Shielded Metal Arc Welding PPT.
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Transcript Shielded Metal Arc Welding PPT.
SMAW
Shielded Metal Arc Welding
OFW/OFC
OXY FUEL WELDING
OXY FUEL CUTTING
Purge
To blow or clean out the lines on the
Oxy/Acetylene setup
Flux
Powdered coating around the electrode
used in SMAW process.
1) Cleans metal/weld while welding
2) Cools Metal/weld/electrode while
welding
3) Stabilizes the arc while welding
4) Keeps out atmospheric gases from the
molten puddle
Electrode
Flux covered conductive rod used as filler
in the SMAW process
Slag
Protective coating over completed weld
made up of burnt flux, impurities that
have rose to the top of weld which aid in
the cooling process.
Crater
Indentation in the weld (below base
metal) usually happens at the end of the
weld
Arc Length
Distance between the tip of the electrode
and the base metal. Also known as Arc
Gap.
Long Arc = large Gap
Short Arc = Small Gap
Shorter the Gap = Cooler the Arc
Longer the Gap = Hotter the Arc
Rod Angle
Angle the electrode is held from the base
metal
1)Base Angle (BA)
2)Direction of Travel Angle (DOTA)
Porosity
Gas Pocket in/on the weld that is a defect
in the weld.
Long arc will cause
Dirty base metal
Broken flux from the rod.
Fusion
Combining or joining of two materials
Penetration
Depth of Fusion
Ductility
Ability of metal to be bent or stretched
without breaking
1) Rolled
2) Bent
3) Stretched
Alloy
What metal is made up of (Elements)
1) Periodic Table
Zinc
Magnesium
Iron
Flashback/Backfire
1)
2)
3)
Hissing or Popping sound from tip of
torch caused by gas and flame going
back into the tip.
Tip to close
Dirty Tip
Malfunction of equipment
Amps
The measure of Electrical Flow
1) electrons traveling
2) Water running out of a garden hose
would be compared to Amps
3) Water Flow/Electrical Flow
Volts
Measure of Electrical Pressure
1) Force of electrons
2) Compared to your finger over a running
garden hose to generate more
pressure.
3) water pressure/Electrical pressure
Puddle
Molten metal that follows the electrode,
this solidifies to create the weld.
Arc Flash/Flash Burn
Dangerous lights produced during Arc
Welding that damage your eyes/skin if not
protected with shaded/filtered lens or
protective clothing.
Dangerous lights: Ultraviolet/Infrared
Arc Flash: Burns unprotected eyes
Flash Burn: Burns unprotected skin
SMAW <125 amps shade 10
Flash/Arc Burn
Ultraviolent/Infrared Light
Butt Joint
Corner Joint
Inside
Outside
Edge Joint
T Joint
Lap Joint
Electrode #’s
Tensile Strength
Welding Position
Special Characteristics
60 = 60,000 psi
1 = All Positions
0 = Deep/DC + / Fast Freeze
70 = 70,000 psi
2 = Flat/Horizontal
1 = Deep/AC/DC + / Fast Freeze
80 = 80,000 psi
3 = Flat Only
3 = Shallow /AC/DC+/DC-
90 = 90,000 psi
8 = Medium / AC/DC+/Low Hydro
X 1000 lbs sq inch
Tensile Strength
Special Characteristics
•Current Type
•Flux Characteristics
•Metal Type
Electrode
•Penetration
E 60 1 1
Position
E 60 11
60,000 psi
Special Characteristics
•Deep Penetration
•Cellulose Potassium flux
•Fast Freeze
Electrode
•AC/DC+ (current)
E 60 1 1
All Position
E 60 1 0
60,000 psi
Special Characteristics
•Deep Penetration
•Cellulose sodium flux
•Fast Freeze
Electrode
•DC+ (current)
E 60 1 0
All Position
E 70 1 8
70,000 psi
Special Characteristics
•Medium Penetration
•Iron Powder Low Hydrogen flux
•AC/ DC+ (current)
Electrode
E 70 1 8
All Position
E 60 1 3
60,000 psi
Special Characteristics
•Shallow Penetration
•Titania Potassium flux
•AC / DC+ / DC - (current)
Electrode
E 60 1 3
All Position
Electrode #’s Quiz Slide
E
Electrode
80
80,000 psi tensile
strength
2
Flat/Horizontal
Position
1 Deep Penetration
Fast Freeze
AC/DC +
Tensile Strength
Welding Position
Special Characteristics
60 = 60,000 psi
1 = All Positions
0 = Deep/DC + / Fast Freeze
70 = 70,000 psi
Electrode
80 = 80,000 psi
E
90 = 90,000 psi
60
Low +
Hydrogen
Flux
2 = Flat/Horizontal
1 = Deep/AC/DC
/ Fast Freeze
60,000
psi tensile
Flat Position
strength
Medium Penetration
3 = Flat Only
Only 3 = Shallow /AC/DC+/DC+
8 = Medium AC/DC
/ AC/DC+/Low
Hydro
3
8
B. Welding Procedures (Cont.)
b. A tapping movement is where the electrode
is quickly tapped on the surface of the metal to
prevent it from sticking to the base metal.
4 Things Required for a Good
Weld
Amp Setting : Heat and (proper current type)
Travel Speed
Rod Angle: (Base Angle/Direction of Travel Angle)
Arc Length: Gap Should Equal Diameter of Electrode
B. Welding Procedures (Cont.)
8. There are two methods used in starting the
arc.
A striking movement is similar to striking a match.
Welding Positions
Flat
Horizontal
Vertical: V Up/V Down (v up Gives deeper penetration)
Overhead
Flame Types
Oxygen
Odorless Gas
Colorless Gas
Line Colors Green
Right Handed Threads on Fittings
Types of Combustible Gases
3 types commonly Used for Fuel in
Oxy/Fuel Welding and Cutting
Acetylene
Propane
Mapp Gas
(methylacetylene-propadiene propane)
acetylene
Colorless Gas
Garlic Odor
Unstable after 15psi Line Pressure
Absorbed into Acetone (cork) to allow
higher pressures in Tank
Red Colored Hoses w/ Left Handed
Threads
Duty Cycle
The amount of time a welding machine
can be operated continuously
70% Duty Cycle= 70% of an hour
70% Duty Cycle = 7 minutes every 10 min
Polarity
DC+
DCEP
Reverse Polarity
DCDCEN
Straight Polarity