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Proposal and Trial for Welding Process Modication for

Circumferential seam weldingDate : 24-06-2016

Objective:

To avoid the GMAW process to weld the root r!" #$ directl$ appl$i!g %AW o!

circ&fere!tial sea& weldi!g of tower sectio!s of &ore tha! 2'&& thic(!ess)

Current practice:

Joint confguration:Do#le-* with 60o i!clded a!gle" +oot face 2&&" +oot

gap 2-,&&)

Welding sequence:

1) +oot r! with GMAW at i!!er side)

2) 2 or , la$ers of %AW po! root of it),) ac( gagi!g 2-, && deep)4) D$e pe!etra!t test o! gaged srface)') .ill p 2-, la$ers of %AW at oter side)6) /ltraso!ic testi!g of e!tire circ&fere!tial sea&)

Observations:

1) Defects are fo!d al&ost at &id thic(!ess of weld oi!t" &ostl$ pla!ar

defects)2) Detailed std$ of defect $et to #e carried ot" #t it &a$ #e #ecase of

a!$ of the followi!g

i) .it ps !ot repeata#le)ii) A #road root face" which does !ot &elt the root face fro&

either side)iii) ac( chippi!g did!t gri!d throgh so!d weld &etal)iv) ha!ge i! i!clded a!gle)v) 3perators s(ill)vi) Machi!e pro#le&)

60o

60o

2-,&&

2&&

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Proposed trial:

Trial !o: 1

Date: 24-06-2016

Trial test specimen size : 400&& ,00&& ,0&&

Joint confguration:Do#le-* with 50o i!clded a!gle" +oot face 4&&" +oot

gap 0&&" Plate thic(!ess of ,0&&)

Welding sequence:

1) +oot r! with %AW at i!!er side)2) , or 4 la$ers of %AW po! it),) ac( gagi!g !til so!d weld &etal is visi#le)4) D$e pe!etra!t test o! gaged srface)') .ill p 1-2 la$ers of %AW at oter side)6) /ltraso!ic testi!g of e!tire circ&fere!tial sea&)

Inerence:

1) %lag re&oval was diclt)2) /T is o(),) *isall$ !ot o()

"urt#er $ction:

%epeat t#e trial wit# modication in weld edge geometr& and welding

electrical parameters'

3ter side

7!!er side50o

0&&

18&

4&&

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Trial !o:

Date: 28-06-2016

Trial test specimen size : 400&& ,00&& ,0&&

Joint confguration:Do#le-* with 60o i!clded a!gle" +oot face 2&&" +ootgap 0-1 &&)

Welding sequence:

1) +oot r! with GMAW at i!!er side)2) 2 or , la$ers of %AW po! it fro& i!!er side),) ac( gagi!g 2-, && deep 9+oot of GMAW to #e re&oved !til we !d

so!d weld &etal;)4) .ill p 2-, la$ers of %AW at oter side)') /ltraso!ic testi!g of e!tire circ&fere!tial sea&)

Inerence:

1) After root r! si!g GMAW" it is fo!d that pe!etratio! has !ot reached

the fll thic(!ess)2) ac( gri!di!g of the root revealed that the e!tire le!gth of weld has lac(

of pe!etratio! to varios depths" after co&pleti!g o!e side weldi!g),) ac( gri!di!g to depth pto 4&& re

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Trial !o: (

Date: 29-06-2016

Trial test specimen size : 400&& ,00&& ,0&&

Objective amendment: GMAW of root ca!!ot #e avoided as this is re