Page 420 - Challenges in Corrosion Costs Causes Consequences and Control(2015)

398 CONSEQUENCES OF CORROSION

In almost all aspects of industry, technology is available to use alloys in ways
that are efficient and environmentally sound. The corrosion environments in which
materials must operate are tough, but suitable materials selection with efficient barrier
coatings has provided excellent solutions. Solid waste disposal is a good alternative
to landfill, which can generate energy as a by-product provided gaseous emissions are
controlled. The available modern materials can be used in incinerators and thereby
combat high-temperature corrosion (55–58).
Rail transport has not been popular in the Western world but the need to reduce
automobile emissions and the resulting environmental damage has led to the devel-
opment of electric-powered mass rail transit systems. The corrosion problems associ-
ated with high-current land-based systems in which current leaks into nearby metallic
structures leading to corrosion are well understood and within the scope of existing
technology (59).
The pollution-has-to-pay policy has been firmly established in the United States,
but not in other parts of the world. This leads to a short-sighted view of saving initial
costs without caring for the consequences. It is advisable to invest more in the cost
of initial design so that the product has a long life and low maintenance.
Sometimes the need to be environmentally acceptable may lead to new problems.
For instance, ozone was suggested to replace biocides with no data available on the
performance in the chlorination of water (60). Corrosion control techniques can have
both favorable as well as ill effects and hence one has to exert balanced judgment
before embarking on a corrosion prevention method. Organotin antifouling coatings
on ships were effective, but they polluted the seawater and hence were banned from
further use. The use of cadmium as a sacrificial anode is restricted because of its
toxicity. Large amounts of zinc are used to protect steel platforms in the sheltered
and shallow waters of the sea, and the effects of zinc on the contamination of waters
are not known.
Corrosion and its control in society parallels engineering at large. Both theoretical
and laboratory work by scientists have helped to lay the groundwork. Large engi-
neering systems are too complicated for accurate performance predictions. So far,
corrosion and its control have been successful: bridges and building structures do
stay up, aircraft safety is high, and cars can survive the rigors of harsh winters and
salt-laden roads.
The well-established corrosion science of materials forms the foundation, but the
practical aspect is the pivotal part that needs to be integrated to achieve maximum
effective corrosion control. It is crucial to stress that cost cutting in times of financial
stringency will certainly increase the probability of serious corrosion failures.

REFERENCES

1. Economic Effects of Metallic Corrosion in the United States, NBS Special Publication
511-1, SD stock no. SN-003-003-01926-7, 1978 and Economic Effects of Metallic Cor-
rosion in the United States, Appendix B, NBS Special Publication 511-2, SD stock no.
SN-003-003-01927-5, 1978.