have to be practical. We have used diagrams for predicting phase balance for donkeys years that do not consider heat input or CCT's. Experience tells you you must control heat input and interpass temperatures when you are welding thin sections and the higher alloyed superduplex. If G48's for duplex/superduplex are done at standard temps of 22C and 35C then there should be no problem, if Client requires higher, 25C/40C, then you have to think again.

One of the biggest problems in welding duplex, especially superduplex is sigma phase precipitation. Most Clients spec's used to say no third phases to be present. What do you do if all your charpies and corrosion tests pass but you have sigma phase present? Years ago some studies were done into trying to quantify allowable percentage of sigma phase. Henry is there a neural solution for this?

To me if it passes the mechanicals and corrosion tests, end of story.

By ssbn727 (*****)

Date 06-01-2014 09:03 Edited 06-01-2014 10:11

Hi Nantong,

I would have to ask Professor Harry Bhadeshia @ Cambridge University if the Bayesian Neural Network he has developed with his colleagues can predict the potential formation of both Sigma as well as Chi phases in the weld metal and HAZ of Super Duplex SS... As far as I know, there have been some semi-empirical models developed that aren't promising once the details were spelled out...

Here is an interesting paper on developing a methodology of avoiding Sigma phase in Zeron 100 Super Duplex Stainless steel... However, in this paper the author still uses the G-48 test with reference to the ASTM A923-94 standard (Standard Test Methods for Detecting Detrimental Intermetallic Phase in Wrought Duplex Austenitic/Ferritic Stainless Steels) and recommended practice for pitting corrosion tests for duplex stainless steel weldments by the use of ferric chloride solution from TWI... But,the author relies more on adjusting certain welding techniques & variables used to achieve optimal welding parameters that are measured via microstructure analysis using a Buehler Omnimet Image Analysis System and a manual point counting technique with reference to ASTM E562-89 (Standard test method for determining volume fraction by systematic manual point count) which one of the 3 types of welding parameter samples used are absent of sigma phase... Nothing new here and yet interesting nonetheless - that is, if one likes to observe a snail race during their free time. :roll:

http://www.jim.or.jp/journal/e/pdf3/46/03/593.pdf

Come to think about it, I do remember reading something about using Eddy Current probes to differentiate the differences between ferrite (Delta?) and sigma phases by understanding that ferrite is ferromagnetic and sigma is paramagnetic and by decreasing the amplitude on the impedance resulting in an interesting non-destructive technique for microstructural evaluation of DSS, or something to that effect...

This one is interesting as well because it describes certain electrochemical etching and describes the author's level of success with the reagents by how they separate the phases via electron microscope... the author also touches base on the use of a SEM (Scanning Electron Microscope with the BSE (Back- Scattered Electron) signal...

There is an application named Thermo-Calc which is a commercial thermodynamic software package available that could be useful and they have other applications that will simulate various conditions also.

http://www.thermocalc.com/products-services/software/

http://www.thermocalc.com/products-services/software/thermo-calc/

http://www.thermocalc.com/academia/researchers/calphad/

Respectfully,
Henry

By nantong (**)

Date 06-01-2014 14:22

Henry, thank you for digging up all the scientific information on this subject, very interesting although I do not understand so much of it. I am a field welding engineer and expect my Client or my Employer to develop at the design stage the required realistic specifications for me to work with in order I can qualify successful welding procedures for my project. This often doesn't happen for example I was on a project which the tanks (CCD's) were made by a a famous bridge builder from Chicago. The ferrite content of the welding procedures were measured by the ASTM E562 point count method production welds were tested using a ferritscope however the specification gave the same acceptance value for ferrite content and ferrite number.

Anyway so much of this is down to statistics and I am sure we are all aware of what Mark Twain is attributed to saying on this subject, "there are lies, damn lies and statistics".

By 46.00

Date 06-01-2014 14:48

Do or Die for C,B and I

By ssbn727 (*****)

Date 06-01-2014 23:26 Edited 06-02-2014 00:55

You're "Weldcome" nantong. :grin:

I concur... This discussion has stimulated my curiosity further... So of course, I wasn't satisfied with the direction I was following in attempting to answer your question:
"Henry is there a neural solution for this?" In a previous post in the thread, I had already asked if anyone has been accepting, or even adopting the Bayesian Neural Network for modeling and prediction of ferrite number in a previous post... And you replied by asking me the question above... After some research and further reading, out of the void that sometimes constitutes part of my memory on any given day... Somehow I remembered about ORFN (Oak Ridge Ferrite Number) that also used neural network analysis... And is an improvement to the FNN-1999 model...The FNN-1999 model, developed with the same data as the WRC1992 constitution diagram, was shown to reduce prediction errors by as much as 40%... I will quote a couple of paragraphs from the article I found in my library and then looked up online for anyone to read...

