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[MW:787] Re:

By Materials & Welding
It would be preferrable to use a Austenitic electrode like E 309 or E NiCrMo3 / E NiCr Fe 3 - as the weld metal is non hardenable and tolerant to diffusible hydrogen as well as higher C.
Adequate preheating of 150°C should help in controlling the HAZ cooling rates, followed by slow cooling after completion of welding

In case austenitic weld is not an option, welding using properly dried E7018 elecrtodes (or equivalent SAW wire flux) will be suitable for the job. Preheating of 150°C and postheating at 250°C to 280°C for 3-4 hrs followed by slow cooling to room temperature should be followed in order to enable removal of dissolved H2
 
For both the cases, PWHT at around 640-660°C will help in softening the HAZ

regards,



> Date: Sun, 18 May 2008 08:12:19 -0700
> Subject: [MW:783] Re:
> From: raghurambathula@gmail.com
> To: materials-welding@googlegroups.com
>
>
> EN8 which is having high carbon content (upto 0.44%) and CE in excess
> of 0.45 needs preheating 100-150 deg.C
> use low hydrogen eletrodes and PWHT to avoid hardening and cold
> cracks.
>
> you might try establishing PQR with the above.
>
> On May 17, 3:43 pm, "PREM SHANKARDUTT NAUTIYAL"
> <prem_nauti...@rediffmail.com> wrote:
> >
> > Dear Friends
> >
> > Can anyone tell whcih SMAW electrode to use to weld EN8 to SA516 Gr.70 and EN24 to SA 516 Gr.70.
> >
> > Both are butt joints around 50mm thk.
> >
> > Regards
> >
> > Prem Nautiyal
> >
> > PREM S NAUTIYAL
> > CELL : 9820313278
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