Cold work steel and manufacturing method thereof

US7909906B2 · kind B2 · utility

Assignee

• UDDEHOLMS AB · SE

Inventors

• Odd Sandberg · Uddeholm, SE
• Lennart Jönson · Karlstad, SE
• Magnus Tidesten · Hagfors, SE

Key dates

• Filing date: Oct 5, 2007
• Grant date: Mar 22, 2011
• Expiry date: Jul 30, 2029

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/008
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A cold work steel has the following chemical composition in weight-%: 1.25-1.75% (C+N), however at least 0.5% C 0.1-1.5% Si 0.1-1.5% Mn 4.0-5.5% Cr 2.5-4.5% (Mo+W/2), however max. 0.5% W 3.0-4.5% (V+Nb/2), however max. 0.5% Nb max 0.3% S balance iron and unavoidable impurities, and a microstructure which in the hardened and tempered condition of the steel contains 6-13 vol-% of vanadium-rich MX-carbides, -nitrides and/or carbonitrides which are evenly distributed in the matrix of the steel, where X is carbon and/or nitrogen, at least 90 vol-% of said carbides, nitrides and/or carbonitrides having an equivalent diameter, Deq, which is smaller than 3.0 μm; and totally max. 1 vol-% of other, possibly existing carbides, nitrides or carbonitrides.