Martensitic stainless steel
Encyclopedia
Martensitic stainless steel is a specific type of stainless steel
alloy.
Stainless steels may be classified by their crystalline structure into three main types: Austenitic
, Ferritic
and Martensitic
. Martensitic steels are low carbon steels built around the Type 410 composition of iron, 12% chromium, and 0.12% carbon. They may be tempered and hardened. Martensite gives steel great hardness, but it also reduces its toughness and makes it brittle, so few steels are fully hardened.
The characteristic orthorhombic martensite microstructure
was first observed by German microscopist Adolf Martens
around 1890. In 1912, Elwood Haynes
applied for a U.S. patent on a martensitic
stainless steel alloy. This patent was not granted until 1919.
Also in 1912, Harry Brearley
of the Brown-Firth
research laboratory in Sheffield, England, while seeking a corrosion-resistant alloy for gun barrels, discovered and subsequently industrialized a martensitic stainless steel alloy. The discovery was announced two years later in a January 1915 newspaper article in The New York Times
. Brearly applied for a U.S. patent during 1915. This was later marketed under the "Staybrite" brand by Firth Vickers
in England and was used for the new entrance canopy for the Savoy Hotel
in 1929 in London
.
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
alloy.
Stainless steels may be classified by their crystalline structure into three main types: Austenitic
Austenite
Austenite, also known as gamma phase iron, is a metallic non-magnetic allotrope of iron or a solid solution of iron, with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of ; other alloys of steel have different eutectoid temperatures...
, Ferritic
Ferrite (iron)
Ferrite or alpha iron is a materials science term for iron, or a solid solution with iron as the main constituent, with a body centred cubic crystal structure. It is the component which gives steel and cast iron their magnetic properties, and is the classic example of a ferromagnetic material...
and Martensitic
Martensite
Martensite, named after the German metallurgist Adolf Martens , most commonly refers to a very hard form of steel crystalline structure, but it can also refer to any crystal structure that is formed by displacive transformation. It includes a class of hard minerals occurring as lath- or...
. Martensitic steels are low carbon steels built around the Type 410 composition of iron, 12% chromium, and 0.12% carbon. They may be tempered and hardened. Martensite gives steel great hardness, but it also reduces its toughness and makes it brittle, so few steels are fully hardened.
The characteristic orthorhombic martensite microstructure
Orthorhombic crystal system
In crystallography, the orthorhombic crystal system is one of the seven lattice point groups. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base and height , such that a,...
was first observed by German microscopist Adolf Martens
Adolf Martens
Adolf Martens , 6 March 1850 – 24 July 1914, was a German metallurgist and the namesake of the steel structure martensite.-References:*...
around 1890. In 1912, Elwood Haynes
Elwood Haynes
Elwood P. Haynes was an American inventor, metallurgist, automotive pioneer, entrepreneur and industrialist. He invented the metal alloys stellite and martensitic stainless steel and designed one of the earliest automobiles made in the United States...
applied for a U.S. patent on a martensitic
Martensite
Martensite, named after the German metallurgist Adolf Martens , most commonly refers to a very hard form of steel crystalline structure, but it can also refer to any crystal structure that is formed by displacive transformation. It includes a class of hard minerals occurring as lath- or...
stainless steel alloy. This patent was not granted until 1919.
Also in 1912, Harry Brearley
Harry Brearley
Harry Brearley is usually credited with the invention of "rustless steel" in the anglophone world.-Life:...
of the Brown-Firth
Firth Brown Steels
Firth Brown Steels was initially formed in 1902, when Sheffield steelmakers John Brown and Company exchanged shares and came to a working agreement with neighbouring company Thomas Firth & Sons...
research laboratory in Sheffield, England, while seeking a corrosion-resistant alloy for gun barrels, discovered and subsequently industrialized a martensitic stainless steel alloy. The discovery was announced two years later in a January 1915 newspaper article in The New York Times
The New York Times
The New York Times is an American daily newspaper founded and continuously published in New York City since 1851. The New York Times has won 106 Pulitzer Prizes, the most of any news organization...
. Brearly applied for a U.S. patent during 1915. This was later marketed under the "Staybrite" brand by Firth Vickers
Vickers
Vickers was a famous name in British engineering that existed through many companies from 1828 until 1999.-Early history:Vickers was formed in Sheffield as a steel foundry by the miller Edward Vickers and his father-in-law George Naylor in 1828. Naylor was a partner in the foundry Naylor &...
in England and was used for the new entrance canopy for the Savoy Hotel
Savoy Hotel
The Savoy Hotel is a hotel located on the Strand, in the City of Westminster in central London. Built by impresario Richard D'Oyly Carte with profits from his Gilbert and Sullivan operas, the hotel opened on 6 August 1889. It was the first in the Savoy group of hotels and restaurants owned by...
in 1929 in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
.