Innovative Stainless Steel Applications in transport ... - Euro Inox

1. Introduction: stainless steels in transport
vehicles
The use of stainless steel in ground transport is by no means new: its track record goes
back nearly three quarters of a century. In the case of railway coaches, it was durability
and ease-of-maintenance considerations, especially, that tipped the balance towards
stainless steel. With design lives of often more than 40 years, rolling stock is an
application for which it is worthwhile considering intrinsically corrosion-resistant
materials.
Buses and coaches have a service life of 20 years and more. For coatings on less
corrosion-resistant materials, such a long time span is difficult to survive without major
maintenance and repair. Condensation and the influence of de-icing salt can make
corrosion protection a challenge. For this reason, stainless steel has also been used
successfully not only for the skin but also the structure of buses and coaches.
Over the years, rail and bus technology has developed – and so has stainless steel. The
refinement of metallurgical processes has further improved the uniformity and
corrosion-resistance of proven chromium-nickel stainless steels. The range of
mechanical treatments to further enhance their mechanical properties has been
extended. New grades have been developed, including chromium-manganese types,
which combine cost reduction with high mechanical strength. Ferritic stainless steels
have given rail and bus manufacturers new and particularly cost-effective options,
especially for the outer skin of vehicles when customers require painting for reasons of
corporate design. It is the purpose of the present publication to give a research-based
overview of the new potential that has emerged over the last few years.
1.1 Rail applications history
Invented in the early 20 th century, stainless steels were soon applied to the rail industry.
The 1930’s brought widespread use of stainless steel for rail coach bodies. Weight
reduction became a priority and laid the ground for levels of speed and comfort that had
not been experienced before. Especially in North America, stainless steel became the
preferred material for rail coaches.
Although stainless steel is neither the lightest of materials nor the least expensive, both
manufacturers and operators soon discovered that its outstanding long-term corrosion
resistance provided maintenance and cost advantages. The fact that painting became
redundant made stainless steel even more attractive. However, it was also a marketing
issue. Long-distance rail travel was positioned as a modern, technologically advanced
option for the demanding customer and stainless steel was an icon for this idea.
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