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 -

ACS-Solutions GmbH
The priority of the company is to design and create highly technological equipment, for professional users. Aiming to reach the devices top techn ...
911 views
Technical Discussions
sandeep sharma
sandeep sharma
09:19 May-17-2005
even after carrying out the magnetic particle test 350 mm dia shaft failed

dear all,
i would be highly obeliged if you can throw the light on a failure of hollow shaft of o.d. 350 mm and id. 100 mm (moc 15Cr Ni Mo4) duly heat treated . Hollow portion is for cooling water (demineralized) to keep its temp down to get better tensile and tortional strength.
This shaft was a used shaft, operator was suspecting leakage so when it was replaced it was decided to test it for cracks by using magnetic particle test. In which this shaft was found O.K. even a hydro test was carried out upto the 35 bar again we could not found the leakage so it was decided to use the shaft.
But after commisioning the shaft it failed within 10 days and at the surface of the fracture there was rusting below the surface covering at least 50 % of area.
What possibly be the mistake made by our NDT people?
Kindly throw some light if you can.

Thanks


 
 Reply 
 
Frank Lund
R & D,
United Kingdom, Joined Apr 2005, 222

Frank Lund

R & D,
United Kingdom,
Joined Apr 2005
222
00:33 May-18-2005
Re: even after carrying out the magnetic particle test 350 mm dia shaft failed

The fact that leakage was suspected indicated a crack reaching to the surface. In many applications to find such defects the EMA technique has been very successful. ELF in Norway switched to EMA after seeing it find defects which were revealed by grinding but not by MPI.

----------- Start Original Message -----------
: dear all,
: i would be highly obeliged if you can throw the light on a failure of hollow shaft of o.d. 350 mm and id. 100 mm (moc 15Cr Ni Mo4) duly heat treated . Hollow portion is for cooling water (demineralized) to keep its temp down to get better tensile and tortional strength.
: This shaft was a used shaft, operator was suspecting leakage so when it was replaced it was decided to test it for cracks by using magnetic particle test. In which this shaft was found O.K. even a hydro test was carried out upto the 35 bar again we could not found the leakage so it was decided to use the shaft.
: But after commisioning the shaft it failed within 10 days and at the surface of the fracture there was rusting below the surface covering at least 50 % of area.
: What possibly be the mistake made by our NDT people?
: Kindly throw some light if you can.
: Thanks
------------ End Original Message ------------




 
 Reply 
 
Nick Welland
Other, Quality and NDT
Aben Technical Services, Australia, Joined Oct 1999, 42

Nick Welland

Other, Quality and NDT
Aben Technical Services,
Australia,
Joined Oct 1999
42
01:14 May-18-2005
Re: even after carrying out the magnetic particle test 350 mm dia shaft failed
----------- Start Original Message -----------
: dear all,
: i would be highly obeliged if you can throw the light on a failure of hollow shaft of o.d. 350 mm and id. 100 mm (moc 15Cr Ni Mo4) duly heat treated . Hollow portion is for cooling water (demineralized) to keep its temp down to get better tensile and tortional strength.
: This shaft was a used shaft, operator was suspecting leakage so when it was replaced it was decided to test it for cracks by using magnetic particle test. In which this shaft was found O.K. even a hydro test was carried out upto the 35 bar again we could not found the leakage so it was decided to use the shaft.
: But after commisioning the shaft it failed within 10 days and at the surface of the fracture there was rusting below the surface covering at least 50 % of area.
: What possibly be the mistake made by our NDT people?
: Kindly throw some light if you can.
: Thanks
------------ End Original Message ------------

1. Was the crack propagating fromthe OD or the bore?
2. Was it a circumferential crack? If so, did it coincide with a change in section, or evident surface marks?
3. Does the corrosion on the exposed fracture surface indicate the crack was through-wall around any part of the periphery?
4. What magnetizing method did the NDT techs use?

