found 16 matching terms.
| Term |
Definition |
| F |
Chemical symbol for Fluorine. |
| Face Centred Cubic Lattice |
An arrangement of atoms in crystals in which the atomic centres are disposed in space in such a way that one atom is located at each of the corners of the cube and one at the centre of each face. Steel in the face-centred cubic arrangement is termed austenite. |
| Fatigue |
The effect on metal of repeated cycles of stress. The insidious feature of fatigue failure is that there is no obvious warning, a crack forms without appreciable deformation of structure making it difficult to detect the presence of growing cracks. Fractures usually start from small nicks or scratches or fillets which cause a localised concentration of stress. Failure can be influenced by a number of factors including size, shape and design of the component, condition of the surface or operating environment. |
| Fatigue Limit |
The maximum value of the applied alternating stress which a test piece can stand indefinitely. |
| Fatigue Testing |
Fatigue tests are made with the object of determining the relationship between the stress range and the number of times it can be applied before causing failure. Testing machines are used for applying cyclically varying stresses and cover tension, compression, torsion and bending or a combination of these stresses. |
| Fe |
Chemical symbol for Iron. |
| Ferrite |
The solid solution of carbon in body-centered cubic iron, a constituent of carbon steels. |
| Ferritic Steel |
A term usually applied to a group of stainless steels with a chromium content in the range of 12- 18o and whose structure consists largely of ferrite. Such steels possess good ductility and are easily worked but do not respond to any hardening or tempering processes. Types of applications include automotive trim and architectural cladding. |
| Ferro Alloys |
Alloys of iron with chromium, manganese, silicon, tungsten, molybdenum or vanadium. Used in steelmaking as a means of introducing these alloying elements into the cast or as deoxidisers. |
| Fettling |
The removal of sand adhering to castings by hammering, tumbling or shot blasting. |
| Fin |
In rolling mill practice a fin is a projection extending from the side of rolled sections. It causes considerable trouble and is the result of overfill. The fin, formed when the bar or shape is fed through one pass, is likely to be rolled back into the bar at the next pass. It is rarely encountered in modern rolling mills. |
| Flame Hardening |
A surface hardening process in which heat is applied by a high temperature flame followed by quenching jets of water. It is usually applied to medium to large size components such as large gears, sprockets, slide ways of machine tools, bearing surfaces of shafts and axles, etc. Steels most suited have a carbon content within the range 0.40-0.55%. |
| Flash |
A fin that arises from metal in excess of that required to fill the final impression in a forging die and is exuded from the parting line between the dies; similarly it can arise at the mould joint in a casting. |
| Forging |
A process of working metal to a finished shape by hammering or pressing and is primarily a "hot" operation. It is applied to the production of shapes either impossible or too costly to make by other methods or needing properties not obtainable by casting. Categories of forgings include Hammer, Press, Drop or Stamping. |
| Fracture |
Fractures are often described by the appearance of the surface of the break in a piece of steel. Crystalline is bright and glittering, failure having developed along the cleavage planes of individual crystals and can be typical of brittle material. A silky fracture has a smooth dull grain indicative of ductile material such as a mild steel. In tensile testing fractures are described by shape, e.g. cup and cone. |
| Freecutting Steels |
Steels which have had additions made to improve machinability. The most common additives are sulphur and lead, other elements used include tellurium, selenium and bismuth. |
