Corrosion Resistance test...failed

Date 10-25-2009 14:20 Edited 10-25-2009 14:25

In general, high heat input would be the factor involved in welding most likely to reduce corrosion resistance. You might provide some specifics such as the base material and filler, where the pitting took place (I would guess the HAZ), the observed interpass temperature during welding and any general measures affecting heating or cooling of the joint, such as wrapping in a blanket. There are people on this board that have a lot more experience with duplex stainless than myself that can be much more specific in their appraisal if you can supply more detail. You might also try:

http://www.eng-tips.com/

A knowledgeable cohort of metallurgical engineers can be found there.

Edit: And as almost went without saying, pay close attention to low carbon contamination on grinding disks and wire wheels.

By welder5354 (**)

Date 10-25-2009 19:06

More specific on the Duplex failure;
4", sch. 120 (SA-790 (S31803)
First pass; GTAW..ER2594 (100X)
Remainder; FCAW......Supercore (E2209TO/1-4)
I may have used a carbon steel disc for grinding, so would that make a difference?
I let the weld cool to 150 deg. between passes, but i also used compressed air to try
and cool it a little faster to speed up the welding process.
Anymore info, will be appreciated.

It doesn't say on the report where the pitting took place.
One coupon was completed in the 6G and the other in the 1G, so i'm not sure
what coupon the lab used for the corrosion test.
Tks so far for the info

By jarcher (**)

Date 10-25-2009 21:29 Edited 10-25-2009 21:52

What I meant about the disk and wire brush was contamination from use on carbon steel or use of a carbon steel brush. If you mean a disk not specifically formulated for SS, I doubt that would have any effect on corrosion unless it left carbide particles in areas that underwent heating during welding. But if you mean a disk previously used on carbon steel, then yes, I imagine it would. Duplex Stainless has a microstructure that is half austenite and half ferrite. On pure ferritic stainless, almost any carbon contamination, even to storage on carbon racks, being carried by forklifts with out protection, or lifting by chains is enough to induce pitting by rainwater, much less saltwater. I'll let somebody that works with Duplex's regularly weigh in authoritatively, but it would stand to reason, since duplex steels are half ferrite they would be much more sensitive to carbon contamination than 300 or 400 series stainlesses. You might be able to get information about where the pitting occurred from the lab, I know the one I use keeps the test samples for several years, although there is no requirement they do so, and that practice seems unique to them. Still whoever ran the corrosion tests may remember.

Edit: BTW, this link mentions something I hadn't considered:

http://www.twi.co.uk/content/jk20.html

Nitrogen depletion.

All my knowledge of duplex is book larn'n, I think somebody that works with it regularly might have better insight into your problems than I do.

By ssbn727 (*****)

Date 10-25-2009 23:46

Hi Welder 5354!

You Might want to read this also since you didn't mention the purity level in ppm's of Oxygen with respect to your purging gas...

http://www.gowelding.com/met/duplex.html

http://www.hse.gov.uk/research/rrpdf/rr298.pdf

http://www.alleghenyludlum.com/pages/al2003/docs/2003%20corr%20props%20PS08075.pdf

http://www.alleghenytechnologies.com/pages/Markets/ATIOilgas/docs/oilgas-articles/DevelopmentofLeanDuplex.pdf

http://www.outokumpu.com/applications/upload/acom_10292653.pdf?docid=681

This one is on cast duplex from The University of Tennessee:

http://www.osti.gov/bridge/servlets/purl/861932-WF06G5/861932.PDF

An oldie but goodie;

http://digital.library.ksu.edu.sa/V8M105R912.pdf

This one is relatively new in comparison:

http://etd.gatech.edu/theses/available/etd-11142008-223912/unrestricted/bhattacharya_ananya_200812_phd.pdf

Well, that's enough for now because the ALCS game is coming on in a minute so, I hope these links will give you a better idea of what happened with your test. ;)

Respectfully,
Henry

By js55

Date 10-26-2009 13:51

King Saud University?
No stone unturned hey Henry? :)

By ssbn727 (*****)

Date 10-26-2009 14:24

Thanks buddy!

I was gonna put some more links but my New York Yankees were getting ready to start and I didn't want to miss a minute which was worth watching every one of them to VICTORY!!!!! :) :) :) They won their 40th, that's right - 40th American League PENNANT!!!!! Another Worlds Series for the Yanks!!! It's gonna be a real tough one for them because The Phillies are an awesome team to watch and both of these teams are so evenly matched,so it will definitely be an incredible series to say the least!!! ;) :) :)

Anywho, sorry for hijacking the thread somewhat but, I'm just as happy as a pig in - well you know without actually being in you know what!!! :) :) :)
LET'S GO YANKEES!!! :) :) :) HERE WE GO STEELERS - HERE WE GO!!! :) :) :) :) :)

Respectfully,
Henry

By js55

Date 10-26-2009 13:15

What were the test regimes?
Were they ASTM standards?
You apparantly did general and pitting corrosion testing?
What were the test temperatures?
Did the customer state a pitting test temp in their specification?
And yes, the location of the corrosion is critical to resolving the problem.

