SYSTEM AND METHOD FOR ANNEALING OF AN ITEM, WHICH COMPRISES HEAT-SENSITIVE PARTS AND ANNEALED ITEM

摘要

A method and a system for stress-relieving annealing one or more first parts of a workpiece, wherein a second part of the workpiece contains heat-sensitive parts. A cooling jacket is placed around the part of the workpiece surrounding heat-sensitive parts such that the part{s) to be annealed are located outside the cooling jacket. The first part(s) are then heated individually by induction up to the annealing temperature of the material in a first annealing zone in the system while simultaneously cooling the second part of the workpiece located in the cooling jacket. After annealing, the workpiece is cooled in a cooling zone, as annealing and cooling of the workpiece occurs under a protecting atmosphere. The annealed workpiece is, e.g., connection ends on a valve housing where the connection ends are shaped by plastic deformation after mounting valve seats, valve body etc. in the central part of the valve housing.