Ferrous and non-ferrous alloys, radioactive alloys, amorphous alloys or alloys containing fibres or filaments.

It also covers cermet, master alloys, metal matrix composites, methods of making amorphous alloys, as well as methods of making alloys by melting, by powder metallurgy or by removing material from alloys to produce alloys of different constitution.

Therefore, the term "alloys" includes:

a) metallic composite materials containing a substantial proportion of fibres or other somewhat larger particles; and

b) ceramic compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides or silicides, e.g. cermet or other metal compounds, e.g. oxynitrides or sulfides, other than as macroscopic reinforcing agents.

When the alloy is produced by a specifically described method (in examples or in claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use/product, then the use or product is classified as well (see informative references for some of them).

In the subclass of B22F, combination sets (C-Sets) are used. Detailed information about C-Sets construction and the associated syntax rules is found in the definitions for B22F.

The phrase "based on" means, in general, at least 50% by weight of the specified constituent or of the specified group of constituents.

The base of the alloy, in a broader sense, is interpreted as the metallic element which is the major constituent of the alloy, whether the content of that element is more or less than 50 wt%. For example: an alloy with Ni: 40 wt%, Fe: 30 wt%, Co: 30 wt%; its base is Ni.

It is possible for an alloy to have more than one base major constituent.

When the alloy contains less than 50 wt% of each constituent, i.e. alloy with more than one base, then, in addition to the subclass C22C corresponding to the major constituent(s), at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

In C22C 5/00 - C22C 30/00 and C22C 37/00 - C22C 45/00, these groups are given for both inventive and additionally disclosed alloys, whether in the claims, description, figures or inventive examples.

The compositions of amorphous alloys are classified in group C22C 45/00.

The methods of making Fe-based amorphous alloys are classified in group C22C 33/003.

The methods of making amorphous alloys (other than Fe-based ones) are classified in group C22C 1/11.

Semi-amorphous alloys are classified both as amorphous and as crystalline ones (groups C22C 45/00 and C22C 5/00 - C22C 38/00).

The compositions of cast-iron alloys are classified in group C22C 37/00.

The methods of making cast-iron alloys are classified in groups C22C 33/08 - C22C 33/12.

Alloys based on a metal not provided for in the groups C22C 5/00 - C22C 45/10, e.g. Ga-based, In-based alloys, are classified in group C22C 28/00.

In the groups C22C 5/00 - C22C 30/00 and C22C 37/00 - C22C 45/00, the principle of multiple classification is applied, for a classification of a 100% disclosed alloy composition.

Metal compounds include:

Note: a silicide, selenide or telluride is not considered as an intermetallic even though much scientific literature designates them as such.

Methods for making non-ferrous alloys.

When the alloy is produced by a specifically disclosed process, then the process is also classified, e.g. in subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B, B21C.

Methods of making alloys containing metallic or non-metallic fibres or filaments are classified in group C22C 47/00.

Non-ferrous alloys made by powder metallurgy containing only metallic or intermetallic constituents.

Subclass B22F covers processes of making or treating metallic powders, working metallic powders, and making workpieces or articles therefrom.

The alloys are classified according to their main component in one of the subgroups C22C 1/0408 - C22C 1/0483:

Making non-ferrous alloys by using mixtures of metal powder with non-metallic powder as starting materials. Non-metallic powders include hard compounds, graphene, sulfides, organic materials, etc.

When specific processes or process steps of powder metallurgy are not covered by any of the subgroups of group C22C 1/05 and covered by subclass B22F, classification should be made in both parent group C22C 1/05 and in the relevant groups of subclass B22F, in order not to lose potentially relevant information.

Hard compounds that are generated in situ in the matrix by reaction during the preparation process.

In situ formation of hard compounds by reacting with carbon during the preparation process.

In situ formation of hard compounds by reacting with gas during the preparation process.

In situ formation of a second phase, e.g. metal phase, other than hard compounds by solid state reaction sintering during the preparation process.

