Final

Low-carbon (mild) steel is

0.02-0.30% carbon, tough and ductile, most commonly used type of carbon steel, mostly produced as rolled steel

Medium carbon steel

0.30-0.45% carbon content, strong and hard but less ductile, not easily welded

High carbon steel

0.45-0.75% carbon, very hard and strong

Never use acetylene at pressures in excess of ________.

15 psi! 5 psi is enough

stainless steel

A metal alloy of steel, contains sufficient chromium to form a passive film of chromium oxide on the surface; noted for its ability to resist rust.

lead angle

Angle between torch or welding rod and the work, parallel to the direction of the weld (45 Deg.)

work angle

Angle between torch or welding rod and the work, perpendicular to the direction of the weld

thermal spray

COATING PROCESSES IN WHICH MELTED (OR HEATED) MATERIALS ARE SPRAYED ONTO A SURFACE

Iron, Carbon (2.1 to 4%) and Silicon (1 to 3%); what metal is this?

Cast Iron

Which metal is the softest?

Cesium

Which metal is the hardest?

Chromium

metalloids

Elements that have properties of both metals and nonmetals.

AC stands for Direct Current

False

I can change the welding current and switch polarity while making a weld

False

I can wear welding gloves while operating the belt/disk sanders

False

I do not have to wear a welding jacket if I am just doing a tack-weld

False

If I start gas welding, I turn on the main valve of the oxygen tank FIRST

False

It is okay to arc weld on coated material

False

The ground clamp does not need to be attached to the welding table or work piece

False

The letter "E" on the electrode denotes "electricity"

False

When operating sheet metal shear, I can cut 2 pieces at a time

False

Steel is the most widely used of all metals, accounting for 95% of worldwide metal production.

False: Iron

If I see pinholes in surface of my weld, this is called undercut

False: it's porosity

FCAW

Flux Core Arc Welding

FCAW:

Flux Cored Arc Welding; a wire consisting of a steel electrode surrounding a powder fill material

MIG Welding

GMAW (gas metal arc welding): pool of solid-steel wire is fed from the machine through a liner; heat, filler rod, shielding gas

Brinell Hardness Test

Indicated the diametric area of impression as the Hardness Number

non metals

Low conductivity, not ductile, not malleable, brittle, dull, gas at room temp

tensile strength

MEASURE WHICH INDICATES THE ABILITY OF A MATERIAL TO WITHSTAND A LONGITUDINAL STRESS

box and pan brake

Machine used for bending sheet metal

soldering

Process of finding two pieces of metal I'm means of the filler materialHaving a lower melting point than the metals to be joined

malleability

REFERS TO A MATERIAL'S ABILITY TO DEFORM UNDER COMPRESSIVE STRESS.

SMAW

Shielded Metal Arc Welding (Stick); requires filler rod, and shielding

hot rolled steel

Steel formed into its final shape by passing it between rollers while it is very hot. Blue scale on surface when cooled

galvanized steel

Steel that has been coated with a protective layer of zinc to prevent rusting

extractive metallurgy

The practice of removing valuable metals from an ore and refining the extracted raw metals into a purer form.

A dirty tip torch can cause backfiring.

True

Aluminum has about 1/3 the density and stiffness of steel

True

Copper is probably the oldest known metal

True

Galvanized steel is widely used in applications where RUST RESISTANCE is needed

True

In Arc welders, the amperage is adjustable and the voltage is constant

True

It is NEVER okay to dip electrode holder into water buckets.

True

Low carbon "Mild" steel has about 0.3% carbon

True

The electrode forms a slag coating over a bead

True

The first two digits on an electrode represent tensile strength

True

Weld speed determines width of bead

True

You have to remove slag before cooling it off with water

True

Iron and Carbon (less than 0.03%); what metal is this?

Wrought Iron

metal

a generally solid substance with: HIGH ELECTRICAL AND HEAT CONDUCTIVITY, LUSTER, HARDNESS, high tensile strength, ductility & malleability

plating

a process in which a metal is deposited on a conductive surface

deep drawing

a process in which sheet metal blank is radically drawn into a forming die by the mechanical action of a punch

lead

a soft heavy, highly malleable metallic element; poor conductor of electricity, very resistant to corrosion

shear strength

ability of a material to resist forces that attempt to cause the internal structure of the material to slide against itself

zinc

bluish-white, lustrous, diamagnetic metal; 3rd most used nonferrous metal

very high carbon steel

carbon content higher than 0.75%, super hard and strong, seldom welded

bronze

copper and tin

brass

copper and zinc

neutral flame

equal amount of oxygen and acetylene

carburizing flame

excess acetylene

oxidizing flame

excess oxygen

rolling

fabricating process in which metal is passed through a pair of adjustable rolls

annealing

heat (metal or glass) and allow it to cool slowly, in order to remove internal stresses and toughen it.

strength

its ability to withstand AN APPLIED STRESS without failure

The Rockwell R Hardness Test

measure the resistance to/ penetration of: a steel ball or a diamond cone; depth of impression is measured

ferrous

metals which contain iron, generally magnetic

nonferrous

metals which do not contain any iron; not magnetic, more resistant to corrosion

The periodic table is divided into three sections:

metals, non-metals, and metalloids

spinning

metalworking process by which a disc or tube of metal is rotated at high speed and formed into an axially symmetric part

flashback

popping and hissing noise; explosion at the tip of the nozzle and a squealing sound and smoke issuing from the nozzle tip

backfire

popping noise; explosion at the tip of the nozzle

case hardening

process of hardening the surface of a metal, often a low carbon steel, by infusing elements into the surface; resulting surface is harder than base material

punching

process of using a press to push a punch through the material and into a die to create a hole in the workpiece

hardness

property of a metal, which gives it the ability to being PERMANENTLY DEFORMED under load;

Quenching

refers to heating and a rapid subsequent cooling; heating to 1500F and rapidly cooling with air =, bring, oil, or water

porosity

refers to the pinholes in the surface of the weld bead

Tempering

relieve the internal stresses and reduce brittleness, slowly heat up the piece below its hardening temperature and a blue line of heat will appear and allow it cool slowly with air

cold rolled steel

sheet steel that has been formed using heavy rollers at room temperature, to improve its surface finish, hardness, and strength

The best metallic conductor of electricity is:

silver

nickel

silvery-white lustrous metal with a slight golden tinge

aluminum

soft, lightweight, ductile, durable metal; good thermal and electrical conductor

ductility

the ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire

compressive strength

the maximum compressive stress that a material can withstand w/o being crushed

ironing

the process of uniformly thinning the workpiece in a specific area

luster

the way light interacts with the surface of metal; radience, shine

sheet metal

thickness <1/4

plate

thickness >1/4

metal finishing

to improve the appearance of the product, to prevent corrosion, cover the surface of a less expensive metal with a more expensive one

perforating

to puncturing of a material with a harder (usually sharp) object to create a hole or aperture

radioactive metals

uranium and plutonium

press brake forming

uses an open-frame single action press to bend, corrugate, curl, notch, perforate, pierce, or punch a sheet metal or plate`

MIG Welding

welding that uses an inert gas or gas mixture for shielding; buzzing sound