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SAW
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7/17/2019 SW
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(SW)
Welding process in which a metal fastener (weld stud) is
joined to a workpiece
The metal fastener is joined under pressure once
sufficiently heated with an electric arc
The fastener or weld stud is positioned for welding
through the use of a stud gun
When the operator activates the stud gun trigger, thefastener (electrode) is welded to the workpiece without the
use of filler metal
The welding duration of SW is typically one second or less
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Principle of operation
This is a combination of arc welding and forge welding
It is based on two steps !irst, electrical contact between the end of the
stud and base metal occurs and an arc is established
The heat of the arc melts the surface of the end of the stud and thework surface
"s soon as the entire cross section of the stud and the area of e#ual
si$e on the base metal are melted ,the stud is forced against the base
metal
The molten end of the stud joins with the molten pool of the work
surface, and as the metal solidifies the weld is produced
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%ne end of a SW fastener is prepared for welding
" ceramic ferrule surrounding the weld end of the fastenerprovides partial shielding of the weld
The ferrule also dams the molten metal to form a fillet type
weld Shielding gases or flu& may or may not be used to protect
the weld
The polarity used in stud welding depends on the type ofmetal being used
Welding aluminum would usually re#uire '*
Welding steel would re#uire '+
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ST' W-'I+. (SW)
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Typical Uses
The arc stud welding process lends itself to a wide range of
applications such as"utomotive
Ship building
"ppliance
"ero/dynamics
0oilers
-ight or heavy construction
*reassembled fabrication designs
!it/up parts design
The process may be utili$ed on a range of material thickness
from about 121 in to several inches
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Applications
sed for welding studs to mild steels , low alloy steels, andsome of the austenitic stainless steels
apable of producing a full cross section weldment with a
minimum of base metal distortion or surface disruption
an be used in locations which do not permit use of other
fastening methods
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Applications Cont…
*rocess lends itself to the automatedconcept or high production shops
apable of producing welds which are lesscostly per unit than other methods
*rocess may be effectively utili$ed with aminimum of time spent in personnel training
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Equipment
onstant urrent () *ower Source
Stud Welding .un
Weld able With Stud .un
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2.3.
4.
5.6.
' () *ower
Source
.round
cable andlamp
Stud gun
(/)
*late (3)
W e l d
c a b l e
ontrol cable
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Poer Source
The typical power source for stud welding should
have the following characteristics4
○ '/ onstant urrent ()
○ %pen circuit voltage range of 51/611 7
○ 8apid current rise time
○ 9igh current output for relatively short timeperiods
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Wel!in" GunsThere are two basic arc stud welding guns available4
*ortable, pistol grip configuration, which is used for hand/
held or manual operation
!i&ed, production gun, which is usually mounted on apositioning device and is usually incorporated with an
automatic fastener loading system
The portable, pistol grip design is offered in three capacities4
-ight 'uty (Stud diameters :; mm to <= mm)
Standard 'uty (Stud diameters :; mm to 6=< mm)
9eavy 'uty (Stud diameters :; mm to :6> mm)
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T#e Wel!in" Stu!
Welding grade studs are made of most commercially
used metals, and normally range in diameters from
:; mm to :6> mm with lengths as re#uired
In addition to straight threaded or unthreaded studs,
it is possible to obtain a wide variety of shapes and
si$es
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Arc S#iel!s ($errules)
oncentrates the arc heat to the immediate weld area
*rotects the molten weld pool from atmospheric
contamination
onfines the molten metal to the weld $one, to form a fillet
*revents charring and disruption of surrounding base
metal surfaces
8educes the possibility of open arc flash? therefore, the
operator and surrounding personnel need only wear
suitable flash type safety glasses
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Wel! %uality
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Capacitor Discharge (CD) stud welding systems use a small
ignition tip at the ase o! the weld stud to produce an arc.
apacitor 'ischarge (') stud welding is generally
used to weld smaller diameter fasteners to thin base
metals
Since the entire weld cycle is completed in
milliseconds, welds can be made without pronounced
distortion and burn/through
%nly smaller studs of 2@ mm ma&imum diameter are
welded with this method
apacitor 'ischarge Stud Welding
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