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I sometimes take for granted that every one knows and uses the
terms in this web site on a daily basis. It has come to
my attention that this is not always true. While these definitions
I provide may be not entirely accurate in a global sense, they are
a step toward the understanding of what I am talking about.
A
Austempering
A heat-treating process
where the steel is cooled from austenitic fast enough to avoid
the formation of pearlite, but held above the martensetic transformation
point for long periods
Austenite
The non magnetic state
steel takes when the carbon is in a face centered cubic form.
Some stainless steels are naturally this state, other
steels are heated to get to this state. Also the first
phase formed as liquid steel turns solid.
B
Bainite
A very tough form of
steel that forms during the austempering process. Can
be created by holding the quenching temperature at 600F to 800F
resulting in upper bainite. If the temperature is held
at 450F-600F, this will allow the formation of lower bainite.
Brass
An alloy of varying amounts
of copper and zink. Of the alloy's I use, yellow brass
is 67% copper and 33% zink, and the red brass is 85% copper and
15% zink
Bronze
An alloy of varying amounts
of copper and tin. The copper content ranges from 70% to
97% with the balance being tin. There are variations such
as Phosphor bronze, and Aluminum bronze.
C
Carbon (C)
Element number 6.
Its addition into iron creates steel. Increases hardenability
and strength. For blades to harden they need to contain
about 0.4% carbon or more.
Carbon Migration (C)
is the term for when
carbon defuses to a lower carbon area. High tempratures
cause acceleration of this effect. Must be watched for
when at pattern welding temperatures.
Case Hardening
is the process of leaving
iron, or mild steel in a carbon rich environment to encourage
carbon migration into the metal. In times past, one of
the few ways to create steel.
Cast Iron
is the form of iron based
metal generally containing above 2.5% carbon.
Cementite
Fe3C also known as Iron
Carbide presents itself in two forms, plate and lathe.
These are very hard and brittle carbides. In hypereutectoid
steels there will be pearlite and some cementite when
slow cooling of the steel from austenite.
Chromium/Chrome (Cr)
Element number 24.
Its addition to steel adds in deep hardening. In amounts
exceeding 13%, it creates stainless steel.
Cobalt (Co)
Element number 27.
Its addition makes steel very hard, wear-resistant,
and high-strength alloys.
Curie Temperature
The critical temperature
at which steel transforms into austenite, and loses it magnetic
properties. Also refered to as AC3 in the transformation
charts.
D
Dagger
is a bladed weapon under
18 inches long. Most are double edged.
Dirk
is another term for a
dagger.
Distal Taper
is a blades gradual narrowing
with distance from its base toward the tip.
E
F
Ferrite
Iron with 0.02% dissolved
carbon
G
Galium (Ga)
is element number 31.
A rare element found in Meteorites, amd in trace amounts
in bauxite and zinc ores
German Silver
Also known as Nickel Silver.
One alloy consists of 65% Copper, 18% Nickel and 17% zink,
another I use has 55% Copper, 25% Zink and 20% Nickel
H
Hardness
The ability of a material
to resist plastic deformation. The common measurement system
used for blades are the Rockwell "C" scale.
Hypereutectoid
Steel with more than 0.83%
carbon.
I
Iridium (Ir)
is element number 77.
It is commonly found only in meteorites. Iridium
is used in high-strength alloys that can withstand high temperatures,
and is notable for being the most corrosion-resistant element
known. It is used in high-temperature apparatus, electrical
contacts, and as a hardening agent for platinum
Iron (Fe)
is element number 26, and
is the main component of Steel.
J
K
Knife
is a bladed weapon commonly
found with a single cutting edge.
L
Low Alloy
M
Magnesium (Mg)
is element number 12.
the main component of Aluminum alloy wheels.
Used as an igniter in thermite welding. The free element
is not found in nature. Once produced from magnesium salts,
this alkaline earth metal is used as an alloying agent to make
aluminium-magnesium alloys
Manganese (Mn)
is element number 25.
Added to steel as a deoxidizer and assists in hardening.
Counters brittleness from sulfur, a required trace mineral
for all known living organisms.
Martensite
is the hardest form and
strongest of the microstructures. Formed from austenite during
quenching portion of the heat treating of steel.
Meteorite
is a chunk of rock from
outer space. Usually from exploded star or planet, comes
to earth as an asteroid or comet. The metallic types
I use are about 93% iron, 6.3% nickel, and the remaining balance
Iridium, Colbolt, and Galium, and maybe a few other things.
Occasionally used as layers in pattern welding.
