Hard-
Surfacing,
Building
Fusion
Welding
Carbon
Welding
Non-Ferrous
Metals
Heating
& Heat
Treating
Braze
Welding
Welding
Cast Iron
Welding
Ferrous
Metals
Brazing
&
Soldering
Equipment
Set-Up
Operation
Equipment
For
OXY-Acet
Structure
of
Steel
Mechanical
Properties
of Metals
Oxygen
&
Acetylene
OXY-Acet
Flame
Physical
Properties
of Metals
How Steels
Are
Classified
Expansion
&
Contraction
Prep
For
Welding
OXY-Acet
Welding
& Cutting
Safety
Practices
Manual
Cutting
Oxygen
Cutting By
Machine
Appendices
Testing
&
Inspecting
6
Heating and Heat Treating.
Probably every oxy-acetylene outfit in service today
is used, at least occasionally, as a
convenient source of heat for bending or forming metals, loosening ”frozen”
nuts, and dozens of other jobs. For some
of these uses, it is merely a convenient heat source, where the relatively high
cost of acetylene is more than balanced
by the time saved. Another widespread use for the heat of the oxy-acetylene flame
is in the brazing of joints
in copper tubing systems, where speed again gives it an advantage over lower-temperature
flames which might
be used. There are several industrial applications of the flame – for example,
flame-hardening and flame- descaling,
which will be covered in Chapter 19 – where the extremely high temperature
of the flame is indispensable.
Fig. 2-4. The oxy-acetylene flame-hardening
process can be used to
produce a hardened surface on a steel shaft, while permitting
retention of a tough, ductile shaft
core. In this application, the shaft is
revolved in front of the flames for a few seconds. Then the
flames are shut off, and a water quench
applied immediately.
