blow holes in double side welding in H-Beam SAW welding
106 views
Skip to first unread message
raw
Jul 18, 2009, 1:31:52 AM7/18/09
to Materials & 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)
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)
welding_...@charter.net
Jul 18, 2009, 8:56:41 AM7/18/09
to material...@googlegroups.com
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 rohit...@gmail.com
Date: Fri, 17 Jul 2009 22:31:52 -0700 (PDT)
To: material...@googlegroups.com
Subject: [MW:2702] blow holes in double side welding in H-Beam SAW welding
--------------------------------------------------------------------
mail2web LIVE – Free email based on Microsoft® Exchange technology -
http://link.mail2web.com/LIVE
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 rohit...@gmail.com
Date: Fri, 17 Jul 2009 22:31:52 -0700 (PDT)
To: material...@googlegroups.com
Subject: [MW:2702] blow holes in double side welding in H-Beam SAW welding
mail2web LIVE – Free email based on Microsoft® Exchange technology -
http://link.mail2web.com/LIVE
raju Pamula
Jul 18, 2009, 11:02:40 AM7/18/09
to material...@googlegroups.com
Can you provide bevel details & Welding sequence for both joints
regards
P.Raju
--------- Forwarded message ----------
From: raw <rohit...@gmail.com>
Date: Sat, Jul 18, 2009 at 8:31 AM
Subject: [MW:2702] blow holes in double side welding in H-Beam SAW welding
From: raw <rohit...@gmail.com>
Date: Sat, Jul 18, 2009 at 8:31 AM
Subject: [MW:2702] blow holes in double side welding in H-Beam SAW welding
Radhakrishnan Venkatraman
Jul 18, 2009, 7:34:57 PM7/18/09
to material...@googlegroups.com
The main reason for blowholes is wind.I think you people are doing welding in openair or may be moisture.Try to avoid these 2 by providing covered environment etc
Heat input to be reduced to avoid waviness
Regards
R.Venkataraman
Heat input to be reduced to avoid waviness
Regards
R.Venkataraman
> Date: Fri, 17 Jul 2009 22:31:52 -0700
> Subject: [MW:2702] blow holes in double side welding in H-Beam SAW welding
Rohit Rawat
Jul 20, 2009, 2:13:29 PM7/20/09
to material...@googlegroups.com
Sir,
This is to inform you that we are using two electrode SAW process.
Thanks,
Rohit Rawat,
Asst.Engg.(QA)
|
|
Rohit Rawat
Jul 20, 2009, 2:06:14 PM7/20/09
to material...@googlegroups.com
Sir,
This is to inform you that we are not doing welding in open air. we do SAW welding inside the building .So, as you are saying, wind cannot be the reason. Their has to be some other reason.
Thanks,
Rohit Rawat,
|
|
PREMSHANKARDUTTNAUTIYAL
Jul 20, 2009, 11:42:32 PM7/20/09
to rohit...@yahoo.co.in, material...@googlegroups.com
Hello Rohit
As you are getting blowholes while welding the second side of the joint, then i suggest that you personally ensure that after chipback grinding, the LPT is clear.
After that with proper baked flux, preheating as per WPS carry out welding from other side.
Regards
Prem Nautiyal
Godrej, Mumbai.
On Tue, 21 Jul 2009 08:00:58 +0530 wrote
>Sir,
>This is to inform you that we are using two electrode SAW process.
>Thanks,
>Rohit Rawat,
>Asst.Engg.(QA)
>
>
>
>From: welding_...@charter.net
>Subject: [MW:2709] Re: blow holes in double side welding in H-Beam SAW welding
>To: material...@googlegroups.com
>Date: Saturday, 18 July, 2009, 6:26 PM
>
>
>
>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 rohit...@gmail.com
>Date: Fri, 17 Jul 2009 22:31:52 -0700 (PDT)>
>
>
>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 rohit...@gmail.com
>To: material...@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)
>
>
>
>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)
>
>
>
>--------------------------------------------------------------------
>mail2web LIVE Free email based on Microsoft® Exchange technology -
>http://link.mail2web.com/LIVE
>
>
>
>
>
>
>
> See the Web's breaking stories, chosen by people like you. Check out Yahoo! Buzz. http://in.buzz.yahoo.com/>mail2web LIVE Free email based on Microsoft® Exchange technology -
>http://link.mail2web.com/LIVE
>
>
>
>
>
>
>
>>
>
PREM S NAUTIYAL
CELL : 9820313278
 |
welding_...@charter.net
Jul 21, 2009, 5:37:31 AM7/21/09
to material...@googlegroups.com
Three things to look for:
1. Trapped flux, since it is occurring on the second side only.
2. A poor ground, measure the temperature of the ground clamp during
operations, if it heats up significantly the second side weld may not be
receiving enough energy to full melts the metals and flux, resulting in
blowhole. Too much of the voltage drop is happening at the ground clamp. (I
mentioned clamp only but look at the complete ground system.)
