 |
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
|
|
| Air-Hardening Steel |
| A steel which because of its high alloy content will form martensite when cooled in air from the austenitic state. |
|
| Alloy Steel |
| A steel in which a deliberate addition of one or more alloying elements, e.g. Mn, Ni, Cr, Mo etc has been made during steelmaking to enhance the properties of the steel. The amounts of each element that must be present in steel before it is classified as an alloy steel are given in Table 1 in BS EN 10020: 1998. At low levels of addition the steels may be classified as low alloy. The same standard classifies steels which do not meet the minimum requirements as 'non-alloy' steels. |
|
| Alpha-Iron |
| The form of iron (also referred to as ferrite) which exists naturally below 910C in which the iron atoms are arranged in a body centred cubic (bcc) crystalline pattern, ie an iron atom at each corner of a cube and a single one right in the middle of the cube. |
|
| Anisotropy |
| Anisotropy is the word used to describe the fact materials in general, and steels in particular, are characterised by mechanical properties which differ depending upon the direction in which they are assessed. Particular use is made of this in cold reduced formable steels intended for deep drawing applications; the production process route is such as to enhance this particular property, which is given a numerical value by a parameter known as the 'r' value. |
|
| Annealing |
| A heat treatment that is used to soften steel and involves heating the steel to a pre-determined temperature, soaking the steel at that temperature for a pre-determined time and then cooling the steel down under controlled conditions. After being annealed a steel will be closer to its equilibrium state and will exhibit improved formability and machinability. The temperature used can depend upon the chemical composition and the initial state of the steel and on the outcome desired of the treatment. This requirement of the treatment gives rise to the terms: stress-relief annealing, recrystallisation annealing, spheroidisation annealing, sub-critical annealing, inter-critical annealing, isothermal annealing, full annealing. |
|
| Arc Furnace |
| A melting unit in which the heat is generated by striking an arc between graphite electrodes and the metal charge, which is usually in the form of solid scrap. |
|
| Arriss |
| Removal of sharp edges / corners in preparation for painting. |
|
| Austempering |
| A heat treatment process in which the steel is quenched from high temperature, when it is austenitic, to a temperature just above the austenite to martensite transformation temperature of the steel. The steel is then held at this temperature until it has transformed completely to bainite. It is then quenched to room temperature. |
|
| Austenite |
| A solid solution of one or more elements in gamma iron. (q.v.) |
|
| Austenitic Steels |
| These are steels which contain sufficient austenite stabilising elements, such as Mn, Ni and N, so that the mircrostructure of the steel is austenitic at room temperature. Such steels cannot be quench or air hardened but will work harden rapidly; they are non-magnetic. Important examples of austenitic steels are 18/8 (18% Cr, 8% Ni) stainless steel and Hadfield's Manganese (14% Mn) steel. |
