Thermit Welding

TM 750-245-4

be joined are forced together under pressure. No

(4) Shielded carbon-arc welding. The arc is

shielding is used.

drawn between a carbon electrode and the workpiece.

(3) Inert-gas shielded stud welding.

This

Shielding is obtained from the combustion of a solid

material fed into the arc or from a blanket of flux on the

process is the same as that used for stud welding, (2)

work or both. Pressure and / or filler metal may or may

above, except that an inert-gas, such as argon or helium

not be used.

is used for shielding.

(4) Submerged arc-welding. The arc is drawn

between an electrode and the workpiece, A grandular

8-6. Thermit Welding

flux completely surrounds the end of the electrode and

This is a welding process in which a weld is made by

shields the entire welding action. Pressure is not used

heating with superheated liquid metal and slag resulting

and filler metal is obtained from the electrode.

from a chemical reaction between a metal oxide and

aluminum. Filler metal, when use, is obtained from the

(5) Inert-gas tungsten-arc welding (TIG). The

liquid metal. Pressure may or may not be used.

arc isdrawn between a nonconsumable tungsten

a. Nonpressure Thermit Welding. In this thermit

electrode and the workpiece. Shielding is obtained from

an inert-gas or gas mixture. Pressure and/or filler metal

welding process, no pressure is used and the filler metal

may or may not be used. Operation of typical inert-gas,

is obtained from the liquid metal.

shielded arc-welding machines, are explained in TM

b. Pressure Thermit Welding.

In this thermit

53431-211-15 and TM 3431-213-15.

process, pressure is used and the liquid metal is not

(6) Inert-gas metal-arc welding (MIG). The

used as a filler metal.

arc is drawn between a filler metal electrode and the

workpiece. Shielding is obtained from an inert-gas, gas

8-7. Gas Welding

mixture, or a mixture of a gas and a flux.

This is a group of welding processes in which a weld is

(7) Shielded metal-arc welding. The arc is

made by heating with a gas flame or flames. Pressure

drawn between a covered metal electrode and the

and/ or filler metal may or may not be used.

workpiece. Shielding is obtained from decomposition of

a. Pressure Gas Welding. A process in which a

the electrode covering. Pressure is not used and filler

weld is made, simultaneously over the entire area of

metal is obtained from the electrode.

abutting surfaces, by heating with gas flames obtained

(8) Atomic-hydrogen welding.

The arc is

from the combustion of a fuel gas with oxygen and by

maintained between two metal electrodes in an

the application of pressure. No filler metal is used.

atmosphere of hydrogen. Pressure and/or filler metal

b. Oxy-Hydrogen Welding. A process in which the

may or may not be used.

heat is obtained from the combustion of hydrogen with

(9) Arc-spot welding. A weld is made in one -

oxygen. No pressure is used and filler metal may or

spot by drawing the arc between an electrode and the

may not be used.

workpiece. The weld is made without preparing a hole

c. Air-Acetylene Welding. A process in which the

in either member. Filler metal, shielding gas, or flux

heat is obtained from the combustion )t) acetylene with

may or may not be used.

air. No pressure is used and filled metal may or may

(10) Arc-seam welding. A continuos weld is

not be used.

made along faying surfaces by drawing the arc between

d. Oxy-Acetylene Welding. A process in which the

an electrode and the workpiece. Filler metal, shielding

heat is obtained from the combustion of acetylene with

gas, or flux may or may not be used.

oxygen. Pressure and/or filler metal may or may not be

b. Carbon Electrode.

used.

(1) Carbon-arc welding. The arc is drawn

between a carbon electrode and the workpiece. No

8-8. Forge Welding

shielding is used. Pressure and / or filler metal may or

This is a group of welding processes in which a weld is

may not be used.

made by heating in a forge or other furnace and by

applying pressure or blows.

(2) Twin carbon-arc welding. The arc is

drawn between two carbon electrodes. Shielding and

a. Roll Welding. A process in which heat is

pressure are not used. Filler metal may or may not be

obtained from a furnace and rolls are used to apply

used.

pressure.

(3) Inert-gas carbon-arc welding. The arc is

b. Die Welding.

A process in which heat is

drawn between a carbon electrode and the workpiece.

obtained from a furnace and dies are used to apply

Shielding is obtained from An inert gas or gas mixture.

pressure.

Pressure and / or filler metal may or may not be used.

8-3