Crack detection
Crack detection
(OP)
Hi,
We deal with tubes which are about 7" dia and 10' tall. Can anyone suggest a non destructive testing method of finding the cracks in these tubes and measuring them. Which would be the fastest way to detect cracks?
Thanks,
Mike
We deal with tubes which are about 7" dia and 10' tall. Can anyone suggest a non destructive testing method of finding the cracks in these tubes and measuring them. Which would be the fastest way to detect cracks?
Thanks,
Mike





RE: Crack detection
thru-thickness cracks ?
material ?
length ?
RE: Crack detection
X ray, magnetic particle
desertfox
RE: Crack detection
Tobalcane
"If you avoid failure, you also avoid success."
RE: Crack detection
RE: Crack detection
http://www.buzzmac.com/
Russell Giuliano
RE: Crack detection
If the cracks of interest penetrate a surface, a surface inspection technique may be used to detect them. If they do not penetrate a surface, then a volumetric technique must be used. In either case, a volumetric technique can provide more information about the cracks.
RE: Crack detection
detection of through thickness & surface cracks
material: steel
length: 7 feet
Diameter: 7" to 8"
Thickness: 0.425"
RE: Crack detection
RE: Crack detection
I2I
RE: Crack detection
What is the matter with not answering the questions posed above? You do not provide any additional information;
NDT for crack detection, hm....mm, lets see
UT -shear and L wave
UT - TOFD, linear and phased array
Liquid PT
Wet fluorescent MT
Fluorescent PT
Acoustic emission
Radiography
Eddy Current
Remote field Eddy Current
Get the drift?
RE: Crack detection
Can anyone know that how to use the ANSYS software to estimate the initial cracks of thermal cyclic loading? we due with the material H13 of rectangle block which is 100 mm and 45mm. I wish can hear your support soon.
RE: Crack detection
You should start a new post instead of jumping into an existing post with different issue.
To your question the initial crack size is the result of the maximum crack that the quality tests conducted on your part can not detect.
For example if you weld two parts and use an X-ray to check for cracks. The crack estimation size will be the largest size that can not be detected by the X-ray method.
n your case you should check the history of the part including all processes and tests conducted on the part and the raw material and select the largest crack that could be in the part that no test that was done on the part/raw material could find.
RE: Crack detection
Sorry for the late reply...We test the tubes with shock loads and then check if the tube has survived the shock by looking for cracks and splits that are too deep and wide (currently this is done by visually inspecting them)......so basically the crack length and depth are important parameters
There are a lot of crack detection systems out there but am looking for one where we can scan the part and get measurements on the length and depth quickly.....X ray & mag particle seems to be a good option but I dont knw which would be the fastest method.
Thanks,
Mike
RE: Crack detection
RE: Crack detection
RE: Crack detection
how many pieces per day are you inspecting ?
how big a crack do you want to detect ? carefull how you answer this, as it'll have a big impact on techinque, cost, time.
is there a particular zone that you're interested in (maybe a weld) ?
what are you doing to the material to make you think you'll develop cracks under (compression) impact loads ?
RE: Crack detection
between 2 to 4 peices per day
material: steel
length: 7 feet
Diameter: 7" to 8"
Thickness: 0.425"
how big a crack do you want to detect ?
The crack sizes vary with the loadings....the sizes range between,
Length: 0.2" to 2"
Depth: Not sure about the depth as we have been inspecting them visually until now.
is there a particular zone that you're interested in (maybe a weld) ?
There are no welds on the surface.....It is just a hollow cylinder, so want to scan the outer surface of the cylinder.
what are you doing to the material to make you think you'll develop cracks under (compression) impact loads?
The cylinder is impacted by a bullet from the inside which blows holes into the cylinder and we want to check if the rest of the body survives this impact.
My plan is to check the part visualy for any indication of surface cracks and then use a NDT method for measuring any cracks that are spotted. There are usually 3 to 4 cracks, so we don't really need to scan the whole cylinder just to measure 3 or 4 cracks?
RE: Crack detection
I'd ask about the bullet but I suspect ths is classified?
RE: Crack detection
Do you know how long does it take to measure a crack using the shear-wave UT method? and before i can get a quote approximately how expensive do you think it might be?
Thanks for the help,
Mike
RE: Crack detection
RE: Crack detection
RE: Crack detection
Due to the 7" dia you will probably need to use an ASME type transducer and shoe if this is inspected to a code. Although, if you were to use an AWS type shoe (much larger) and contour it to your dia. then it would be much faster. You would also need to make a calibration standard, this is very simple.
With the ASME type transducer your looking at about 1 hour to inspect a 7" dia x 10'. With the AWS transducer it will be more like 1/2 of an hour.
RE: Crack detection
RE: Crack detection
RE: Crack detection
1.5" is a little small for an AWS transducer. I would lean towards one of each. Also, after rereading your requirements, you might consider looking at Wet fluorescent MT using a coil. this will give you a length only, no way to verify depth. Unless it's thru wall. This method is quicker, but requires the use of an inspection booth (something to keep out white light).