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 method for doing this was known as the Harvey process. 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 1890s were sometimes referred to as the Mauve Decade, because William Henry Perkins aniline dye allowed the widespread use of that colour in fashion, and also as the Gay Nineties, under the then-current usage of the word gay which referred simply to merriment and frivolity, with no... Case hardening or Surface hardening is the process of hardening the surface of steel whilst leaving the interior unchanged. ...

This type of armor was used in the construction of capital ships until superseded by Krupp armour in the late 1890s. It was invented by the American engineer Hayward Augustus Harvey. The capital ships of a navy are its important warships; the ones with the heaviest firepower and armor. ... The 1890s were sometimes referred to as the Mauve Decade, because William Henry Perkins aniline dye allowed the widespread use of that colour in fashion, and also as the Gay Nineties, under the then-current usage of the word gay which referred simply to merriment and frivolity, with no... Look up engineer in Wiktionary, the free dictionary. ...

Before the appearance of compound armour in the 1880s, armour plating was made from uniform homogenous iron or steel plates backed by several inches of teak to absorb the shock of projectile impact. Compound armour appeared in the mid-1880s and was made from two different types of steel, a very hard but brittle high-carbon steel front plate backed by a more elastic low-carbon wrought iron plate. The front plate was intended to break up an incoming shell, whilst the rear plate would catch any splinters and hold the armour together if the brittle front plate shattered. // Events and Trends Technology Development and commercial production of electric lighting Development and commercial production of gasoline-powered automobile by Karl Benz, Gottlieb Daimler and Maybach First commercial production and sales of phonographs and phonograph recordings. ... Species Tectona grandis Tectona hamiltoniana Tectona philippinensis Teak (Tectona), also called jati is a genus of tropical hardwood trees in the family Verbenaceae, native to the south and southeast of Asia, and is commonly found as a component of monsoon forest vegetation. ... // Events and Trends Technology Development and commercial production of electric lighting Development and commercial production of gasoline-powered automobile by Karl Benz, Gottlieb Daimler and Maybach First commercial production and sales of phonographs and phonograph recordings. ... 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. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... in Economics see elasticity (economics) in Materials Science the word elastomer refers to a material which is very elastic, like rubber. ... A wrought iron railing in Troy, New York. ...

Compound armour was made by pouring molten steel between a red-hot wrought iron backing plate and a hardened steel front plate to weld them together. This process produced a sharp transition between the properties of the two plates in a very small distance. As consequence, the two plates could separate when struck by a shell, and the rear plate was often not elastic enough to stop the splinters. With the discovery of nickel-steel alloys in 1889, compound armour was rendered obsolete. Welding is a joining process that produces coalescence of materials (typically metals or thermoplastics) by heating them to welding temperature, with or without the application of pressure or by the application of pressure alone, and with or without the use of filler material. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ... Alloy is a combination, either in solution or compound, of two or more elements, which has a combination of at least one metal, and where the resultant material has metallic properties. ... 1889 (MDCCCLXXXIX) was a common year starting on Tuesday (see link for calendar). ...

Harvey armour used a single plate of steel, but re-introduced the benefits of compound armour. The front surface was converted to high carbon steel by "cementing". In this process, the steel plate would be covered with charcoal and heated to approximately 1200 degrees Celsius for two to three weeks. The process increased the carbon content at the face to around 1 percent; the carbon content decreasing gradually from this level with distance into the plate, reaching the original proportion (approximately 0.1–0.2 percent) at a depth of around an inch. After cementing, the plate was chilled first in an oil bath, then in a water bath, before being annealed to toughen the back of the plate. The water bath was later replaced with jets of water to prevent the formation of a layer of steam which would insulate the steel from the cooling effect of the water. The process was further improved by low temperature forging of the plate before the final heat treatment. Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents of animal and vegetable substances. ... A degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701-1744), who first proposed a similar system in 1742. ... Annealing, in metallurgy and materials science, is a heat treatment wherein the microstructure of a material is altered, causing changes in its properties such as strength and hardness. ... This article is about smithing. ...

Whilst the American navy used nickel steel for Harvey armour (roughly carbon 0.2 percent, manganese 0.6 percent, nickel 3.5 percent), the British used normal steels since their tests had shown that ordinary steel subjected to the Harvey process had the same resistance to penetration as nickel steel, although it was not quite so tough.

Harvey armour was taken up by all of the major navies, since 13 inches of Harvey armour offered the same protection as 15.5 inches of nickel-steel armour. It was in turn rendered obselete by the development of Krupp armour in the late 1890s. The 1890s were sometimes referred to as the Mauve Decade, because William Henry Perkins aniline dye allowed the widespread use of that colour in fashion, and also as the Gay Nineties, under the then-current usage of the word gay which referred simply to merriment and frivolity, with no...

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