The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Oct. 24, 2017

Filed:

Apr. 08, 2014
Applicant:

Boa Balg- Und Kompensatoren-technologie Gmbh, Stutensee, DE;

Inventors:

Klaus Hirth, Malsch, DE;

Immo Gärtner, Karlsruhe, DE;

Jürgen Telatinski, Stutensee, DE;

Uwe Wild, Karlsbad, DE;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16L 11/15 (2006.01); C21D 8/10 (2006.01); F16L 27/11 (2006.01); F16L 51/02 (2006.01); B21C 37/20 (2006.01); C23C 8/22 (2006.01); C23C 8/26 (2006.01); C23C 8/32 (2006.01); C21D 9/14 (2006.01);
U.S. Cl.
CPC ...
F16L 11/15 (2013.01); B21C 37/20 (2013.01); C21D 8/10 (2013.01); C21D 8/105 (2013.01); C21D 9/14 (2013.01); C23C 8/22 (2013.01); C23C 8/26 (2013.01); C23C 8/32 (2013.01); F16L 27/11 (2013.01); F16L 51/025 (2013.01); C21D 2211/001 (2013.01); C21D 2221/00 (2013.01); C21D 2221/10 (2013.01);
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.


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