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Steel Making

Vanadium
Vanadium has a very marked effect upon alloy steels rich in c...

Plant For Forging Rifle Barrels
The forging of rifle barrels in large quantities and heat-tre...

Manganese
Manganese adds considerably to the tensile strength of steel,...

Steel For Chisels And Punches
The highest grades of carbon or tempering steels are to be re...

Non-shrinking Oil-hardening Steels
Certain steels have a very low rate of expansion and contract...

Tungsten
Tungsten, as an alloy in steel, has been known and used for a...

Phosphorus
PHOSPHORUS is an element (symbol P) which enters the metal fr...

Leeds And Northrup Optical Pyrometer
The principles of this very popular method of measuring tempe...

Heat Treatment Of Axles
Parts of this general type should be heat-treated to show the...

Oil-hardening Steel
Heat slowly and uniformly to 1,450 deg.F. and forge thorough...

Composition Of Transmission-gear Steel
If the nickel content of this steel is eliminated, and the pe...

Application To The Automotive Industry
The information given on the various parts of the Liberty eng...

Placing Of Pyrometers
When installing a pyrometer, care should be taken that it re...

Robert Mushet
Robert (Forester) Mushet (1811-1891), born in the Forest of D...

Making Steel Balls
Steel balls are made from rods or coils according to size, st...

Piston Pin
The piston pin on an aviation engine must possess maximum res...

S A E Heat Treatments
The Society of Automotive Engineers have adopted certain heat...

Properties Of Steel
Steels are known by certain tests. Early tests were more or l...

Protective Screens For Furnaces
Workmen needlessly exposed to the flames, heat and glare from...

Refining The Grain
This is remedied by reheating the piece to a temperature slig...



Hardening High-speed Steels






Category: HIGH-SPEED STEEL

We will now take up the matter of hardening high-speed steels. The
most ordinary tools used are for lathes and planers. The forging
should be done at carbon-steel heat. Rough-grind while still hot
and preheat to about carbon-steel hardening heat, then heat quickly
in high-speed furnace to white heat, and quench in oil. If a very
hard substance is to be cut, the point of tool may be quenched in
kerosene or water and when nearly black, finish cooling in oil.
Tempering must be done to suit the material to be cut. For cutting
cast iron, brass castings, or hard steel, tempering should be done
merely to take strains out of steel.

On ordinary machinery steel or nickel steel the temper can be drawn
to a dark blue or up to 900 deg.F. If the tool is of a special form
or character, the risk of melting or scaling the point cannot be
taken. In these cases the tool should be packed, but if there is
no packing equipment, a tool can be heated to as high heat as is
safe without risk to cutting edges, and cyanide or prussiate of
potash can be sprinkled over the face and then quenched in oil.

Some very adverse criticism may be heard on this point, but experience
has proved that such tools will stand up very nicely and be perfectly
free from scales or pipes. Where packing cannot be done, milling
cutters, and tools to be hardened all over, can be placed in muffled
furnace, brought to 2,220 deg. and quenched in oil. All such tools,
however, must be preheated slowly to 1,400 to 1,500 deg. then placed in
a high-speed furnace and brought up quickly. Do not soak high-speed
steel at high heats. Quench in oil.

We must bear in mind that the heating furnace is likely to expand
tools, therefore provision must be made to leave extra stock to
take care of such expansion. Tools with shanks such as counter
bores, taps, reamers, drills, etc., should be heated no further
than they are wanted hard, and quench in oil. If a forge is not
at hand and heating must be done, use a muffle furnace and cover
small shanks with a paste from fire clay or ground asbestos. Hollow
mills, spring threading dies, and large cutting tools with small
shanks should have the holes thoroughly packed or covered with
asbestos cement as far as they are wanted soft.





Next: Cutting-off Steel From Bar

Previous: Quality And Structure



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