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.
Patent No.:
Date of Patent:
Jun. 11, 1991
Filed:
Oct. 16, 1989
Helmut Brandis, Krefeld, DE;
Bernd Huchtemann, Krefeld, DE;
Peter Schuler, Krefeld, DE;
Dietrich Werner, Krefeld, DE;
Thyssen Edelstahlwerke AG, Krefeld, DE;
Abstract
Boron-containing steel products having boron contents of up to 200 ppm are obtained by an annealing process in the temperature range of between 850.degree. and 1050.degree. C. The characterizing feature of the invention is that the products are annealed in the state of equilibrium in a non-oxidizing gaseous atmosphere with a boron potential supplied by a pulverulent boron oxide source having a value such that the products retain or adsorb their boron content. The boron source is quantitatively about 100 g of B.sub.2 O.sub.3 per m.sup.3 of annealing space. In an annealing gas atmosphere mainly consisting of hydrogen, the steam partial pressure can be adjusted at atmospheric pressure in the presence of B.sub.2 O.sub.3 to the required boron activity within the range of between 10.sup.-3 to 10.sup.-5. The products can also be simultaneously case hardened during annealing. The case hardening agent can be mixed with pulverulent boron oxide as the boron source.