Iron-carbon phase diagram, showing the conditions under which austenite (γ) is stable in carbon steel.

Austenite is a metallic, non-magnetic solid solution of carbon and iron that exists in steel above the critical temperature of 1333°F (about 723°C). It is named after Sir W.C. Roberts-Austen. Its face-centred cubic (FCC) structure allows it to hold a high proportion of carbon in solution. Image File history File links An English version of Diag phase fer carbone. ... Image File history File links An English version of Diag phase fer carbone. ... In physical chemistry and materials science, a phase diagram is a type of graph used to show the equilibrium conditions between the thermodynamically-distinct phases. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. ... In crystallography, the cubic crystal system (or isometric crystal system) is the most symmetric of the 7 crystal systems. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ...

As it cools, this structure either breaks down into a mixture of ferrite and cementite (often in special forms such as pearlite and bainite), or undergoes a slight lattice distortion known as martensitic transformation. The rate of cooling determines the relative proportions of these materials and therefore the mechanical properties (e.g. hardness, tensile strength) of the steel. Quenching (to induce martensitic transformation), followed by tempering (to break down some martensite and retained austenite), is the most common heat treatment for high-performance steels. Iron-carbon phase diagram, showing the conditions under which ferrite (α) is stable. ... Cementite or iron carbide is a chemical compound with the formula Fe3C, and an orthorhombic crystal structure. ... Pearlite occurs at the eutectoid of the iron-carbon phase diagram (near the lower left). ... Iron-carbon phase diagram, showing the eutectoid temperature and composition, at which bainite can form. ... Martensite, named after the German metallurgist Adolf Martens, is a class of hard minerals occurring as lathe- or plate-shaped crystals. ... In materials science, hardness is the characteristic of a solid material expressing its resistance to permanent deformation. ... The tensile strength of a material is the maximum amount of tensile stress that it can be subjected to before it fails. Modes of failure typically vary with the type of material being stressed. ... Quenching is a general term for non-radiative de-excitation. ... Tempering is a heat treatment technique for metals and alloys, most often the toughening of martensitic steel. ... Martensite, named after the German metallurgist Adolf Martens, is a class of hard minerals occurring as lathe- or plate-shaped crystals. ... Heat Treatment is a group of manufacturing techniques used to alter the hardness and toughness of a material. ...

The addition of certain other metals, such as manganese and nickel, can stabilize the austenitic structure, facilitating heat-treatment of low-alloy steels. In the extreme case of austenitic stainless steel, much higher alloy content makes this structure stable even at room temperature. On the other hand, such elements as silicon, molybdenum, and chromium tend to de-stabilize austenite, raising the eutectoid temperature. General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Atomic mass 54. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ... HSLA Steel (High Strength Low Alloy Steel) is a type of steel alloy that provides many benefits over regular steel alloys. ... The pinnacle of New Yorks Chrysler Building is clad with stainless steel In metallurgy, stainless steel (inox) is defined as a ferrous alloy with a minimum of 10. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... General Name, Symbol, Number molybdenum, Mo, 42 Chemical series transition metals Group, Period, Block 6, 5, d Appearance gray metallic Atomic mass 95. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ...

A Blacksmith causes phase changes in the iron-carbon system in order to control the material's mechanical properties, often using the quenching-and-tempering process described above. In this context, the color of light emitted by the workpiece is an accurate gauge of temperature, with the transition from red to orange corresponding to the formation of Austenite in medium- and high-carbon steel. Blacksmith Blacksmith at work Blacksmith at work Blacksmiths fire Hot metal work from a blacksmith A blacksmith is man or woman designing, making and hot shaping metal products, such as wrought iron gates, grills, railings, light fixtures, furniture, sculpture, tools, decorative and religious items, cooking utensils and weapons. ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ...

Maximum carbon solubility in austenite is 2,03%C at 1147°C.

See also

• Eutectoid

Eutectoid transformation occurs when a solid solution decomposes into a fixed two solid constituents at a fixed temperature. ...

External link

• Fe-Fe₃C phase diagram