Preparation of alloys based on metals and containing less than 5% by weight of dispersed reinforcing phases.

Porous products obtained by processes involving a molten metal bath.

Processes for making alloys containing metal or non-metallic compounds wherein the metal is the major constituent. The processes cover both wet and dry processes as well as pre-treatments of the added compounds and after-treatments.

Spray casting composite powder, including fibres : C22C 1/1042

When a filler material can only be of a fibrous nature, classification is made in group C22C 47/00, C22C 49/00. When the filler material is chosen from alternatives which can be fibrous or non-fibrous, classification is made in group C22C 1/10. When both fibrous and non-fibrous fillers are present, classification is made in group C22C 47/00, C22C 49/00 and also in group C22C 32/00 if the composition is of importance.

When the composition of a product is expressed in ranges and is the basis of the invention or when specific examples are given in the description, the composition, respectively the examples, should also be classified in the database Alloys. When the composition is expressed in general terms or is not the basis of the invention, the composition is indexed by deep-indexing according to the scheme of B22F and in accordance with the rules presented in the annex.

methods of separation of constituents of alloys such as purification, recovery, removing of undesirable material(s) etc.

In these groups, the last place rule is followed combined with multiple classifications.

Noble metal alloys, i.e. where the noble metal (Ag, Au, platinum group) is the major constituent.

When the alloy is produced by a specifically described method (in examples or claims), then the method is classified as well (subclasses C22F, C23C, C23D, B23K, C25B, B22D, C25D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of noble metals, and alloys based thereon, is classified in group C22F 1/14.

In groups C22C 5/06 - C22C 5/10, the principle of multiple classification is applied.

For example: a silver alloy with Cu as the next major constituent is classified in group C22C 5/08.

When the alloy contains less than 50 wt% of each constituent, with a noble metal being a major constituent, then, in addition to the corresponding group under C22C 5/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

For example: for an alloy with 45 - 55 wt% Au, 35 - 45 wt% Cu and the rest is other metallic constituents, both groups C22C 5/02 and C22C 30/02 are given.

Mercury alloys, i.e. where Hg is the major constituent.

When the alloy is produced by a specifically described method (in examples or in claims), then the method is classified as well (subclasses C22F, C23C, C23D, B23K, C25B, B22D, C25D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of non-ferrous, and alloys based thereon, is classified in group C22F 1/16.

When the alloy contains less than 50 wt% of each constituent, with Hg being a major constituent, then, in addition to the corresponding group under C22C 7/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Copper alloys, i.e. where Cu is the major constituent.

When the alloy is produced by a specifically described method (in examples or in claims), then the method is classified as well (subclasses C22F, C23C, C23D, B23K, C25B, B22D, C25D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of copper, or alloys based thereon, is classified in group C22F 1/08.

In these groups, the principle of multiple classification is applied.

Depending on the next major constituent to Cu, the corresponding group under C22C 9/00 is/are given.

For example: a Cu alloy consisting of 30 wt% Sn, 30 wt% Zn, the balance being Cu, both groups C22C 9/02 and C22C 9/04 are given.

When the alloy contains less than 50 wt% of each constituent, with Cu being a major constituent, then, in addition to the corresponding group under C22C 9/00, group C22C 30/02 is given, and, depending on the remaining main alloying elements, C22C 30/00 and/or C22C 30/04 and/or C22C 30/06 may also be given.

Lead alloys, i.e. where Pb is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of lead, or alloys based thereon, is classified in group C22F 1/12.

In C22C 11/08 - C22C 11/10, the principle of multiple classification is applied.

A lead alloy with Bi as the next major constituent and comprising Sn is classified in group C22C 11/10.

For example: a Pb alloy consisting of 25 wt% Cu, 25 wt% Sn, the balance being Pb, both groups C22C 11/04 and C22C 11/06 are given.

