Ferrous Metals

STEEL
o Carbon + Iron
o Steels according to carbon content
 Low carbon
 Medium Carbon
 High Carbon
o Alloying Elements
 Carbon
 Sulfur
 causes brittleness
 use manganese
 Silicon
 hardener
 Phosphorus
 yield strength
 resistance to atmospheric corrosion
 Nickel
 Hardness
 Tensile strength
 Elastic Limit
 Chromium
 Hardness
 Strength
 wear and corrosion resistance
 Chrome-Nickel (Stainless)
 Three general groups
o Austenitic
 Large percentage of chromium and nickel
o Ferritic
 Chromium + small amounts of Al
 No carbon
o Martensitic
 Chromium only
 Corrosion resistant
 18-8
 Chrome Vanadium
 Strength
 Toughness
 Resistance to wear and fatigue
 Molybdenum
 Reduces grain size of steel to increase both impact strength and elastic limit
 Ultimate strength
 Tough and wear resistant
 Adaptable for welding
 Tungsten
 Extremely high melting point
 retain hardness at elevated operating temps

Electrochemical test reagents
o Ammonium fluoride
o Dimethylglyoxime
Nonferrous metals

ALUMINUM
o Two general classes of aluminum
 Casting alloys
 Two basic groups
o physical properties are determined by the alloying elements and cannot
be changed
o Alloying elements make it possible to heat treat to change physical
properties
 Produced by three casting methods
o Sand mold
o Permanent mold
 Two specific types of permanent mold
 permanent mold with metal cores
 semipermanent mold with sand cores
o Die cast
 Wrought alloys
 Two general classes
o Non-heat-treatable
o heat-treatable
 Naming
Wrought
Cast
1xxx Pure Al
Pure Al
 Excellent corrosion resistance
 high thermal and electrical
conductivity
 excellent workability
2xxx Copper
Copper
 grain structure
 Best known is 2024
Silicon w/
3xxx Manganese
 Good working characteristics
added
 Most popular is 3003
Cu/Mg
4xxx Silicon
Si
 Lowers melting temp.
 Therefore good for
welding/brazing
5xxx Magnesium
Magnesium
 Good welding
 corrosion resistant
Unused
6xxx Magnesium
 Medium strength
Silicon
 good forming
 corrosion resistant
 Most popular is 6061
7xxx Zinc
Zinc
 Principal alloy is 7075
 Coupled with Mg to become heattreatable and very high strength
Tin
8xxx Others
Other
9xxx Unused
o
Aluminum Numenclature
S
W/O S
R
A
H
T
O
SRT
W
o
F
O
H
W
T
H1
H2
H3
Wrought
Cast
Wrought gawa ng Reynolds
May konting binago galing sa OG
Temper designation (H1, H2, etc)
Hardened by heat treatment
Heat treatable alloy in annealed soft state
Heat treated and strain hardened
Intermediate heat treatment
Hardness (Temper) Identification
As fabricated
Annealed, recrystallized
Strain hardened
Solution heat treated
Heat treated (other than FOH)
Strain hardened only
Strain hardened and partially annealed
Strain hardened and stabilized
2
4
6
8
9
¼ hard
½ hard
¾ hard
Full hard
Extra hard
Types of heat treatment


Solution heat treatment
o Natural
Precipitation Heat treatment
o artificial
Methods of heat treatment



Solution heat treat
Quenching
Age hardening



Annealing
Normalizing
Tempering
Types ulit


Magnesium
o Magnesium ang sa ASTM
Titanium
o Three basic types of crystals
A
Alpha
B
beta
C
Combined alpha and beta











all around
good weldability
tough and strong both cold and hot
resistant to oxidation
bendability
excellent bend ductility
strong both hot and cold but vulnerable to contamination
strong when cold and warm but weak when hot
good bendability
moderate contamination resistance
excellent forgeability
o

Two basic compositions
 Pure Ti
 A-55
 A-70
 Alloyed Ti
 C-110M
Copper
o Beryllium copper
 One of the most successful
 97 Cu 2 Be
o Brass
 Zinc + Copper + Al, Fe, Pb, Mn, Mg
 Muntz metal
 Brass with 60Cu 40Zn
 Excellent corrosion resistant in salt water
o Bronze
 AKA Red Brass
 Contains Tin
 True bronzes
 Up to 25Sn
 Most useful when less than 11percent



Copper Aluminum
 Aluminum Bronze
o Ranks high in aircraft usage
o Up to 16Al
Cast Aluminum Bronze
 89Cu 9Al
 Ductile
 Corrosion resistant
 bearings and pump parts
Manganese Bronze
 high strength, tough, corrosion resistant Cu-Zn alloy


Silicon Bronze
 95Cu 3Si 2Mn,Zn,Fe,Sn,Al
Nickel
o Monel
 68Ni 29Cu
o K-Monel
 Adding Al to Monel
o Two nickel alloys
 Monel
 68Ni 29Cu
 Inconel
 80Ni 14Cr
Two types of Alloy


Substitutional
Interstitial