Martensitic Stainless Steel

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 stainless steels are low carbon steels built around the Type 410 composition of iron, 12% chromium, and 0.12% carbon. They are usually tempered and hardened. Tempered martensite gives steel good hardness and high toughness. Untempered martensite is low in toughness and therefore brittle.

The characteristic body centered tetragonal 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.

Martensitic stainless steel can be tested by Nondestructive testing using the Magnetic particle inspection method, unlike austenitic stainless steel.

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.

Famous quotes containing the words stainless steel, steel and/or stainless:

    I stir my martinis with the screw,
    four-inch and stainless steel,
    and think of my hip where it lay
    for four years like a darkness.
    Anne Sexton (1928–1974)

    For when they meet, the tensile air
    Like fine steel strains under the weight
    Of messages that both hearts bear—
    Pure passion once, now purest hate....
    Allen Tate (1899–1979)

    The American people is out to get the kaiser. We are bending every nerve and every energy towards that end; anybody who gets in the way of the great machine the energy and devotion of a hundred million patriots is building towards the stainless purpose of saving civilization from the Huns will be mashed like a fly. I’m surprised that a collegebred man like you hasn’t more sense. Don’t monkey with the buzzsaw.
    John Dos Passos (1896–1970)