Welding Flashcards
How do you adjust the flame
With just the acetylene burning you adjust the oxygen until a well defined white cone appears with a second bluish cone. At this point you have a betray flame
What is the volume ratio of oxygen to acetylene on a neutral flame
1 to 1
What kind of metals are welded with the neutral flame
Mild steel Stainless Cast iron Copper Aluminum
What is a carbonizing flame
The welding flame has a white inner cone with a white feathered cone enveloped with a blue feather
The metal will boil which allows it to absorb carbon. When cold it becomes brittle and subject to cracking
What is an oxidizing flame
Has a pointed inner cone with a small and narrow outer envelope
Slightly more than 1 volume of oxygen to 1 volume of acetylene
What metals are welded withe oxidizing flame
Zinc
Copper
Manganese steel
Cast iron
What is a flame backfire
This is a loud pop when the flame goes out
What causes backfires on torches
- Operating torch at lower pressures
- Touching tip against the work.
- Overheating the tip
- Obstruction of the top
What does E-6010 stand for
E- electric welding
60- tensile strength
1- welding position
0- special characteristics
What is tensile strength
The resistance of a material to break under tension
Express in psi ( pounds per square inch
What are the different position numbers
1- any position
2- horizontal or flat
3- flat only
What are the special characteristic numbers 0-4
0-cellulose sodium, dcr 1- cellulose potassium, Ac or DCR 2- Titania sodium, Ac or dcs 3-Titania potassium, Ac, DCS or DCR 4- Titania iron powder, all three
What are the special characteristic numbers 5- 8
- Low hydrogen sodium, DCR
- Low hydrogen potassium, AC or DCR
7- iron powder iron oxide, all three
8- iron powder low hydrogen , Ac or DCR
What is polarity
Indicates the direction of current flow
What is DC straight (DCS) polarity
The stinger is connected to the negative and ground to the positive
What is DC reversed (DCR) polarity
Stinger connected to the positive and work connected to the negative
Why choose straight or reversed polarity
Straight gives you more heat when required to melt metal
Reverse gives weld greater holding power by less heat
What are the essentials for arc welding
- Correct electrode
- Correct Arc length
- Correct current
- Correct travel speed
- Correct electrode angle
What are the 4 rules for General welding in the safety appendix
- Wear appropriate gloves
2 appropriate shaded lens for goggles and welding helmets
3 no cutting or welding in areas with combustibles unless precautions have been taken - No cutting or welding on piping or empty or sealed containers unless vented and purged
What are the 8 practices for General welding in the safety appendix
- No low cut shoes with unprotected tops
- No oily or greasy clothing , wear fire retardant clothing
- Shields or barriers for observers
- No cutting or welding directly on concrete
- Don’t leave hot metal unattended unless properly marked
- Adequate ventilation or respirator
- Take precautions for hot falling metal when elevated work
8 no butane lighters
Arc rules from safety appendix
- Welding machine frame grounded
Arc welding practices
- Check cables, holders, grounds, machine ect… For serviceability
Gas welding rules from appendix (3 rules)
- Don’t alter or repair cylinder valves, don’t use a regulator for one type of gas and use on another.
- No oil or grease on or near oxygen
- Never use leaky hoses or couplings
Gas weld practices
7
- Follow all precautions for gas cylinders for storage and handling
- Use only an approved lighter to light a torch
- Always close cylinder valve and release pressure after use
- Never keep a connected torch in a toolbox even if the pressure is released
- Check hoses, fittings, couplings valves, ect for serviceability
- Keep cylinders vertical and secured from falling
- Never place acetylene cylinder horizontally
What do you do for metal handling according to the safety appendix
- Use a bar to separate sheets of metal to insert crane hooks or cables
- Before lifting everyone is clear of load
- Wear gloves
- Stay clear when cutting bands off of banded steel
- Truck driver ensures properly loaded and tied down
- when lifting or moving keep hands clear of load, use a tag line
- Store steel so there is no danger of falling
- Racks should be guarded to prevent injury
What are the different flame types for the oxygen-acetylene welding?
Acetylene burning in atmosphere
- Excess Acetylene
- Neutral Flame
- Reducing or carbonizing
- Oxidizing
What are the type of defects in welds.
- Blow holes
- Inclusions
- Porosity
What is blowholes?
Cavitation caused by gas entrapment. Usually forms due to improper manipulation of the electrode and failure to maintain pool long enough to float out entrapped gas., slag and other foreign material
What is inclusions
Impurities or foreign substances forced into the puddle during weld.
What is porosity
Tiny pinholes generated by atmospheric conditions.
Types of welds
- Surface weld
- Fillet weld
- Groove weld
- plug/slot weld
What is a surface weld
1 or more stringers on unbroken metal to obtain desired properties and dimensions
What is a fillet weld
A triangle in the cross section of two joint pieces at right angle to each other in a lap, T, or corner
What are the diffent type of groove welds
- Square
- Single V
- Double V
- Single U
- Double U
- Single J
- Double J
What are the 4 main welding positions
- Horizontal
- Flat
- Overhead
- Vertical
What is an electrode
Used as a filler to join metal
What is a bead
Narrow layer of metal deposited by the electrode
What is a ripple
The shape of the bead
What is a pass
Each layer of beads
What is a crater
A depression in base metal
What is penetration
The depth of fusion with the base metal
What is reinforcement
Amount of weld piled up above the pieces being joined together
What is a plug/slot weld
Used to join overlapping pieces by welding through holes or slots
What is the toes of a weld
Point where metal and weld meet
What is the face of a weld
Exposed surface of a weld bounded by the toes
What is the Root
Opposite of the face (first pass you make)
What is the Throat of a weld
Distance between the root and face of the weld
