Method for making an abrasion-resistant steel plate

US7462251B2 · kind B2 · utility

Assignee

• USINOR · FR

Inventors

• Jean Beguinot · Le Creusot, FR
• Jean-Georges Brisson · Le Creusot, FR

Key dates

• Filing date: Nov 13, 2003
• Grant date: Dec 9, 2008
• Expiry date: Sep 4, 2024

Classification

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

Abstract

The invention concerns a method for making an abrasion-resistant steel part consisting of 0.1%≦C≦0.23%; 0%≦Si≦2%; 0%≦AI≦2%; 0.5%≦Si+AI≦2%; 0%≦Mn≦2.5%; 0%≦Ni≦5%; 0%≦Cr≦5%; 0%≦Mo≦1%; 0%≦W≦2%; 0.05%≦Mo+W/2≦1%; 0%≦B≦0.02%; 0%≦Ti≦0.67%; 0%≦Zr≦1.34%; 0.05%≦Ti+Zr/2≦0.67%; 0%≦S≦0.15%; N<0.030, optionally 0% to 1.5% of Cu; optionally Nb, Ta and V such that Nb/2+Ta/4+V≦0.5 %; optionally Se, Te, Ca, Bi, Pb contents ≦0.1%; the rest being iron and impurities. Additionally: 0.095%≦C*=C−Ti/4−Zr/8+7×N/8, Ti+Zr/2−7×N/2≦0.05% and 1.05×Mn+0.54×Ni+0.5O×Cr+0.3×(Mo++W1/2)1/2+K>1.8, with K=1 if B≧0.0005% and K=0 if B<0.0005%. After austenitization, the method consists in: cooling at a speed >0.5° C./s between AC3 and T=800−270×C*−90×Mn−37×Ni−70×Cr−83×(Mo+W/2) and about T−50° C.; then cooling at a speed 0.1<Vr<150×ep−1.7 between T and 100° C., (ep=thickness of plate in mm); cooling down to room temperature and optionally planishing. The invention also concerns the resulting plate.