Abstract: A process for manufacturing a bellows, made of austenitic high-grade steel with high compressive strength and fatigue strength, forms a single-layer or multilayer sleeve into a bellows with hydraulic forming. The pressure resistance and fatigue strength are improved by the bellows being cleaned after the forming and by the bellows being exposed to a surrounding area containing carbon and/or nitrogen atoms at temperatures between 100° C. and 400° C., preferably 200° C. to 320° C. With this a hardening of the bellows takes place by means of the diffusing in of carbon and/or nitrogen atoms. A bellows made of austenitic high-grade steel with one or more layers created in this manner has the edge layer hardened by the incorporation of carbon and/or nitrogen atoms up to a hardening depth of at least 5% of the wall thickness.

Abstract: A process for manufacturing a heat-insulated uncoupling element as well as an uncoupling element itself are proposed, wherein the heat insulation is provided along the corrugated area of bellows. The heat insulation consists of a coating, which contains heat-insulating granular material. The mobility of the bellows is also ensured here after application of the heat insulation.

Abstract: A process for manufacturing a bellows, made of austenitic high-grade steel with high compressive strength and fatigue strength, forms a single-layer or multilayer sleeve into a bellows with hydraulic forming. The pressure resistance and fatigue strength are improved by the bellows being cleaned after the forming and by the bellows being exposed to a surrounding area containing carbon and/or nitrogen atoms at temperatures between 100° C. and 400° C., preferably 200° C. to 320° C. With this a hardening of the bellows takes place by means of the diffusing in of carbon and/or nitrogen atoms. A bellows made of austenitic high-grade steel with one or more layers created in this manner has the edge layer hardened by the incorporation of carbon and/or nitrogen atoms up to a hardening depth of at least 5% of the wall thickness.

Abstract: A process for manufacturing a heat-insulated uncoupling element as well as an uncoupling element itself are proposed, wherein the heat insulation is provided along the corrugated area of bellows. The heat insulation consists of a coating, which contains heat-insulating granular material. The mobility of the bellows is also ensured here after application of the heat insulation.