Abstract: In the partial thermochemical vacuum treatment of metallic workpieces (1), in particular in the carburization and case hardening of workpieces (1) of case-hardening steel in a carbon-containing atmosphere, surface regions (3, 4, 5, 6) to be treated and surface regions not to be treated abut one another. In order to restrict the surface treatment to the cavities (2) of the workpieces (1) the external surface regions not to be treated are covered by reusable dismountable mould bodies (11) of a temperature-resistant material with at least one mould cavity (15). In this connection the mould body (11) consisting of a lower part (12) and an upper part (13) with openings (12b, 13b) encloses several workpieces (1) in such a way that no treatment takes place on the external surface regions of the workpieces (1). An electrically conducting mould body (11) is suitable in particular for a thermochemical treatment under the action of a plasma. Graphite or CFC is used as material for the mould bodies (11).

Abstract: In the partial thermochemical vacuum treatment of metallic workpieces (1), in particular in the carburization and case hardening of workpieces (1) of case-hardening steel in a carbon-containing atmosphere, surface regions (3, 4, 5, 6) to be treated and surface regions not to be treated abut one another. In order to restrict the surface treatment to the cavities (2) of the workpieces (1) the external surface regions not to be treated are covered by reusable dismountable mould bodies (11) of a temperature-resistant material with at least one mould cavity (15). In this connection the mould body (11) consisting of a lower part (12) and an upper part (13) with openings (12b, 13b) encloses several workpieces (1) in such a way that no treatment takes place on the external surface regions of the workpieces (1). An electrically conducting mould body (11) is suitable in particular for a thermochemical treatment under the action of a plasma. Graphite or CFC is used as material for the mould bodies (11).

Abstract: Method for the treatment of alloy steels and refractory metals such as Ti, Zr and Nb, especially for depassivation and subsequent thermochemical surface treatment in a process chamber (1, 2) under the action of pressure and temperature, wherein, in a first process step, a first gas or gas mixture from the group N.sub.2, H.sub.2 or NH.sub.3 is admitted for the depassivation into a process chamber (1), a pressure greater than 1 bar a and a temperature between 100.degree. C. and 1,000.degree. C. is established in the chamber (1), and in a second process step a second gas or gas mixture from the group of N-, C- or B-containing gases is admitted into a process chamber (1, 2) for the thermochemical surface treatment, and a temperature between 100.degree. C. and 1,000.degree. C. at a pressure greater than or equal to 1 bar a is established.

Abstract: In a vacuum heat treating oven operating with hydrogen under pressure as the cooling medium, especially for the quenching of greatly heated metal workpieces (5), a method is provided for the automatic control of the progress of the process and for monitoring safety of operation. The housing (4) of the heat treating oven is for this purpose connected to gas inlet lines (9 and 10), one for the admission of the cooling gas and one for the admission of the flushing gas (H.sub.2 and N.sub.

Abstract: In a vacuum heat treating oven operating with hydrogen under pressure as the cooling medium, especially for the quenching of greatly heated metal workpieces (5), a method is provided for the automatic control of the progress of the process and for monitoring safety of operation. The housing (4) of the heat treating oven is for this purpose connected to gas inlet lines (9 and 10), one for the admission of the cooling gas and one for the admission of the flushing gas (H.sub.2 and N.sub.