C21D

MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS

GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS

MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B

In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme.

C21D1/00

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

C21D1/02

Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation

C21D1/04

with simultaneous application of supersonic waves, magnetic or electric fields

C21D1/06

Surface hardening

C21D1/08

with flames

C21D1/09

by direct application of electrical or wave energy

by particle radiation

C21D1/10

by electric induction

C21D1/18

Hardening C21D1/02 takes precedence

Quenching with or without subsequent tempering quenching devices C21D1/62

C21D1/185

from an intercritical temperature

C21D1/19

by interrupted quenching

C21D1/20

Isothermal quenching, e.g. bainitic hardening

C21D1/22

Martempering

C21D1/25

Hardening, combined with annealing between 300 degrees Celsius and 600 degrees Celsius, i.e. heat refining ("Vergüten")

C21D1/26

Methods of annealing

C21D1/28

Normalising

C21D1/30

Stress-relieving

C21D1/32

Soft annealing, e.g. spheroidising

C21D1/34

Methods of heating C21D1/06 takes precedence

C21D1/38

Heating by cathodic discharges

C21D1/40

Direct resistance heating

C21D1/42

Induction heating

C21D1/44

in heat-treatment baths

C21D1/46

Salt baths

C21D1/48

Metal baths

C21D1/50

Oil baths

C21D1/52

with flames

C21D1/53

Heating in fluidised beds

C21D1/54

Determining when the hardening temperature has been reached by measurement of magnetic or electrical properties

C21D1/55

Hardenability tests, e.g. end-quench tests

C21D1/56

characterised by the quenching agents

C21D1/58

Oils

C21D1/60

Aqueous agents

C21D1/607

Molten salts

C21D1/613

Gases

Liquefied or solidified normally gaseous material

C21D1/62

Quenching devices

C21D1/63

for bath quenching

C21D1/64

with circulating liquids

C21D1/667

for spray quenching

C21D1/673

for die quenching

C21D1/68

Temporary coatings or embedding materials applied before or during heat treatment

C21D1/70

while heating or quenching

C21D1/72

during chemical change of surfaces

C21D1/74

Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material

C21D1/76

Adjusting the composition of the atmosphere

C21D1/763

using a catalyst

C21D1/767

with forced gas circulation

Reheating thereof

C21D1/773

under reduced pressure or vacuum

C21D1/78

Combined heat-treatments not provided for above

C21D1/785

Thermocycling

C21D1/82

Descaling by thermal stresses mechanically B21, B23; chemically C23; electrolytically C25F1/00

C21D1/84

Controlled slow cooling cooling-beds for metal rolling B21B43/00

C21D3/00

Diffusion processes for extraction of non-metals

Furnaces therefor local protective coatings C21D1/72

C21D3/02

Extraction of non-metals

C21D3/04

Decarburising

C21D3/06

Extraction of hydrogen

C21D3/08

Extraction of nitrogen

C21D3/10

Furnaces therefor

C21D5/00

Heat treatments of cast-iron

C21D5/02

improving the malleability of grey cast-iron

C21D5/04

of white cast-iron

C21D5/06

Malleabilising

C21D5/08

with oxidation of carbon

C21D5/10

in gaseous agents

C21D5/12

in solid agents

C21D5/14

Graphitising

C21D5/16

Packing agents

C21D6/00

Heat treatment of ferrous alloys

C21D6/001

containing Ni C21D6/004 takes precedence

C21D6/002

containing Cr C21D6/004 takes precedence

C21D6/004

containing Cr and Ni

C21D6/005

containing Mn

C21D6/007

containing Co

C21D6/008

containing Si

C21D6/02

Hardening by precipitation

C21D6/04

Hardening by cooling below 0 degrees Celsius

C21D7/00

Modifying the physical properties of iron or steel by deformation apparatus for mechanical working of metal B21, B23, B24

C21D7/02

by cold working

C21D7/04

of the surface

C21D7/06

by shot-peening or the like

C21D7/08

by burnishing or the like

C21D7/10

of the whole cross-section, e.g. of concrete reinforcing bars

C21D7/105

of concrete reinforcing bars

C21D7/12

by expanding tubular bodies

C21D7/13

by hot working

C21D8/00

Modifying the physical properties by deformation combined with, or followed by, heat treatment hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02

