NDE to assess the thickness of clad 2

[sayee1]

Does anybody know of a suitable and proven technique for measuring the thickness of 6625/8825 clad on a cs(API 5L X60/X65/A694 F65). My client asks to use Ut for doing the same, is it feasible to do so? Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668

 

[PVRV]

I am not aware of any other method.

 

[sayee1]

I am a welding engg and a beginner for NDE, can you elaborate on how UT can be used the measuremet of clad thk or do you have any refernces for how this can be used? Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668

 

[ElderX]

Back in one of my previous lives we developed a technique using magnetic lift-off much like that used for measuring coatings and glass liners. You also may be able to measure using eddy current.

For the UT technique if the layer is thick enough >0.060" you should be able to measure it's thickness. The theory is; because the clad and the CS have different acoustic impedance and if the ratio is large enough you should see a reflection (return signal) from the clad/cs interface. You can then deterimine the thickness of the cladding by the time of flight. It would require a sample of the clad with a known thickness to calibrate on. It is theoretically feasible. I would try the eddy current or magnetic gage though first as it would be easier in my opinion.

 

[quadswift]

After 'Elder' message,
You could try using the U/T from the carbon steel side. If the cladding is on the thin side, the interface may get mixed up in the probe dead zone / noise area.

Quadswift

 

[sayee1]

Thanx a lot, quadswift and ElderX Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668
End of all knowledge is the attainment of immortality!

 

[RNicastro]

Look for a company using the TMI-150 Ultrasonic B-Scan. Properly set up you can see the interface between the clad and the steel. I used this instrument for 12 years to inspect the clad on Pulp Digesters and it was fairly accurate. We had to play to get the velocy correction but it is fairly simple if you are a level II. A gentleman at Longview in KC Missouri by the name of Kirk Henning is very knowledgeable with this proceedure. Give him a try and I will E-mail him this post.