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RE: [MW:4317] AFFECT POLARITY IN HEAT INPUT

By Materials & Welding
The Code recognises that a change in polarity will affect heat input.  Thats why Sc IX assigns a change in polarity, QW-409.4 is a supplementary essential variable, and any change in polarity must be requalified with a new PQR.  Without impacts QW-409.4 is a non-essential variable and must only be appropriately addressed on the WPS.
 
John

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Singh Rishi (TIPO - QA/QC)
Sent: Sunday, February 14, 2010 11:40 PM
To: materials-welding@googlegroups.com
Subject: RE: [MW:4314] AFFECT POLARITY IN HEAT INPUT

If one checks the heat input formula, there is no variable for the polarity.

 Therefore , as per standard,  Polarity  doesn’t influence the H.I .

 

 We all understand that actual H.I differs from calculated  H.I as current / voltage/ travel speed are never a single value ( specially in manual welding )

Best Regards,

Rishi Raj Singh

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of ali asghari
Sent: Saturday, February 13, 2010 9:59 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:4297] AFFECT POLARITY IN HEAT INPUT

 

thank you

but my inyention is distribution of heat is differed by polarity , therefore H.I depend to polarity.is it true?

regards

On Sat, Feb 13, 2010 at 2:04 AM, <george.dilintas@gr.bureauveritas.com> wrote:

It is because of the difference of the electrons flow I think

  From: Ali Asghari [asghariali@rocketmail.com]
  Sent: 11/02/2010 23:44 PST
  To: materials-welding@googlegroups.com
  Subject: [MW:4291] AFFECT POLARITY IN HEAT INPUT

 

Hi All

all know that heat input is independent from polarity.but  i see in GTAW that in DCEN ,70%HEAT generated in arc concentrated in parent metal & in DCEP 30% HEAT concentrated in base metal.

can anybody clarify it?

regards.

 

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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.

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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.

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