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A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y 2 0 1 5
3 8
F
rench researchers began adding
chromium or nickel to heat treated
alloy steels during the 1880s and
1890s, while German researchers began
combining chromium with nickel in the
1890s. These alloy additions were in
the 2% to 5% range and required heat
treatment to achieve higher strength.
Before 1895, there was no process for
producing low-carbon chromium to be
added to iron. Further, controlling carbon
is themost important factor inmaking
chromium steels. At this point, German
chemist Hans Goldschmidt invented
the thermite process, which combines
chromiumore with aluminumpowder in a
heavy-walled container to generate enough
heat to separate the chromiummetal
without carbon contamination. This paved
the way to studying alloys withmuch higher
chromium content and low carbon.
The first metals researcher to make
use of this new low-carbon chromium
was a Frenchman named Leon Guillet.
He published his research during 1904-
1906 covering the full range of chromium
additions that would later be alloys within
the commercial range of stainless steel.
Guillet’s work showed three basic alloy
types: One was low carbon with high
chromium that could not be hardened and
therefore called
ferritic
. Another was higher
carbon that could be hardened as any
alloy steel and called
martensitic
. Finally,
he studied alloys with both chromium
and nickel. With sufficient nickel, these
alloys were
austenitic
. The first time an
all-austenitic microstructure was seen, it
occurred at ambient temperature.
These three categories continue to
define the range of today’s stainless
steels. Guillet’s studies covered the
metallographic and mechanical
properties that could be measured
during his era. However, he completely
missed the fact that some of his alloys
were resistant to corrosion in both acids
and the normal atmosphere. They were
“stainless.” Because Guillet was the first
to publish on alloys that would later be
classified as stainless steels, Carl Zapffe
in his classic
Stainless Steels
book (ASM
International, 1949) awarded him first
place in the discovery of these alloys.
Two other researchers who studied iron-
chromium and iron-chromium-nickel
alloys just a few years after Guillet include
the well-known French metallurgist
Albert Portevin and an Englishman, W.
Giesen. Portevin studied the straight
iron-chromium alloys with both low and
high carbon. Giesen did most of his work
on the iron-chromium-nickel austenitic
steels, which had to be low carbon. Both
published their results in the same edition
of the Iron and Steel Institute’s
Carnegie
Scholarship Memoirs
, Vol 1, 1909.
DISCOVERYOF
STAINLESS STEEL
The first researcher to discover the
groundbreaking property of corrosion
resistance was Philip Monnartz of
Germany. He began his work in 1908 and
published in the journal
Metallurgie
in
1911. Quoting from Zapffe, “His research
disclosed the stainlessness of stainless
steels—and provided as brilliant a
piece of work as stands in the literature
on stainless steels.” First, Monnartz
Hans Goldschmidt
invented the thermite
process.
Leon Guillet was the first
metallurgist to study
iron-chromium and iron-
chromium-nickel alloys.
Philip Monnartz, the
inventor of stainless steel.
METALLURGY LANE
STAINLESS STEEL: THE STEEL THAT DOES NOT RUST — PART 1
ONE OF THE GREATEST ADVANCES IN MODERN METALLURGY WAS THE DISCOVERY OF A STEEL
THAT DOES NOT RUST, WHICH OCCURRED AFTER RESEARCH INTO HIGH CHROMIUM STEELS BEGAN.
Metallurgy Lane, authored by ASM life member Charles R. Simcoe, is a yearlong series dedicated to the early history of the U.S. metals
and materials industries along with key milestones and developments.