06:59 Aug-18-2009 Subsurface crack detection by MT in Martensitic Stainsless Steel
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.
03:57 Aug-19-2009 Re: Subsurface crack detection by MT in Martensitic Stainsless SteelIn Reply to Jedispin at 06:59 Aug-18-2009 (Opening).
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 SteelIn 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.
The NEW Next Generation Advanced UT platform, TD Focus ScanRX - Also available as a card stack solut
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
Available to order from stock in a range of 5MHz – 7.5MHz and from
16 to 64 elements. Designed w
ith piezo-composite elements, Phoenix
phased array probes provide high-resolution imaging to maximise
sensitivity; accurate ultrasonic detection and sizing of defects
in welds; and effective corrosion mapping. Housed in a rugged
stainless steel case for on-site industrial NDT applications.