High Strength Steel Sheet is Fastest Growing Lightweight Material
7 September 1999
High Strength Steel Sheet is Fastest Growing Lightweight Material In the Automotive Industry Says American Iron and Steel Institute
Growth of High Strength and Ultra High Strength Steel Sheet
Exceeds that of Aluminum for All Auto Applications
DETROIT, Sept. 7 -- During the past two decades, automakers'
use of high strength and ultra high strength steel has outpaced the growth
rate of aluminum by 13 percent, making it the fastest growing automotive
lightweighting material.
According to data published annually by American Metal Market (most
recently, March 1, 1999), since 1977 vehicle makers' use of strong,
lightweight, high strength steel sheet grades has increased by 162 percent,
while the use of all grades of aluminum (castings, extrusions, foil, sheet,
etc.) has increased by 143 percent. High strength steel sheet has replaced
older, carbon steel grades, but the growth of aluminum has come largely in the
form of castings, principally at the expense of cast iron.
Use of high strength steel sheet saves weight because vehicle makers can
use thinner gauges without sacrificing strength and performance. The
Auto/Steel Partnership defines high strength steel sheet as steels with
incoming yield strength of 210Mpa (30ksi) or greater. Ultra high strength
steels have as-produced yield strengths of at least 550Mpa (80ksi).
"As automakers experiment with various materials to take weight out of
their vehicles, they quietly have found a solution in a material with which
they are most familiar -- steel sheet," said Darryl C. Martin, senior
director, Automotive Applications, American Iron and Steel Institute (AISI).
"While we take the challenge of increased use of aluminum sheet very
seriously, it is important to point out that aluminum has had negligible
penetration into the auto body due to the superior performance characteristics
of today's steel sheet."
Today's vehicle, on average, includes about 1800 pounds of steel in the
form of sheet, bars, and other steels, which accounts for about 55 percent of
the vehicle mass, a proportion that has remained constant for more than a
decade. About 1500 pounds of this amount is steel sheet, of which 328 pounds
are high strength steel sheet, according to American Metal Market
(March 1, 1999).
American Metal Market reports that the total amount of aluminum in a
vehicle, on average, is 236 pounds.
"Steel sheet producers are aggressively defending their share of curb
weight through programs such as UltraLight Steel Auto Body (ULSAB), ULSAC
(closures), ULSAS (suspensions), Light Truck Structure study (LTS),
participation in the Auto/Steel Partnership and unremitting improvements in
our material and its applications," said Martin. ULSAB comprises more than 90
percent high strength steel sheet.
"When you look back to the late '70s and the history of automotive
lightweighting, automakers consistently have relied on steel sheet -- their
long-time material of choice," said Martin. "As they continue to improve
their designs, they clearly are finding that they can achieve their
competitive goals as well as meet customers' needs for affordable, fuel
efficient vehicles that provide greater safety and improve performance through
the use of ever increasing amounts of high strength steel sheet.
"As vehicle makers continue to apply advanced high strength steel sheet
and steel sheet designs, they are reaping significant weight savings at
virtually no cost premium," said Martin. "They are improving fuel efficiency
and enhancing vehicle performance virtually for free, compared to using more
expensive materials such as aluminum sheet. This means that automakers can
invest those savings in other technologies that offer greater potential
environmental and fuel consumption paybacks, such as improvements in
powertrain efficiency.
Steel is inexpensive and strong. It is the world's most recycled metal.
It is easy to handle and form into a wide variety of complex shapes. It is an
optimal material for designing safe vehicles. And, steel sheet offers
engineers the greatest design flexibility for packaging engines, passengers
and cargo.
American Iron and Steel Institute (AISI) is a non-profit association of
North American companies engaged in the iron and steel industry. The
Institute comprises 47 member companies, including integrated and electric
furnace steelmakers, and 178 associate and affiliate members who are suppliers
to or customers of the steel industry. For a broader look at steel and its
applications, the Institute has its own website at http://www.steel.org .
The Automotive Applications Committee (AAC) is a subcommittee of the
Market Development Committee of AISI and focuses on advancing the use of steel
in the highly competitive automotive market. With offices and staff located
in Detroit, cooperation between the automobile and steel industries has been
significant to its success. This industry cooperation resulted in the
formation of the Auto/Steel Partnership, a consortium of DaimlerChrysler, Ford
and General Motors and the member companies of the AAC.
This release and other steel-related information are available for viewing
and downloading at American Iron and Steel Institute/Automotive Applications
Committee's website at http://www.autosteel.org .
Automotive Applications Committee member companies:
AK Steel Corporation
Bethlehem Steel Corporation
Dofasco Inc.
Ispat Inland Inc.
LTV Steel Company
National Steel Corporation
Rouge Steel Company
Stelco Inc.
US Steel Group, a unit of USX Corporation
WCI Steel, Inc.
Weirton Steel Corporation