When the alloy contains less than 50 wt% of each constituent, with Pb being a major constituent, then, in addition to the corresponding group under C22C 11/00, group C22C 30/04 is given, and, depending on the rest of the main alloying elements, groups C22C 30/00 and/or C22C 30/02 and/or C22C 30/06 may also be given.

Antimony or bismuth alloys, i.e. where Sb or Bi is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of antimony, bismuth, or alloys based thereon, is classified in group C22F 1/16.

When the alloy is intended for a particular use/product then the use/ product is classified as well.

When the alloy contains less than 50 wt% of each constituent, with Sb or Bi being a major constituent, then, in addition to the corresponding group under C22C 12/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Tin alloys, i.e. where Sn is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of tin, or alloys based thereon, is classified in group C22F 1/16.

In these groups, the principle of multiple classification is applied.

A tin alloy with Bi as the next major constituent is classified in group C22C 13/02 (last place rule).

For example: a Sn alloy consisting of 25 wt% Bi, 25 wt% Zn, the balance being Sn; both groups C22C 13/00 and C22C 13/02 are given.

When the alloy contains less than 50 wt% of each constituent, with Sn being a major constituent, then, in addition to the corresponding group under C22C 13/00, group C22C 30/04 is given, and, depending on the rest of the main alloying elements, groups C22C 30/00 and/or C22C 30/02 and/or C22C 30/06 may also be given.

Titanium alloys, i.e. where Ti is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of titanium, or alloys based thereon, is classified in group C22F 1/183.

When the alloy contains less than 50 wt% of each constituent, with Ti being a major constituent, then, in addition to the corresponding group in C22C 14/00, at least one group under C22C 30/00 is given depending on the rest of the main alloying element(s).

Zirconium alloys, i.e. where Zr is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use/product, then the use/product is classified as well.

Changing the physical structure of zirconium, or alloys based thereon, is classified in group C22F 1/186.

When the alloy contains less than 50 wt% of each constituent, with Zr being a major constituent, then, in addition to the corresponding group under C22C 16/00, at least one group under C22C 30/00 is given depending on the rest of the main alloying element(s).

Zinc alloys, i.e. where Zn is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of zinc or cadmium, or alloys based thereon, is classified in group C22F 1/165.

In these groups, the principle of multiple classification is applied.

For example: a Zn alloy consisting of 20 wt% Cu, 20 wt% Al, the balance being Zn; both groups C22C 18/02 and C22C 18/04 are given.

When the alloy contains less than 50 wt% of each constituent, with Zn being a major constituent, then, in addition to the corresponding group under C22C 18/00, group C22C 30/06 is given, and, depending on the rest of the main alloying elements, groups C22C 30/00 and/or C22C 30/02 and/or C22C 30/04 may also be given.

Nickel or cobalt alloys, i.e. where Ni or Co is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use/product, then the use/product is classified as well.

Changing the physical structure of nickel, cobalt, or alloys based thereon, is classified in group C22F 1/10.

In these groups, the principle of multiple classification is applied.

In groups C22C 19/05 - C22C 19/058, multiple symbols may be given for Ni-based alloys depending on the Cr content and the presence of Mo, W in it.

For example: a nickel alloy with 8 - 32 wt% Cr comprising also Mo is classified in groups C22C 19/057, C22C 19/056, C22C 19/055 and C22C 19/053. Depending on the composition, groups C22C 19/002 - C22C 19/007 may also be given.

Cobalt alloys are classified in group C22C 19/07. Depending on the composition, groups C22C 19/002 - C22C 19/007 may also be given.

When the alloy contains less than 50 wt% of each constituent, with Ni or cobalt being a major constituent, then, in addition to the corresponding group under C22C 19/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Cadmium alloys, i.e. where Cd is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of cadmium, or alloys based thereon, is classified in group C22F 1/165.

When the alloy contains less than 50 wt% of each constituent, with Cd being a major constituent, then, in addition to the corresponding group under C22C 20/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

In an alloy consisting of 40 - 50 wt% Cd, 40 - 50 wt% Pb and the rest other metallic constituents, the corresponding groups under C22C 20/00 and C22C 30/00 are given. At least one group is also given in C22C 11/00 for the lead-base alloy.