By G.S.Crisi (****)

Date 10-26-2009 16:57

A very important question nobody asked: what was the chemical composition of the corrosive solution the coupon was inmersed into?
Giovanni S. Crisi
Sao Paulo - Brazil

By welder5354 (**)

Date 10-27-2009 00:37

The specimen was tested to Norsok Standard M-601 (Rev 4, July 2004) and the specimen was tested
according to ASTM G48-03. Method A at 40 deg C for a period of 24 hours. The test specimen was pickled
in a solution of 20% HNO3 and 5% HF at 60 deg C for 5 minutes according to customer instructions.
So we are the client and the customer is Based offshore, somewhere in the Atlantic Ocean.
This is the company's website < http://www.sveis.no/dok/tekniskestandarder/M-601_0_1.pdf
tks..i've learned a lot so far, as this is not your typical test for most welders.

By G.S.Crisi (****)

Date 10-27-2009 11:52

Being a chemical engineer, I'll look at your problem from a chemical point of view.

First. You say, and paragraph 4.3.5 of Norsok standard confirms it, that the coupon was pickled for 5 minutes in the nitric and hydrofluoric acids solution at 60ºC. Scrictly speaking, pickling doesn't make part of the corrosion test. Its purpose is to remove the dirtyness (oil and grease for example) and the very very thin chromium oxyde layer that exists on the duplex alloy surface, so as to leave the coupon metal clean and pure before starting the corrosion test.
Nevertheless, 20% nitric and 5% hydrofluoric acids solutions at 60ºC is a mighty corrosive environment, so it's possible (quite possible, I'd say) that corrosion on your coupon began at this point. Carbon steel would be eaten away in a few minutes if submerged in that solution.

Second. You dont say, and neither does Norsok standard, the chemical composition of the solution used for the 24 hours corrosion test. It's a very important information we don't have at this moment. I'll take a look at ASTM G48-03 (if I can find it), and see.

Third. It's essential that you look at the coupon AFTER the corrosion test. If the corrosion is limited to the weld bead and heat affected zone, the problem lays on the weld and we should investigate the reason. If, on the other hand, the pitting is spread all over the coupon (and a weight loss of 48 grams/square meter suggest so), then the problem lays on the duplex alloy, i.e., it didn't withstand corrosion as it was supposed to, and we should also investigate the reason. But for this it's essential that we know the chemical composition of the testing solution. I'll see if I can find ASTM G48 in the University library and will come back to you.

Giovanni S. Crisi

By welder5354 (**)

Date 10-28-2009 02:26

Hello, i wrote the lab for more info, as to why the corrosion test failed.
The lab says that there were two small pitt marks on the surface of the weld.
So would that be the reason why the corrosion test failed or part of it?
Tks everybody, i've been learning a great deal from those memos.

By ssbn727 (*****)

Date 10-28-2009 03:29 Edited 10-28-2009 03:35

Hi Welder 5354!

Were the pitting marks on the face surface, or the root surface? This is really important because, if it was on the root surface then, the culprit would more than likely be the ppm level of Oxygen within the purging gas as being too high, if that is where the pitting marks were found. :)

Respectfully,
Henry

By welder5354 (**)

Date 10-28-2009 15:24

pitting marks were on the cap, so it looks like welder error.
Maybe a little roll over because it was done in the 6G position.

By G.S.Crisi (****)

Date 10-28-2009 19:55

I've read ASTM G48. It says that its purpose is to check the corrosion resistance of stainless alloys to oxydizing chloride environments. It makes sense why your client has used it, taking into account that the welded material will be used on an offshore platform.
The corrosive solution employed is a 6% ferric chloride solution in water, a weak corrosive medium. Stress corrosion produced by chlorides on stainless steels can be discarded because the alloy coupon is just submerged into the solution, without any stress acting on it.
jarcher comment on carbon contamination from grinding disks used for carbon steel also makes sense. In fact, grinding disks for carbon steels are made of silicon carbide (Carborundum is a well known brand) and when used on stainless steels their carbon combines with chrome, thus giving way to intergranular corrosion. In this case, however, the corrosion showed up as pitts on the weld surface. Discarding stress and intergranular, galvanic corrosion is the most probable cause.
Now, according to the lab, there were only two small pitts on the weld surface. I can't understand how two small pitts can account for a weight loss of 48 grams/square meter, i.e., 12 times greater than the allowed maximum. There must have been other signs of corrosion that the lab didn't report. It would be very interesting to know how they looked like.
You see, everybody else in this exchange of ideas is putting the fault on the weld. As a chemical engineer, and looking at the problem from a chemical point of view, I'm prone to put the fault on the base material.
Giovanni S. Crisi

By welder5354 (**)

Date 10-28-2009 20:32

I had to material check for ferrite count.
It was 55-60, so would that be another factor for the high weight loss.

