Welding Unit Exam

What's the Definition of Welding?

Joining together (metal pieces or parts) by heating the surfaces to the point of melting using a blowtorch, electric arc, or other means, and uniting them by pressing, hammering, etc.

What mixture creates the hottest flame known to man? (5700F)

Acetylene/Oxygen

Characteristics of oxy-fuel

Cutting torch

Characteristics of SMAW

Shielded Metal Arch Welding

(Electrode Welding)

Characteristics of GMAW

Gas Metal Arch Welding

(Mig Welding)

Welding process most commonly used on farms

GMAW (MIG Welding)

Personal Protective Equipment (PPE)

Anything device worn that prevents injury

(Welding Helmet, Safety glasses, proper clothing, gloves)

What's the minimum shade of lens needed while using electric arc welding

#10

What's the minimum shade of lens needed while using electric arc welding

#10

What level does Acetylene become volatile

15 psi

What is Backfire

When Flame goes out with a loud pop

(Pressure too low to tip,

Touching tip to work,

Overheating the tip,

Obstruction of the tip)

What is Flashback

When flame goes back into the mixing chamber of the torch and burns with a shrill hissing or squealing noise

What should you yell before striking an arc when electric arc welding

COVER

What are the 4 types of extinguishers?

Type A, B, C, D

What does a Type A Extinguisher put out

Ordinary Combustibles (Wood, Paper)

What does a Type B Extinguisher put out

Flammable Liquids (Paint, Gasoline, Oil)

What does a Type C Extinguisher put out

Electric equipment (Electric motor, circuit panel)

What does a Type D Extinguisher put out

Combustible Metals (Zirconium)

True or False; Safety is everyone's responsibility

True

True or False; Safety glasses are to be worn at all times when working in shop

True

True or False; When Welding & cutting processes produce ultraviolet & infrared rays that eyes and skin must be protected

True

True or False; If a gas regulator malfunctions, discard and replace with a new regulator

True

True or False; Only use an approved spark type striker to light a torch

True

True or False; Welding and cutting should only be performed in well ventilated areas

True

True or False; Oxygen cylinder value should be opened all the way

True

How far open should the Acetylene cylinder be

No more than 1/2 turn

True or False; Acetylene needle valve should be closed first when shutting off a torch

True

What PSI are oxygen cylinders charged with

2200psi

How is a acetylene kept stable when stored at high pressures in the cylinder

It dissolves in a solvent like acetone and absorbing it onto the porous material

What is the ratio of oxygen to acetylene gas that will produce a neutral flame

1:1

What are electrodes coated with?

Flux

What is the purpose of Flux

acts as a cleansing and deoxidizing agent,

Releases carbon dioxide to form a gas shield,

Forms slag over completed weld,

Provides easier arc starting, stabilizes arc better and reduces splatter, Permits a better penetration and improves quality of weld

What do the Identification numbers on electrodes mean

"E6011"

E-Electric

60-60,000- lbs tensile strength

3rd digit- welding position

4th digit- Special characteristics (coatings, weld quality, arc type, penetration)

Where should Electrodes be stored

A dry place at room temperature

What are two methods of striking an arc with a "stick" welder

Tapping and Scratching

What is GMAW more commonly known as?

Mig Welding

What shielding gas is most commonly used for welding steel?

Argon and Carbon Dioxide Mixture

What 3 events occur when the trigger is pulled on a MIG welding gun?

Current flows

Shielding gas flows

Wire is fed through the gun

Definition of Ampere

The amount of current that flows in a circuit

Definition of Volt/Voltage

Force that causes current to flow (Electrical Pressure)

Definition of Undercutting

a groove or depression that forms along the edge of the weld, where the base metal has been melted and eroded by the welding arc

What's the definition of Overlap

a discontinuity that occurs when molten weld metal extends beyond the intended weld toe and covers the base metal surface without fusing to it

What are three things that can be adjusted on a MIG welder?

Gas flow rate

Wire speed

Voltage