Process for manufacturing iron-carbon-manganese austenitic steel sheet with excellent resistance to delayed cracking, and sheet thus produced

US9200355B2 · kind B2 · utility

Assignees

• Arcelormittal France · FR
• Thyssenkrupp Steel AG · DE

Inventors

• Colin Scott · Metz, FR
• Philippe Cugy · Thionville, FR
• Christian Allely · Metz, FR

Key dates

• Filing date: Jul 6, 2007
• Grant date: Dec 1, 2015
• Expiry date: Dec 16, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/12799
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

An austenitic steel sheet excellent in resistance to delayed cracking, the composition of said steel comprising, in weight: 0,35%<C<1,05%, 15%<Mn<26%, Si<3%, Al<0,050%, S<0,030%, P<0,080%, N<0,1%, at least one metallic element X chosen among vanadium, titanium, niobium, molybdenum, chromium: 0,050%<V<0,50%, 0,040%≦Ti<0,50%, 0,070%<Nb<0,50%, 0,14%<Mo<2%, 0,070%<Cr<2% and optionally, one or several elements chosen among 0,0005%<B<0,010%, Ni<2%, Cu<5%, the remainder being iron and unavoidable impurities inherent to fabrication, including hydrogen, the quantity Xp of said at least one metallic element under the form of carbides, nitrides or carbonitrides being, in weight: 0,030%<VP<0,40%, 0,030%<Tip<0,50%, 0,040%<Nbp<0,40%, 0,14%<Mop<0,44%, 0,070%<Crp<0,6%, the hydrogen content Hmax designating the maximal hydrogen content that can be measured from a series of at least five specimens, and the quantity Xp, in weight, being such that (I) <3,3.