Austenite (or gamma phase iron) is a metallic non-magnetic solid solution of iron and an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1000 K (about 727 °C); other alloys of steel have different eutectoid temperatures. It is named after Sir William Chandler Roberts-Austen (1843-1902). Behavior in Plain-Carbon Steel As austenite cools, it often transforms into a mixture of ferrite and cementite as dissolved carbon falls out of solutio… (More on Austenite)