By G.S.Crisi (****)

Date 10-28-2009 23:19

I agree with you.
Giovanni S. Crisi

By ssbn727 (*****)

Date 10-29-2009 02:46

No because, that is well within the range of 40 to 60% in the material... Now the ferrite content is up to 80% as cast but through subsequent heat treatment as part of the manufacturing process the phases are more or less somewhat balanced to what I mentioned above so, 55 to 60 is still within range and probably better than what used to be the normal result of earlier heat treatment techniques which have substantially improved since the seventies when Duplex and Super duplex SS were gaining so much popularity as a replacement for 316 stainless in many applications. mainly because of superior corrosion resistant in certain environments as well as high yield strength also.

Respectfully,
Henry

By ssbn727 (*****)

Date 10-29-2009 02:38 Edited 11-06-2009 06:19

This is more than likely one your probable culprits the root pass deposit of the ER 2594 (100X) using GTAW...Now I don't know the exact chemical composition of the root pass filler but if there was an insufficient amount of nickel necessary in order to hold the all weld metal ferrite levels low enough for good ductility the conditions as such would certainly be enough to warrant enough IGSCC (Inter-Granular Stress Corrosion Cracking) throughout the thickness of almost the entire weld metal deposit passes to cause enough corrosion and show the pitting marks as well, because if the base/parent metal has a 5 to 6% Nickel content and the root filler doesn't have at least an 8 to 10% of Nickel in order to keep the ferrite number low enough to avoid brittle fracture due to IGSCC that is, so long as excessive dilution is avoided, then IGSCC can originate where the first pass of the flux cored deposit of Supercore (E2209TO/1-4) diluted, and more than likely excessively with the root pass made up of an alloy mix with insufficient Nickel. this is one of many probabilities however slim it may be, I'm leaning more towards excessive dilution due to the higher heat input from the FCAW process... So the next questions would be: What were the parameters used in welding with the FCAW process, and what were the parameters for the GTAW process and finally, what was the exact composition of purging gas used - NOT the shielding gas!!!

I ask this because if there wasn't a slight amount of Nitrogen added to the purging gas this could also have led to setting up the conditions for IGSCC as well as having too many ppm's of oxygen in the purging gas, not the shielding gas!!! In summary, if there isn't sufficient data bought forth for us to analyze completely to cover all possible scenarios by having all of the pertinent information available to review, then we could come up with all types of possible root causes that may or may not bear fruit with or without complete confidence! ;)

Nanjing you need to reread the original post where Welder 5354 does mention the base or as you might understand it as the parent material being:

4", sch. 120 (SA-790 (S31803) which is 2205, or 22% Chromium version.

Respectfully,
Henry

By Nanjing Date 10-29-2009 07:55 Edited 10-29-2009 07:57

Henry I missed that bit! No wonder it failed. How can you expect a 22%Cr filler to pass a G48 test at 40C? Remember the sample is fully immersed in the ferric chloride solution so the sides and cap will be in contact with the test solution. 25C is a tough test for this FCAW filler. Norsok does not require corrosion tests on 22%Cr. Why weld 22%Cr with superduplex anyway? If you want it to pass you should weld it out with the 25%Cr filler however you will probably still have problems due to dilution lowering the PREN.

By the way 31803 is not 2205.

By ssbn727 (*****)

Date 10-29-2009 15:18 Edited 10-29-2009 15:31

Nanjing, According to Sandvik, yes it is! ;) And they make lots of tons of this base/parent metal stuff! :) :) :) Now if you are referring to the filler, then you are correct since it is a 2209 that is recommended to use on the 2205 Duplex base/parent metal. the 2594 was used only for the root pass only and since it has more nickel than the base/parent metal, as I explained before in order to keep the ferrite number low enough to avoid brittle fracture due to IGSCC that is, so long as excessive dilution is avoided which is what probably occurred in the first passes deposited of the Supercore FCAW filler afterwards. This to me, doesn't make sense anymore since the most current FCAW filler metals used for welding 2205 Duplex already have a higher percentage of nickel in them compared to the earlier versions of the same number designated FCAW filler metal.

Respectfully,
Henry

By Nanjing Date 10-30-2009 01:23

Henry the bottom line is the corrosion test failed because the wrong filler wire was used.

As to the 31803 and the 2205 have a look at the chemistries. 2205 has a tighter band for moly and nitrogen to increase the pitting resistance. Regarding nickel content that is increased to maintain the ferrite austenite balance in the as-welded condition. If solution anealling is performed after welding a matching consumable is used.

By ssbn727 (*****)

Date 10-30-2009 02:39 Edited 10-30-2009 05:54

The UNS number S 31803 is the equivalent for 2205 Duplex Grade!!! Please look at yout AISI or UNS Grades chart, and you will then understand what I am talking about because you must be thinking of something completely different and totally incorrect with respect to the context in which the two sets of numbers coincide -CAPECHE!!! Of course there may just be some rather slight variations in the chemical compositions with respect to the infintisimile differences in tenths to thousandths of a percent in content of each respective element but, and here's where it means everything... The Duplex grade is 2205 and one of the UNS numbers for 2205 Duplex stainless steel is S 31803 - PERIOD!!! CASE CLOSED!!! ;) :) :)

Respectfully,
Henry

By Nanjing Date 10-30-2009 03:43

Henry, UNS number for 2205 is S32205. Difference in Chemistry is not infinitisimal as you say. Cr, Mo and N all have higher minimum levels for the 2205 as these are the three main elements that affect pitting corrosion. Have a look in ASTM. Case closed now.

