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   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Annealing Of High-speed Steel
For annealing high-speed steel, some makers recommend using g...

Heavy Forging Practice
In heavy forging practice where the metal is being worked at...

Nickel-chromium
A combination of the characteristics of nickel and the charac...

Heating
Although it is possible to work steels cold, to an extent de...

Carburizing Low-carbon Sleeves
Low-carbon sleeves are carburized and pushed on malleable-ir...

Bessemer Process
The bessemer process consists of charging molten pig iron int...

Typical Oil-fired Furnaces
Several types of standard oil-fired furnaces are shown herew...

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

Tempering Colors On Carbon Steels
Opinions differ as to the temperature which is indicated by t...

Hardness Testing
The word hardness is used to express various properties of me...

Liberty Motor Connecting Rods
The requirements for materials for the Liberty motor connecti...

Correction By Zero Adjustment
Many pyrometers are supplied with a zero adjuster, by means ...

Quenching
It is considered good practice to quench alloy steels from th...

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

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...

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

Compensating Leads
By the use of compensating leads, formed of the same materia...

Complete Calibration Of Pyrometers
For the complete calibration of a thermo-couple of unknown e...

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

Testing And Inspection Of Heat Treatment
The hard parts of the gear must be so hard that a new mill f...



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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