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Steel


#1

Folks:

After reading Orchid for a while now, I though the following may
be of interest to some members. I have to admit that it is fairly
well generalized, but does give an overall view.

There are 4 common types of steel that you can encounter:

  • Plain carbon/low alloy - Plain carbon and low alloy steels
    make up most of the steel made. These steels are used to make
    nails, screws, hasps, hinges, rails, brackets, auto springs, etc.
    Designations for these steels include 1018, 1020, 1040, 4140,
    4150, 8620, etc.

  • Hardenable stainless steels - Hardenable stainless steel is
    used where a hard, corrosion resistant material is needed, either
    for cosmetics such as knife blades or where the application
    requires it. Designations for these steels include 410, 420,
    440C, etc. These are not as “stainless” as the non-hardenable
    grades shown below.

  • Tool Steels - Tool steels are special purpose steels used for
    dies, punches, shear blades, drill bits, router bits, etc.
    Designations for these steels include A-2, O-1, D-2, S-2, M-2,
    etc.

The above steels are all hardenable to greater or lesser degrees
depending on the grade, by heating above approximately 1350F and
rapidly cooling them. The cooling rate needed for full hardening
depends on the grade. Steels like 1018 or 1020 require very rapid
cooling while 410, 420, 440 or A2 only need an air cool.

One other thing these steels all have in common is that they are
all magnetic.

  • Non-hardening stainless steels - These stainless steels are
    relatively soft (Rb 60 - Rb 100) and used for flatware,
    decorative trim, jewelry, etc. Designations for these steels
    include 302, 303, 304, 310, 316, etc.

The annealing of these steels is similar to gold, silver &
copper alloys in that you heat them to a high temperature ( 1800F

  • 2000F ) and quench to anneal and obtain the lowest hardness.
    This also gives the most corrosion resistance in these steels.
    The difference is that you cannot appreciably harden it by aging.

These steels are all Non-magnetic.

Hope you can use it

Lee


#2

Lee - please correct me if i’m wrong, but a blacksmiths book i
have in the shop, the title and author escape me, printed the
standard formula for annealing (softening) low carbon (soft)
iron/steel. slowly kiln heating the item to about 1300F and
alowing the piece to slowly cool in the kiln, or in the air.
quenching the piece would make it brittle. a local toolmaker i
know, would quench his steel in oil when annealing and water
when hardening. what do you think? can you suggest any other
referance material? sincerely. kim-eric lilot


#3

Diehl Steel - Home Page
http://www.diehlsteel.com/

Welcome to Uddeholm
http://www.uddeholm.com/

Hope these links work for you. Lots of on steel
types and heat treating on these pages.

Kevin Willis
Advantage Tool & Microweld
betkev@aol.com


#4

Kim

To anneal most simple steels (High med or low carbon) you heat
to 1500 - 1600 F and cool very slowly to room temp. A good way
to cool the steel is to place it in a container of wood ashes so
that it sits suspended in the ash and this will insulate the
steel as it cools. Even with W1 tool steel (the most basic high
carbon steel) quenching in oil will harden it some. Alloy steels
like High Speed Tool steel are a whole different ball game and
must be annealed in accordance with the mfrs. directions.

Jim


@jbin
James Binnion Metal Arts
2916 Chapman St
Oakland, CA 94601
510-436-3552


#5
  slowly kiln heating the item to about 1300F and alowing the
piece to slowly cool in the kiln, or in the air. quenching the
piece would make it brittle. a local toolmaker i know,  would
quench his steel in oil when annealing and water when
hardening. 

When steel is heated, there is a temperature at which the iron
in the steels transforms to a different structure. This
temperature, the transformation temperature, is about 1360F for
plain carbon steels and may be up to 1500F for higher alloys.
When cooling from above the transformation temperature, the
structure again changes, but the new structure is determined by
the cooling rate. By definition, annealing is the slow cooling
from above the transformation temperature and hardening is rapid
cooling.

The rate of cooling is critical. Since a plain carbon steel
requires a very rapid cooling to harden - in agitated water - air
cooling would be considered a “slow” cool. Remember too that the
size of the piece greatly affects the cooling rate.

In regard to your question about water vs oil quenching, if the
steel were heated over the transformation temperature, quenching
in either would develop hardness in the steel; a small amount in
plain carbon to full hardness in many other steels. Except for
the plain carbon steels, most other steels would become hard if
quenched in oil from over the transformation temperature.

In addition to annealing and hardening there is another process
that is used to soften steel. This is called “tempering” or
"drawing" and consists of reheating the steel after hardening,
the higher the temperature used ( but below the transformation
temperature ) the softer the steel will become. Tempering is used
to remove brittleness from a hardened steel and to adjust the
hardness to a required range. Heating to 1300F as in your
question, would not transform the steel, but would soften it by
tempering. In this case, the cooling rate is not critical and
even if water quenched, no hardening will result. This process is
sometimes referred to as a “subcritical anneal”.

The above also apply to cold worked steels that require
softening.

There are many books on steels put out by the steel companies
and your local steel service center (distributor) may give you
some of these.

I hope the above answers your questions, if not, try again.

Lee


#6

Before you rely on the formulas in this kind of book too much,
check the dates if this is a very old book it could be
referenceing a different grade of steel than you think.

Reminds me of one of grandma’s friends with a recipe problem.
she followed it exactly used a dime’s worth of stew meat.