The cost of poor
F
or almost 100 years, virtually all branches of the oil and gas industry have been using welding processes in their metal assembly
work. Techniques and materials have improved each year in the search for increasingly high levels of efficiency. Despite using
welding stations on the cutting edge of technology, the stage prior to welding, i.e. preparing the pipe ends to be welded
together, is often neglected or done with inappropriate techniques.
Cracking
Cracking is one of the most frequently observed defects in welding. It is caused by excessive mechanical stress in the weld bead. The
most common types of cracking are hot and cold cracking.
Hot cracking
As indicated by its name, this type of cracking appears when the metal is still hot and in the process of solidifying. The design
of the weld assembly is one of the factors that cause this type of defect. This can be explained by the fact that the
narrower the bevel is, the greater the mechanical stress resulting from the metal solidifying. If this stress is
too high, cracking is liable to occur during the change in phase. Therefore, it is important for
PREPARATION
Amongst
the numerous
factors liable to
affect welding quality, poor
preparation is a recurrent
cause, as
Thomas
Regourd, Protem,
France,
highlights.
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