Stainless steel might be
celebrating its 100th anniversary this year, but with its
unique properties and producers ability to tweak its
alloying ingredients to fit multiple end-use applications, it
remains well-suited to meet todays challenges, industry
The exact birthdate of stainless
steel is unclear, given that five or six people claimed to have
invented the corrosion- and heat-resistant material.
Nevertheless, the International Stainless Steel Forum (ISSF)
unit of the World Steel Association will mark stainless
steels 100th anniversary with a traveling exhibition that
will premiere at the groups annual conference May 15 in
by members of the Team Stainless network, which includes the
ISSF as well as Euro-Inox, the International Chromium
Development Association, the International Molybdenum
Association and the Nickel Institutewill retrace the
history of stainless steel, as well as provide reminders of its
major markets and applications, its raw materials, its ability
to be recycled and its cost advantages, said ISSF
secretary-general Pascal Payet-Gaspard.
Other groups are expected to
celebrate next year, as some place the commercialization of
stainless steel as starting in 1913, not 1912.
Despite its centennial
celebration, stainless steel is a relative newcomer to the
materials world. "Some (original equipment manufacturers) act
as if it was just invented recently," quipped Michael
Stateczny, executive vice president of Outokumpu Stainless
Inc.s plate products unit in New Castle, Ind. "But the
industry has clearly made a lot of progress over the years.
While stainless is now 100 years old, it is clearly a material
for the 21st Century. Its future is very bright. With its
corrosion resistance, high strength-to-weight ratio and
high-temperature resistance, stainless steel has the
characteristics to be used in very demanding environments and
to meet current and future global challenges, including helping
to supply fresh water, clean air and energy."
Global consumption of stainless
steel has grown an average of 6 percent per year for the past
30 years, a much higher rate than any of its competing
materials enjoyed, according to Payet-Gaspard. The fastest
growth rates come from such emerging economies as China, India
and countries in Southeast Asia.
Harold M. Cobb, a metals
industry veteran and author of The History of Stainless
Steel, said the material is currently the
third-most-important metal globally, following carbon steel and
aluminum, with its 200 or so different alloys used in many
China, while not part of
stainless steels early history, is considered to be the
prime mover in the stainless market these days, so its
appropriate that the 100th anniversary celebration of stainless
would begin there. Although China started producing stainless
steel just 25 years ago, by 2006 it had become the largest
producer as well as the largest user of stainless and today
accounts for more than a third of the 52 million tonnes per
year produced globally.
Tracing stainless steels
beginnings is no easy task, given that several people claimed
to be its discoverer. In fact, Cobb said, as early as the 19th
Century there were at least 25 scientists in England, France,
Germany and the United States working on iron alloys with
varying amounts of chromium, nickel and carbon to increase
steels corrosion resistance. In the end, a handful of men
from four different countries developedsomewhat
inadvertentlythe corrosion-resistant steel alloys now
known as stainless. Some of them never pursued patents.
Some of the lesser-known
stainless pioneers between 1905 to 1912 were Leon Alexandre
Guillet of France, who researched iron, chromium and nickel
alloys; Albert Marcel Portevin, who took over Guillets
research and, with W. Giesen of England, published information
on stainless steels that were roughly equivalent to modern
austenitic, martensitic and ferritic stainless steels;
Germanys Philipp Monnartz and William Borchers, who found
evidence of the relationship between a minimum level of
chromium (10.5 percent) and corrosion resistance, as well as
the importance of low carbon content and the role of molybdenum
in increasing corrosion resistance to chlorides; and Frederick
M. Becket and Christian Dantsizen of the United States, who
have been credited with discovering a number of ferritic
chromium stainless steels.
