IPC Definitions - January 01, 2012

C22F - Definition fr

Definition statement

This subclass covers:

Processes for changing the physical structure of non-ferrous metals and non-ferrous alloys. Included in this subclass are processes drawn to:

Relationship between large subject matter areas

Subclass C21D provides for processes of modifying the physical structure of ferrous metals or alloys, general devices for heat treatment of ferrous or non-ferrous metals or alloys, and making ferrous metals or alloys malleable by decarburization, tempering or other metallurgical treatments. C22C provides for ferrous and non-ferrous metals or alloys that may have a specified physical structure, e.g. microstructure, resulting from heat treatment or physical deformation.

Subclass C22F provides for decarburization of non-ferrous metal and non-ferrous alloys to modify the physical structure thereof. Subclass C22B covers the decarburization of metalliferous material for purposes of refining.

Group C23F 17/00 provides for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered in the present subclass (C22F).

References relevant to classification in this subclass

This subclass does not cover:

Powder metallurgical apparatus or processes, not specifically modified for making alloys

B22F

Heat treatment, e.g. annealing, quenching, tempering, adapted for particular metallic articles; furnaces therefor

C21D 9/00

Electrolytic production or refining of metals

C25C

Single crystals or homogeneous polycrystalline material with defined structure; production thereof

C30B

Informative references

Attention is drawn to the following places, which may be of interest for search:

Casting of metals

B22D

Processing of pig iron, e.g. refining, manufacture of wrought iron or steel

C21C

General methods or devices for heat treatment, e.g. hardening, quenching, tempering

C21D 1/00

Removing material from alloys to produce alloys of different constitution

C22C 3/00

Coating material with metallic material; cementation (carburizing, nitriding, etc.) processes

C23C

Glossary of terms

In this subclass, the following terms or expressions are used with the meaning indicated:

Aging (or ageing)

A process in which the hardness or strength of a metal alloy having a constituent in supersaturated solid solution is increased over time as the constituent precipitates out as a secondary phase containing the constituent. When occurring at room temperature the process is termed "natural aging", while a process that occurs when subjecting the metal alloy to elevated temperature is termed "artificial aging". Aging for a longer time than that corresponding to maximum strength or hardness at the particular temperature is termed "over-ageing".

Alloy

A composition of plural elements at least one of which is a free metal. Also includes material containing any combination of fibres, filaments, whiskers and particles, e.g. carbides, diamond, oxides, borides, nitrides or silicides, or other metal compounds, e.g. oxynitrides or sulfides, embedded in a metallic matrix.

Hardening

The increase in resistance to deformation.

Normalizing

A process of heating metallic material above its critical temperature and cooling in air thereby establishing a fine uniform grain size and improving the micro-structural uniformity.

Quenching

The rapid cooling of metallic material either from elevated temperature to room temperature or cooling of metal to sub-ambient temperature.

Tempering

Involves the heating of a previously quenched or normalized metallic material to an elevated temperature, and then cooling under suitable conditions to obtain the desired mechanical properties.

Synonyms and Keywords

The term "aging" (or "ageing") is also termed precipitation hardening or strengthening.