C21D8/005

of ferrous alloys C21D8/02 - C21D8/12 take precedence

C21D8/02

during manufacturing of plates or strips C21D8/12 takes precedence

In this group classification is made according to the most important feature in one subgroup only; for other features indexing codes of C21D are added

C21D8/0205

of ferrous alloys

C21D8/021

involving a particular fabrication or treatment of ingot or slab

C21D8/0215

Rapid solidification; Thin strip casting

C21D8/0221

characterised by the working steps

C21D8/0226

Hot rolling

C21D8/0231

Warm rolling

C21D8/0236

Cold rolling

C21D8/0242

Flattening; Dressing; Flexing

C21D8/0247

characterised by the heat treatment

C21D8/0252

with application of tension

C21D8/0257

with diffusion of elements, e.g. decarburising, nitriding

C21D8/0263

following hot rolling

C21D8/0268

between cold rolling steps

C21D8/0273

Final recrystallisation annealing

C21D8/0278

involving a particular surface treatment C21D8/0294 takes precedence

C21D8/0284

Application of a separating or insulating coating

C21D8/0289

Application of a tension-inducing coating

C21D8/0294

involving a localised treatment

C21D8/04

to produce plates or strips for deep-drawing

In this group classification is made according to the most important feature in one subgroup only; for other features indexing codes of C21D are added

C21D8/0405

of ferrous alloys

C21D8/041

involving a particular fabrication or treatment of ingot or slab

C21D8/0415

Rapid solidification; Thin strip casting

C21D8/0421

characterised by the working steps

C21D8/0426

Hot rolling

C21D8/0431

Warm rolling

C21D8/0436

Cold rolling

C21D8/0442

Flattening; Dressing; Flexing

C21D8/0447

characterised by the heat treatment

C21D8/0452

with application of tension

C21D8/0457

with diffusion of elements, e.g. decarburising, nitriding

C21D8/0463

following hot rolling

C21D8/0468

between cold rolling steps

C21D8/0473

Final recrystallisation annealing

C21D8/0478

involving a particular surface treatment C21D8/0494 takes precedence

C21D8/0484

Application of a separating or insulating coating

C21D8/0489

Application of a tension-inducing coating

C21D8/0494

involving a localised treatment

C21D8/06

during manufacturing of rods or wires

C21D8/065

of ferrous alloys

C21D8/08

for concrete reinforcement

C21D8/10

during manufacturing of tubular bodies

C21D8/105

of ferrous alloys

C21D8/12

during manufacturing of articles with special electromagnetic properties

In this group classification is made according to the most important feature in one subgroup only; for other features indexing codes of C21D are added

C21D8/1205

involving a particular fabrication or treatment of ingot or slab

C21D8/1211

Rapid solidification; Thin strip casting

C21D8/1216

the working step(s) being of interest

C21D8/1222

Hot rolling

C21D8/1227

Warm rolling

C21D8/1233

Cold rolling

C21D8/1238

Flattening; Dressing; Flexing

C21D8/1244

the heat treatment(s) being of interest

C21D8/125

with application of tension

C21D8/1255

with diffusion of elements, e.g. decarburising, nitriding

C21D8/1261

following hot rolling

C21D8/1266

between cold rolling steps

C21D8/1272

Final recrystallisation annealing

C21D8/1277

involving a particular surface treatment C21D8/1294 takes precedence

C21D8/1283

Application of a separating or insulating coating

C21D8/1288

Application of a tension-inducing coating

C21D8/1294

involving a localized treatment

C21D9/00

Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles

Furnaces therefor

C21D9/0006

Details, accessories not peculiar to any of the following furnaces control devices C21D11/00

C21D9/0012

Rolls; Roll arrangements

C21D9/0018

for charging, discharging or manipulation of charge

C21D9/0025

Supports; Baskets; Containers; Covers

C21D9/0031

Rotary furnaces with horizontal or slightly inclined axis

C21D9/0037

Rotary furnaces with vertical axis; Furnaces with rotating floor

C21D9/0043

Muffle furnaces; Retort furnaces

C21D9/005

Furnaces in which the charge is moving up or down for wire, strip C21D9/54

C21D9/0056

Furnaces through which the charge is moved in a horizontal straight path C21D9/0043 takes precedence

