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[MW:2709] Re: blow holes in double side welding in H-Beam SAW welding

By Materials & Welding
I am assuming that you are using the single electrode SAW process.
Typically blowholes on the second side are a result of flux being trapped
during the root pass on the first side boiling and escaping through the
molten metal of the second side weld. After the first side is done look
carefully at the send side weld prep, look for flux trapped in the root
area,

Wviness control you could try additional preheat this might help. Contact
Tipmate http://tipmateusa.com/index.html their nozzle extensions might help
the waviness problem with a possible increase in production rates.

Best regards,
Richard Beldyk PhD, PE
AWS CWEng
ASNT NDT Level III

Original Message:
-----------------
From: raw rohit30584@gmail.com
Date: Fri, 17 Jul 2009 22:31:52 -0700 (PDT)
To: materials-welding@googlegroups.com
Subject: [MW:2702] blow holes in double side welding in H-Beam SAW welding

Hi everyone out there,
I am presently working in kirby building systems . we do PEB
fabrication .we use material ASTM A572 typ1 gr50 .the p[roblem is when
we do doubl;e side welding, blow holes occur in second side . what is
the basic reason .allso waviness occurs in flanges of thickness 6mm
and less,
thanks,
rohit rawat
QA(quality assurance)

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