CARBON (C): Has by far the greatest influence of any of the elements.
Steel could not exist without carbon. Martensite, along with banite give steel
a microstructure of hard, tough carbide.
None of the other elements so dramatically alter the strength and hardness as do small changes in carbon content.
Carbon iron crystalline structures have the widest number and variety known to exist in
metallurgy. They also combine with other elements to furnish steel with an
assortment of iron alloy carbide systems.
MANGANESE (Mn): Is normally present in all steel and functions as a
deoxidizer. It also imparts strength and responsiveness to heat treatment. It is
usually present in quantities less than 1.00 %......
NICKEL (Ni): Increases strength and toughness but is ineffective in
increasing hardness. It is generally added in amounts ranging from 1 percent to 4
percent. In some stainless steels it is sometimes as high as 20 %.......
SILICON (Si): Has a beneficial effect upon tensile strength and improves
hardenability of an alloy. It has a toughening effect when used in combination
with certain other elements.
conductivity of an alloy. Amounts are usually 0.30 % ,spring steels may contain up to 2%
CHROMIUM (Cr): Increases the depth penetration of hardening and also the
responsiveness to heat treatment. It is usually added with nickel (Ni) for use in
stainless steels. Most of the chromium (Cr) bearing alloys contain 0.50 to 1.50
percent chromium; some stainless steels contain as much as 20 percent or
more. It can affect forging, causing a tendency in the steel to crack.
VANADIUM (V): Retards grain growth within steel even after long exposures
at high temperatures, and helps to control grain structures while heat treating. It
is usually present in small quantities of 0.15 to 0.20 for grain refining which increases toughness .
Additional amounts up to about 4-5 % for carbides. Most tool steels
which contain this element seem to absorb shock better that those that do not
contain vanadium (V).
MOLYBDENUM (Mo): Adds greatly to the penetration of hardness and
increases toughness of an alloy. It causes steel to resist softening at high
temperatures, which defeats the purpose of forging. If the alloy has below 0.020
percent molybdenum (Mo), you should be able to forge this alloy with little difficulty.
TUNGSTEN (W): Also known as wolfram, is used as an alloying element in
tool steels, as it tends to impart a tight, small, and dense grain pattern and keen
cutting edges when used in relatively small amounts. It will also cause steel to
retain its hardness at higher temperatures and hence will have a detrimental
effect upon the steel's forgeability (otherwise known as "red hard")
SULFUR (S): Is usually regarded as an impurity in most alloys and its addition
to steel is held to a minimum as it is damaging to the hot forming characteristics
of steel. It is, however added to increase machinability. A word of caution, some
alloys are offered in different forms, an example is E52100. This particular steel
can be had in either a "Bearing Quality" or " free machining grade " the latter having
sulfur (S) added to increase machinability.
LEAD (Pb): Increase the machinability of steel and has no effect upon the
other properties of the metal. It is usually added to an alloy only upon request
and then in quantities of 0.15 to 0.30 percent.
PHOSPHORUS (P): Is present in all steel. It increases yield strength and
reduces ductility at low temperatures. It is also believed to increase resistance to
atmospheric corrosion. Phosphorus (P) is usually treated as an impurity in most alloys.
Some common blade steels....and their element content.
52100: Carbon 1.00% Manganese 0.35% Silicon 0.25% Chromium 1.50%
5160: Carbon .60% Manganese .85% Phosphorus .035% max .80% chromium Sulphur .040% max .
1084: Carbon .80%/.94% Manganese .60%/.90%
1095: Carbon .90%/1.04% Manganese .60%/.90%
15N20: Carbon .75% Manganese .75% Silicon .25% Nickel 1.5%
O-1: Carbon 1.00% Manganese .60% Silicon .30% Chromium .50% Vanadium .30% Molybdenum 1.10 v L-6: Carbon .75% Manganese .70% Silicon .25% Chromium .80% Nickel 1.5% Molybdenum .30%
A-2: Carbon 1.00% Manganese 0.85% Silicon 0.35% Chromium 5.25% Molybdenum 1.10% Vanadium 0.25%
D-2: Carbon 1.55% Manganese 0.35% Silicon 0.45% Chromium 11.50% Molybdenum 0.90% Vanadium 0.80%
some of the text above has been Changed
and some of the changed information came from Robert Cella metallurgist
with permition of Ed Caffrey
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