"Furthermore, composition dependent effects of alloying elements were taken into account and the consequences of this were clearly demonstrated... A more recent model, which is also based on neural networks, also demonstrates significant improvements compared to the WRC1992 constitution diagram... Another major shortcoming that is present in the traditional constitutional diagrams as well as the newer models, including the recently developed neural network models, is the absence of any consideration of welding conditions and how they may influence the ferrite content of welds... In particular, the weld cooling rate will have a significant effect on the final ferrite content...There are two ways in which the cooling rate will influence the ferrite content: 1) The cooling rate will alter the extent of the diffusion-controlled transformation of ferrite to austenite during cooling in the solid state, and it may influence the solidification behavior." Well, going back a few years ago, I did remember reading an article in the back of the Welding Journal that was titled:

"Improved Ferrite Number Prediction Model that Accounts for Cooling Rate Part1: Model Development Details of a prediction model based on a neural network system of analysis are described BY J.M.VITEK, S.A.DAVID, AND C.R.HINMAN"

http://www.aws.org/wj/supplement/WJ_2003_01_s10.pdf

This is from the original article: "SUMMARY and CONCLUSIONS: A new model (ORFN©) that takes welding conditions into account when predicting FN of stainless steel welds has been developed. Several simplifications and assumptions were required during the development of the model. However, the new ORFN© model represents the first prediction model that quantitatively accounts for the effect of weld conditions on FN. It has been shown that the ORFN© model correctly predicts the variation in FN due to solidification model changes and suppression o the solid-state ferrite to austenite transformation at high cooling rates.The ORFN©model is particularly useful for high-speed welds, duplex stainless steel welds,and high-power density process welds."

http://web.ornl.gov/~webworks/cppr/y2001/pres/113776.pdf

http://web.ornl.gov/~webworks/cppr/y2001/pres/113800.pdf

Here's a more recent paper in the AWS Welding Journal:

http://www.nxtbook.com/nxtbooks/aws/wj_201204/index.php?startid=118-s#/146

I think I'm going to make a comparison analysis of the two models (Bayesian & ORFN) in order to find out which one is more accurate... I'll let you know what results & conclusions I come up with. :roll:

Oh wait! It's already been done in the Bayesian paper! :surprised:

Now I'm done. :cool:

Respectfully,
Henry

By nantong (**)

Date 06-02-2014 12:37

All good reading and thank you again Henry for your endeavour's but this is all basically R&D stuff. Over the years how much of this stuff has filtered down into the field in understandable language as Harry Ebert indicates in JS 55's post, very little or none I think.

Can anyone give me a fabrication code or national standard which specifies an acceptance criteria for phase balance and G48 tests when welding duplexes?

By js55

Date 06-02-2014 13:23

nantong,
I would suspect there will be no answer to your question. Messing with acceptance criteria with G48 or phase balance in a national standard is similar to hardness testing of Grade 91 material with ASME. Nobody is willing to carve it in stone because too much acceptable material would then be rendered unacceptable at tremendous expense.
It is best left to engineering practice with cognizance of the intended service.

By js55

Date 06-02-2014 13:15

nantong,
Yeah, 25/40 starts to get into the wooly booger range. The evolution had been that we became so well versed at how to detect these things that we were making it more and more difficult to pass specifications AT ALL.
In my experience sigma in supers will almost ALWAYS be present. Given the stoichiometry of the elements (Mo especially) and their volume percent's in supers, it is essentially unavoidable. And yet, in that primitive stage we were seeing specifications requiring 0%. The debate was raging at that time. It may still be.
What we learned was that just because we can see something that is thought to be detrimental does not mean that it is actually detrimental in a particular service, or AT ALL. Another example of this is the use of NiCrMo-3 for AL6XN. 3 has been the workhorse for this alloy for decades and yet, being stabilized with Cb it forms CbN (the N in AL6XN) and contributes to microfissuring. We can see it. And yet, in the literature I had read at the time there had been no failures attributed to it. It is still used today with great success. We did tons and tons of it on nukes.
In fact, being conservative I will usually specify NiCrMo-10 (stabilized with W) to punch the Mo due to segregation, and have had customers move me back to 3 because that is what they have used historically and were comfortable with it.

By js55

Date 06-02-2014 13:33

I think one other thing to keep in mind as well is that sometimes it is not so much a problem of materials, or detection, or welding, but of, for lack of a better way to put it, too enthusiastic an engineering effort. They constantly push the envelope in design. These materials may demonstrate astonishing properties. But as soon as they do we start asking more of them.
First comes a design need.
Then the materials.
Then well after the fact the welding.
Sometimes the welding doesn't even get there and we have to over kill the filler metals because there is no interim choice. 9% Ni and 6 Mo's, as well as SDSS's, come to mind.

