"He hath showed thee, O man, what is good; and what doth the Lord require of thee, but to do justly, and to love mercy, and to walk humbly with thy God." Micah 6:8. The life of Enoch is descriptive of the Christian's life, and it is said that... Read more of THE CHRISTIAN'S WALK A WALK WITH GOD. at Difficult.caInformational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Furnace Data
In order to give definite information concerning furnaces, fu...

Carbon-steel Forgings
Low-stressed, carbon-steel forgings include such parts as car...

Crankshaft
The crankshaft was the most highly stressed part of the entir...

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

Heating Of Manganese Steel
Another form of heat-treating furnace is that which is used ...

Open Hearth Process
The open hearth furnace consists of a big brick room with a l...

The Leeds And Northrup Potentiometer System
The potentiometer pyrometer system is both flexible and subst...

The Theory Of Tempering
Steel that has been hardened is generally harder and more br...

Heat Treatment Of Steel
Heat treatment consists in heating and cooling metal at defin...

Standard Analysis
The selection of a standard analysis by the manufacturer is t...

Shrinking And Enlarging Work
Steel can be shrunk or enlarged by proper heating and cooling...

A Satisfactory Luting Mixture
A mixture of fireclay and sand will be found very satisfactor...

The Pyrometer And Its Use
In the heat treatment of steel, it has become absolutely nece...

Effects Of Proper Annealing
Proper annealing of low-carbon steels causes a complete solu...

Chromium
Chromium when alloyed with steel, has the characteristic func...

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

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

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

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

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



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



Add to del.icio.us Add to Reddit Add to Digg Add to Del.icio.us Add to Google Add to Twitter Add to Stumble Upon
Add to Informational Site Network
Report
Privacy
SHAREADD TO EBOOK


Viewed 4038