Glossary Of Metallurgical Terms

Term

Details.

Age Hardening

Age hardening is a heat treatment process in which the alloy components are heated and quenched rapidly and then held at specified temperatures for longer duration to precipitate the alloying elements slowly. This process increase the mechanical properties of the alloy components generally at the cost of ductility. It is carried out for Stainless Steels or some other non-ferrous alloys.

Alloy

Alloy is a chemical compound / physical mixture of two or more elements. Alloys show metallic properties. At least one of the constituent element of an alloy is metal.

Alloy Steel

A ferrous / iron based alloy containing significant amount of other alloying elements such as nickel, chromium, vanadium, molybdenum, etc. Commonly found iron alloying elements such as carbon, manganese, sulfur, silicon, etc. along are excluded from this term.

Austenite

Austenite is a solid solution of one or more elements in face-centered-cubic (FCC) iron. In Austenite the solute is generally assumed to be carbon.

Bainite

A Decomposition of product of Austnite consisting of an aggregate of ferrite and carbide. It’s appearance is feathery if formed in the upper part of the temperature range and acicular if formed in the lower temperature range

Binder

A Material other than water added to the foundry sand to bind the particles together (sometimes with the application of heat).

Brinell Hardness Test (BHN)

A test to determine the hardness of a material by forcing a hard steel or carbide ball of specified diameter into that material under specified load. It is equal to the applied load in Kilograms divided by surface area of the indent created by the ball in square millimeters.

Carbon Steel

Ferrous / Iron based mixture of Iron and Iron carbide with maximum carbon addition upto 2 percent. This may also contain other deoxydation elements such as Manganese, Silicon, etc. is lower quantities

Cast Iron

An Iron containing carbon in excess of the solubility of the carbon in Austenite at Eutectic temperature.

Equilibrium Diagram

A graphical representation of the temperature, pressure and composition limits of the phase fields in an alloy system as they exists under the system of complete equilibrium.

Eutectic

An isothermal reversible reaction in which a liquid solution is converted into two or more intimately mixed solids on cooling. The number of solids formed being the same as the number of components in the system.

Eutectoid

An isothermal reversible reaction in which a solid phase is converted into two or more intimately mixed solids on cooling. The number of solids formed being the same as the number of components in the system.

Ferrite/strong>

A solid solution of one or more elements in body-centered-cubic (BCC) irondf.

Inoculation

The addition of a material in molten metal to form nuclei for crystallization.

Mechanical Properties

Metal resist change in shape, size and form after application of load. Such changes are measured for applicable load and documented for that material. Common Mechanical properties are Tensile stress, Young’s Modulus of Elasticity, etc. Mechanical properties of a material depend upon alloying elements, grain size, etc.

Metal

An opaque lustrous elemental chemical substance that is good conductor of heat and electricity. When polished, metals are good reflector of light.

Metallurgy

The science and technology of metals. It is also the process for extracting metals from their ores and refining them.

Noble Metal

A metal whose potential is highly positive relative to the hydrogen electrode and hence cannot be corroded or oxidized easily.

Peritectic

An isothermal reversible reaction in which a liquid phase reacts with a solid phase to produce another solid phase on cooling.

Peritectioid

An isothermal reversible reaction in which a solid phase reacts with a second solid phase to produce third solid phase on cooling.