ABBREVIATIONS

DEFINITION

DEFINITION OF SOME USEFUL PROCESS OVER STEEL
HEAT TREATMENT

Heat Treatment

Heat treatment is an operation or combination of operations involving the heating and cooling of a metal or alloy when in solid form to obtain certain desirable conditionor properties. Heating and cooling for the sole purpose of mechinal working are excluded from the meaning of the definition.

Annealing

The term annealing usually implies to relatively slow cooling. In annealing the Temperature, rate of heating and cooling and the time depends upon the composition, shape and size of the steel that is being treated. The purpose of annealing is to remove stress to induce softness, to reduce hardness, to alter ductility, thoughness, improve machinability, facilitate cold working, to produce a desired micro-structure, to change etectric, magnetic or other physical and mechanical properties.

Distoration

The deviation from the desired size, shape or form, as occuring in heat treatment.

HARDNESS PROCESS

Hardening

Any process of increasing the hardness of metal or alloy superior to that obtained when the alloy is not quenched by suitable treatment usually heating above the critical temperature range and cooling by Quenching. The term is usually restricted to the formation of martensite.

Case Hardening

Hardening a ferrous alloy in order to change the outer surface or case substantially harder than the inner surface or core, by inward diffusion from a gas or liquid followed by appropriate thermal treatment. The term is usually applied to carburizing, cyaniding or nitriding treatment followed by quenching to produce a hard case and a core of suitable properties.

Tempering

The reheating of quench hardened or normalized steel below transformation range and the cooling slowing at a desired rate. The object of this process a desired combination of mechanical properties such as release of stress, restore, some ductillity, develop toughness though regulation or readjustment of the embrittled structural constituents of the metal.