Re: NDT Methods (TOFD) for Flaw Detection during Welding

[ NDT-net Forum ]
[ Follow Ups ] [ Post Followup ] [ Help ]

Re: NDT Methods (TOFD) for Flaw Detection during Welding
Posted by: Hassan Rahimi , E-mail: hassan_rahimi@hotmail.com, on June 10, 2000 at 08:34 :
In Reply to: Re: NDT Methods (TOFD) for Flaw Detection during Welding posted by : Shaun Lawson on February 19, 1998 at 19:15:28:
: >>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
: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Follow Ups:

Post a Followup:

Name:

E-Mail:

Subject:

Comments:
: : >>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 : : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Optional Link URL: Example: "http://www....html". Alternative write "http://www.ndt.net/wshop/attach/filename.htm" if you transfered a filename.htm via FTP

Link Title: is important! Information on my Home Page

Optional Image URL: http://www....gif

Attention! Please click the button only once. This may take a moment to process
[ NDT-net Forum ] [ Help ]

Optional Link URL:	Example: "http://www....html". Alternative write "http://www.ndt.net/wshop/attach/filename.htm" if you transfered a filename.htm via FTP
Link Title: is important!	Information on my Home Page
Optional Image URL:	http://www....gif