Method for producing workpieces from lightweight steel having material properties that are adjustable across the wall thickness

US9593392B2 · kind B2 · utility

Assignee

• Salzgitter Flachstahl GmbH · DE

Inventors

• Daniela John · Hannover, DE
• Manuel Otto · Lehre, DE
• Rune Schmidt-Jürgensen · Hannover, DE
• Thomas Evertz · Peine, DE
• Zacharias Georgeou · Wolfsburg, DE
• Bianca Springub · Hannover, DE

Key dates

• Filing date: Feb 10, 2011
• Grant date: Mar 14, 2017
• Expiry date: Oct 11, 2033

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D9/46
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A method for producing a workpiece having properties which are adjustable across a wall thickness or strip thickness of the workpiece, includes the steps of subjecting the workpiece to a decarburizing annealing treatment under an oxidizing atmosphere and to an accelerated cooling and/or a cold forming for generating a property gradient of the workpiece, wherein the workpiece is made of an austenitic lightweight steel which has an alloy composition which includes by weight percent 0.2% to 1% carbon, 0.05% to<15% aluminum, 0.05% to 6.0% silicon, 9% to<30% manganese, and at least one element selected from the group consisting of chromium, copper, boron, titanium, zirconium, vanadium and niobium, wherein chromium=4.0%; titanium+zirconium=0.7%; niobium+vanadium=0.5%, boron=1%, the remainder iron including common steel companion elements.