where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -
890 views
Technical Discussions
Rolf Diederichs
Director,
NDT.net, Germany, Joined Nov 1998, 609

Rolf Diederichs

Director,
NDT.net,
Germany,
Joined Nov 1998
609
01:00 Feb-16-1998
NDT Methods (TOFD) for Flaw Detection during Welding

This issue is addressed to Dr. Shaun Lawson who provided this
News topic on NDTnet 02/98.

It is written [1] :
'Defects were deliberately implanted into the testpieces by Nordon welders
at various stages of weld completion'

I wonder what types and sizes of inclusions were implanted for this trials.

From our former TOFD themes on NDTnet we know about certain POD problems
with the TOFD method.

I would appreciate if Dr. Lawson could provide more detailed information.

Rolf Diederichs


[1] http://www.ndt.net/news/1998/surrey/surrey.htm
NDT Methods for Flaw Detection during Welding.
The final ultrasonic TOFD trials of the BRITE-EURAM II project 'NDT Methods for Flaw Detection During Welding' took place in Oct 1997. The aim of the trials was to demonstrate NDT using TOFD whilst welding was taking place - i.e. the ultrasonic probes were to be placed a short distance behind the weld torch. The trials successfully demonstrated the techniques and methods developed during the four year study to undertake NDT during welding.
.......
'The trials successfully demonstrated the techniques and methods developed during the four year study to undertake NDT during welding. A number of welded test plates were prepared - one set of TIG welded 25mm thick steel, the other submerged arc welded 80 mm thick steel. Defects were deliberately implanted into the testpieces by Nordon welders at various stages of weld completion - Figure 2 shows an example of this work in progress. These defects included tungsten inclusions (for TIG welds), root cracks, porosities, lack of fusion, slag inclusions (for SA welds) and lack of penetration. The techniques that are required in order to implant suitably representative defects into the welds were developed by Nordon at an early stage in the project.'



 
 Reply 
 
Shaun Lawson
Shaun Lawson
09:15 Feb-19-1998
Re: NDT Methods (TOFD) for Flaw Detection during Welding
>>It is written [1] :
>>'Defects were deliberately implanted into the testpieces by Nordon welders
>>at various stages of weld completion'
>>
>>I wonder what types and sizes of inclusions were implanted for this trials.

Both TIG and SAW welding testpieces were manufactured . All deliberately
implanted defects were between 15mm and 30 mm in length - their
volumetric size varied with their type. Note though it is very difficult to
produce a 'defect' of exact requirements !

I have summarised defect types and their detectability in the article :-
http://www.ndt.net/article/0298/forum/defects.htm

The thinner TIG plates caused most problems - though Tungsten inclusions
were hard to detect at all completions. At very thin completions the
automated software had difficulty resolving the diffference between the
lateral/backwall waves and the defects - though these were often
discernable by manual means.

>>From our former TOFD themes on NDTnet we know about certain POD problems
>>with the TOFD method.

Note that the real aim of the trials was to determine whether defects
could be detected at high temps, during welding and at incomplete weld
completions rather than to demonstrate POD for any particular defect type.


Shaun.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dr. Shaun Lawson (tel: 01483 259681)
Mechatronic Systems & Robotics Research Group
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~




 
 Reply 
 
Hassan Rahimi
Hassan Rahimi
08:34 Jun-10-2000
Re: NDT Methods (TOFD) for Flaw Detection during Welding
: >>It is written [1] :
: >>'Defects were deliberately implanted into the testpieces by Nordon welders
: >>at various stages of weld completion'
: >>
: >>I wonder what types and sizes of inclusions were implanted for this trials.

: Both TIG and SAW welding testpieces were manufactured . All deliberately
: implanted defects were between 15mm and 30 mm in length - their
: volumetric size varied with their type. Note though it is very difficult to
: produce a 'defect' of exact requirements !

