Corrosion Science Chemistry Research Article | Page 11

The Effects and Economic Impact of Corrosion
11
The panel found that the automotive sector probably had made the
greatest anticorrosion effort of any single industry. Advances have been
made in the use of stainless steels, coated metals, and more protective
finishes. Moreover, several substitutions of materials made primarily for
reasons of weight reduction have also reduced corrosion. Also, the panel
estimates that 15% of previously unavoidable corrosion costs can be
reclassified as avoidable. The industry is estimated to have elimi- nated
some 35% of avoidable corrosion by improved practices.
In examining the aircraft, pipeline, and shipbuilding sectors, the panel
reported that both gains and losses have occurred, most of them tending
to offset each other. For instance, in many cases, the use of more expen-
sive materials has reduced the need for corrosion-related repairs or re-
painting. Overall, it was thought that for the U.S. economy other than in
motor vehicle and aircraft applications, total corrosion costs have been
reduced by no more than 5% with a further reduction of unavoidable
costs by about 2%.
The updated study shows that the total 1995 cost of metallic corrosion
was reduced (from what it would have been in 1975 terms) by some
14%, or to 4.2% of the GNP. Avoidable corrosion, which was 40% of
the total, is now estimated to be 35% but still accounts for slightly more
than $100 billion per year. This figure represents the annual cost to the
economy, which can be reduced by broader application of corrosion-
resistant materials, improvement in corrosion-prevention practices, and
investment in corrosion-related research. Table 2 compares the results of
the 1978 and 1995 Battelle/NIST studies.
Factors Influencing Corrosion. Some of the factors that influence cor-
rosion and its costs are shown in Fig. 4. Corrosion costs are reduced by
the application of available corrosion technology, which is sup-
Table 2 Cost of metallic corrosion in the United States
Billions of U.S. dollars
Industry
1975 1995
82.0
33.0 296.0
104.0
31.4
23.1 94.0
65.0
3.0
0.6 13.0
3.0
47.6
9.3 189.0
36.0
All industries
Total
Avoidable
Motor vehicles
Total
Avoidable
Aircraft
Total
Avoidable
Other industries
Total
Avoidable
Source: Economic Effects of Metallic Corrosion in the United States, Battelle Columbus Laboratories and the National In-
stitute of Standards and Technology (NIST), 1978, and Battelle estimates