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 -

829 views
Technical Discussions
Jeff
NDT Inspector
Nucor Steel, USA, Joined Apr 2005, 6

Jeff

NDT Inspector
Nucor Steel,
USA,
Joined Apr 2005
6
01:54 Aug-10-2004
Surface waves

I work for a steel company. They want to know if I can inspect steel plate for cracks running transverse along the plate surface. One problem scale is on the surface. I was wondering if surface waves would penetrate the scale and give me the surface indications I am looking for. These defects are not very deep. Our customers are finding these defcts after the scale is blown off. If uktrasound is not the answer give me some ideas. I have already kicked around MT and PT butspeed is not in their favor.

Jeff Medford


    
 
 
Guest
Guest
03:26 Aug-10-2004
Re: Surface waves
Try the ACFM (Alternating Current Field Measurement) technique for detection.
----------- Start Original Message -----------
: I work for a steel company. They want to know if I can inspect steel plate for cracks running transverse along the plate surface. One problem scale is on the surface. I was wondering if surface waves would penetrate the scale and give me the surface indications I am looking for. These defects are not very deep. Our customers are finding these defcts after the scale is blown off. If uktrasound is not the answer give me some ideas. I have already kicked around MT and PT butspeed is not in their favor.
: Jeff Medford
------------ End Original Message ------------




    
 
 
Christopher Dragan
Engineering
ITWL, Poland, Joined Nov 2002, 3

Christopher Dragan

Engineering
ITWL,
Poland,
Joined Nov 2002
3
07:53 Aug-11-2004
Re: Surface waves
How deep this cracks are? If they are limited to 3 - 4 mm you can succesfully use eddy current technique. If this cracks running along plate surface that should be quite good visible.


    
 
 
Godfrey Hands
Engineering,
PRI Nadcap, United Kingdom, Joined Nov 1998, 289

Godfrey Hands

Engineering,
PRI Nadcap,
United Kingdom,
Joined Nov 1998
289
09:51 Aug-11-2004
Re: Surface waves
----------- Start Original Message -----------
: I work for a steel company. They want to know if I can inspect steel plate for cracks running transverse along the plate surface. One problem scale is on the surface. I was wondering if surface waves would penetrate the scale and give me the surface indications I am looking for. These defects are not very deep. Our customers are finding these defcts after the scale is blown off. If uktrasound is not the answer give me some ideas. I have already kicked around MT and PT butspeed is not in their favor.
: Jeff Medford
------------ End Original Message ------------

Jeff,
Surface waves should propagate underneath a layer of scale, but cannot be generated through them with conventional contact or immersion techniques using piezo transducers.
In immersion, the surface wave will continuously "leak" back out into the couplant liquid (water) and become very inefficient.

If the waves could be generated at the sides of dry plates, they could potentially propagate right across the plates if the frequency is low enough.

Another method using surface waves is to generate the surface wave using the EMAT technique, where the sound pulse is generated on the surface of the plate through the scale. Not many NDT companies are dong this however.

What depth of crack are you looking for?

Godfrey Hands




    
 
 

Product Spotlight

Semi-Automated Phased Array Immersion System for Small Composite Parts

Turn-key semi-automated system as an improved and affordable solution for inspection of small comp
...
osite parts. Includes support table, immersion tank, scanner, PA instrument, PC, Analysis software, database, wedge management and other options.
>

NovaScope 6000

The all-digital Novascope 6000 is a portable, ultra-high precision thickness gauge for high-speed
...
thickness measurement. Novascope 6000 has unmatched capabilities and unique features including: •Superior Resolution with high contrast, high-speed color RF display •High pulser voltage •Real-time video output •Increased internal/external data storage •Programmable SetUp features •Battery & AC Powered
>

NOVO Armor 15 & NOVO Armor 22

The Armor Kit Contains the NOVO Armor, which provides additional mechanical protection to the NOVO 1
...
5WN & NOVO 22WN Detectors, the Armor Stand and a traveling soft cover. - Newest shock absorbent technology case - Water resistant design - Supports wired & wireless communication - Multiple positioning options - Tripod connection using the Built-in 1/4” threads - Simple Detector battery replacement
>

SITEX CPSERIES

Teledyne ICM’s CPSERIES has been designed with a view to revolutionizing the handling and perfor
...
mances of portable X-Ray sets. Despite having managed to halve the weight of similar portable X-Ray generators available on the market (while continuing to provide the same power output), the SITEX CPSERIES generators feature a shutter, a laser pointer, a beryllium window, an aluminum filter and two integrated diaphragms (customized sizes are available upon request). Without compromising the robustness and reliability for which ICM products are renowned, the small size and light weight of the SITEX CPSERIES will radically change the way that you perform your RT inspections. And you will see a positive impact in terms of both quality and return on investment (ROI).
>

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