Bainite steel and methods of manufacture thereof

US8956470B2 · kind B2 · utility

Assignee

• The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland · GB

Inventors

• Harshad Kumar Dharamshi Hansraj Bhadeshia · Cambridge, GB
• Carlos Garcia-Mateo · Madrid, ES
• Peter H. Brown · Glenview, US

Key dates

• Filing date: Jul 31, 2009
• Grant date: Feb 17, 2015
• Expiry date: Jun 12, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/002
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A steel (known as super bainite steel) containing between 90% and 50% bainite, the rest being austenite, in which excess carbon remains within the bainitic ferrite at a concentration beyond that consistent with equilibrium; there is also partial partitioning of carbon into the residual austenite. In one embodiment of the disclosure, the steel contains in weight percent: carbon 0.6 to 1.1%, silicon 1.5 to 2.0%, manganese 0.5 to 1.8, nickel up to 3%, chromium 1.0 to 1.5, molybdenum 0.2 to 0.5%, vanadium 0.1 to 0.2%, balance iron save for incidental impurities. Excellent properties are obtained if the manganese content is about 1% by weight.