By ssbn727 (*****)

Date 10-30-2009 04:30 Edited 10-30-2009 04:40

[deleted]

By Nanjing Date 10-30-2009 04:52

[deleted]

By ssbn727 (*****)

Date 10-30-2009 02:50

Btw, it's NOT A SUPER DUPLEX Grade of stainless steel!!! It is a regular Duplex grade of Stainless steel!!! Check your numbers real good before you challenge my technical proficiency because if you don't, you make yourself seem rather uninformed by throwing all sorts of bad data in order to challenge my technical proficiency regarding this query. And without showing anything to back yourself up with your claim!!!

I STRONGLY SUGGEST THAT YOU STUDY THIS WEBPAGE AND EAT YOUR PIECE OF HUMBLE PIE!!!

http://www.matweb.com/search/quicktext.aspx?SearchText=UNS+S31803

Henry

By Nanjing Date 10-30-2009 03:32

Henry, do not get all upset. Welder 5354 is asking why his corrosion tests have failed and I am simply telling him why it failed. He has used a 22%Cr filler and tested at 40C which is the temperature for a super duplex test. Test failed because of this, nothing to do with anyything else. I have given him the reason why it has failed but I wonder why he used a 22%Cr base metal with 25%Cr root and 22%Cr fill then tested at 40C. Maybe I am missing something, perhaps you could explain to me.
If you read my posts I never said the base material was super duplex. If you care to look at the chemisties of both materials you will see that it is possible for both materials to be the same however if your job specification calls up 2205 and you order 31803 it is possible to have 31803 which will not meet your specification. Many clients nowadays specify 2205 with a minimum PREN of 35 as it is considered significantly better then 31803. None of the data I have given is incorrect. I have come across this problem before where the contractor thought he could save money on the fill as it is only the pipe internal surface and root which was in contact with the process fluid.
BTW I did not challenge your technical profficiency. Please do not challenge mine.

By ssbn727 (*****)

Date 10-30-2009 05:24 Edited 11-06-2009 06:14

Nanjing!

I already explained to you why they specified the 25% Cr root pass, and i'll quote it once again... Quote:

By ssbn727 (****) Date 10-28-2009 22:38

"This is more than likely one of your probable culprits the root pass deposit of the ER 2594 (100X) using GTAW...Now I don't know the exact chemical composition of the root pass filler but if there was an insufficient amount of nickel necessary in order to hold the all weld metal ferrite levels low enough for good ductility the conditions as such would certainly be enough to warrant enough IGSCC (Inter-Granular Stress Corrosion Cracking) throughout the thickness of almost the entire weld metal deposit passes to cause enough corrosion and show the pitting marks as well, because if the base/parent metal has a 5 to 6% Nickel content and the root filler doesn't have at least an 8 to 10% of Nickel in order to keep the ferrite number low enough to avoid brittle fracture due to IGSCC that is, so long as excessive dilution is avoided, then IGSCC can originate where the first pass of the flux cored deposit of Supercore (E2209TO/1-4) diluted, and more than likely excessively with the root pass made up of an alloy mix with insufficient Nickel. this is one of many probabilities however slim it may be, I'm leaning more towards excessive dilution due to the higher heat input from the FCAW process... So the next questions would be: What were the parameters used in welding with the FCAW process, and what were the parameters for the GTAW process and finally, what was the exact composition of purging gas used - NOT the shielding gas!!!

I ask this because if there wasn't a slight amount of Nitrogen added to the purging gas this could also have led to setting up the conditions for IGSCC as well as having too many ppm's of oxygen in the purging gas, not the shielding gas!!!

In summary, if there isn't sufficient data bought forth for us to analyze completely to cover all possible scenarios by having all of the pertinent information available to review, then we could come up with all types of possible root causes that may or may not bear fruit with or without complete confidence!"

Then you have the audacity to say this:

"If you read my posts I never said the base material was super duplex."

Well then what the heck is this???

By Nanjing (**) Date 10-28-2009 18:22 Edited 10-28-2009 18:35 Quote:

"I take it that it is 25% Cr super duplex not standard 22% Cr you do not say."

This is when I referred to the original poster's first post on this thread, and btw, the time lines do not lie so, please do not take me for a fool because you'll find yourself caught with your pants on fire if you dare underestimate my powers of understanding how these threads and posts work!!!

Look, I do not disagree with what you think is the probable root cause of why the pitting marks occurred, I just disagree with your blanket statement that the only UNS number for grade 2205 duplex stainless steel is only S32205 because it is clear that I proved not only to you, but to anyone else who wants to notice that there is more than one UNS number for Grade 2205 Duplex Stainless steel which is both S32205 and S31803 as well yet you still fail to agree with me and hold your ground that there is only one UNS number for 2205 grade Duplex stainless steel despite the overwhelming proof I have provided compared to nothing that you have put up so far to counter my assertion. And that is the main reason that you make yourself look so ignorant like a horse with blinders on!!!

