|  | C |
SECTION C — CHEMISTRY AND METALLURGY

METALLURGY

|  | C21 |
METALLURGY OF IRON

|  | C21D |
HARDENING AND ANNEALING OF STEEL, IRON, OR ARTICLES MADE THEREFROM; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING MALLEABLE BY DECARBURISATION, TEMPERING, OR OTHER TREATMENTS (cementation by diffusion processes Fulltext... Hierarchy... Expanded...C23C)

|  | C21D 1/00 |
General methods or devices for heat treatments, e.g. annealing, hardening, quenching, tempering

|  | C21D 1/02 |
· | Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation

|  | C21D 1/04 |
· | with simultaneous application of supersonic waves, magnetic or electric fields

|  | C21D 1/06 |
· | Surface hardening by heating

|  | C21D 1/08 |
· · | with flames

|  | C21D 1/10 |
· · | by electric induction

|  | C21D 1/12 |
· · | Apparatus therefor

|  | C21D 1/18 |
· | Tempering

|  | C21D 1/20 |
· · | Bainitic hardening

|  | C21D 1/22 |
· · | Martempering

|  | C21D 1/24 |
· · | Low tempering

|  | C21D 1/26 |
· | Methods of annealing

|  | C21D 1/28 |
· · | Normalising

|  | C21D 1/30 |
· · | Stress-relieving

|  | C21D 1/32 |
· · | Soft annealing

|  | C21D 1/34 |
· | Methods of heating (Fulltext... Hierarchy... Expanded...C21D 1/06 takes precedence)

|  | C21D 1/38 |
· · | Heating by cathodic discharges

|  | C21D 1/40 |
· · | Direct resistance heating

|  | C21D 1/42 |
· · | Induction heating

|  | C21D 1/44 |
· · | in heat-treatment baths

|  | C21D 1/46 |
· · · | Salt baths

|  | C21D 1/48 |
· · · | Metal baths

|  | C21D 1/50 |
· · · | Oil baths

|  | C21D 1/52 |
· · | with flames

|  | C21D 1/54 |
· | Determining when the hardening temperature has been reached by measurement of magnetic or electrical properties

|  | C21D 1/56 |
· | with special quenching agents

|  | C21D 1/58 |
· · | oils

|  | C21D 1/60 |
· · | aqueous agents

|  | C21D 1/62 |
· | Quenching devices

|  | C21D 1/64 |
· · | with circulating liquids (in general Fulltext... Hierarchy... Expanded...F28D)

|  | C21D 1/66 |
· · | combined with induction heating

|  | C21D 1/68 |
· | Protective coatings for locally preventing heat-treatment

|  | C21D 1/70 |
· · | whilst heating and quenching

|  | C21D 1/72 |
· · | during chemical change of surfaces

|  | C21D 1/74 |
· | Methods of treatment in inert gas, controlled atmosphere, vacuum, or pulverulent material (production of gases Fulltext... Hierarchy... Expanded...C01, Fulltext... Hierarchy... Expanded...C10)

|  | C21D 1/76 |
· · | Adjusting the composition of the atmosphere

|  | C21D 1/78 |
· | Combined heat-treatments not previously covered, to produce special technological properties

|  | C21D 1/80 |
· · | Hardening, combined with annealing between 300° and 600°C, i.e. heat refining (Vergüten)

|  | C21D 1/82 |
· | Descaling by thermal stresses (mechanically Fulltext... Hierarchy... Expanded...B21, Fulltext... Hierarchy... Expanded...B23; chemically Fulltext... Hierarchy... Expanded...C23)

|  | C21D 3/00 |
Diffusion processes for extraction of non-metals; Furnaces therefor (local protective coatings Fulltext... Hierarchy... Expanded...C21D 1/72; furnaces in general Fulltext... Hierarchy... Expanded...F27)