By nantong (**)

Date 06-03-2014 23:53

When I asked if anyone could think of a code or national standard that covered this I was thinking of the only one I have worked with which does that is the Norwegian standard Norsok M-601. Have a look at the standard it is a free download from the Norsok website. Straight to the point, about 16 lines covering G48 corrosion tests and phase balance. G48 test samples have to be pickled before testing, never quite understood that. Please have a look and give your comments.

By js55

Date 06-04-2014 12:04

nantong,
I will. Currently I know absolutely nothing of the Norwegian standards. It will be a good refresher as well. It's been a long time since I dealt with duplex of any note. We do some 2205 from time to time for customers that don't really understand and therefore don't ask much.

By js55

Date 06-04-2014 12:36

nantong,
The version I have found first is Rev 1 '94'. Offhand I don't see anything pertaining to pickling (simply saying normal weld cleaning operation) so that may be later revs. You may be meaning G48 has it. I do not have G48 in my head any longer. Been too long.
However, as a guess, and it is just a guess, I would say that passivating the surface is doing a favor in that impurities could set up electrolytic cells that cause corrosion and give a false failure. We are talking about a pitting test. And it would be eliminating an uncontrolled variable that allows an apples to apples comparison.
I also noticed it is for 25 Cr versions only. Which actually makes sense.

By nantong (**)

Date 06-04-2014 18:12

JS55 the version I have is the 2004 edition unfortunately I do not have the skills of Henry to add links to a pdf file. On Baidu, the Chinese equivalent of Google, (I don't know if you can access Baidu from outside China) I have found a 2008 edition with the relevant sections added as shown below. I am surprised for 6Mo super austentic there is no mention of micro-structural examination required in 4.3.6 but it does seem like the best I have seen for a national standard to outline the minimum required standard.

4.3.5 Corrosion testing Welds in stainless steels Type 6Mo, Type 25Cr duplex and nickel based alloys shall be corrosion tested according to ASTM G 48, Method A. The test temperature shall be 40 ºC and the exposure time shall be minimum 24 h. The test specimen shall have a dimension of full wall thickness by 25 mm along the weld and 50 mm across the weld. The test shall expose the external and internal surface and a cross section surface including the weld zone in full wall thickness. Cut edges shall be prepared according to ASTM G48. The whole specimen shall be pickled before being weighed and tested. Pickling may be performed for 5 min at 60 °C in a solution of 20 % HNO3 + 5 % HF. The acceptance criteria are as follows: • there shall be no pitting at 20 X magnification; • the weight loss shall not exceed 4,0 g/m2.

4.3.6 Micro-structural examination Type 22 and 25Cr duplex stainless steel shall be examined and the test samples shall comprise a cross section of the weld metal, HAZ and the base metal of the pipe. The micro-structure shall be suitably etched and examined at 400X magnification and shall have grain boundary with no continuous precipitations and the inter-metallic phases, nitrides and carbides shall not in total exceed 0,5 %. For the stainless steel Type 22 and 25Cr duplex the ferrite content in the weld metal root and in the last bead of the weld cap shall be determined in accordance with ASTM E 562 and shall be in the range of 30 % to 70 %.

By js55

Date 06-04-2014 18:42

nantong,
I see they bumped the 25Cr to 40C from 35C, making it tougher. The 94 version had only the 6Mo at 40C.
And clearly the pickling is in the rev.
Also, 30-70 is common, and reasonable.
I also think "no continuous precipitations" and the intermetallics at .5% is reasonable. Watch your heat input. :smile:

By nantong (**)

Date 06-04-2014 21:28

JS55 yes the test temperature is increased from 35C to 40C but the samples have to be pickled first to remove any scaling which will increase their corrosion resistance. I first disagreed with this as I did not think it was representative of what we are doing in the field but when you think of it a ferric chloride test is a pretty aggressive accelerated corrosion test and is not representative of what you meet in the field with regard to process medium anyway.

I think it is a very good workable standard, standard 22% Cr duplex is pretty easy to weld and the current generation of higher alloyed stainless steels are also ok if you take care in as you say watch your heat input (and your interpass temperatures).

By js55

Date 06-05-2014 12:01

nantong,
Scaling! Good God! Didn't think of that.
And yes, the test is aggressive enough to allow something convenient and relatively quick, yet this asset becomes a liability for the reason you say. It is not representative of anything in service.
Were it to be representative it would be useless in that corrosion would take place so fast it would only demonstrate that this particular alloy cannot be applied to this particular media. Once you have an alloy that could withstand this media in practice you no longer have an adequate test.
Its the same issue with creep rupture tests. You have to have something that reduces the time frame but once you do that you get farther from reality.
Of course, the added problem with corrosion is the almost infinite possibilities of conditions. As we have discovered, even seawater is not created equal when considering CSCC.

