GB262439A - Improvements in surface treatment for metal articles - Google Patents

Abstract

262,439. Fourment, M. Dec. 5, 1925, [Convention date]. Induction furnaces.-In a process for the surface treatment of metal articles to produce a coating thereon, the articles are heated by high frequency induced currents to the proper temperature for the diffusing of the coating substances into the metal articles. Gear wheels 4 are embedded in the treating substance 5 in a vessel 2 formed of a suitable dielectric material such as silica, and the inducing element comprises a copper tube 1 through which water circulates, and which is connected to a source of high frequency current. Heat losses are reduced by cover 3. In another form, the article is immersed in molten zinc, aluminium &c. contained in a suitable receptacle heated by induced currents as in the form shown in Fig. i, or by a suitable source of heat. In a third form, Fig. 3, the vessel 12 containing the article 11 is provided with apertures 13, 14 for the circulation of the gaseous treating substance, e.g. carbon monoxide. In a fourth form, the article is embedded in the treating substance in a closed pot which is placed in a container which is similar to that in Fig. 3, and which is in communication with a gas under pressure or an apparatus producing a vacuum, or with an inert or active gas. In a fifth form, Fig. 5, the article in the form of a bar, band, wire &c., 21 is caused to move at a slow rate through the treating mixture 23 in a vessel 22 heated by a copper tube 24.