NYTimes.com:
The modern car is still 60% of steel by weight.But automotive
steel has changed quite a bit since the
Ford
company's first Model T rolled off the assembly line in
1908. Metallurgists and manufacturers have learned to
manipulate steel's microstructure through precise control of
processing to create sheet steels of increasing strength.
Prompted by crash-worthiness requirements and the need to make
cars lighter to improve gas mileage, automakers are replacing
conventional steels with advanced high-strength ones.Where once
a single grade of steel might have sufficed, the typical "body
in white," as automakers call a car's basic skeleton, might now
be a patchwork of a dozen or more steels of different types and
strengths, tailored through computer modeling to handle the
stress and strain of normal driving—and of severe
crashes.