Finally I agree if there isn't sufficient Nitrogen or Nickel to keep the ferrite level from rising substantially enough to disrupt the phase balance which is why they probably used the 25% Cr GTAW filler for the root as well as the process in order to control dilution as well as to deposit more Nickel if it was present in the chemistry of the GTAW filler rod into the root so that when the subsequent FCAW filler was to be deposited after wards, the added nickel in the root filler would evenly dilute into the following FCAW passes and therefore theoretically control the ferrite content but, they probably didn't use a purging gas with a slight enough amount of Nitrogen in order to counteract the loss of Nitrogen in the root deposit coalescing with the base/parent metal.

This is more than likely one scenario although, the FCAW filler could also have been made up of the other UNS number of grade 2205 duplex stainless as opposed to the same one as the base/parent metal also.

However, when you kept insisting that there is only one UNS number for Grade 2205 duplex SS, I kept trying to convince you that you were incorrect up to the point where I submitted indisputable proof, yet you still were adamant that there was only one UNS number - is the MAIN reason why I am not only upset with your utter ignorance, but I'm also in fact pizzed off at you for your obvious denial in you own statements in this thread, and that is totally unacceptable. So, if you want to finally concede that you were wrong and ignorant towards what I was attempting to prove to you, and to admit that you did indeed made such statement as the one's I posted above and apologize -I will then be more than willing to accept it!!!

Henry

By Nanjing Date 10-30-2009 06:18

Henry, I said "I took it to be superduplex" because I saw the post with 40C as the test temperature but did not see the post which you pointed out to me later which stated the actual grade used, correct? I told you I had missed it. As soon as I saw that it is clear what welder 5354's prolem was.
How you can write screeds of drivel on something that a blind man can see. YOU DO NOT DO G48 CORROSION TESTS AT 40C ON STANDARD 22%Cr DUPLEX. DO YOU NOT KNOW THIS? (I write in capitals as I do not know how to make the letters bold like you!).

By ssbn727 (*****)

Date 10-30-2009 06:32

[deleted]

By Nanjing Date 10-30-2009 06:56

[deleted]

By ssbn727 (*****)

Date 10-30-2009 07:05

[deleted]

By Nanjing Date 10-30-2009 09:22

[deleted]

By ssbn727 (*****)

Date 10-30-2009 20:59 Edited 10-30-2009 21:11

[deleted]

By Nanjing Date 10-30-2009 22:42

My goodness Henry you can write so much.

Two points.

1. The descaling process is a standard Norsok requirement and does not form part of the actual corrosion test.

2. The weld was filled and capped with E2209.

On point 1 I asked if the lab was familiar with doing these tests. If experienced they should know to weigh the samples prior to testing.

on point 2 have you personal experience of testing this 22%Cr filler wire at a temperature set for 25%Cr?

I wonder if welder5354 has been in touch with his consumable supplier to complain? What do you think the manufacturer will say in reply when you tell him you tested his wire at an excessive temperature? He will say you have screwed up testing at that temperature.

There you go Henry, no need for War and Peace that is it in a nutshell. Select the right welding consumable for the job.

By Shane Feder (****)

Date 10-31-2009 02:46

Henry,
Why all the bold writing ? It makes it seem like you are shouting and that is not very professional is it ?
I will try and clarify this disagreement and hopefully not get shot down in flames.
Grade 2205 has two UNS numbers S31803 and S32205.
Sandvik make a 2205 which is UNS S31803
Avesta / Outukumpu make a 2205 which is UNS S32205

ASME IX QW 422 has
SA-790 = S31803
A -790 = S32205

The OP stated SA-790 so the correct UNS is S31803.

This excerpt from a paper by the Australian Stainless Steel Development Association may help explain.
" The standard S31803 composition has over the years been refined by many steel suppliers, and the resulting restricted composition range was endorsed as UNS 32205 in 1996. S32205 gives better guaranteed corrosion resistance, but much of the S31803 currently produced also complies with S32205."

Based on that note nanjing is correct regarding the statement that you could purchase Grade 2205 S31803 for a project and it may not comply with the clients specifications for 2205.
Therefore they are both Grade 2205 materials but they are not equivalent.

BTW, I worked with nanjing for 2 1/2 years and other than the late Chuck Meadows I have never met a person with a greater knowledge of welding exotic materials.
Regards,
Shane

By ssbn727 (*****)

Date 10-31-2009 03:16 Edited 10-31-2009 03:35

[deleted]

By Nanjing Date 10-31-2009 05:55 Edited 10-31-2009 06:45

Henry, dear friend, you still not have not responded to my repeated question. With your vast experience in welding do you consider testing 22%Cr weld metal at 40C acceptable and a normal industry practice?

