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 -
1239 views
Technical Discussions
creed
NDT Inspector,
n.n., Joined Jul 2009, 33

creed

NDT Inspector,
n.n.,
Joined Jul 2009
33
04:48 Dec-06-2012
Eddy current testing for welds

Hi everyone,
I have quick questions related to Weld Eddy Current Tesing:
1. " When we use 100kHz probe, Can we detect subsurface defects within 2mm depth? because we used the calibration block with 2mm depth slot signal is reference level (eg. 80% of full screen)?
2. With the thin thickness of parent metal in weld testing will affect to the ECT signal? and How to control if YES?
Eg: the weld with the parent metal thickness is 2 or 3mm whilst we us ED slot calibration block with 5mm thick.
Thanks

 
 Reply 
 
John Hansen
Director, - Eddy Current Technology
ETher NDE Ltd, United Kingdom, Joined Oct 1999, 73

John Hansen

Director, - Eddy Current Technology
ETher NDE Ltd,
United Kingdom,
Joined Oct 1999
73
10:32 Dec-06-2012
Re: Eddy current testing for welds
In Reply to creed at 04:48 Dec-06-2012 (Opening).

1) At 100 kHz in Carbon Steel (Ferromagnetic) the Standard Depth of Penetration (aka skin depth) is about 0.03 mm. This means that as standard then eddy current can only be considered a surface method.

2) I think your question is now answered unless your material is non-magnetic.

All the best

John Hansen

1
 
 Reply 
 
Franlk Lund
R & D,
United Kingdom, Joined Apr 2005, 221

Franlk Lund

R & D,
United Kingdom,
Joined Apr 2005
221
11:45 Dec-06-2012
Re: Eddy current testing for welds
In Reply to creed at 04:48 Dec-06-2012 (Opening).

Creed,

1. The calibration slot starts from the inspection surface, so it gives a path for the interrogating current to penetrate into the test block by going down and up the flanks of the slot. If your slot is on the other side of the block, then the interrogating current in the slotless surface is not interrupted and will not see the slot.

2. Things get different when your 2mm deep vertical slot penetrates to the other side of the 2mm thick test piece. Of course, a slanted defect can have a 2mm pocket depth without penetrating a 2mm thick plate.

Cheers,
Frank

 
 Reply 
 
creed
NDT Inspector,
n.n., Joined Jul 2009, 33

creed

NDT Inspector,
n.n.,
Joined Jul 2009
33
22:41 Dec-06-2012
Re: Eddy current testing for welds
In Reply to John Hansen at 10:32 Dec-06-2012 .

Thanks John and Franlk.
Your answers make me feel open-minded. Prior I had stupid perpective in checking thin material might affected to signal.
Cheers.

 
 Reply 
 

Product Spotlight

EKOSCAN Phased Array

In order to always fit your needs, EKOSCAN can manufacture any type of UT transducer, either convent
...
ional or Phased Array. As an ISO 9001: 2015 certified company, EKOSCAN is extremely careful as far a material selection and manufacturing processes are concerned. Our probes guarantee our customers the benefits of latest innovations regarding piezo-composite, backing, impedance adaptation layer, etc. Specific probes for hostile environment: high temperature, high pressure, corrosive environment,etc. Specific probes designed to fit your specific application: optimization of every parameter to guarantee you the best detection.
>

Eddy Current inspection : RotoETscan Rotating Head

The rotating head RotoETscan detects the presence of longitudinal surface or sub surface defects a
...
t high speed. The rotating head is often installed directly on the production line. It is generally dedicated to the control of long products such as tubes, bars and wires, made of ferrous or non-ferrous material. It can also be used for inspection of small parts (billets).
>

NEW - TD Focus-ScanRX

The NEW Next Generation Advanced UT platform, TD Focus ScanRX - Also available as a card stack solut
...
ion. Key Improvements 1. Data acquisition is significantly faster than current design 2. Better aesthetic – closely aligns with HandyScan RX 3. Improved IP rating (Target IP66) 4. Ruggedized housing 5. Connectors are protected from impact and ingress 6. Integrated stand and separate retractable handle easy to keep clean) 7. Touchscreen with ruggedized display glass 8. 3-Axis encoder input
>

UCI Hardness Tester NOVOTEST T-U2

UCI hardness tester NOVOTEST T-U2 is is used for non-destructive hardness testing of: metals and
...
alloys by scales of hardness: Rockwell (HRC), Brinell (HB), Vickers (HV); non-ferrous metals, alloys of iron etc., and using five additional scales for calibration; with tensile strength (Rm) scale determines the tensile strength of carbon steel pearlitic products by automatic recalculation from Brinell (HB) hardness scale.
>

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