Krupp armour was a type of steel armour used in the construction of capital ships starting shortly before the end of the 19th century. It was developed by Krupp Arms Works in 1893 and quickly replaced Harvey armor as the primary method of protecting naval ships. The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. ... A hoplite wearing (only) a helmet, breastplate greaves and a shield. ... The capital ships of a navy are its important warships; the ones with the heaviest firepower and armor. ... Harvey armour was a type of steel armour developed in the early 1890s in which the front surfaces of the plates were case hardened. ...

The initial manufacturing of Krupp armour was very similar to Harveyized armor, however while the Harvey process generally used nickle-steel, the Krupp process added as much as 1% chromium to the alloy in order to gain additional hardness. Also, while Harveyized armor was carburized by heating the steel and physically placing charcoal its surface for long durations (often several weeks), Krupp armour achieved greater depth of carbon cementation by instead applying carbon-bearing gases to the heated steel. Once the carburization process was complete, it was then transformed into face hardened steel by rapidly heating the cemented face, allowing the high heat to penetrate thirty to forty percent of the steel's depth, then quickly quenching first the superheated side then both sides of the steel with powerful jets of either water or oil. General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... An alloy is a combination, either in solution or compound, of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. ... In materials science, hardness is the characteristic of a solid material expressing its resistance to permanent deformation. ... Carburization (often referred to as carburizing) is the name of the process by which carbon is introduced into a metal. ... In geology, cementation is the process of deposition of dissolved mineral components in the interstices of sediments. ... The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. ... A quench refers to a rapid cooling. ... In physics, superheating (sometimes referred to as boiling retardation, boiling delay, or defervescence) is the phenomenon in which a liquid is heated to a temperature higher than its standard boiling point, without actually boiling. ... Water (from the Old English waeter; c. ... Mineral oil or liquid petrolatum is a by-product in the distillation of petroleum to produce gasoline. ...

Krupp armour was swiftly adopted by the world's major navies; ballistic tests showed that 10.2 inches (25.9 cm) of Krupp armour offered the same protection as 12 inches (30.4 cm) of Harvey armor. By the early 20th century it was in turn rendered obsolete by the development of Krupp cemented armour. Mid-19th century tool for converting between different standards of the inch An inch is an Imperial and U.S. customary unit of length. ... A centimetre (US: centimeter) is a factor of the SI unit of length: there are one hundred centimeters in the base unit of measure, the metre. ...

References

• Brown, David K. (2003). Warrior to Dreadnought, warship development 1860-1905. Caxton Publishing Group. ISBN 1-84067-5292.
• Gene Slover's US Navy Pages - Naval Ordnance and Gunnery
• Article on armour plates in 1911 edition of Encyclopedia Britannica