Please no more rants. Welder 5354 has asked for help and you have become preoccupied with UNS numbers for some reason. Help welder 5354. Tell him if it is ok to use 22%Cr filler in a 40C G48 test and that the problem lies elsewhere. I note everyone else who originally commented on this has kept their heads down. How about you DR Crisi? What is your opinion? Do you recommend testing this filler at this temperature? I feel sorry for welder 5354 who came on here looking for some help and this thread has degenerated into Henry's insecurity about not having a degree and having a liver transplant and basically trying to cover up the real issue that he did not see that the problem was with with the filler wire selection for the test temperature. By the way Henry I do not drink too much... I spill most of it.

By ssbn727 (*****)

Date 10-31-2009 12:18

To my dear "Friend Nanjing!" (I am being very Sarcastic when I type this in case you're wondering!)

I wasn't planning on replying to anymore of your responses, but you decided to twist e verything around once again!!! You say I mentioned my liver transplant in this thread, and nothing could be further from the truth you poor excuse for a human being wh until now, I only thought that maybe, just maybe you were slightly ineabreated while reading the responses, and then you stoop down to using such a low life tactic is this??? How really pathetic you are!!! Your friend Shane actually compared you to my friend Chuck Meadows as someone who had as much knowledge as he did regarding stainless steels??? You could not hold a candle to him, and I feel bad enough that I even have to associate you in the same paragraph with Chuck who was truly superior than you as well as MAN enough to admit when he overlooked something more than once, or even flat out made a mistake when pointed out to him, and that is something you cannot do as you have demonstrated throughout this entire thread!!!

You want an answer to your stupid and MOOT QUESTION??? HERE IT IS!!! WRITE WHAT YOU MEAN, AND MEAN WHAT YOU WRITE!!! BEFORE YOU CHALLENGE ANYONE TO ANYTHING IN HERE!!! FINALLY, PROFESSOR CRISI ALREADY ANSWERED THE MAIN GIST OF YOUR QUESTION ALREADY SO, I'M JUST GONNA COPY AND PASTE IT ONCE AGAIN FOR YOUR EYES:

G.S.Crisi (****) Date 10-27-2009 07:52 Rating 3 (***)

Being a chemical engineer, I'll look at your problem from a chemical point of view.
First. You say, and paragraph 4.3.5 of Norsok standard confirms it, that the coupon was pickled for 5 minutes in the nitric and hydrofluoric acids solution at 60ºC. Scrictly speaking, pickling doesn't make part of the corrosion test. Its purpose is to remove the dirtyness (oil and grease for example) and the very very thin chromium oxyde layer that exists on the duplex alloy surface, so as to leave the coupon metal clean and pure before starting the corrosion test.
Nevertheless, 20% nitric and 5% hydrofluoric acids solutions at 60ºC is a mighty corrosive environment, so it's possible (quite possible, I'd say) that corrosion on your coupon began at this point. Carbon steel would be eaten away in a few minutes if submerged in that solution.

This percentage of pickling solution is obviously the root cause of such weight losss because the 6% ferric chloride solution by in itself could not dissolve 12 times the allowable maximum all by itself, so the fault lies in the actual percentage of nitric and Hydrofluoric acid used for pickling as the only logical cause for such an extraordinary amount of weight loss!!! So your point is MOOT regarding the 40 degrees C as being the main culprit because a difference of 5 degrees over what is normal industry practice could not account for such a huge amount of weight loss - CAPECHE???

Dear Friend??? Having friends like yourself Nanjing, then who needs enemies!!! As far as the degree is concerned, i do'nt need your lousy excuse for something to wipe my a$$ with - No Thanks!!! I've got Scott tissue which works just fine!!! The filler wire for the FCAW portion is the correct one for alloy 2205 if, and I'll emphasize a big if it was straight alloy 2205... If it was alloy for 2205+ which is formulated for the other UNS number-S32205 then, the FCAW filler would be incorrect because of the slightly different chemical composition which at this point none of us really know what is consists of... If the GTAW filler used exclusively for the root pass only was not of a type with sufficient enough N as well as Ni which also DO NOT know the exact chemical make up of either, and there wasn't enough Ni or any for that matter used in the purging medium along with too much Oxygen in PPM's then it's quite possible, and I emphasize quite possible that all of these scenario's or most of them combined in one combination or another could account for the failure in the corrosion test however, I'm leaning towards the pickling medium being too strong as the actual culprit at this point!!! So there you have it phukhead, err - I mean Nanjing, Come-Mierda, or whatever your name is!!!

In summary, no one aside from the folks who have ALL of, and I say ALL of this pertinent data could know exactly what is the ROOT cause of the corrosion test failure!!! We can only speculate as we do most of the time and that is why we have discussion like this one... Unfortunately, when a person like yourself comes in here tooting their proverbial horn like you did and totally makes such an a$$ out of themselves like you did, doesn't help welder 5354 by being so adamant with your ignorance and then avoid admitting your own mistakes, only cheapens the discussion by the way you pathetically attempted to turn around and deflect your own insecurities towards me!!! that was the straw that broke the proverbial camel's back and it's as simple as that!!! So once again - GIVE IT UP ALREADY!!!