3. If it is occurring on both side looks at the electrode spacing.
With a double electrode system if the electrodes do come too close together
the magnetic/electrical field will interfere with other, even if one is AC
and the other DC, and if too fair apart the second electrode will interfere
with the outgassing of the first. At the melt point of the electrode they
should be separated between 15 to 18 mm if you have a single molten puddle.
If you have two molten puddles then make sure that the electrodes are
separated at the melt point by at least 25mm.
The 18 to 25mmm zone is to be avoided, sometimes you get good welds but
many times you will have blowholes.
(The above measurements are for 3.2 mm electrodes 700 Amp 30Vdc, 750 A
32Vac 16mm separation, DC electrode 90deg to base metal, AC electrode
102degree from base metal)
As others have mentioned backchipping or grinding to sound metal, to assure
that all flux/slag is removed prior to welding the second side is important.
Best regards,
Richard Beldyk PhD, PE
AWS CWEng
ASNT NDT Level III
Original Message:
-----------------
From: Rohit Rawat rohit...@yahoo.co.in
Date: Mon, 20 Jul 2009 23:43:29 +0530 (IST)
To: material...@googlegroups.com
Subject: [MW:2721] Re: blow holes in double side welding in H-Beam SAW
welding
Sir,
This is to inform you that we are using two electrode SAW process.
Thanks,
Rohit Rawat,
Asst.Engg.(QA)
--- On Sat, 18/7/09, welding_...@charter.net
<welding_...@charter.net> wrote:
From: welding_...@charter.net <welding_...@charter.net>
Subject: [MW:2709] Re: blow holes in double side welding in H-Beam SAW
welding
To: material...@googlegroups.com
Date: Saturday, 18 July, 2009, 6:26 PM
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
mail2web.com - Microsoft® Exchange solutions from a leading provider -
http://link.mail2web.com/Business/Exchange
1. Trapped flux, since it is occurring on the second side only.
2. A poor ground, measure the temperature of the ground clamp during
operations, if it heats up significantly the second side weld may not be
receiving enough energy to full melts the metals and flux, resulting in
blowhole. Too much of the voltage drop is happening at the ground clamp. (I
mentioned clamp only but look at the complete ground system.)
3. If it is occurring on both side looks at the electrode spacing.
With a double electrode system if the electrodes do come too close together
the magnetic/electrical field will interfere with other, even if one is AC
and the other DC, and if too fair apart the second electrode will interfere
with the outgassing of the first. At the melt point of the electrode they
should be separated between 15 to 18 mm if you have a single molten puddle.
If you have two molten puddles then make sure that the electrodes are
separated at the melt point by at least 25mm.
The 18 to 25mmm zone is to be avoided, sometimes you get good welds but
many times you will have blowholes.
(The above measurements are for 3.2 mm electrodes 700 Amp 30Vdc, 750 A
32Vac 16mm separation, DC electrode 90deg to base metal, AC electrode
102degree from base metal)
As others have mentioned backchipping or grinding to sound metal, to assure
that all flux/slag is removed prior to welding the second side is important.
Best regards,
Richard Beldyk PhD, PE
AWS CWEng
ASNT NDT Level III
Original Message:
-----------------
Date: Mon, 20 Jul 2009 23:43:29 +0530 (IST)
To: material...@googlegroups.com
Subject: [MW:2721] Re: blow holes in double side welding in H-Beam SAW
welding
Sir,
This is to inform you that we are using two electrode SAW process.
Thanks,
Rohit Rawat,
Asst.Engg.(QA)
--- On Sat, 18/7/09, welding_...@charter.net
From: welding_...@charter.net <welding_...@charter.net>
Subject: [MW:2709] Re: blow holes in double side welding in H-Beam SAW
welding
To: material...@googlegroups.com
Date: Saturday, 18 July, 2009, 6:26 PM
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,
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 rohit...@gmail.com
Date: Fri, 17 Jul 2009 22:31:52 -0700 (PDT)
To: material...@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)
--------------------------------------------------------------------
mail2web LIVE – Free email based on Microsoft® Exchange technology -
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 rohit...@gmail.com
Date: Fri, 17 Jul 2009 22:31:52 -0700 (PDT)
To: material...@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)
--------------------------------------------------------------------
http://link.mail2web.com/LIVE
See the Web's breaking stories, chosen by people like you. Check out
Yahoo! Buzz. http://in.buzz.yahoo.com/
--------------------------------------------------------------------
See the Web's breaking stories, chosen by people like you. Check out
Yahoo! Buzz. http://in.buzz.yahoo.com/
mail2web.com - Microsoft® Exchange solutions from a leading provider -
http://link.mail2web.com/Business/Exchange
Reply all
Reply to author
Forward
0 new messages