Molybdenum (Mo)
is element number 42.
Deepens hardening, enhances corrosion resistance and
increases wear resistance. It has the sixth highest melting
point of any element, it is often used in high-strength steel
alloys.
N
Nickel (Ni)
is element number 28.
Contributes to the silvery part of the pattern welded layers.
aids in strength and toughness when added to steel
Nickel Silver
Also known as German Silver.
One alloy consists of 65% Copper, 18% Nickel and 17% zink,
another I use has 55% Copper, 25% Zink and 20% Nickel
Normalizing
is relaxing the
stress that was created in the steel during forging and grinding.
O
P
Pearlite
Structure made up of
alternating bands of ferrite and cementite, that forms when
simple steels are cooled slowly. Under a microscope it
has a mother of pearl appearance, giving it its name.
Periodic Table
The chart from Chemistry
class showing all the elements laid out according to family's
and various properties. Elements are listed by name and
a number assigned by atomic weight.
Phase
A physical condition of
the arrangement of atoms in a crystal. IE steam is a phase of
water
Q
Quench
Term used for the controlled
cooling of metals
R
S
Silicon (Si)
is element number 14.
It deoxidizes, improves hardness.
Stainless Steel
is the term used when
available chrome in steel is above 13%. Its very difficult
and costly to heat treat Stainless, therefore inexpensive
blades that have been made from Stainless are not heat treated
properly, giving stainless steels, an undeserved bad reputation
for blades.
Steel
is created when carbon
is added to iron.
Steel types: Numbers
10xx
simple carbon steel with
0.30 to 0.90 Mn. The xx is for the numbers that
denote the steel's carbon contentIE 1095 would be 0.95% C The speical made 1087FG I have is 0.87 C 0.80 Mn and 0.025 V
4150
C 0.5 Cr 0.95 Mo 0.25
5160
C 0.6 Cr 0.8 Mn 0.8
6150
C 0.5 Cr 0.85 V 0.15
9260
C 0.6 Mn 0.85 Si 2.0
Cr 0.4 Ni 0.8 Mo 0.1
8670m
C 0.7 Mn 0.5 Si 0.25
Cr 0.4 Ni 0.8 Mo 0.2
Tool Steel: Letters
15N20
C 0.75 Mn 0.75 Si 0.25 Ni 1.5
A-203/E
C 0.09 Mn 0.64 Si 0.34
Ni 3.58 Cr 0.03 Mo 0.01
D-2
C 1.5 Mn 0.60 Si 0.40 Cr
12.0 Ni 0.30 V 1.0 Mo 0.90
HSS
this is not really a grade,
but a general term meaning high speed steel
L-6
C 0.75 Mn 0.70 Si 0.25
Cr 0.80 Ni 1.5 Mo 0.30
M-2
C 1.0 Mn 0.30 Cr 4.0 Ni 0.30
V 2.50 Mo 5.50 W 6.0
O-1
C 0.95 Mn 1.20 Cr 0.50 Si 0.30
V 0.20 W 0.50
S-7
C 0.50 Cr 3.25 Mo 1.40
Sulfur (S)
Element number 16.
It can make knife steels brittle.
Sword
is a blade usually over
18 inches long.
T
Tin (Sn)
Element number 50.
Titanium (Ti)
Element number 22.
It weighs about half that of Iron, but is almost as strong.
rarely used for blades, but often used for decoration.
Forms carbides, reduces hardness in stainless steels.
Titanium can be alloyed with other elements such as iron,
aluminium, vanadium, molybdenum and others, to produce strong
lightweight alloys
Tempering
is the gentle heating
of a hardened blade to cause the stress from harneding to relax
brittleness, increase toughness, and relieve stress.
Troosite
is an old term referring
to tempered martensite
Tungsten (W)
Element 74, also known
as Wolfram. Added to increases wear resistance and raises
hot strength and hot-hardness. It has the highest melting
point of all the non-alloyed metals and the second highest of
all the elements after carbon.
U
V
Vanadium (V)
Element number 23.
Increases hardenability, and fine grain structure
W
Wootz
A high carbon steel created
in a process originating probably in India. This involved
sealing iron and carbon in a chamber and heating to extremely
high temperatures. The excessive carbides in the material
produced and their segregation would produce a visible pattern in
the steel, resembling a fine layered pattern welding.
These blades also produced a very abrasion resistant edge.
Wulfram (W)
Old name for Tungsten
X
Y
Z
Zink (Zn)
Element number 30.
Its fumes are toxic, but where alloyed, its safe enough at normal
room temteratures.
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