RT Film Stainless steels 1

[sixxerxxre]

hello there,

anyone who knows where I can find some images of radio film with a defect of root welding called " rochage " in french and " sugaring " or oxidation in english ?
is this type of defect easy to interpret on RT Films ?

GTAW of stainless steel tubes butt weld and full penetration and inadequately protected by gas backing...

thank you

 

[DekDee]

sixxerxxre,
Not sure where to find - you could try the Agfa site, I remember a few years ago they had reference films of known defects.
Oxidation is generally very easy to see on the radiograph - unfortunately discolouration (especially for DSS & SDSS) cannot be seen on the radiograph.
Hope that helps,
Regards,
DD

 

[sixxerxxre]

thank you
while searching for a link i found this :

http://www.ge-mcs.com/download/x-ra...rial-radiography-image-forming-techniques.pdf

: very interesting but not yet found anything about " sugaring " or " root caking ".
still looking for

 

[weldstan]

Gross oxidation "sugaring" in the root is readily detectable with RT. It is noted that "sugaring" is not addressed as a rejectable dicontinuity in ASME Codes. I would suggest that you make a test weld with sugaring and x-ray it to produce your own film for future reference.

 

[Duwe6]

Having done RT, you Nuke guys will find it very hard to image. It requires very fine-grain film, and at least a 16" source-to-film distance [2-ft is much better], and a moderate wall thickness. With jumbo-wall pipe, the thickness moves the root 2 to 3" away from the film. This gives excellent definition of the cap and poor definition of the weld. Further, stainless gives some X-ray diffraction lines using a gamma source, and a 'carnival' of diffraction lines using an X-ray tube source.

 

[weldstan]

I should have mentioned it is readily observable on thin welds. On thick welds typical for nuclear, see Duwe6.

 

[sixxerxxre]

thanks to all
not found yet, as suggested by weldstan, they should produce an oxidized coupon and perform a RT shot to get a reference sample.

 

[kjell123898]

hi,
we have done a lot of RT images with this type of internal oxidation caused by lack of backing gas and please find one example attached below

 

[sixxerxxre]

grat thanks to kjell123898
i followed the link, the RT film is explicit !
not sure any operator can do it...