Process for the thermomechanical treatment of steel

US6939418B2 · kind B2 · utility

Assignee

• Muhr und Bender · DE

Inventors

• Christian Bilgen · Mülheim an der Ruhr, DE
• Eberthard Kast · Erkrath, DE
• Andreas Kleemann · Weißensee, DE
• Hans-Günther Krull · Duisburg, DE
• Thomas Muhr · Attendorn, DE
• Horst Weiss · Karlsruhe, DE

Key dates

• Filing date: Apr 30, 2002
• Grant date: Sep 6, 2005
• Expiry date: Jun 3, 2022

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S148/908
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process for thermomechanical treatment of steel for torsionally-strained spring elements, the initial material being heated with a heating rate of at least 50 K/s and austenitized, and then, being formed in at least one forming step with the formed product being quenched to below the martensite temperature to martensite and then tempered. To improve the strength or toughness properties of the spring steel in the strain direction of the torsionally strained spring elements so that the increase of vibration strength is considerable, the initial material is heated to a temperature above the recrystallization temperature and then formed at such a temperature, that dynamic and/or static recrystallization of the austenite occurs, and that the recrystallized austenite of the formed product is quenched.