heat-treating


heat-treating
Changing the properties of materials such as metals or glass by processes involving heating.

It is used to harden, soften, or modify other properties of materials that have different crystal structures at low and high temperatures. The type of transformation depends on the temperature that the material is heated to, how fast it is heated, how long it is kept heated, what temperature it is first cooled to, and how fast it is cooled. For example, quenching hardens steel by heating it to high temperatures and then quickly immersing it in room temperature oil, water, or salt brine to "freeze" the new crystal structure; in cryogenic treatments the cooling bath ranges from -180 to -70 °C (-300 to -100 °F), and it is often used in treating high-carbon and high-alloy steels. The two main approaches to softening a metal (to restore its ductility) are annealing, in which its temperature is slowly raised, held for some time, and slowly cooled, and tempering, in which it is slowly heated in an oil bath and held for some hours.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Heat treating film — Heat treating film. См. Пленка побежалости. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • Electron beam heat treating — Electron beam heat treating. См. Электроннолучевая термообработка. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • Heat treatment — is a method used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment… …   Wikipedia

  • heat — heatable, adj. heatful, adj. heatless, adj. heatlike, adj. /heet/, n. 1. the state of a body perceived as having or generating a relatively high degree of warmth. 2. the condition or quality of being hot: the heat of an oven. 3. the degree of… …   Universalium

  • heat — /hit / (say heet) noun 1. the quality or condition of being hot. 2. the sensation of hotness or warmth; heated bodily condition. 3. Psychology a blended sensation, caused by stimulating the warmth and cold receptors on the skin. 4. Physics energy …   Australian English dictionary

  • heat treatment — noun : a process or an instance of heat treating …   Useful english dictionary

  • heat — [[t]hit[/t]] n. 1) the condition or quality of being hot; the state of a body having or generating a high degree of warmth 2) degree of hotness; temperature: moderate heat[/ex] 3) the sensation of warmth or hotness 4) a bodily temperature higher… …   From formal English to slang

  • tempering — Heat treating of metal alloys, particularly steel, to reduce brittleness and restore ductility. In tempering, steel is slowly heated to a temperature between 300 and 1,300 °F (150 and 700 °C), depending on desired properties, in an oil or salt… …   Universalium

  • Пленка побежалости — Heat treating film Пленка побежалости. Тонкое покрытие или пленка, обычно оксидов, сформированная на поверхности металла во время термообработки. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и …   Словарь металлургических терминов

  • steel — steellike, adj. /steel/, n. 1. any of various modified forms of iron, artificially produced, having a carbon content less than that of pig iron and more than that of wrought iron, and having qualities of hardness, elasticity, and strength varying …   Universalium