Nevertheless, the first
commercial production of stainless, in 1912 and 1913, is
credited to Benno Strauss and Edward Maurer of Germanys
Krupp Steel Works, the predecessor to ThyssenKrupp AG; Harry
Brearley, a metallurgist at Brown Firth Research Laboratories
in Sheffield, England; and, to a lesser extent, chemist,
metallurgist and inventor Elwood Haynes, the founder of Haynes
Stellite Works, the forerunner of Haynes International Inc.,
While Brearley usually gets the
credit for the commercialization of stainless, the discoveries
by Strauss, Maurer and Haynes are said to pre-date
Brearleys achievements. The Krupp engineers were granted
patents for two chromium-nickel stainless steels in 1912, which
would make 2012 the 100th anniversary of stainless.
Strauss and Maurer actually
discovered stainless steels, including 18-8 (18-percent
chromium, 8-percent nickel), quite by accident, according to
Cobb. They were trying to find an alloy resistant to high
temperatures that could be used for Krupps steel furnaces
when they noticed that metal in the company yard wasnt
rusting at all; unlike other steels, it didnt need to be
painted or coated to preserve the integrity of its surface. On
Oct. 17, 1912, they patented austenitic stainless steel.
The steel became known as
nirosta, which means "doesnt rust" in German, a spokesman
for Pittsburgh-based Allegheny Technologies Inc. said. While
commercial production of 18-8 stainless began in Europe shortly
after, Cobb said, it was not produced in the United States
until 1928, when the former Allegheny Steel and U.S. Steel Co.
obtained licenses from Krupp. In the United States, it was
sometimes referred to as "Allegheny metal."
Brearleys discovery of
martensitic chromium stainless steel also was unexpected. The
British metallurgist actually developed hardenable chromium
stainless steel while looking for alloys that could be used to
make a better rifle barrel. Although he experimented in 1912
with various alloys ranging from 6- to 15-percent chromium and
various percentages of carbon, it wasnt until August 1913
that he produced an alloy that was approximately 13-percent
chromium and 0.24-percent carbon. Cobb said the alloy really
didnt improve gun barrels much, but material from the
cast was eventually made into cutlery bladesthe first
commercial cast of stainless steel.
Brearley applied for a U.S.
patent for the alloy in 1915, only to find that Haynes had
already done so, although that patent was rejected and
Haynes stainless alloy wasnt patented until 1919.
The patent battle was finally resolved when the two
metallurgists pooled their funding with a group of investors
and formed American Stainless Steel Corp. in Pittsburgh. There
are varying stories behind Haynes motivation, ranging
from his being tired of using a rusty razor to his wife urging
him to develop a metal that could be used to make tableware
that would not need polishing.
In the early days of stainless,
its alloys remained fairly simple, Payet-Gaspard said, falling
into three basic families: ferritics, austenitics with nickel,
and austenitics. Duplex stainless steela cross of
ferritic and austenitic stainless that has very good corrosion
resistance and other mechanical propertieswasnt
discovered until 1930 by Avesta Ironworks in Sweden.
In 1934, Armcothe
predecessor to West Chester, Ohio-based steelmaker AK Steel
Corp.pioneered the use of stainless steel scrap in its
manufacturing process to reduce costs and conserve chromite
ore, according to James L. Wainscott, chairman, president and
chief executive officer of AK Steel. Today, approximately 80
percent of all stainless steel is made from recycled scrap.
In the late 1940s, AK Steel
developed the first commercially produced
precipitation-hardening stainless steels. Because of their
strength and hardness, these alloys were later used on the
fuselage of the XB-70 supersonic bomber, as well as the Apollo
spacecraft that went to the moon, Wainscott said.
Cobb said it took a long time
for duplex stainless steels, which to this day make up just 1
to 2 percent of the global stainless market, to catch on, as
they couldnt be made inexpensively until argon-oxygen
decarburization (AOD) vessels were used. Created in order to
lower the carbon content of stainless steelstherefore
controlling weld decay and rusting, which sometimes occurs in
the cooling of heat-treated and annealed metalCobb said
the worlds first AOD vessel for the refining of stainless
steel was put in operation in 1968. It had taken Joslyn
Manufacturing & Supply Co., Fort Wayne, Ind., about 12
years to perfect the AOD vessel, making it one of the longest
research and development efforts in the metals industry. AOD
vessel production was commercialized in 1980; by 1990, about
100 AOD vessels had been installed in stainless steel mills
around the world.
