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 -

Sonatest Ltd
From our three distinct business centres in the UK, USA and CANADA, Sonatest design and produce a leading range of high performance ultrasonic NDT equipment and accessories.

751 views
Technical Discussions
Jedispin
Jedispin
06:59 Aug-18-2009
Subsurface crack detection by MT in Martensitic Stainsless Steel

Hi,

I would like to have some information regarding subsurface crack detection by MT in Martensitic Stainsless Steel. I would like to know, what is the maximum depth that we can detect such a crack for martensitic stainless steel.

Do a study has been already done regarding subsurface crack detection on different material.

    
 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 821

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
821
03:57 Aug-19-2009
Re: Subsurface crack detection by MT in Martensitic Stainsless Steel
In Reply to Jedispin at 06:59 Aug-18-2009 (Opening).

Hi,

I will answer your question assuming that you are inspecting parts of that material on a regular basis. Maybe you should get a Ketos Ring of a similar material. This way, you will be able to properly verify the sensitivity of your system and will know exactly how deep you can go. The drawing can be found in ASTM E1444.

    
 
 
John Brunk
Engineering, NDT Level III
Self employed, part-time, USA, Joined Oct 1999, 158

John Brunk

Engineering, NDT Level III
Self employed, part-time,
USA,
Joined Oct 1999
158
06:46 Aug-19-2009
Re: Subsurface crack detection by MT in Martensitic Stainsless Steel
In Reply to Jedispin at 06:59 Aug-18-2009 (Opening).

Martensitic stainless steels, including maraging steel that has not been heat
treated to reform a substantial percentage of austenite, has extremely
limited depth of penetration for very low-frequency eddy current inspection.
Based on this I would be surprised if you could detect subsurface defects with
an electromagnetic yoke. With full-wave rectified current and high amperage
and a Ketos-type ring as Michel suggested, you might find an answer that
pleases you. There are both ferromagnetic and non-ferromagnetic forms of
martensite, but the ferromagnetic form structure often predominates, especially
in maraging steels.

    
 
 

Product Spotlight

MUSE Mobile Ultrasonic Equipment

The MUSE, a portable ultrasonic imaging system, was developed for in-field inspections of light-weig
...
ht structures. The MUSE consists of a motor-driven manipulator, a water circulation system for the acoustic coupling and a portable ultrasonic flaw detector (USPC 3010). The MUSE provides images of internal defects (A-, B-,C- and D-scan).
>

NEW Wheel Type Phased Array Probe

DOPPLER NEW Wheel Type Phased Array Probe, more stable, new tyre makes lesser acoustic attenuation
...
, much lighter makes easier to handle, more slim size, magnetic and mechanical encoder optional etc...more
>

Immersion systems

ScanMaster ultrasonic immersion systems are designed for high throughput, multi shift operation in a
...
n industrial or lab environment. These fully integrated systems provide various scanning configurations and incorporate conventional and phased arrays technologies to support diverse applications, such as inspection of disks, bars, shafts, billets and plates. All of ScanMaster immersion systems are built from high accuracy scanning frames allowing for scanning of complex parts and include a multi-channel ultrasonic instrument with exceptional performance. The systems are approved by all major manufacturers for C-scan inspection of jet engine forged discs. Together with a comprehensive set of software modules these flexible series of systems provide the customer with the best price performance solutions.
>

Spot weld inspection with Phased Array – PHAsis.one

The first PAUT spot weld inspection device offering a physical resolution of the spot weld diamete
...
r better than 0.35mm. Precise: more than 700 real UT measurements per spot weld. Easy to go: minimal training required due to the user friendly inspection software. Be sure: safe evaluation due to the imaging result display and automated creation of an evaluation proposal for the spot weld quality.
>

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
s