Btw, are you stuttering here as you write this??? Because I've never thought one could such a thing with a keyboard!!! ;) ;) ;) Quote: "I feel sorry for welder 5354 who came on here looking for some help and this thread has degenerated into Henry's insecurity about not having a degree and having a liver transplant and basically trying to cover up the real issue that he did not see that the problem was with with the filler wire selection for the test temperature.' Hmmmm... "with with???" Quote: "By the way Henry I do not drink too much... I spill most of it." Where? In your eyes??? Then it's no wonder your constantly unable to read or pickup everything that is pertinent in this thread :) :) :)

GIVE IT A REST ALREADY!!! IT'S OBVIOUS WHO IS BEING INSECURE HERE, AND IT CERTAINLY IS NOT ME, MY DEAR FRIEND NANJING!!! :) :) :)

Henry

By Nanjing Date 11-01-2009 01:05

Henry, my old friend you have at least answered my question at last!:

"So your point is MOOT regarding the 40 degrees C as being the main culprit because a difference of 5 degrees over what is normal industry practice could not account for such a huge amount of weight loss - CAPECHE???"

Henry if you had any experience at all you would know 22%Cr duplex is tested at 22-25C and super duplex is tested at 35-40C with a norm of plus or minus 2C. This can mean welder 5354 has tested his samples at possibly 18C over the normal temperature. This shows you have no frontline experience in corrosion testing duplex welding consumables. If you decide to reply please cut and paste a welding consumable manufacturer's recommendations for corrosion testing 22%Cr duplex.

I am sure your friend Chuck will be sitting on a cloud somewhere shaking his head at your technically incorrect statements.

I will persevere to give advice to you and others on this forum when I can however I do not have much spare time.

If you care to reply please keep it brief and to the point.

I truly hope you get better soon (and I am not being sarcastic, you need help).

By ssbn727 (*****)

Date 11-01-2009 01:44 Edited 11-01-2009 02:28

Hah, Hah, Hah!!! You fell for my ruse after all!!!TRICK OR TREAT!!! :) :) :) What I actually gave you were the PRE Numbers for Alloy 2205 and you fell for the bait my Dear friend!!! :) :) :) Yeah Chuck is most definitely shaking his and laughing out loud how you fell right into my trap!!! :) :) :) Actually you can go up to 30 C with Alloy 2205+ so you're not totally correct, but nice try in any event!!! Now please give it a rest because it's a shame to see you making yourself look so obtuse!!! ROTFLMFAO - ROTFLMFAO - ROTFLMFAO!!! :) :) :) :) :) HAPPY HALLOWEEN!!!!!!! ;) ;) ;) You do know the equations on how to figure them out, don't you!!! ;) I mean after all, you should???

Henry

By Nanjing Date 11-01-2009 01:58

You are trully clueless! Welder 5354 tested at 40C. u say u can go up to 30C. What do u expect to happen at 40C? Henry I am trying to help you, I want to give you the benefit of my knowledge and experience but you will not listen. If you do not want to believe me please consult others,eg DR Crisi (I do not know where he has gone.. maybe in hiding).

By ssbn727 (*****)

Date 11-01-2009 02:05 Edited 11-01-2009 02:28

[deleted]

By Nanjing Date 11-01-2009 03:14

PREN= Cr+3.33Mo+16 N (or something like that, of the top of my head!).

Now answer my question. Is 22%Cr filler suitable for testing at 40C? If u think it is please substantiate it. Simple question.. give me a straight forward answer answer.

By ssbn727 (*****)

Date 11-01-2009 07:13 Edited 11-01-2009 13:42

I apologize for the late response, but I was celebrating my NY Yankees Baseball team winning their 2nd consecutive win over the Philadelphia Phillies, so I wasn't paying attention as to whether or not you even responded!!! Okay, let's see what you wrote... Hmmm, I thought so!!! You most definitely need to get your eyes checked Nanjing... Why??? It's really quite simple yet ohhh sooo subtle that it escaped your eyes completely and here's what I mean exactly as well as without any ambiguity whatsoever!!! ;)

First off this is where you misread my question and proved just how important it is for you to get you eyesight checked...Get rid of the the percentage of "Nickel" and you are correct for the PRE Number, as opposed to the PREN Number which is what you thought I wrote so, although I will not be as critical as you were with me, it just proves to me and everyone else again that you need to get your eyes checked my dear friend Nanjing!!! :) :) :)

Okay, now that I've clarified what your problem really is, I'll answer your straightforward question with a straightforward answer (Did you actually think that I would do such a thing Nanjing???)...

NO!!! Why??? Because you'll surpass the critical pitting temperature, or CPT @ around 22 -23 degrees C to a maximum of around 24-25 degrees C with heats that have lower percentages of Ni as well as N & Mo in their chemical compositions in both the Base/parent metals & welding filler metals, and since there are only a few brand manufacturers of both base/parent metals which have slightly elevated amounts of these alloying elements while simultaneously staying within the bounds of what is still considered an Alloy 2205 grade of duplex Stainless Steel, only slightly enhanced when one observes it with appropriate over alloying N, a "smidgen" (which in my book is a really, really small amount in order to increase pitting and crevice corrosion) more of Mo & Ni (which slows the formation of brittle intermetallic compounds as well as increasing yield strength) as well, then combining them with similarly enhanced weld filler metals of the 2209 grade, one can quite possibly increase the level of the CPT only slightly more to about a maximum of up to 30 degrees C and that would only be feasible if cost was not a factor at all!!!

