UT test on Duplex SS (22 % Cr) Pipe

Date 05-25-2004 14:34

First thing you have to do is to get in contact with the manufacturer (Krautkramer in this case) and ask him. No doubt he'll give you all the information you need. Even more, if to solve your problem you need to buy a new part (a special probe, for example), the answer will be inmediate.
Giovanni S. Crisi
Sao Paulo - Brazil

P.S. Don't you gentlemen think that this site is marvelous? From Sao Paulo, Brazil, South America, I'm answering a question posed by a gentleman who lives in Azerbaijan, on the Caspian sea. As far as I know, Azerbaijan was one of the republics that made part of the Soviet Union and is very rich in petroleum.

By NDTIII

Date 05-25-2004 18:40

What I would recommend to you is take a small section of the Duplex pipe and put some reflectors in it of a known size such as side drilled holes or notches. This can then be used as your calibration block. No special probes are required.
Velocity charts only give you theoretical values and differ from manufacturer to manufacturer. No one can argue with the velocity of an actual section of the pipe to be examined.

By LarryL

Date 05-26-2004 13:06

Professor Crisi, yes this site is a marvelous one that demonstrates the ease with which individuals may communicate across the world via the Internet. What really makes it marvelous, though, is the willingness of all of its welding experts, like yourself, to respond to questions and educate welding simpletons like myself!

LarryL

By GOKHANYAMAN (*)

Date 05-26-2004 13:55

Hi Crisi,

I complately agree with you. Its really marvelous, so many experienced supervisors, engineers, Inspectors are around here. And we may share our experience and knowledge with others from many countries.

I am still looking for UT procedure for SS and Duplex SS, mostly its required to prepare ASME calibration Block from production pipe, however I could not find if special prob required or not (waiting for response).
Also, you are right about Azerbaijan Respublic where very rich in Petroleum.
My greetings to Sao Poulo..

Regards..

Gokhan

By jwright650 (*****)

Date 05-26-2004 14:08

Hi Gokhan,
I am not familiar with UT'ing Duplex SS pipe, however, unless I'm missing something entirely(quite possible), I don't see why you can't use the same frequency and size crystal/wedge combination you would use for the other grade of SS. I agree with NDTIII that you could use a sample of the material that you plan to use and place known reflectors in it and calibrate off of that, and it would then match your velocities of the material being inspected. A different probe(transducer) may not be necessary.
John Wright

By jwright650 (*****)

Date 05-26-2004 14:12

LarryL and Giovanni,
I agree that this site is unique in the facts you both described.
John Wright

By NDTIII

Date 05-26-2004 14:44

I also agree. This site is fantastic for answering questions people have.

But to answer Gokhan's question, there are no special probes or procedures required for duplex. I have done it in the past. It is simply more attenuative than normal stainless steel and may or may not have a different velocity. Chances are it does.
If your concern is the attenuation, experiment with a refracted longitudinal wave probe. RD Tech and Panametrics manufacturers excellent L-wave probes.
As I stated earlier, if you use a piece of the material to be inspected and experiment with varying frequencies, it shouldn't take you long to come up with a claibration that provides a good signal to noise ratio and a procedure for it.

By jwright650 (*****)

Date 05-26-2004 14:50

NDTIII,
I haven't seen a USK-7 for a while. I thought my old USN-50 was getting to be dated equipment.
John Wright

By NDTIII

Date 05-26-2004 14:56

Ha! You are right. They are old, but still a useful workhorse. Believe it or not, some people still prefer them to the new digital units. The analog display had its advantages over the earlier digitals such as the USN-50. The proccessors on the earlier units didn't have the power or speed to display the entire waveform, so the sampling rate was low. That was a disadvantage because sometimes everything would look like a crack and sometimes everything would look like root, depending on your sampling rate and delay time.

By GOKHANYAMAN (*)

Date 05-27-2004 07:34

Hi NDT III/LarryL and Jwright650,

I agree with you all, if we combine all post and to summarize that as below:

Its not required any other special set up or other things except for L-Wave probes and a Piece of materials which shall be UT tested. We need little bit more trail and practice, as well.
In addition that, there is another info that saying Weld cap should be grinded flush.!!

By the way not only this site fantastic, People here are fantastic, as well. Even you do not know him/her and you share what you have known about welding, NDT, Metalurgy, experience etc..

Thanks to All.. :)

Gokhan

By g32141

Date 07-26-2004 06:08

As long as you have an accurate velocity measurement you can make your cal blocks and from there determine if your current probes or technique will work.
Too bad you don't have one of the newer digital machines because they are very good at determining velocities from a known thickness.
Where are you working in Azerbaiajan? I was in Baku twice working on a laybarge there.

By vonash

Date 07-27-2004 22:37

Oh Phooey. You guys don't know spit about UT.

By NDTIII

Date 07-28-2004 03:32

OK so why don't you enlighten us?

By vonash

Date 07-31-2004 00:40

That was a tongue in cheek post. I meant a little levity.

By NDTIII

Date 07-31-2004 06:48

I know. I was just kidding too.