Another big advance in 1968,
Stateczny said, was when Allegheny Steelfounded in 1901
by Harry E. Sheldon and his father-in-law, Alfred
Hicksbecame the first producer to use continuous casting,
as opposed to ingot-cast stainless steel. Currently, about 95
percent of stainless steels are continuously cast.
Other milestones in stainless
steels history include the iconic Chrysler Building in
New York. In 1928, Walter P. Chrysler and architect William Van
Alen chose the still largely unproven material to top the
skyscraper, which was dedicated in 1930. It was the first major
architectural use of stainless steel. Seven arcs of stainless
steel sheet and triangular windows make up the 10-story dome of
the building. The dome is topped with a 185-foot-high stainless
steel needlepoint finial weighing 37 tons. The 76-story
building was the tallest in the world until it was surpassed a
few years later by the Empire State Building, which also used
stainless steel extensively.
The materials use in rail
cars was another big milestone. Rail cars previously had been
made solely from carbon steel and typically weighed between
130,000 and 240,000 pounds. But stainless steel was a boon for
lightweighting, and the Budd-Michelin rail carintroduced
in 1932ushered in a new age of rail transportation.
Weighing just 13,500 pounds apiece, they allowed a train to use
a 90-horsepower engine vs. the 300- to 900-horsepower engines
used previously. Cobb said that it also saved Edward G. Budd
Manufacturing Co. from being forced to close its Philadelphia
rail car plant.
The company tested its stainless
steel rail cars in 1934 in a spectacle that came to be known as
the "Dawn to Dusk" dash, with Chicago Burlington & Quincy
Railroads Pioneer Zephyr breaking all rail speed limits,
traveling more than 1,000 miles from Denver to Chicago in just
13 hours and burning far less fuel. By 1940, about 600
stainless rail cars had been built.
Budd also has the distinction of
building the first stainless steel cargo plane, dubbed the Budd
RB-1 Conestoga, in 1943. According to Cobb, the U.S. Navy
ordered 600 of the planes, based on the Douglas DC-3, sight
unseen, given the shortage of aluminum during World War II.
In the 1960s and 1970s, AK Steel
developed the Nitronic family of stainless steels, which are 50
percent stronger than commercially available 300 series
stainless alloys, Wainscott said. These stainless steels are
used in a wide range of products, including automotive hose
clamps, safety belt anchors, truck and bus frames, water supply
and control structures, sewage treatment plant structures, bulk
solids handling equipment, magnetic ore separator screens, coal
buckets and hopper cars.
In the 1980s and 1990s, AK Steel
introduced aluminized stainless steel to the automotive exhaust
market. Due to its corrosive-resistant properties, most
automotive exhaust systems on the road today are made with
aluminized stainless steel. As auto engines become even more
efficient, AK Steels stainless steel products will
continue to help automotive customers design exhaust systems
that accommodate the additional heat generated by
high-compression power plants, Wainscott said.
Today, stainless steeldue
to its adaptabilityis seen as one of the most versatile
metals, being used in such end-use markets as cookware,
cutlery, hardware, appliances, aerospace, automotive, building
and construction, and much more. One of stainless steels
up-and-coming applications is in reinforcing bar. "Carbon rebar
costs less, but stainless has the advantage of enabling bridges
and roads to last longer," said Bill Sales, senior vice
president of nonferrous operations at Reliance Steel &
Aluminum Co., Los Angeles. "It is an application that has
tremendous opportunity for growth."
In general, thats seen to
be the case for stainless steel. "I think the use and uses of
stainless will continue to grow as people continue to recognize
its life-cycle cost advantages," ATIs spokesman said.