METAL-ARC WELDING AND CUTTING
Upon completion of this chapter, you will be able to do the following:
Identify the equipment of arc-welding systems and describe the procedures
and techniques used in shielded metal-arc welding.
Identify the different types and classes of bare and covered electrodes and
select the proper electrode and heat settings for typical welding.
Describe the safety equipment used in metal-arc welding and the correct
procedures for striking, establishing, maintaining, and breaking the arc.
Describe the characteristics of aluminum, their effect on its weldability, and
the procedures required to prepare aluminum for welding.
Recognize the basic techniques used in gas tungsten-arc (GTA) welding, and
describe the function and maintenance requirements of associated welding
Specify the methods used in making gas metal-arc (GMA) welds in various
positions, and describe some of the equipment used.
State the procedures to be followed in metal and carbon-arc cutting
Explain the procedures to follow in air carbon-arc cutting.
equipment and with the units of measurement used
or units of measurement used in this chapter, study
Electric welding processes include shielded
the applicable parts of NEETS, modules 1 and 2.
metal-arc welding, shielded gas metal-arc welding,
stud welding, and resistance welding. This chapter
deals primarily with the first two processes; shielded
SHIELDED METAL-ARC WELDING
metal-arc welding and shielded gas metal-arc
welding. The other processes are summarized
briefly at the end of the chapter along with the arc
Most of your metal-arc welding will be done by
This is a
the shielded metal-arc process.
nonpressure process, and the heat necessary for
coalescence is generated by an electric arc between
To understand the operation of electrical
a heavily covered electrode and the base metal. The
welding equipment, you must have a basic
arc develops an intense heat that melts the base
be familiar with the terms used to describe electrical
metal and forms a molten pool of metal. At the