Aluminium alloys, i.e. where Al is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of aluminium, or alloys based thereon, is classified in groups C22F 1/04 - C22F 1/057.

In these groups, the principle of multiple classification is applied.

Depending on the next major constituent to Al, the corresponding group under C22C 21/00 is given. In the case of more than one next major constituent(s), then at least one group under C22C 21/00 is given.

An Al-alloy with Cu as the next major constituent comprising Si, Mg and Zn as additional alloying elements is classified in groups C22C 21/14, C22C 21/16 and C22C 21/18.

When the alloy contains less than 50 wt% of each constituent, with Al being a major constituent, then, in addition to the corresponding group under C22C 21/00, at least one group under C22C 30/00 is also given depending on the remaining main alloying elements.

Manganese alloys, i.e. where Mn is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of manganese, or alloys based thereon, is classified in group C22F 1/16.

When the alloy contains less than 50 wt% of each constituent, with Mn being a major constituent, then, in addition to the corresponding group under C22C 22/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Magnesium alloys, i.e. where Mg is the major constituent, i.e. the base of the alloy.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of manganese, or alloys based thereon, is classified in group C22F 1/06.

In these groups, the principle of multiple classification is applied.

Depending on the next major constituent to Mg, the corresponding group under C22C 23/00 is given. In a case of more than one next major constituent(s), then multiple groups under C22C 23/00 are given.

For example: a Mg alloy consisting of 20 wt% Zn, 20 wt% Al, the balance being Mg, both groups C22C 23/02 and C22C 23/04 are given.

When the alloy contains less than 50 wt% of each constituent, with Mg being a major constituent, then, in addition to the corresponding group under C22C 23/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Alkali or alkaline earth metal alloys, i.e. where Li, Na, K, Rb, Cs, Fr, Ca, Sr, Ba or Ra is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of alkali, alkali-earth metals, or alloys based thereon, is classified in subclass C22F.

When the alloy contains less than 50 wt% of each constituent, with an alkali or alkaline earth metal being a major constituent, then, in addition to the corresponding group under C22C 24/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Beryllium alloys, i.e. where Be is the major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of beryllium, or alloys based thereon, is classified in group C22F 1/16.

When the alloy contains less than 50 wt% of each constituent, with Be being a major constituent, then, in addition to the corresponding group under C22C 25/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

In case there are other compounds present apart from the main compound, this additional information concerning the composition of the further compound will be given by an indexing code; fullerenes and carbon nanotubes are also indicated by means of an indexing code.

In case the composition is expressed in general terms or is not the basis of the invention, the composition is indexed with the orthogonal indexing codes of subclass B22F.

Rhenium or refractory metal alloys other than Ti or Zr based alloys, i.e. where Re, V, Cr, Nb, Mo, Hf, Ta or W is another major constituent.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of refractory metals, i.e. V, Cr, Nb, Mo, Hf, Ta, W, or alloys based thereon, is classified in group C22F 1/18.

In these groups, the principle of multiple classification is applied.

When the alloy contains less than 50 wt% of each constituent, with refractory metals, i.e. V, Cr, Nb, Mo, Hf, Ta and/or W being another major constituent, then, in addition to the corresponding group under C22C 27/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Alloys not otherwise provided for, such as alloys based on Ga, Ge, In or rare earth metals.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Changing the physical structure of non-ferrous metals and non-ferrous alloys is classified in subclass C22F.

When the alloy contains less than 50 wt% of each constituent, then, in addition to the corresponding group under C22C 28/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Alloys containing more than 50 wt% of carbides, oxides, nitrides, borides, oxynitrides or sulfides, i.e. cermet.

Depending on the composition of either the matrix or the main metallic or non-metallic compound, the composition is classified in one of the subgroups of C22C 29/00.

