- published: 04 Feb 2016
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Austenite, also known as gamma-phase iron (γ-Fe), is a metallic, non-magnetic allotrope of iron or a solid solution of iron, with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1,000 K (1,340 °F; 730 °C); other alloys of steel have different eutectoid temperatures. It is named after Sir William Chandler Roberts-Austen (1843–1902).
From 912 to 1,394 °C (1,674 to 2,541 °F) alpha iron undergoes a phase transition from body-centred cubic (BCC) to the face-centred cubic (FCC) configuration of gamma iron, also called austenite. This is similarly soft and ductile but can dissolve considerably more carbon (as much as 2.04% by mass at 1,146 °C (2,095 °F)). This gamma form of iron is exhibited by the most commonly used type of stainless steel for making hospital and food-service equipment.
Austenitization means to heat the iron, iron-based metal, or steel to a temperature at which it changes crystal structure from ferrite to austenite. An incomplete initial austenitization can leave undissolved carbides in the matrix.
PIOLHO
Paulo Malária e Scubi Jenné
Acordei com a cabeça coçando
Tinha um troço em cima dela andando
Futuquei com a unha o cabelo
E aí veio o piolho no pelo.
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É um bicho que perturba a gente
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Estou nervoso nem sei o que faço
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A minha mina perguntou noutro dia
Que uma estranha coceira sentia
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É um bicho que perturba a gente
Piolho, piolho,
Já está me deixando doente
Fui um dia tirar pasaporte
Pois eu queria viajar para o Norte
Me recusaram o salvo conduto
Só por causa do piolho maluco!
Piolho, piolho,
É um bicho que perturba a gente
Piolho, piolho,