Materials & Welding

In welding Type 304 to mild steel for instance, the choice of filler metal is a key point. If you use Type E308 filler metal, the diluted weld metal with the formation of martensite (a brittle structure) may contain cracking, because the filler metal cannot tolerate dilution by both base metals. A proper filler metal, in this case, is Type E309 ( typically contains 24% Cr and 13% Ni.) , for applications below 315 deg C in general. The procedure of estimating the micro structure of the E309-type diluted weld metal can be done by using a Schaeffler diagram ; the diluted weld metal will contain about 4% of ferrite and no martensite in the austenitic matrix, which is resistible to cracking On Wed, Jun 30, 2010 at 6:57 PM, limesh M < limesh78@gmail.com > wrote: Dear All What would be the problem if we use E 308L electrode instead of E 309L to join P1 to P8 dissimilar material joining in oilfield sour service? On what basis we are selecting E 309 L over E 308 L in P1 to P8 diss...

Dear All   In Jacket TKY joint fabrication which types of tack welds are commonly used and where I can get tack welding details     Thanks -- S.Sreevalsan Email.sreevalsan68@gmail.com sreevalsan69@yahoo.com sreevalsan@justice.com -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

Hi all,          I have to clarify regarding the MPI that can detect sub-surface. I can't see any code or std mention abt how much depth(6mm) can it detect the defects. Please inform me which std mention may i refer?   Thanks & regards, P.Mahendran --- On Wed, 30/6/10, manoj john <manojacgnr@gmail.com> wrote: From: manoj john <manojacgnr@gmail.com> Subject: Re: [MW:5796] MPI vs DPI To: materials-welding@googlegroups.com Date: Wednesday, 30 June, 2010, 8:48 AM Mpi  can be used only on ferromagnetic materials.  It can detect subsurface defects.   DPI can be used on any material.  It can detect only the defects which are open to the surface. On Tue, Jun 29, 2010 at 5:35 PM, mohammed helal < eng_hilal79@yahoo.com > wrote: The major difference  is the DPI is only for the defects that open to the surface and the MPI  for the subsurface defect ( 6 mm deep). Eng.MOHAMMED ABD EL-AZ...

Dear All What would be the problem if we use E 308L electrode instead of E 309L to join P1 to P8 dissimilar material joining in oilfield sour service? On what basis we are selecting E 309 L over E 308 L in P1 to P8 dissimilar metal joining? Thanks and Regards -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

Declan We are doing some fabrication on normal carbon steel but we don't have the MPI set at this moment. My client would like to have some NDT tested. I need to convince my client that DPI is good enough to get the fabrication tested. Regards, Amir Zakee On 6/30/10, Declan Foley < declan1foley@eircom.net > wrote: > > > MPI is for ferromagnetic materials only. It is supposedly useful for > defects of depth 6mm, but ask anyone who performs the tests and they > will tell you it is not! > > DPI can be conducted on any material. It is not recommended on materials > that have porous surfaces such as castings and the like. > > Strictly speaking they are both considered surface tests. As regards > substituting one for the other, I have never come across any situation > where you couldn't. What are you testing? > > Declan > > On 29/06/2010 17:35, mohammed helal wrote: >> The major difference is the DPI is only for the defects...

Dear all, I need some guidance about the tolerances, critical aspects of inspections as per requirements of API 650. Kindly guide with relevant material and references. Regards Rajneesh gaur -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

basically both are superior visual testing ie indications are get magnified that can detect by naked eye easily.pt is ment for non porus metals mt is ment for ferrromagnetic(strongly attracted towords magetic field) materials.In mpi we can be used for surface and subsurface but pt is only for surface indications.In mt  get result  as fast (within min) compared pt(min 30 min.) In mt skill is necessory to perform mt compared to pt. --- -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

Can some one Help me on... (A) ASME Section 3NC-2573, ASME Section 2SA-613 (B) Soundness is to be 51mm Severity level 2 as per ASTM E446 / E186 Delta ferrite %5 for Stainless Steels Regards P -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

Friends, - Magnetic Particles Testing is USED on Metals  can take Magnetic Field, like all Steel and Iron Except for Gamma Iron and Austenitic Steel be it Stainless Ni-Cr or Manganese Steel - Parts. - It basically a surface discontinuity test. - I would like to correct as DPI can also be tested on Castings of any metal and or its process of production by which such castings produced, to check the Cracks etc, it works on the Principle of Capillary action of Liquid. - The Die is poured on test piece, to be checked, after its proper surface cleaning, some local grinding etc, then Colored die is applied. - After that the DIEs poured/spread allowed to go in all crevices and possible discontinuities, we intend to check. - Then after reasonably 5 to 15 minutes the same part/test PC/surface is cleaned with dry cloth of cotton and then surface is cleaned by WET rinsed Cloth/cotton. - This removes the apparent surface color, once then the Developer the Chalk powder is sprayed ov...

MPI is for ferromagnetic materials only. It is supposedly useful for defects of depth 6mm, but ask anyone who performs the tests and they will tell you it is not! DPI can be conducted on any material. It is not recommended on materials that have porous surfaces such as castings and the like. Strictly speaking they are both considered surface tests. As regards substituting one for the other, I have never come across any situation where you couldn't. What are you testing? Declan On 29/06/2010 17:35, mohammed helal wrote: The major difference  is the DPI is only for the defects that open to the surface and the MPI  for the subsurface defect ( 6 mm deep). Eng.MOHAMMED ABD EL-AZIM HILAL         MECHANICAL ENGINEER      CSWIP 3.1 - NDT (RT- MT - PT) OTISHAN CONSULTANT ENGINEER  00966-502612218  -  0020103124557 ...

Dear Sudhakar,   The welding parameters are ok including heat input. Pickling is not necessary for DSS welds unless you notice discoloration of welds and moreover it is not required for welding procedure coupons. Hence, pickling and passivation shall not be required for PQR coupons.   Confirm the following before you test for G48.   PRE for filler metal shall have 40-45, minimum shall be 40 Check ferrite content in the deposited weld metal (35-65) Minimize root gap to 2 mm (to avoid Ni dilution)   In order to achieve better corrosion resistance, follow “ Cold Pass ” technique for second layer/ pass for SDSS welding. In general for CS and LAS, the second layer/pass is called hot pass, where as in DSS it is called cold pass. It means that the welding current for second layer shall be 75% of root pass in order to achieve better phase balance (austenite+ferrite) and also to have better corrosion resistance in root, wh...

Dear Mr.Goswami and Mr.Prabhu, Thanks a lot for the inputs. 10 days before i have taken a trail to check this test.  The details are as follows Material: A 790 UNS 32750  Size: 2"/160 (8.56mm thk)  Position: 6G  Interpass temp: 100 deg max Heat input maintained: 0.7 to 1.21 kj/mm Filler wire: ER 2594, (1.6 mm for root, rest 2.4mm) Shielding gas and purging gas: Argon(98%)+N2(2%) Flow rate: shielding 10 to 15 LPM Purging: 8 to 12 LPM For the joint preparation we have used the SS discs and after welding we did the pickling. Susprisingly in the result the weight loss observed was 41.67 gm/m2 and there were pits observed on the root side. I was shocked to see the result and I'm not understanding why it happened.  Before sending to Lab we did not check the ferrite count. Thanks again.. Sent from my iPhone On 30-Jun-2010, at 12:35 PM, "Prabhu Kumar L" < l.prabhukumar@saipem-india.com > wrote: Dear Sudhakar,   In addition to the restriction men...