|  | C21D 3/02 |
· | Extraction of non-metals

|  | C21D 3/04 |
· · | Decarburising

|  | C21D 3/06 |
· · | Extraction of hydrogen

|  | C21D 3/08 |
· · | Extraction of nitrogen

|  | C21D 3/10 |
· | Furnaces therefor

|  | C21D 5/00 |
Heat treatments of cast-iron

|  | C21D 5/02 |
· | improving the malleability of grey cast-iron

|  | C21D 5/04 |
· | of white cast-iron

|  | C21D 5/06 |
· · | Malleabilising

|  | C21D 5/08 |
· · · | with oxidation of carbon

|  | C21D 5/10 |
· · · · | in gaseous agents

|  | C21D 5/12 |
· · · · | in solid agents

|  | C21D 5/14 |
· · · | Graphitising

|  | C21D 5/16 |
· · · · | Packing agents

|  | C21D 7/00 |
Modifying the physical properties of iron or steel by deformation (apparatus for mechanical working of metal Fulltext... Hierarchy... Expanded...B21, Fulltext... Hierarchy... Expanded...B23, Fulltext... Hierarchy... Expanded...B24, e.g. shot-peening Fulltext... Hierarchy... Expanded...B24C)

|  | C21D 7/02 |
· | by cold working

|  | C21D 7/04 |
· · | of the surface

|  | C21D 7/06 |
· · · | by shot-peening or the like

|  | C21D 7/08 |
· · · | by burnishing or the like

|  | C21D 7/10 |
· · | of the whole cross-section, e.g. of concrete reinforcing bars

|  | C21D 7/12 |
· · · | by expanding tubular bodies

|  | C21D 7/13 |
· | by hot working

|  | C21D 7/14 |
· · | by hot working combined with a heat treatment (treating with no heat other than that of shaping Fulltext... Hierarchy... Expanded...C21D 1/02; hot working methods in general Fulltext... Hierarchy... Expanded...B21)

|  | C21D 9/00 |
Heat treatment, e.g. annealing, hardening, quenching, tempering, adapted for particular articles; Furnaces therefor (furnaces in general Fulltext... Hierarchy... Expanded...F27)

|  | C21D 9/02 |
· | for springs

|  | C21D 9/04 |
· | for rails (apparatus for heat treatment of railway rails on the spot Fulltext... Hierarchy... Expanded...E01B 31/18)

|  | C21D 9/06 |
· · | with diminished tendency to become wavy

|  | C21D 9/08 |
· | for tubular bodies or pipes

|  | C21D 9/10 |
· · | shotgun barrels

|  | C21D 9/12 |
· · | barrels for ordnance

|  | C21D 9/14 |
· · | wear- or pressure-resistant pipes

|  | C21D 9/16 |
· | for explosive shells

|  | C21D 9/18 |
· | for knives, scythes, scissors, or like hand cutting tools

|  | C21D 9/20 |
· | for blades for skates

|  | C21D 9/22 |
· | for drills; for milling cutters; for machine cutting tools

|  | C21D 9/24 |
· | for saw blades

|  | C21D 9/26 |
· | for needles; for teeth for card-clothing

|  | C21D 9/28 |
· | for plain shafts

|  | C21D 9/30 |
· | for crankshafts; for camshafts

|  | C21D 9/32 |
· | for gear wheels, worm wheels, or the like

|  | C21D 9/34 |
· | for tyres; for rims

|  | C21D 9/36 |
· | for balls; for rollers

|  | C21D 9/38 |
· | for roll bodies

|  | C21D 9/40 |
· | for rings; for bearing races

|  | C21D 9/42 |
· | for armour plate

|  | C21D 9/44 |
· | for equipment for lining mine shafts, e.g. segments, rings, props

|  | C21D 9/46 |
· | for sheet metals

|  | C21D 9/48 |
· · | deep-drawing sheets

|  | C21D 9/50 |
· | for welded joints

|  | C21D 9/52 |
· | for wires; for strips

|  | C21D 9/54 |
· · | Furnaces for treating strips or wire

|  | C21D 9/56 |
· · · | Continuous furnaces for strip or wire

|  | C21D 9/58 |
· · · · | with heating by baths

|  | C21D 9/60 |
· · · · | with induction heating

|  | C21D 9/62 |
· · · · | with direct resistance heating

|  | C21D 9/64 |
· · · | Patenting furnaces

|  | C21D 9/66 |
· · · | Tower-type furnaces

|  | C21D 9/68 |
· · · | Furnace coilers; Hot coilers (cold coilers Fulltext... Hierarchy... Expanded...B21C)

|  | C21D 9/70 |
· | Furnaces for ingots, i.e. soaking pits