chapter 29 shielded metal arc welding
why must materials be beveled when welding thicker materials?
beveling increaes the surface are of the bond and helps ensure penetration through the base metal
what is the process of surface preparation before welding ?
cleaning and fitting pieces to be welded, this includes, cleaning them from contaminants and oxides
a ________ machine is a type of machine that provides an even supply of ampere to the electrode
constant current
a ___________ is a raging that indicates how long a welding machine can be used at a given output current without damaging it
duty cycle
the work piece connector can also be correctly referred to as the ground
false
electrode with a heavy iron powder flux
fast fill electrode
an electrode providing deep penetration and only moderate amounts of fill
fast freeze electrode
what metals work best in the arc welding process
ferrous metals= mild steel, carbon steel, and cast iron
an electrode that produces a medium arc and has a moderate deposition rate
fill- freeze electrode
requires welding to be performed in combination of different positions
fixed pipe welding position
the easiest position for the beginning welder to master
flat welding position
the electrode leads carries current from the machine to the electrode _____________ an insulated clamp that holds the welding electrode
holder
a welding position in which the weld axis is horizontal and the two parts aligned apppin the same vertical plane
horizontal welding position
___________ are foreign materials , such as slag, tapped within the finished weld
inclusions
an electrode that produces a medium penetrating arc and a smooth moderately high deposition rate
low hydrogen electrode
in this position the electrode is pointing up at a downward facing joint
overhead welding position
the direction of flow of an electric current
polarity
waste that forma on top of the head is called
slag
sheilded metal arc welding is also known as
stick welding
what is the purpose of the flux on the welding rod ?
the flux chemically reacts to heat of the arc using the oxygen around the molten weld to form an oxygen free shield around the weld pool
on a 4 digit electrode what do the the first two digits indicate
this indicates that maximum tensile strength of the weld in psi
what do the numbers in the electrode code E6010 indicate.
this indicates this electrode has a tensile strength of 60,000 psi, and maybe be used in all positions best with DC electrode positive current to provide deep penetration and a thin slag covering
amperage is the most important setting on a SMAW welding machine
true
what is SMAW welding?
using a consumable electrode coasted in flux, and electrical arc is formed between the electrode and base metal. the base metal and the electrode melt to form a weld pool
the weld progresses from top to bottom
vertical welding position
what parameters do welders hav control of during the welding process
welders control current, electrode selection, arc length, electrode angle, electrode motion, and travel speed
The cables that connect the welding power source to the work are known as welding
welding leads
what equipment is required in shielded metal arc welding
welding machine, electrode, workpiece, welding leads, consumable electrode, and a filler rod
the next to last digit on a welding rod indicates
welding position
