The 5 Base Metals STEEL

STAINLESS STEEL

CAST IRON

COPPER/BRASS

ALUMINUM

Steel – A Ferrous Metal

A iron alloy containing less than 2% carbon Melting point of 1535 degrees C or 1535 degrees F

2795Boils at 3000 degrees C or 5432 degrees FFrom Iron, add coke, limestones lots of air and

boom steel is created

Steel Forms

Bars – Solid shapes, hot or cold rolled, rounds, squares, or flats

Billets – A section of an ingot Blooms – A slab of steel, usually the same thickness and

width Plates – Large flat slabs thicker than ¼” (inch) Shapes – Can be in the forms of beams or any other

shape needed Sheets – Hot or cold rolled with varying thicknesses Wires – Drawn form bars of steel

Steel Nomenclature

Created by S.A.E and A.I.S.I

Referred to by a four digit designation (e.g. 1060, 8620, 4340)

The first two digits refer to types of alloys in the steel (e.g. 1018 means it is plain carbon)

The last two digits refer to the carbon content in hundredths (e.g. 1018 is .18% carbon.

1018 means that we have a plain carbon steel with .18% carbon

Stainless Steel – A Ferrous Metal

A iron alloy containing less than 2% carbon

Contains chromium and sometimes nickel

Melting point of 1535 degrees C or 2795 degrees F

Boiling point of 3000 degrees C or 5432 degrees F

Why do we use Stainless Steel?

Better aesthetics

Minimizes oxidation and corrosion

Can have the ability to be ultrahigh-strength steel

Stainless Steel Classification Designated with the same 4 digit coding of steel

Ferritic

11 to 27 percent chromium

Low carbon content (.1 to .35 percent)

Used in jewelry, car accessories, and is considered very weak

Austenitic

Non-magnetic

16 to 26 chromium and 6 to 22 percent nickel

Very low carbon content

Wieldable, somewhat machinable, but cannot be hardened by heat treatments

Used in low strength structural purposes

Martensitic

Higher carbon content .15 to 1.2 percent

4 to 18 percent chromium with usually no nickel

Magnetic

Not easily machined or welded but possible

Good for knives and such

Cast Iron – A Ferrous Metal

Contains 2% or more carbon Can be Gray, White, Ductile, Malleable, or

WroughtSomewhat unpredictable to work with due to its

high carbon content Two most common are Gray and White

Cast Iron

Gray

Most Common type of cast iron

About 4% carbon

Cheap to make, good compression strength, good machinability, and good vibration dampening

Broken up into three classes based on minimum tensile strength

Class 20 – 20,000 lb/in^2

Class 40 – 40,000 lb/in^2

Class 60 – 60,000 lb/in^2

Cast Iron

White

2.5 to 3.5 percent carbon and .5 to 1.5 percent silicon and 1 to 3 percent nickel, molybdenum, or chromium

Same class system as Gray Cast Iron

Very hard and very brittle

Great wear resistance

Ideal for rolling/crushing machines or tools

Cast Iron Ductile – ability to be drawn into a wire

4% carbon and 2.5% silicon

Is composed of spherulites (Key factor in the ductile part)

This removes the stress risers which potentially allow cracking in the metal

Tensile strength at around 120,000 lb/in^2

Designated by three individual number sets

e.g. 60:40:18, 65:45:12

First Set – Tensile Strength (amount of energy required to rip the material apart)

Second Set – Yield Strength (the point at which the material begins to deform)

Third Set – Percent Ultimate Elongation (the permanent deformation of the material)

Copper/Brass – A non-ferrous Metal

Copper

One of the first metals used

Dozens of types of ores but not many are commercially important

Predominantly found in Michigan, Utah, Nevada, Montana, Arizona, Alaska, Chile, Canada, Africa, England, Spain, Peru, Mexico, and Bolivia

Most practical copper is found near the surface of the earth

Usually used for wire and electrical components (must be extremely pure)

Good conductivity and good corrosion resistance but will react with sulfur, oxygen, and chlorine when heated

Its tensile strength is considerably less than steel and it modulus of elasticity is roughly half that of steel

Copper/Brass Continued

Brass

A type of Copper, Bronze, and Zinc

However may contain more elements besides Copper and Zinc

Roughly, Brass is 70% Copper, 29% Zinc, and 1% Tin

Most common types are Muntz, Red, and Free Machining

Muntz – also called Malleable Brass, is 60% Copper and 40% Zinc

Tensile strength of 52,000 lb/in^2

Red – 85% Copper and 15% Zinc

Tensile strength of 38,000 lb/in^2 but can be cold rolled (Hardened) to 70,000 lb/in^2

Free Machining

60% Copper, 40% Zinc, .75% Tin, and .25% Lead