1. For radiography of 60 mm thickness of S.S. C0 60 is preferred with Slow films comparing to IR 192 code permits.
2. High strength IR 192 for short exposure time even the penetrating strength ate same for low strength( exposure time more).
3. Transverse (shear wave) probes of 2 MHz for stainless steel will give more Hash (grass echo) due to coarse grain structure. You will not able to see indications on screen due to the grass echoes. So we could not do the Ultrasonic Testing of 60 mm thick weld joint with shear wave probe for sure. If you see ASME section 5 article 4 for C.S. weld we can use a plate as Side drilled hole(SDH) cal. block but in stainless steel welds you should make a block with weld and the SDH shall be drilled in weld. For 60 mm thick the dB difference will be more than 6 dB to pick up a hole from S.S plate and S.S. weld.
Twin crystal probes manufactured by RTD are longitudinal wave probes which can penetrates effectively in S.S. weld material. When you make the crystal in angle beam both longitudinal & shear wave will present in steel.
To avoid the confusion between the signals of long & Shear ,twin crystal probes are preferred and these probes having a fixed focal point. you can use that probe for particular Zonal scanning. You have to use at least three probes with different angle and focal spots to cover the complete weld.
Creep wave probes may be used to cover the surface discontinuities.
Regards,
Nilesh Pathare.
Dear friends ,
As per my suggestion, you better to select Co.60 only because the Ir -192 source is can do max .50 mm is sufficient but the code says can do upto 69mm .practically you can select the source Co -60 and you can save time as well as will achieve the sensitivity ,what the code and spec. recommended.
R.Ramu
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Shashank Vagal
Sent: Sunday, August 30, 2009 1:21 PM
To: materials-welding@googlegroups.com
Subject: [MW:3083] Re: Regarding the NDT to be carried out for 60 mm thick austenitic stainless steel plates
Nilesh,
Why would you do these things?
1. No co60 for 69 mm SS?
2. High Strength and Low Strength Ir 192 are same in their pen power.
3. UT of 60 mm SS - well, can you please pass me the proc? I am curious. Twin crystal for what reasons?
Shashank Vagal
--- On Sun, 30/8/09, SENTHILKUMAR SWAMINATHAN <skumarswami@yahoo.co.in> wrote:
From: SENTHILKUMAR SWAMINATHAN <skumarswami@yahoo.co.in>
Subject: [MW:3082] Re: Regarding the NDT to be carried out for 60 mm thick austenitic stainless steel plates
To: materials-welding@googlegroups.com
Date: Sunday, 30 August, 2009, 2:44 PM
High Curie or Low Curie only helps in time factor. But Ir 192 Penetration is same from Low and High. If am wrong correct me.
S.Senthilkumar
--- On Sun, 30/8/09, Yadav Shiva <luvshiv2002@gmail.com> wrote:
From: Yadav Shiva <luvshiv2002@gmail.com>
Subject: [MW:3080] Re: Regarding the NDT to be carried out for 60 mm thick austenitic stainless steel plates
To: materials-welding@googlegroups.com
Date: Sunday, 30 August, 2009, 2:38 PMhi,
you can go for high strength - 192, but dont go for cobalt 60 since we use for thickness ranging more than 100 to & 150 mm above.
On Sun, Aug 30, 2009 at 11:48 AM, Nilesh Pathare <patharenil@gmail.com> wrote:
Hi,
If your specification permits for RT or UT you can carry out any of these test for 60 mm Thick S.S.
For RT you may need cobalt 60 or High strength iridium 192.
For Ultrasonic Testing you shall use the RTD Twin crystal longitudinal wave Angle probes.
Regards,
Nilesh Pathare.On Sun, Aug 30, 2009 at 10:35 AM, Stephen <stephenipr@gmail.com> wrote:
I wanted to know which NDT to be carried out for 60 mm thick
austenitic stainless steel plates welded using TIG welding
--
Best Regards,
Nilesh Pathare
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Best Regards,
Nilesh Pathare
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