When the composition is expressed in general terms or is not the basis of the invention, the composition is indexed with the orthogonal indexing codes of subclass B22F.

Alloys of multiple bases, i.e. with more than one element as major constituents.

When the alloy is produced by a specifically described method (examples, claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

In these groups, the principle of multiple classification is applied.

Depending on whether the alloy contains Cu, Sn, Pb and/or Zn, the corresponding group under C22C 30/00 is given. When the alloy comprises more than one of Cu, Sn, Pb and/or Zn, then additional group(s) under C22C 30/00 is/are given.

For example: an alloy consisting of 40 wt% Cu, 40 wt% Sn and 20% Zn is classified in C22C 30/02, C22C 30/04 and C22C 30/06.

In addition to the corresponding group under C22C 30/00, other groups in C22C may also be given based on the specific embodiments.

Dispersion hardened alloys with less than 5wt% of dispersed compounds, e.g. ODS aluminium are also classified in this group.

Depending on the composition of the main metallic or non-metallic compound, the composition is classified in one of the subgroups of C22C 32/00.

Exception: ODS steels (including those containing less than 5wt% Oxide Dispersions) are classified in C22C 33/0261 when the oxide dispersions are the single non-metallic constituent.

All other ferrous alloys obtained by powder metallurgy and having metallic or non-metallic compounds therein are classified in C22C 33/0214 - C22C 33/0228 or C22C 33/0292.

When a filler material can only be of a fibrous nature, classification is made in groups C22C 47/00 and C22C 49/00. When the filler material is chosen from alternatives which can be fibrous or non-fibrous, classification is made in group C22C 1/10. When both fibrous and non-fibrous fillers are present, classification is made in groups C22C 47/00 and C22C 49/00 and also in group C22C 32/00 if the composition is of importance.

Methods of making ferrous alloys, cast irons, amorphous ferrous alloys not provided in any of subclasses C21D, C22B or C21B.

Use of master alloys for the production of ferrous alloys.

The compositions of the amorphous alloys are classified in group C22C 45/00.

The methods of making amorphous alloys (other than Fe-based ones) are classified in group C22C 1/11.

Methods of changing the physical structure of ferrous alloys are classified in subclass C21D.

The cast iron compositions are classified in group C22C 37/00.

Master alloy compositions are classified in group C22C 35/00.

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Iron or steel alloys containing metal or non-metallic compounds are classified as follows:

When the composition is expressed in general terms or is not the basis of the invention, the composition is indexed with the orthogonal indexing codes of subclass B22F.

Master alloys used for the production of iron or steel.

Ferrous alloys and steels are classified in group C22C 38/00.

The cast iron compositions are classified in group C22C 37/00.

Methods of changing the physical structure of ferrous alloys or metal alloys are classified in subclass C21D.

Making ferrous alloys by melting using master alloys is classified in group C22C 33/06.

Fe-based master alloys are classified in group C22C 35/005.

Cast iron alloy compositions.

Making cast iron alloys is classified in groups C22C 33/08 - C22C 33/12.

If the cast iron contains spheroidal or nodular graphite, then it is classified in group C22C 37/04.

In these groups, principle of multiple classification is applied.

Depending on whether the cast iron contains Cr, Al or Si, the corresponding groups under C22C 37/00 are given.

When a cast iron contains spheroidal graphite, as well as Cr, Ni and Si, additional groups C22C 37/04, C22C 37/08 and C22C 37/10 are given.

Iron-based alloys and all types of steels, such as low-alloy steels, dual-phase steels, tool steels, spring steels, maraging steels, stainless steels, ferritic, austenitic, martensitic, bainitic and pearlitic.

Cast iron compositions are classified in group C22C 37/00.

Fe-based amorphous alloys are classified in group C22C 45/02.

Methods of changing the physical structure of ferrous alloys are classified in subclass C21D.

When the alloy is produced by a specifically described method (in examples or in claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

In these groups, the principle of multiple classification is applied.

