Objectives
After completing this chapter, you will be able to:
Identify types and grades of steel and steel alloys.
Identify shapes and forms of steel and steel alloys.
Select the appropriate steel fi ller based on the
steel to be welded.
Explain joint preparation, weld backing, and
preheating for steels.
Recall welding procedures and techniques for
welding steel using DCEN.
Recall correct torch positioning for various types
of welds.
Differentiate between stringer beads and weave
beads.
Recognize groove and fi llet weld defects.
Recall factors that infl uence postweld treatment.
Key Terms
annealing
casting
chromium-molybdenum steels
forging
heat treating
martensite
quenching
stringer beads
tempering
travel angle
weave beads
wetted
work angle
Introduction
The GTAW technique required for a given job
depends on many factors, including the weld joint
design. Welders must constantly monitor and adjust
many critical variables in order to produce a high-
quality weld. The effects of these variables can be seen
in the behavior of the weld pool as the weld is being
made. Welding skill is acquired by practice, practice,
and more practice. Changing one variable at a time is
the best way to determine what the weld needs.
The following questions should be considered
when practicing welding:
Is the weld the right size?
Is the weld too high or too low?
Is the proper travel speed being used?
Is the torch angle correct?
Is the welding rod being held at the proper
angle?
Is the weld pool fl owing properly?
Is the current (amperage) correct?
Is the voltage (arc length) correct?
Is the weld in the proper location?
Is the fi llet weld leg the proper size?
Also, it is important to remember to fi ll the crater
at the end of the weld and hold the torch over the end
of the weld until it cools. This allows the postfl ow of
shielding gas to protect the hot metal.
127
Chapter Chapter
Manual Welding
Techniques
Previous Page Next Page