Best regards
Nick


 
 Reply 
 
S.R.G.PRABHU
S.R.G.PRABHU
01:53 May-18-2005
Re: even after carrying out the magnetic particle test 350 mm dia shaft failed

I always doubt the success of MPI, as either it is done in a hurried manner or the technique and technicians are not up to the standard.Why can't we switch to other latest methods?

----------- Start Original Message -----------
: dear all,
: i would be highly obeliged if you can throw the light on a failure of hollow shaft of o.d. 350 mm and id. 100 mm (moc 15Cr Ni Mo4) duly heat treated . Hollow portion is for cooling water (demineralized) to keep its temp down to get better tensile and tortional strength.
: This shaft was a used shaft, operator was suspecting leakage so when it was replaced it was decided to test it for cracks by using magnetic particle test. In which this shaft was found O.K. even a hydro test was carried out upto the 35 bar again we could not found the leakage so it was decided to use the shaft.
: But after commisioning the shaft it failed within 10 days and at the surface of the fracture there was rusting below the surface covering at least 50 % of area.
: What possibly be the mistake made by our NDT people?
: Kindly throw some light if you can.
: Thanks
------------ End Original Message ------------




 
 Reply 
 
Simon Amalraja
Simon Amalraja
04:04 May-24-2005
Re: even after carrying out the magnetic particle test 350 mm dia shaft failed
----------- Start Original Message -----------
: The fact that leakage was suspected indicated a crack reaching to the surface. In many applications to find such defects the EMA technique has been very successful. ELF in Norway switched to EMA after seeing it find defects which were revealed by grinding but not by MPI.
: : dear all,
: : i would be highly obeliged if you can throw the light on a failure of hollow shaft of o.d. 350 mm and id. 100 mm (moc 15Cr Ni Mo4) duly heat treated . Hollow portion is for cooling water (demineralized) to keep its temp down to get better tensile and tortional strength.
: : This shaft was a used shaft, operator was suspecting leakage so when it was replaced it was decided to test it for cracks by using magnetic particle test. In which this shaft was found O.K. even a hydro test was carried out upto the 35 bar again we could not found the leakage so it was decided to use the shaft.
: : But after commisioning the shaft it failed within 10 days and at the surface of the fracture there was rusting below the surface covering at least 50 % of area.
: : What possibly be the mistake made by our NDT people?
: : Kindly throw some light if you can.
: : Thanks
------------ End Original Message ------------

You can also try UT Leak Detection. You need to plug both ends and try to pressurise it and look for the leak by Leak Detectors of reputed makes.

If you are in India, contact me for further details.

D.Simon Amallraja.
Mobile: 09866343309.


 
 Reply 
 

Product Spotlight

HD-CR 35 NDT Computed Radiography System

Portable high-resolution CR scanner for all radiography applications - weld testing, profile images
...
and aerospace. No matter what type of radiographic testing you are performing, the unique TreFoc Technology of the HD-CR 35 NDT imaging plate scanner always guarantees the highest image quality.
>

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
>

Content on Demand by Eddyfi Technologies

Finding yourself in front of a screen practicing safe social distancing instead of out in the fiel
...
d? At Eddyfi Technologies, we are doing our part in helping you be better prepared for what comes next. We introduce to you Eddyfi on Demand. Fill your schedule with webinars, how-to videos, informative technical papers and our NEW addition: Eddyfi Academy. There, you will have access to FREE online courses and obtain certificates of attendance once completed in order for you to include these e-learning sessions in your log of required training hours. Join us today. Stay safe, stay Beyond Current.
>

Compact NDT inspection-heads for measurements with active thermography

The compact inspection head is suitable for thermographic ndt tasks. The uncooled infrared camera
...
is specially developed for NDI-tasks and offers a thermal sensitivity until now known only from thermal imagers with cooled detector. All required components and functions are integrated into the inspection-head. You will only need an ethernet cable to connect the sensor with the evaluation system.
>

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