Ferrous alloys or steels containing Cr (and no Ni) are classified in groups C22C 38/18 - C22C 38/38. It is noted that, depending on the alloying elements present in the composition groups, C22C 1/11 - C22C 16/00 and C22C 38/60 may also be given in addition to one of the groups C22C 38/18 - C22C 38/38.

Ferrous alloys or steels containing Cr and Ni are classified in groups C22C 38/40 - C22C 38/58. It is noted that, depending on the alloying elements present in the composition groups, C22C 1/11 - C22C 16/00 and C22C 38/60 may also be given in addition to one of the groups C22C 38/40 - C22C 38/58.

Due to lack of an IPC entry, steels or ferrous alloys containing Cr with Ni with more than 1.5 wt% of Si are classified in C22C 38/34, i.e. using the class for steels or ferrous alloys containing Cr with more than 1.5 wt% of Si.

For example: a stainless steel consisting of by mass %, C: 0.03 - 0.12%, Si: 0.1 - 1%, Mn: 0.1 - 2%, Cr: 20% to 28%, Ni: 15 - 35%, W: 4 - 10%, Ti: 0.01 - 0.3%, Nb: 0.01 - 1%, sol. Al: 0.0005 - 0.04%, B: 0.0005 - 0.01%, REM: 0.0005 - 0.2%, and the balance Fe and impurities, is classified in groups C22C 38/02, C22C 38/04, C22C 38/58, C22C 38/44, C22C 38/50, C22C 38/48, C22C 38/005 and C22C 38/54.

When the ferrous alloy or steel contains Cr, whereas Ni is being optionally added, then if specific examples exist with Cr without Ni as well as with Cr and Ni, the composition is classified in both groups C22C 38/18 - C22C 38/38 and C22C 38/40 - C22C 38/58.

Group C22C 38/004 covers very low carbon steels, i.e. with carbon content less than 0.01 wt%, when: a) the carbon range discloses a specific low limit being less than 0.01 wt% or b) the examples disclose carbon contents less than 0.01 wt%. Specific disclosures such as C 0.0001 - 0.0050 wt% (or 1 - 50 ppm) are classified in group C22C 38/004. General disclosures, however, such as C 0 - 0.03 wt% not accompanied by specific carbon contents less than 0.01 wt%, are not classified in group C22C 38/004.

Group C22C 38/002 covers ferrous alloy or steel which contain elements for which no entry is provided in the groups C22C 38/001 and C22C 38/004 - C22C 38/60, such as P, In, Mg and precious metals.

When the alloy contains less than 50 wt% of each constituent, with Fe being a major constituent, then, in addition to the corresponding group under C22C 38/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Alloys which are radioactive or contain an element with radioactive isotopes, e.g. uranium, promethium and technetium.

When the alloy is produced by a specifically described method (in examples or in claims), then the method is classified as well (subclasses C22F, C21D, B22F, C23C, B23K, C25D, C25B, B22D, B21J, B21B or B21C).

When the alloy is intended for a particular use or product, then the use or product is classified as well.

When the alloy contains less than 50 wt% of each constituent, then, in addition to the corresponding group under C22C 43/00, at least one group under C22C 30/00 is also given depending on the rest of the main alloying elements.

Amorphous alloys and metallic glasses.

The methods of making Fe-based amorphous alloys are classified in group C22C 33/003.

Semi-amorphous alloys are classified both as amorphous and as crystalline ones having corresponding groups under C22C 45/00 and C22C 5/00 - C22C 38/00.

When the alloy is intended for a particular use or product, then the use or product is classified as well.

Depending on the major constituent, i.e. the base of the alloy, the corresponding group under C22C 45/00 is given.

Fe-based amorphous alloys are classified in group C22C 45/02.

Ni- or Co-based amorphous alloys are classified in group C22C 45/04.

Amorphous alloys with a major constituent which is not disclosed in any of groups C22C 45/001 - C22C 45/10 are classified in the group C22C 45/00.