arc welding notes for metals 1
TRANSCRIPT
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ARC WELDING NOTES
ARC WELDING Shielded Metal Arc Welding (SMAW). Electricity a! it "#$%! aga!e! ga% 'eteen t& c&nd#ct&r!. r&d#ce! an arc a! inten!e a! *+++,.
T-E! O, WELDERS
Rectiier
D.C. (Direct C#rrent) Electricity i! c&n/erted r&$ A.C.
(Alternating C#rrent) thrgh tran!&r$er! and rectiier!.
I. A.C. 0 D.C. D#al %#r%&!e
ELECTRODES
1!#ally 234 l&ng
5 2 5Cla!!iicati&n 6rand na$e! dier '#t the A.W.S. n#$'er
!y!te$ i! the !tandard7
E8a$%le 9 E:+2; 9 E
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III. 20; heat at the 'a!e
and =0; heat at the r&d.
I?. Characteri!tic!
2. Dee% %enetrati&n
g&&d &r thic $etal!
=. r&ne t& arc 'l&
;. Alternating C#rrent 5 (A.C.)
STRI@ING AN ARC Lie !triing a $atch tch the electr&de t& the $etal
then circle #% and 'ac d&n t& the dia. & the r&d aay r&$ the 'a!e
$etal.
M&ti&n 5 (A/&id e8ce!!i/e $&/e$ent)
A. Straight 5 ,eed in drag the %#ddle
ROD OSITION
V. ,lat R&d %er%endic#lar t& 'a!e $etal. Incline a't =+ r&$
%er%endic#lar t&ard directi&n & tra/el. Drag the eld.
(6achand)
VI. La%% &r In!ide C&rner Angle r&d ;+ t& 3 t& 'a!e $etal.
Incline =+ t&ard directi&n & tra/el. Drag eld.
WELD OINTS
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6#tt "&int %re%are "&int. Metal $#!t 'e clean. Alay! tac /ee thic
%iece! &r %enetrati&n. 1!e a !light $&ti&n 'ac &rth.
,lange (edge "&int) Alay! tac. Ea!ie!t eld. Thic %iece! !hld
'e /eed.
La%% "&int ?ery c&$$&n. l#g r&!ette !l&t eld! are all /ariati&n! &
the la% eld. C&ncentrate heat &n '&tt&$ %late. 1!e a !light ea/e
$&ti&n. Alay! tac.
In!ide C&rner (Tee "&int) EF#al eld &n each %late. ,ini!hed "&int
!hld 'e c&nca/e t& lat. 1!e a cl&!e arc. C&ncentrate heat &n
'&tt&$ %late. Alay! tac.
O#t!ide "&int All& &r nat#ral /ee. Alay! tac. 1!e a !light ea/e.
WELDING OSITIONS
,lat
&ri>&ntal (&n a /ertical %lane).
?ertical
O/erhead
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RO6LEMS
Arc 6l&
?II. A $agnetic &rce delect! the eld int& !%litting.
?III. C#re Ree!ta'li!h grnd. Sh&rten arc length.
1nderc#t
I
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r&tecti/e eF#i%$ent All the li!ted eF#i%$ent %r&tect! y r&$ heat
!%latter and har$#l ray!. (1ltra/i&let Inrared).