 |
C 21 D | 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 C 23 C; surface treatment of metallic material involving at least one process provided for in class C 23 and at least one process covered by this subclass C 23 F 17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C 30 B)
|