Page 413 - Challenges in Corrosion Costs Causes Consequences and Control(2015)

HISTORICAL IMPLICATIONS OF CORROSION 391

Dissimilar corrosion was encountered in 1769 when Commodore the Hon. John
Byron began a circumnavigation of the globe in his coppered ship, Dolphin. In addi-
tion to the prospect of the uncharted Coral Sea reef scything through the hull, the
ship’s captain heard repeated thumps below the stern windows of the cabin. John
Byron recorded in his log that he feared the ship’s very loose rudder would drop off
at any time, for its iron printles, which were in contact with the copper sheathing,
were corroded away to needle thickness. With no prospect of repair, this was another
worry in addition to the multitude of others with which he had to contend.
Bimetallic corrosion and other forms of corrosion continued to cause service fail-
ures. In 1962, a report was sent to the British Ministry of Defense stating that a copper
alloy end plate had fallen off a seawater evaporator in a submarine because the steel
bolts with which it was secured had effectively dissolved through galvanic action. In
1982, the nose wheels failed on two Royal Navy Sea Harriers that had returned from
the Falklands War. Studies showed that the galvanic action was responsible for the
corrosion that occurred between the magnesium wheel alloy and its stainless steel
bearing.
In general, corrosion means rust, an almost universal object of hatred. Rust is
specifically referred to as the corrosion of iron. But corrosion is a destructive phe-
nomenon that affects almost all metals. The Roman philosopher Pliny the Elder (AD
23-AD 79) wrote about ferrum corrumpitur or “spoiled iron.” (42) At this time, the
Roman Empire was established as the world’s foremost civilization because of its use
of iron in weaponry and other artifacts.
Corrosion has its beneficial consequences. Techniques such as bluing and gilding
were used to protect steel objects as heat treatment resulted in protective oxide films
(43).
Corrosion costs society in three major ways: (i) it is very expensive monetarily;
(ii) it is a major waste of natural resources at a time of increased concern over damage
to the environment; (iii) it can result in fatal accidents.
The cost of corrosion has already been dealt with in the first chapter. The annual
cost of corrosion in the United States was estimated in 1949 to be $5 billion, 2.1%
of GNP. The cost of corrosion in the United Kingdom was estimated to be £1.365
million (1971 prices). By 1975, the estimated cost of corrosion in the United States
had risen to $70 billion, 4.2% of GNP. The cost of corrosion consists of the cost of
replacement as well as indirect costs and may occur for any of the following reasons:
(i) lost production shutdown or failure; (ii) maintenance; (iii) compliance with envi-
ronmental and consumer regulations; (iv) loss of product quality in a plant owing to
contamination from corrosion of the materials used to make the production line.; (v)
high fuel and energy costs as a result of steam, fuel, water, or compressed air leakage
from corroded pipes.
Serious problems arose in the United States in 1981 when the report of the Nuclear
Regulatory Commission to Congress in Washington stated that the “vast majority” of
steam-generating PWRs were suffering from failures of stainless steel cooling tubes.
Though this corrosion did not predict any danger to the public, it was estimated that
the maintenance bill would top $6 billion. Extra working capital because of increased