The Collaborative International Dictionary
Alloy steel \Al"loy steel\ Any steel containing a notable quantity of some other metal alloyed with the iron, usually chromium, nickel, manganese, tungsten, or vanadium.
Wiktionary
n. steel that has been alloyed with other materials in order to improve its mechanical properties
WordNet
n. steel who characteristics are determined by the addition of other elements in addition to carbon
Wikipedia
Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low-alloy steels and high-alloy steels. The difference between the two is somewhat arbitrary: Smith and Hashemi define the difference at 4.0%, while Degarmo, et al., define it at 8.0%. Most commonly, the phrase "alloy steel" refers to low-alloy steels.
Strictly speaking, every steel is an alloy, but not all steels are called "alloy steels". The simplest steels are iron (Fe) alloyed with carbon (C) (about 0.1% to 1%, depending on type). However, the term "alloy steel" is the standard term referring to steels with other alloying elements added deliberately in addition to the carbon. Common alloyants include manganese (the most common one), nickel, chromium, molybdenum, vanadium, silicon, and boron. Less common alloyants include aluminum, cobalt, copper, cerium, niobium, titanium, tungsten, tin, zinc, lead, and zirconium.
The following is a range of improved properties in alloy steels (as compared to carbon steels): strength, hardness, toughness, wear resistance, corrosion resistance, hardenability, and hot hardness. To achieve some of these improved properties the metal may require heat treating.
Some of these find uses in exotic and highly-demanding applications, such as in the turbine blades of jet engines, in spacecraft, and in nuclear reactors. Because of the ferromagnetic properties of iron, some steel alloys find important applications where their responses to magnetism are very important, including in electric motors and in transformers.
Usage examples of "alloy steel".
At ten miles from Chah Bahar, McLanahan and Jamieson launched the next two missiles--these were AGM-88 HARMs (High-speed Anti-Radiation Missiles), supersonic radar seekers loaded with a 150-pound conventional high-explosive warhead with tungsten alloy steel cubes embedded in the explosive to triple the warhead's destructive power.
Airtight, reinforced concrete and alloy steel doors closed over the top of the shaft.
And all cloth grows old and yellow and brittle, so old cloth, duplied, merely meant more old cloth, and alloy steel objects could not be reproduced, but only duplied, without the alloying materials, so there were only soft-iron knives and patched garments.
He produced from inside his clothing a small collapsible grapple of alloy steel to which was attached a thin, extremely stout, silken cord of a length to more than reach the ground.
That featureless, gray, smoothly curving wall of alloy steel loomed so incredibly high above them—.
She came back with the alloy steel knife, of which duplied copies so far had been only soft iron.
Even then, if you add just the right percentages you can get a different alloy steel with properties you might want.
Apparently they had not considered the possibility that the Lensman would attempt to flank them by blasting through an inch and a half of high-alloy steel.
The wire was alloy steel, the stuff airplane controls are made from.