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Re: [MW:30299] Minor Cracks in SAW Welds Cap

By Materials & Welding
 the information provided is still very limited. however based on the provided details  , my observation is as per below:
1. Flux quality is not good. Further ( not proper preheating, preheating maintenance, recycling of flux ratio is not proper, cold flux with  mixture of foreign materials).
2.The  crack pattern seams crater cracks. this type of crack are developed due to  various reasons- mostly due to foreign metallic material entrapment. like: copper entrapment ( needed to check coated copper of wire ( in the form of powder) are mixing on  continual interval or not) ,
3. The Heat Input is very high . needed to  reduce if feasible.
4. Width to depth ratio is not proper( need to review micro-structure of crack section) 
5. Check presence of any foreign material at crack region through micro-structure 
6. Check for solidification pattern at crack region ( if solidification issue found than change the current and voltage  accordingly   to ensure  W/D ratio within acceptance range)
7. Since thickness is around 40mm and its capping run issue, so adequate preheating of 50-100 deg C might be maintained during welding. further  preheating might not be resolve this issue 

Check as per above and inform any progress

Regards

Rishikesh kumar



 


On Thu, Dec 19, 2019 at 1:06 PM Gowtham Rajendran <rajgowthamiwe@gmail.com> wrote:
Mr.Rishikesh Kumar &  Raghuram Bathula,

Material - S355ML
Thickness - 40 mm  
Consumable - F7A8-EM12K
Process - SAW ( Tandem)
Heat Input - 3.15 Kj/mm
Preheat - Not applicable
Post heat - Not applicable


On Tue, 17 Dec 2019 at 11:32, Rishikesh Kumar <rishikr06@gmail.com> wrote:
Can your share more information  like material, consumable, welding process and sequence, heat input,etc . then anybody might help in right direction...


On Tue, Dec 17, 2019 at 11:28 AM Gowtham Rajendran <rajgowthamiwe@gmail.com> wrote:
Dear All,

In the cap pass of the SAW Welding, we have observed some minor cracks while performing MPI as you can find in the attached pics.

With pipes welded with the same parameters and almost the same condition, we are finding this kind of defect in some pipes, if anyone has come across such kind of defects, kindly share your experience and possible root cause.

Thanks in advance for your valuable inputs.


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