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2676 views
08:08 Nov-21-2008
Theo Micottis
ASTM A578

Hi everybody,I need some explanations about A578.I have had to check a bush with this dimensions: outer dia 600 inner 500. The clad surface was on the inner dia thickness 5mm. The acceptance level was S7. So I carried out examination from the clad surface as written in S7.1 using a MSEB 2 probe.The examination was carried out only to verify unbond.The final customer said me that I made the examination from the wrong side and also I used the wrong probe from the clad surface.Could someone help me to interpret this specification.THANK YOU


 
08:17 Nov-24-2008

Nigel Armstrong

Engineering, - Specialist services
United Kingdom,
Joined Oct 2000
1094
Re: ASTM A578 Theo

Did nobody notice that A578 is for testing of PLATES and you are testing a cylindrical item? This is a deviation and it should be noted on the report that the test was not completely in accordance with A578 requirements for that and concomitant technical reasons.

There are two conflicting requirements in the case of your test item which do not apply when plates are tested - a large diameter probe to be used from the clad side (inner diameter). This is the worst combination for test integrity due to possible loss of contact and should be avoided.

Supplemetary Requirement S7.1 states test from clad side, so as S7 was specified then that is correct, if unwise with regard to the test surface curvature and coupling with the transducer.

Clause 4.2. requires a larger diameter transducer (24 - 30mm diameter) than the MSEB 4. With an inner diameter of just 500mm then a smaller transducer should be used to give better contact.

personally I would have tested from the OD with a suitable 2MHz 1" diameter single crystal probe. Should be more reliable and easier to keep in view both base metal/clad interface and ID signal to look for any amplitude drop.

Hope this helps

Nigel


----------- Start Original Message -----------
: Hi everybody,I need some explanations about A578.I have had to check a bush with this dimensions: outer dia 600 inner 500. The clad surface was on the inner dia thickness 5mm. The acceptance level was S7. So I carried out examination from the clad surface as written in S7.1 using a MSEB 2 probe.The examination was carried out only to verify unbond.The final customer said me that I made the examination from the wrong side and also I used the wrong probe from the clad surface.Could someone help me to interpret this specification.THANK YOU
------------ End Original Message ------------




 
08:17 Nov-24-2008

Nigel Armstrong

Engineering, - Specialist services
United Kingdom,
Joined Oct 2000
1094
Re: ASTM A578 Theo

Did nobody notice that A578 is for testing of PLATES and you are testing a cylindrical item? This is a deviation and it should be noted on the report that the test was not completely in accordance with A578 requirements for that and concomitant technical reasons.

There are two conflicting requirements in the case of your test item which do not apply when plates are tested - a large diameter probe to be used from the clad side (inner diameter). This is the worst combination for test integrity due to possible loss of contact and should be avoided.

Supplemetary Requirement S7.1 states test from clad side, so as S7 was specified then that is correct, if unwise with regard to the test surface curvature and coupling with the transducer.

Clause 4.2. requires a larger diameter transducer (24 - 30mm diameter) than the MSEB 4. With an inner diameter of just 500mm then a smaller transducer should be used to give better contact.

personally I would have tested from the OD with a suitable 2MHz 1" diameter single crystal probe. Should be more reliable and easier to keep in view both base metal/clad interface and ID signal to look for any amplitude drop.

Hope this helps

Nigel


----------- Start Original Message -----------
: Hi everybody,I need some explanations about A578.I have had to check a bush with this dimensions: outer dia 600 inner 500. The clad surface was on the inner dia thickness 5mm. The acceptance level was S7. So I carried out examination from the clad surface as written in S7.1 using a MSEB 2 probe.The examination was carried out only to verify unbond.The final customer said me that I made the examination from the wrong side and also I used the wrong probe from the clad surface.Could someone help me to interpret this specification.THANK YOU
------------ End Original Message ------------




 
02:27 Nov-24-2008
Theo Micottis
Re: ASTM A578 Thank you very much Nigel. In reality this was my task in the exam for the third level UT. They gave me this standard for the unbond test and I really didn't think they gave me a wrong specification or at least with some deviations.I read S7.1 and I was quite sure of my choice. Well I failed my exam it will be better next time.You have been very useful.
Thank you very much

THEO


 
00:21 Nov-25-2008

S.V.Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
782
Re: ASTM A578 Theo,

That test was meant to know whether you can catch the mistake! Don't assume that the given procedure is correct. As a level III, you are supposed to correct and contest another level III if needed.