And it would probably require much more welder training for qualifying just to the WPS alone, and then subsequently towards production which would also have to be factored into the overall costs and I don't have to tell yo u how hard that is to convince as well as how rare it is to occur - yet it has in the past on occasion!!! ;) ;) ;) IMHO, I would rather switch to either a richer grade of Duplex, or switch to a Super Duplex grade all together, but that would require approval from both the owner as well as the EOR and that's as possible as it is for one to win the Powerball & Super Seven numbers lotterysimultaneously!!!;) ;) ;)

In summary, for alloy 2205, 22 to 25 degrees C maximum is the recommended CPT for ASTM G48-03 Method A only, before pitting in the weld and too much of the allowable weight/mass loss of the sample is reached even though the increased amount of weight/mass loss doesn't come close to 12 times the amount of weight/mass loss shown in this test since it is also required that the test be interrupted once more than 5% of the total weight/mass has been lost, and this must have happened way before the test reached the 24th hour!!! So this fact, makes me even more convinced that the pickling solution which is NOT required to be used in the ASTM G48-03, Method A corrosion test was indeed a factor in such a substantial amount of weight/mass loss of the specimen in question as Professor Crisi so eloquently pointed out in his previous post!!! The pickling solution really was indeed a factor in contributing to such a substantial amount of weight/mass loss of the specimen in question.

Although, it is quite possible without any regards for increased costs whatsoever to increase the maximum CPT to around up to 30 degrees C if increased scrutiny with respect to the chemical compositions of favorable heats in both base/parent metal as well as weld filler metal were incorporated in order to achieve the increased results of those CPT's before pitting would start show so prevalently as well as such a substantial amount of weight/mass loss. So there you have it Nanjing!!! You managed to persuade it out of me finally!!! ;) ;) ;) Anywho, it was fun watching you react in the way you did durng this discussion nonetheless!!! :) :) :) Promise me that you will go to the EYE DOCTOR??? SEE YA!!! WOULDN'T WANT TO BE YA!!! :) :) :)

Your Dear Freund, (intentionally spelled that way! ;) )
Henry

By Nanjing Date 11-01-2009 09:49

Henry. 40C it was tested at. Just answer my question. Is this a normal temperature for testing 22%Cr? Cut the bull.... you are talking round in circles! You cannot admit you are wrong on this as it will prove you are just a joke once and for all.

By 3.2 Inspector (***)

Date 11-01-2009 11:22

He always does that, he simply refuse to answer a straight forward question.

3.2

By Nanjing Date 11-01-2009 12:07

3.2, he must be a Philadelphia lawyer then not an engineer then!

By ssbn727 (*****)

Date 11-01-2009 13:50

Now I'm really disappointed in both of you guys!!! I would have thought by now that both of you would have realized by now that I am obviously correct as well as vindicated in not only my observations, but also my own experiments on both of your capabilities, or rather lack of combined capabilities to read properly even as I intentionally used both bold type face as well as italics combined intentional , yet subtle changes in some of the technical nomenclature to no avail even though your friend Shane acknowledged the use of these visual aids, in the hopes that both of you would be able to distinguish as well as comprehend all of my responses to you, and since you have both failed miserably on multiple occasions to become enlightened by my attempts up until now...

I've reached the point where even if I have already given you the answer to your multiple queries directed specifically towards me, both of you are still incapable of articulating it and I suppose it is because of the distinct differences between being familiar with the British, or "King's English" version of the English language which is obviously is quite different than the American Northeastern dialect to be more specific, version of the English language that I use to communicate with just about everyone I know and even most folks whom I do not have any previous communication just fine!!! And it is a shame - PERIOD!!! :( :( :(

However, I will not give up in pointing out to both of you that in my second to most current previous post before this one, I have answered your query as specifically as possible, so all you both need to do is to re-read my last two posts in this thread ,and you should then understand that both of you desperately need to seek the attention of an eye doctor!!!

Here's a tip... All you have to do is to look at the date and time of when my last two posts in this thread by comaring them with this one which will be when I'm finished writing and posting it, my most current post in the thread... Once you are able to figure that out and I pray that you both do, then you will both see the obvious error, or rather lack of sufficient eyesight in both of you at this time!!! ;) ;) ;) Tah- Tah Gentlemen!!! for I am done here!!! Find the answer and do what you will with it!!! :) :) :) I really do not care anymore!!! :) :) :)

Your Dearest Freund, (Once again, intentionally spelled in this manner for your amusement!;) )
Henry

P.S. I must admit to you both that I have had what I generally considered a rather bizarre, yet amusing time during my attempt to establish a meaningful relationship with both of you during this discussion as it has on many different occasions, reminded me of being spontaneously cast on "Saturday Night Live," the Famous and still running show on late night and can be found in the NBC network of American Broadcast Televison!!! :) :) :) Auf Wiedersehen!!! ;) ;) ;)