Steel components with wear resistant carbide coating - obtd. by chemical vapour deposition and used esp. on components in polymer extrusion or moulding machines

摘要

Steel with a relatively low carbon content is coated with a min of 5 microns of one or more carbides from gps. III to VI without the formation of a decarburised edge-or intermediate zone. The pref steel contains less than 0.6% C, less than 6% Cr, and less than 2% V. The carbide is pref stoichiometric, without free carbon and pref includes TiC and/or VC. The coating is pref obtd by CVD, where the steel is first heated in inert gas to 500-700 deg C., and then at 500 deg C to near the austenite temp in a carburising gas, followed by using a gas mixt for CVD of the carbide. Esp used for the bores of tubes, bushes, nozzles, worms or housings.