Coltello: differenze tra le versioni

Versione delle 16:09, 1 ott 2006

Versione delle 09:43, 6 ott 2006

Riga 14:

===Lame===

[[Victorinox|Forschner/Victorinox]] makecostruisce inexpensivecoltelli kitchenda knivescucina economici; high-endcostruttori di coltelli di manufacturersalta includequalità sono[[Wüsthof Dreizack|Wüsthof]], [[Global (cutlery)|Global]], [[Henckels]], [[Kershaw Knives]] and Böker (Tree Brand).

====Materiali====

KnifeLe bladeslame aredei typicallycoltelli madesono ofnormalmente di [[steelacciaio]]. AllTutto knifel'acciaio steelper iscoltell temperedè temprato, ossia [[martensite]], whichcostituita meansda thatuna astruttura cristallina molto fine-grained crystalcon structureirregolarità withdel lattice[[reticolo irregularitiescristallino]] thatche makeindurisce itil hardmateriale. It is formed as it is [[quench|quenched]], changing it from the [[austenite|austenitic]] structure that it has at high temperature to a hard, but brittle martensitic structure. The blade is then [[tempering|tempered]] by heating to an intermediate temperature for a period to make it less brittle. Knife steel has fairly low nickel content, because nickel tends to keep steel in the austenitic structure, even when cold. Steels having high carbon but low chromium content ("carbon steel") are prone to rust and pitting if not kept dry and oiled.

[[Stainless steel]] knives have gained popularity in the latter half of the twentieth century. Stainless steel is steel with very high (12–18%) [[chromium]] content — stainless knife steels are high in carbon, but "carbon steel" means there is not also a lot of chromium. Stainless steel is highly resistant to [[corrosion]] (though knife steel is less so than higher nickel stainless steel) because, except in acid, one of the metals or one of the oxides is always stable Stainless steel knives usually only rust under extreme conditions. Stainless steel usually has particles of chromium (or other alloy metal) carbides. These explain its reputation for long wear (the carbides are harder than the metal) and for being harder to sharpen and not taking as good an edge as rustable, low alloy ("carbon") steel (the ceramic particles themselves cannot be sharpened easily.), although tests indicate that stainless steel knives hold an edge better than regular steels.<ref>by Razor Edge Systems, described in their book "The Razor Edge Book of Sharpening".</ref> The bulk hardness and toughness of stainless steel tend to be lower than those of low alloy steel. Stainless and semi-stainless steels include D2, S30V, 154CM, ATS-34, and 440C.