I did not respond earlier because I don't have ready access to the specification but my analysis was same as Nigel's (and I acknowledged that separately to him a few hours ago). I felt inspired to comment on this from a Trainer's perspective.

Best wishes for the future.

Swamy
NDT Guru (Trainer)

----------- Start Original Message -----------
: Thank you very much Nigel. In reality this was my task in the exam for the third level UT. They gave me this standard for the unbond test and I really didn't think they gave me a wrong specification or at least with some deviations.I read S7.1 and I was quite sure of my choice. Well I failed my exam it will be better next time.You have been very useful.
: Thank you very much
: THEO
------------ End Original Message ------------




 
07:54 Nov-25-2008

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
804
Re: ASTM A578 Gentlemen,

I like what you've said. More so, I believe that any technician should challenge another technician or client when they know the inspection that is required of them is wrong. Unfortunatly , sometimes people will bow under pressure because they are afraid to loose their job... It just happened to someone I know last week. He didn't do the inspection with the right procedure per code and now the client is in a rush to get another part of the same out the door. So, they pressured him to do the same inpsection on this piece although the client is aware that they don't have the proper equipment to do the work by code.

All they care is to get the part out the door. Yet those people don't realise that if they are cut doing the work improperly, they may loose this big contract and that after loosing many of these big contract, they will ultimetly also loose their jobs!!! Funny when you think of it. These people are engineers, metallurgist, etc... So, one would assume that they would know better. Just to show you that sometimes education doesn't give you common sense.

Cheerio's

Michel

----------- Start Original Message -----------
: Theo,
: That test was meant to know whether you can catch the mistake! Don't assume that the given procedure is correct. As a level III, you are supposed to correct and contest another level III if needed.
: I did not respond earlier because I don't have ready access to the specification but my analysis was same as Nigel's (and I acknowledged that separately to him a few hours ago). I felt inspired to comment on this from a Trainer's perspective.
: Best wishes for the future.
: Swamy
: NDT Guru (Trainer)
: : Thank you very much Nigel. In reality this was my task in the exam for the third level UT. They gave me this standard for the unbond test and I really didn't think they gave me a wrong specification or at least with some deviations.I read S7.1 and I was quite sure of my choice. Well I failed my exam it will be better next time.You have been very useful.
: : Thank you very much
: : THEO
------------ End Original Message ------------




 
09:22 Nov-25-2008
Theo Micottis
Re: ASTM A578 Thank you for your reply. You're right I made a mistake, but the other guys who set the same exam applied this standard from the outside diameter and they pass the exam.So as you can imagine that was not a test but a mistake of the examiners. This is a big lesson for the future that I will never forget.

YOURS SINCERELY

Theo MICOTTIS


 
20:55 Mar-12-2010
Stan Kujawa
Re: ASTM A578 In Reply to Theo Micottis at 08:08 Nov-21-2008 (Opening).

Hi My name is Stan,

I am currently working on a quote with a ASTM A578 spec for a forging made out of 4140 that has a od of 64-66" OD x 31.25" ID x 7.75 " thick. I am looking for any special concerns, list of equip required and anything else you would liketo contribute such as average inspection time for sucha product. I also had anothe request for sms engineering ndt testing spec of 600015-155. The same would go with this spec as far as information you may have. If you have copies of both specs please forward to my email address.

 
10:09 Aug-23-2010
Emily Soh
Re: ASTM A578 In Reply to Theo Micottis at 08:08 Nov-21-2008 (Opening).

Dear sir,
Pls advice me. I have a plate eg. 120mm thk x 1metre x4metre to do UT.
Mat'ls are suspected having small and big porosity (at random distribution)
(i) Can UT detect defects free? If yes, what is the ASTM standard?
(ii) Acc. to ASTM A388, UT can detect defect (small and big) porosity at 1/8"(3.175mm) and above.
(iii) Another spec. UT can detect at 1/16"(1.5875mm) defect and above. Pls advice the ASTM standard. Acc. to ASTM ______ ???

 


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