Contents Go


Stainless Steel

Etymology of Stainless Steel


Stainless steel means steel which is hardly got rusty (A word, stain meaning rust plus suffix “less” meaning denial)

History of Stainless Steel

Motive for Development

Development of integrated steel mill technology enabled the mass production of iron from the end of 19th century to the early 20th century. But rust on iron was a problem. Research was been carried out to solve this problem, such as surface treatment, electric protection and additive of alloy, including research for control of rust by addition of double alloy elements which motivates the development of stainless steel.

replace text

Added Cr to steel
  • Knife Blade(1.5%Cr)
  • A small portion of Cr : Rust Occurrence, A large portion of Cr : Bad molding
  • corrosion(1820) : M. Faraday (England)

replace text

13% Cr
17% Cr
  • 1904 ~ 1909
  • L. Guillet, A. Portevin (France)
  • Giesen (Germany)

replace text

Ferrite Martensite Austenite
  • L. Guillet (France) :
    Announcement of 3 types of stainless steel
  • 1910∼1915 (Study for properties of corrosion)
    Austenite series : Maurer, Strauss (Germany)
    Ferrite series : Danitzen, Becket (America)
    Martensite series : Brearley (England)

Stabilized Stainless Steel / Precipitation Hardening Stainless Steel

Reason why Stainless Steel is Hardly Got Rusty

When stainless steel maintains chrome(Cr) more than 12%, it naturally forms thin Cr2O3 layer (10~50 μm) (passivity layer) to protect steel from the entrance of oxygen.

Structure of Passivity Layer

Structure of Passivity Layer table
Classification Normal Carbon Steel Stainless Steel



Coating Feature Oxygen easily enters from the outside since
it has thick and perforate coating
Oxygen hardly enters from the outside since
it has thin and close coating