By ssbn727 (*****)

Date 06-04-2014 22:30 Edited 06-04-2014 22:39

Well now that you mentioned it, take a look @ this paper...

http://www.forcetechnology.com/NR/rdonlyres/C6B2B08F-7C49-4508-966F-E0E3C1D20E1E/7458/ChallengesinPrequalificationCorrosionTestingofCRAs.pdf

Oh yeah, I forgot about this one also:

http://www.arcmachines.com/news/case-studies/duplex-stainless-steel-tubing

Respectfully,
Henry

By js55

Date 06-05-2014 12:06

Henry,
You are as well, an asset and a liability. I still have not yet finished all of the Bhadeshia stuff (whom I like very much but often can't comprehend) you have posted over the years, try though I might. The growing stack of unread articles in my office is but a constant reminder of my ignorance.
the hurrier I go the behinder I get.
But dont' stop. :smile:

By ssbn727 (*****)

Date 06-06-2014 01:53

J,

Thank you for those kind words... Please don't make anymore copies of the articles I posted... Instead, do what I do... I bookmark them into the designated titled folder for each of the articles and have no trouble locating them... And if they're in .pdf, Word, You Tube, or whatever format then I save those in my dedicated library hard drive which is external from my "Puter's" drive... I got a 4 terabyte hard drive for Christmas and I haven't even put anything that resembles a decent fraction of it's total storage capacity which makes 4 separate multi-terabyte drives that still have about at least 70 to 95% free space but, I have been filling two of them with movies and E-books so that will change soon enough...
It works great for me. :surprised:

Respectfully,
Henry

By ssbn727 (*****)

Date 06-04-2014 22:25 Edited 06-05-2014 04:03

Here you are nantong;

https://www.standard.no/en/sectors/energi-og-klima/petroleum/norsok-standard-categories/m-material/m-6013/

Scroll down the page and look for "free Download" in order to access the 2008 version of the standard... In case you run into any problems, here's the direct link to the .pdf:

http://www.standard.no/en/PDF/FileDownload/?redir=true&filetype=Pdf&preview=true&item=132364&category=5

Here's Baidu's version of the same standard:

http://wenku.baidu.com/view/cbf3316d58fafab069dc02f5.html

Here's the Yumpu copy of 2004 integrated into a pleasant reading app:

https://www.yumpu.com/en/document/view/6129822/norsok-standard-m-601-welding-and-inspection-of-piping

in case anyone is interested, here's another different standard from NORSOK, "Material data sheets and element data sheets for piping - M630"

http://www.norsok-mds-d47.de/pdf/norsok.pdf

Respectfully,
Henry

By nantong (**)

Date 06-05-2014 15:35

Great stuff Henry, I believe you were connected with the Silent Service but the way you come up with all this information I think you must have connections with the Secret Service!

BTW (off topic) I don't know how old you are but, knowing your connection with submarines, when I was a really young kid I used to watch an American programme in the early 60's called "The Silent Service" with my father who fought with the Royal Navy during World War II. The episodes were all based I believe on true stories and the American Navy even provided a submarine for filming the episodes. Have you heard of it? I would love to watch it again. At the moment I am watching the fourteen series of Bonanza. Great stuff!

By ssbn727 (*****)

Date 06-06-2014 01:37

Not a chance because if I was, our President would be getting a mouthful from me for his latest - well, you know what I mean... Mistakes to put it mildly! :twisted:

Your father was one of the not so many left alive of the Allied effort that could proudly proclaim as being part of The Greatest Generation for sure!!! God bless him...

Me and my brothers used to sit down in front of the Television with my father every Sunday to watch Bonanza... Great stuff indeed! That show taught me about responsibility, integrity, honor, how to act with maturity, etc... And that program gave me previews & lessons on how to, and not to react in many different situations one could end up experiencing in one form or another... Bonanza prepared me somewhat to face the many versions of life's lessons we all go through... One of my all time favorites!

I used to watch the reruns of that series and enjoyed every episode... I did a quick search and found the complete first season of 39 episodes so far... When I find the second season, I'll post those episodes also... Enjoy the first season nantong! :smile:

By nantong (**)

Date 06-06-2014 10:19

Thanks a million Henry, brings back memories.

By BIGBOB

Date 06-16-2014 18:11

Wow................ I'm pretty sure my mind is officially blown! You guys are a wealth of information and I do truly appreciate the responses. As far as the material usage, this is an engineering decision, I'm more of an applications type guy. I just try and find the appropriate way of applying what the engineering staff has recommended. There is absolutely no way that I can even come close to comprehending the information that was given to me. I obviously need to read more.... :confused:

Bob