|  | C |
SECTION C — CHEMISTRY AND METALLURGY

|  | C |
Note(s) Definitions for Section C: Alkali metals: Li, Na, K, Rb, Cs, Fr Alkaline earth metals: Ca, Sr, Ba, Ra Lanthanides: elements with atomic numbers 57 to 71 inclusive Rare earths: Sc, Y, Lanthanides Actinides: elements with atomic numbers 89 to 103 inclusive Refractory metals: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W Halogens: F, Cl, Br, I, At Noble gases: He, Ne, Ar, Kr, Xe, Rn Platinum group: Os, Ir, Pt, Ru, Rh, Pd Noble metals: Ag, Au, Platinum group Light metals: alkali metals, alkaline earth metals, Be, Al, Mg Heavy metals: metals other than light metals Iron group: Fe, Co, Ni Non-metals: H, B, C, Si, N, P, O, S, Se, Te, noble gases, halogens Metals: elements other than non-metals Transition elements: elements with atomic numbers 21 to 30 inclusive, 39 to 48 inclusive, 57 to 80 inclusive, 89 upwards

METALLURGY

|  | C21 |
METALLURGY OF IRON

|  | C21B |
MANUFACTURE OF IRON OR STEEL (preliminary treatment of ferrous ores or scrap Fulltext... Hierarchy... Expanded...C22B 1/00; electric heating per se Fulltext... Hierarchy... Expanded...H05B)

|  | C21B |
Note(s) This sub-class covers the production of iron or steel from source materials, e.g. the production of pig-iron, and apparatus specially adapted therefor, e.g. blast furnaces, air heaters (furnaces in general Fulltext... Hierarchy... Expanded...F27).

|  | C21C |
PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON AND STEEL (refining or remelting metals in general Fulltext... Hierarchy... Expanded...C22B 9/00); TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS [2]

|  | C21D |
MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING, OR OTHER TREATMENTS (cementation by diffusion processes Fulltext... Hierarchy... Expanded...C23C; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials Fulltext... Hierarchy... Expanded...C30B)