Verfahren und Einrichtung zum Oberflaechenhaerten von Werkstuecken mittels Elektronenstrahlen
During the surface treatment of workpieces by means of electron beams, several areas must often be treated. The energy applied causes the austenitizing of the edge layer of a workpiece. As a result of cooling, the austenite in converted into martensite and causes hardening, this is also known as self-quenching. During the hardening of several surfaces, the hardening of the next layer requires a high cycle time before it can cool down to ambient temperature. The time required is to be reduced. As is already known, no cooling medium, e.g. water is to be used; this would lead to corrosion or would disturb the vacuum process. According to the invention, the workpieces are exposed to a stream of cooling gas in a cooling station at atmospheric pressure after a surface is hardened by means of the electron beam; at intervals, an atomozing liquid is injected into the stream of cooling gas. In the intermediate time, the next workpiece is supplied to the electron beam system to harden the next su rface. The facility, comprising electron beam system, cooling station and conveying device, is depicted in Fig. 2. The process is used for hardening parts in mechanical engineering, e.g. hardening several sides of guide strips.
DE 1995-19500879 A: 19950113