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Hillger Ing. Büro
was founded in 1984 and develops special ultrasonic imaging systems for high-tech materials.

980 views
09:47 May-17-2008
felix
reference selection

how can i define the selection of a reference standard in an automatic ut inspection of steel pipes. can i use to inspect a pipe with one heat treatment one with double treatment? can i use as reference a pipe with a steel grade diferent if the pipe to inspect have the same heat treatment? how much will affect a heat treatment diferent to the acoustic properties in a steel pipe? thanks for your help.


 
02:47 May-19-2008

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
806
Re: reference selection Hi Felix,

Before I can tell you how to select a reference standard, you must remember what NDT is all about. It the practice of evaluating a part or piece of material without impairing its future usefulness. To do this, you compare a known (your reference standard) with an unkwon (the part being inspected).

From this first part of my answer, it goes without saying that any reference standard should be as close to the real thing as possible. Sometimes, you may get away with a 1018 steel IIW Block and inspect 4030 steel. The difference will be little, but the best thing if you can, should be a reference standard that is a true representaiton of the part being inspected. Also, if you read different Codes and Specifications, they will spedify that you should get a Reference Standard made up of the same material, heat treatment, surface finish and dimensions as what you will be inspecting.

Also not mentionned too often, have your Reference Standard and the part being tested at the same temperature.Temperature does affect material velocity.

Hope this will help you.

Michel

----------- Start Original Message -----------
: how can i define the selection of a reference standard in an automatic ut inspection of steel pipes. can i use to inspect a pipe with one heat treatment one with double treatment? can i use as reference a pipe with a steel grade diferent if the pipe to inspect have the same heat treatment? how much will affect a heat treatment diferent to the acoustic properties in a steel pipe? thanks for your help.
------------ End Original Message ------------




 
03:33 May-19-2008
felix
Re: reference selection thanks a lot Michel, about the codes and specifications, could you tell me wich one speak about the heat treatment and surface conditions....

regards, felix.


----------- Start Original Message -----------
: Hi Felix,
: Before I can tell you how to select a reference standard, you must remember what NDT is all about. It the practice of evaluating a part or piece of material without impairing its future usefulness. To do this, you compare a known (your reference standard) with an unkwon (the part being inspected).
: From this first part of my answer, it goes without saying that any reference standard should be as close to the real thing as possible. Sometimes, you may get away with a 1018 steel IIW Block and inspect 4030 steel. The difference will be little, but the best thing if you can, should be a reference standard that is a true representaiton of the part being inspected. Also, if you read different Codes and Specifications, they will spedify that you should get a Reference Standard made up of the same material, heat treatment, surface finish and dimensions as what you will be inspecting.
: Also not mentionned too often, have your Reference Standard and the part being tested at the same temperature. Temperature does affect material velocity.
: Hope this will help you.
: Michel
: : how can i define the selection of a reference standard in an automatic ut inspection of steel pipes. can i use to inspect a pipe with one heat treatment one with double treatment? can i use as reference a pipe with a steel grade diferent if the pipe to inspect have the same heat treatment? how much will affect a heat treatment diferent to the acoustic properties in a steel pipe? thanks for your help.
------------ End Original Message ------------




 
02:38 May-19-2008

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
806
Re: reference selection Presently 2 Codes that I'm working to are ASTM A418-05 and ASTM A388-07. They both deals with Steel Forgings. For A388 paragraph 7 tell you of the Forging Preparation while in A418 it is paragraph 4.2

One thing that I also forgot to mention and we do omit to do is that when we calibrate our set up should be the same as what we re inspecting. I've seen guys calibrating for weld inspection horizontally while the weld they will be inspecting is vertical. Just the fact that your couplant will be running off during the inspection (and not during your calibration) is enough to change your result. With a change in couplant thickness you may loose as much as 5 dB!!!

Food for taught!!!
Michel
----------- Start Original Message -----------
: thanks a lot Michel, about the codes and specifications, could you tell me wich one speak about the heat treatment and surface conditions....
: regards, felix.
:
: : Hi Felix,
: : Before I can tell you how to select a reference standard, you must remember what NDT is all about. It the practice of evaluating a part or piece of material without impairing its future usefulness. To do this, you compare a known (your reference standard) with an unkwon (the part being inspected).
: : From this first part of my answer, it goes without saying that any reference standard should be as close to the real thing as possible. Sometimes, you may get away with a 1018 steel IIW Block and inspect 4030 steel. The difference will be little, but the best thing if you can, should be a reference standard that is a true representaiton of the part being inspected. Also, if you read different Codes and Specifications, they will spedify that you should get a Reference Standard made up of the same material, heat treatment, surface finish and dimensions as what you will be inspecting.
: : Also not mentionned too often, have your Reference Standard and the part being tested at the same temperature. Temperature does affect material velocity.
: : Hope this will help you.
: : Michel
: : : how can i define the selection of a reference standard in an automatic ut inspection of steel pipes. can i use to inspect a pipe with one heat treatment one with double treatment? can i use as reference a pipe with a steel grade diferent if the pipe to inspect have the same heat treatment? how much will affect a heat treatment diferent to the acoustic properties in a steel pipe? thanks for your help.
------------ End Original Message ------------




 
01:21 May-28-2008
tj
Re: reference selection ----------- Start Original Message -----------
: how can i define the selection of a reference standard in an automatic ut inspection of steel pipes. can i use to inspect a pipe with one heat treatment one with double treatment? can i use as reference a pipe with a steel grade diferent if the pipe to inspect have the same heat treatment? how much will affect a heat treatment diferent to the acoustic properties in a steel pipe? thanks for your help.
------------ End Original Message ------------

The reference standard should be defined in the code you are inspecting to or by customer request (if applicable). If ASME is used, the standard will be defined per procedure. The norm is for the reference to be the same material and heat treatment as part to be inspected. The heat treatment difference between specimens will have an effect on test results.Hope it helps!



 


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