Re: [MW:13137] what is the root cause for copper crack in saw welding ?

When you weld vessels or drums sometimes from the electrical cable also copper entraps into the weld. One beauty is that copper in the weld tends to penetrate deeper during gouging. Hence first the defect depth has to be identified and the copper deposists which causes cracks need to be grinded out.

Thanks & Reagrds

J.Gerald Jayakumar
00968-93281596

From: kannayeram gnanapandithan <kgpandithan@gmail.com>
To: materials-welding@googlegroups.com
Sent: Sunday, December 4, 2011 11:19 AM
Subject: Re: [MW:13136] what is the root cause for copper crack in saw welding ?

we have lot of exp in this subject, while welding water wall panel by
saw, accidently contact tip touches the weld zone and get short
circuited then tip melting takes place, in this unless overweld on
this area, no harm otherwise fissing and cracks takes place. we have
design and developed new contact tip to overcome this problebm

Pandithan
cethar limited

On 11/30/11, Biplab Pal <biplab.mech@googlemail.com> wrote:
> Dear MPK,
> Copper is one of the elements which causes HOT CRACK.
> There are two types of Hot Crack
> 1. Solidification Cracks: Occurs in the Weld Metal (Usually along the
> centerline of the weld) as a result of the solidification process.
> 2. Liquation cracks: Occurs in the course grain HAZ, in the near
> vincity of the fusion line as a result of heating the material to an
> elevated temperature, high enough to produce liquation of the low
> melting point constituents placed on grain boundaries.
>
> Weld bead solidification started above 1400 deg C, and the melting
> points of copper is near 1100 deg C.
> This is the basic reason.
>
>
> On Tue, Nov 29, 2011 at 7:02 PM, mpk mpk <ranmi2007@gmail.com> wrote:
>> Dear Experts,
>>
>> What is the Root cause for copper crack in SAW welding ?
>>
>> thanks,
>>
>> MPK
>>
>> --
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>>
>
>
>
> --
> Thanks & Regards
> Biplab Pal
> Industrial Services, Inspection Engineer.
> SGS India Pvt. Ltd.
> Kolkata Branch
> E-mail: biplab.mech@gmail.com
>
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