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Cutting-off Steel From Bar
To cut a piece from an annealed bar, cut off with a hack saw,...

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

Preventing Carburizing By Copper-plating
Copper-plating has been found effective and must have a thick...

Temperatures To Use
As soon as the temperature of the steel reaches 100 deg.C. (...

Composition And Properties Of Steel
It is a remarkable fact that one can look through a dozen tex...

A Chromium-cobalt Steel
The Latrobe Steel Company make a high-speed steel without tun...

Pyrometers
Armor plate makers sometimes use the copper ball or Siemens' ...

Fatigue Tests
It has been known for fifty years that a beam or rod would fa...

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

The Influence Of Size
The size of the piece influences the physical properties obta...

Carbon Steels For Different Tools
All users of tool steels should carefully study the different...

Quality And Structure
The quality of high-speed steel is dependent to a very great ...

Temperature For Annealing
Theoretically, annealing should be accomplished at a tempera...

Heat Treatment Of Lathe Planer And Similar Tools
FIRE.--For these tools a good fire is one made of hard foundr...

Rate Of Cooling
At the option of the manufacturer, the above treatment of gea...

Carbon Tool Steel
Heat to a bright red, about 1,500 to 1,550 deg.F. Do not ham...

Quenching Tool Steel
To secure proper hardness, the cooling of quenching of steel ...

Flange Shields For Furnaces
Such portable flame shields as the one illustrated in Fig. 1...

Conclusions
Martien was probably never a serious contender for the honor ...

Tensile Properties
Strength of a metal is usually expressed in the number of pou...



Hardening






Category: ALLOYS AND THEIR EFFECT UPON STEEL

The forgings can be hardened by cooling in still air
or quenching in oil or water from a temperature between 1,650 and
1,750 deg.F.

The physical properties do not vary greatly when the carbon is
within the range of composition given, or when the steel is hardened
and tempered in air, oil, or water.

When used for valves the following specification of physical properties
have been used:

Yield point, pounds per square inch 70,000
Tensile strength, pounds per square inch 90,000
Elongation in 2 in., per cent 18
Reduction of area, per cent 50

The usual heat treatment is to quench in oil from 1,650 deg.F. and
temper or draw at 1,100 to 1,200 deg.F. One valve manufacturer stated
that valves of this steel are hardened by heating the previously
annealed valves to 1,650 deg.F. and cooling in still air. This treatment
gives a scleroscope hardness of about 50.

In addition to use in valves this steel should prove very satisfactory
for shafting for water-pumps and other automobile parts subject to
objectionable corrosion.

TABLE 2.--COMPARISON OF PHYSICAL PROPERTIES FOR HIGH-CHROMIUM
STEELS OF DIFFERENT CARBON CONTENT --------------------------------------------------------------------------
C 0.20 C 0.27 C 0.50
Mn 0.45 Mn 0.50
Cr 12.56 Cr 12.24 Cr 14.84
-----------------------------------------------------------------------
Quenched in oil from degrees Fahrenheit 1,600 1,600 1,650
Tempered at degrees Fahrenheit 1,160 1,080 1,100
Yield point, pounds per square inch 78,300 75,000 91,616
Tensile strength, pounds per square inch 104,600 104,250 123,648
Elongation in 2 in., per cent 25.0 23.5 14.5
Reduction of area, per cent 52.5 51.4 33.5
--------------------------------------------------------------------------

TABLE 3.--COMPARISON OF PHYSICAL PROPERTIES BETWEEN AIR, OIL AND
WATER-HARDENED STEEL HAVING CHEMICAL ANALYSIS IN
PERCENTAGE OF
-------------------------------------------------------------------------
Carbon 0.24
Manganese 0.30
Phosphorus 0.035
Sulphur 0.035
Chromium 12.85
Silicon 0.20

-------------------------------------------------------------------------
Hardened Elastic Tensile
Hardening from, Tempered limit, strength,ElongationReduction
medium degrees at, degrees per lb. lb. Per in 2 in. of area,
FahrenheitFahrenheit sq. in. sq. in. per cent per cent
-------------------------------------------------------------------
930 158,815 192,415 13.0 40.5
1,100 99,680 120,065 21.0 59.2
Air 1,650 1,300 70,785 101,250 26.0 64.6
1,380 66,080 98,335 28.0 63.6
1,470 70,785 96,990 27.0 64.7
-------------------------------------------------------------------
930 163,070 202,720 8.0 18.2
Oil 1,650 1,100 88,255 116,480 20.0 56.9
1,300 77,950 105,505 25.5 63.8
1,380 88,255 98,785 27.0 66.3
-------------------------------------------------------------------
930 158,815 202,050 12.0 34.2
Water 1,650 1,100 90,270 120,735 22.0 59.8
1,300 66,080 102,590 25.8 64.8
1,380 67,200 97,890 27.0 65.2
-------------------------------------------------------------------------

This steel can be drawn into wire, rolled into sheets and strips
and drawn into seamless tubes.





Next: Corrosion

Previous: Annealing



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