: I have summarised defect types and their detectability in the article :-
: http://www.ndt.net/article/0298/forum/defects.htm

: The thinner TIG plates caused most problems - though Tungsten inclusions
: were hard to detect at all completions. At very thin completions the
: automated software had difficulty resolving the diffference between the
: lateral/backwall waves and the defects - though these were often
: discernable by manual means.

: >>From our former TOFD themes onNDTnet we know about certain POD problems
: >>with the TOFD method.

: Note that the real aim of the trials was to determine whether defects
: could be detected at high temps, during welding and at incomplete weld
: completions rather than to demonstrate POD for any particular defect type.

:
: Shaun.
: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
: Dr. Shaun Lawson (tel: 01483 259681)
: Mechatronic Systems & Robotics Research Group
: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~




 
 Reply 
 
rejumohan
rejumohan
05:56 Dec-02-2002
Re: NDT Methods (TOFD) for Flaw Detection during Welding
: This issue is addressed to Dr. Shaun Lawson who provided this
: News topic on NDTnet 02/98.

: It is written [1] :
: 'Defects were deliberately implanted into the testpieces by Nordon welders
: at various stages of weld completion'

: I wonder what types and sizes of inclusions were implanted for this trials.
sir,
please send me some details of ndt.i am afinal year student in engineering studying in india.ihave to submit aseminar on ndt welding.please do the needful
: From our former TOFD themes on NDTnet we know about certain POD problems
: with the TOFD method.

: I would appreciate if Dr. Lawson could provide more detailed information.

: Rolf Diederichs

:
: [1] http://www.ndt.net/news/1998/surrey/surrey.htm
: NDT Methods for Flaw Detection during Welding.
: The final ultrasonic TOFD trials of the BRITE-EURAM II project 'NDT Methods for Flaw Detection During Welding' took place in Oct 1997. The aim of the trials was to demonstrate NDT using TOFD whilst welding was taking place - i.e. the ultrasonic probes were to be placed a short distance behind the weld torch. The trials successfully demonstrated the techniques and methods developed during the four year study to undertake NDT during welding.
: .......
: 'The trials successfully demonstrated the techniques and methods developed during the four year study to undertake NDT during welding. A number of welded test plates were prepared - one set of TIG welded 25mm thick steel, the other submerged arc welded 80 mm thick steel. Defects were deliberately implanted into the testpieces by Nordon welders at various stages of weld completion - Figure 2 shows an example of this work in progress. These defects included tungsten inclusions (for TIG welds), root cracks, porosities, lack of fusion, slag inclusions (for SA welds) and lack of penetration. The techniques that are required in order to implant suitably representative defects into the welds were developed by Nordon at an early stage in the project.'
:




 
 Reply 
 

Product Spotlight

Teletest Focus+

Teletest Focus+ electronics have superior capabilities than rivals on the market. Beyond the usual
...
test features, Focus+ has 24 transmit channels and 24 receive channels, with an additional on-board switching capabilities. The instrument's frequency range is 10–300 kHz.
>

IRIS 9000Plus - Introducing the next generation of heat exchanger inspection.

Representing the seventh generation of the IRIS system, the IRIS 9000 Plus has nearly 200 years of c
...
ombined field inspection experience incorporated in its design. This experience combined with a strong commitment to quality and a history of innovation has made Iris Inspection Services® the undisputed leader in IRIS technology.
>

Silverwing RMS PA - Phased-array corrosion mapping

Eddyfi Technologies integrated two market leading solutions, Silverwing’s RMS and M2M’s instru
...
ments to provide a high-speed, remote access ultrasonic phased-array inspection system with live total focusing method (TFM).
>

FAAST-PA! OEM Patented phased Array for high speed UT inspection

Multiangle, Multifocus, Multifrequency, Multibeam. Instead of stacking UT electronics and having m
...
any PA probes, FAAST-PA is able to transmit all delay laws within ONE single shot in Real time.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window