C21D9/0062

Heat-treating apparatus with a cooling or quenching zone

C21D9/0068

for particular articles not mentioned below

C21D9/0075

for rods of limited length of unlimited length C21D9/52

C21D9/0081

for slabs; for billets

C21D9/0087

for chains, for chain links

C21D9/0093

for screws; for bolts

C21D9/02

for springs

C21D9/04

for rails

C21D9/06

with diminished tendency to become wavy

C21D9/08

for tubular bodies or pipes

C21D9/085

Cooling or quenching

C21D9/10

shotgun barrels

C21D9/12

barrels for ordnance

C21D9/14

wear-resistant or pressure-resistant pipes

C21D9/16

for explosive shells

C21D9/18

for knives, scythes, scissors, or like hand cutting tools

C21D9/20

for blades for skates

C21D9/22

for drills

for milling cutters

for machine cutting tools

C21D9/24

for saw blades

C21D9/26

for needles

for teeth for card-clothing

C21D9/28

for plain shafts

C21D9/30

for crankshafts

for camshafts

C21D9/32

for gear wheels, worm wheels, or the like

C21D9/34

for tyres

for rims

C21D9/36

for balls

for rollers

C21D9/38

for roll bodies

C21D9/40

for rings

for bearing races

C21D9/42

for armour plate

C21D9/44

for equipment for lining mine shafts, e.g. segments, rings or props

C21D9/46

for sheet metals

C21D9/48

deep-drawing sheets

C21D9/50

for welded joints

C21D9/505

Cooling thereof

C21D9/52

for wires

for strips

; for rods of unlimited length

C21D9/525

for wire, for rods C21D9/54 takes precedence

C21D9/54

Furnaces for treating strips or wire

C21D9/56

Continuous furnaces for strip or wire

C21D9/561

with a controlled atmosphere or vacuum

C21D9/562

Details

C21D9/563

Rolls; Drums; Roll arrangements

C21D9/564

Tension control

C21D9/565

Sealing arrangements

C21D9/567

with heating in fluidised beds

C21D9/573

with cooling

C21D9/5732

of wires; of rods

C21D9/5735

Details

C21D9/5737

Rolls; Drums; Roll arrangements

C21D9/58

with heating by baths

C21D9/60

with induction heating

C21D9/62

with direct resistance heating

C21D9/63

the strip being supported by a cushion of gas

C21D9/64

Patenting furnaces

C21D9/66

Tower-type furnaces

C21D9/663

Bell-type furnaces

C21D9/665

inverted or side-facing

C21D9/667

Multi-station furnaces

C21D9/67

adapted for treating the charge in vacuum or special atmosphere

C21D9/673

Details, accessories, or equipment peculiar to bell-type furnaces

C21D9/675

Arrangements of charging or discharging devices

C21D9/677

Arrangements of heating devices

C21D9/68

Furnace coilers

Hot coilers cold coilers B21C47/00

C21D9/70

Furnaces for ingots, i.e. soaking pits

C21D10/00

Modifying the physical properties by methods other than heat treatment or deformation

C21D10/005

by laser shock processing

C21D11/00

Process control or regulation for heat treatments

C21D11/005

for cooling

C21D2201/00

Treatment for obtaining particular effects

C21D2201/01

Shape memory effect

C21D2201/02

Superplasticity

C21D2201/03

Amorphous or microcrystalline structure

C21D2201/04

Single or very large crystals

C21D2201/05

Grain orientation

C21D2211/00

Microstructure comprising significant phases

C21D2211/001

Austenite

C21D2211/002

Bainite

C21D2211/003

Cementite

C21D2211/004

Dispersions

Precipitations

C21D2211/005

Ferrite

C21D2211/006

Graphite

C21D2211/007

Ledeburite

C21D2211/008

Martensite

C21D2211/009

Pearlite

C21D2221/00

Treating localised areas of an article

C21D2221/01

End parts (e.g. leading, trailing end)

C21D2221/02

Edge parts

C21D2221/10

Differential treatment of inner with respect to outer regions, e.g. core and periphery, respectively

C21D2241/00

Treatments in a special environment

C21D2241/01

under pressure

C21D2241/02

Hot isostatic pressing

C21D2241/03

in zero gravity (e.g. in space)

C21D2251/00

Treating composite or clad material

C21D2251/02

Clad material

C21D2251/04

Welded or brazed overlays

C21D2261/00

Machining or cutting being involved

C21D2281/00

Making use of special physico-chemical means

C21D2281/01

Seed crystals being used

C21D2281/02

temperature gradient