The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 28, 1992
Filed:
Jul. 31, 1990
Fujimitsu Masuyama, Nagasaki, JP;
Humio Mitsuura, Nagasaki, JP;
Mitsubishi Jukogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
High strength heat-resistant low alloy steels have a chemical composition of, on weight basis, a carbon content of 0.03-0.12%, a silicon content not higher than 1%, a manganese content of 0.2-1%, a phosphor content not higher than 0.03%, a sulfur content not higher than 0.03%, a nickel content not higher than 0.8%, a chromium content of 0.7-3%, a molybdenum content of 0.3-0.7%, a tungsten content of 0.6-2.4%, a vanadium content of 0.05-0.35%, a niobium content of 0.01-0.12% and a nitrogen content being 0.01-0.05% with the balance of iron and inevitable impurities, wherein the molybdenum content and the tungsten content satisfy the relationship 0.8%.ltoreq.(Mo+1/2W)%.ltoreq.1.5%; or a carbon content of 0.03-0.12%, a silicon content not higher than 1%, a manganese content of 0.2-1%, a phosphor content not higher than 0.03%, a sulfur content not higher than 0.03%, a nickel content not higher than 0.8%, a chromium content of 0.7-3%, a molybdenum content of 0.3-1.5%, a vanadium content of 0.05-0.35%, a niobium content of 0.01-0.12%, a nitrogen content of 0.01-0.05% and, occasionally, a further content of one or more of tungsten, in a content of 0.5-2.4%, boron, in a content of 0.0005-0.015%, aluminum, in a content not higher than 0.05%, and titanium, in a content of 0.05-0.2%, with the balance of being iron and inevitable impurities. The low alloy steels are obtained by subjecting a starting metal having the above chemical composition to a heat treatment by heating it to a temperature above 1100.degree. C. (A) and subsequent cooling to the ordinary temperature, then, subjecting the so treated metal to a plastic working at a temperature in the range from the ordinary temperature to a temperature at which no recrystallization occurs during the working or in the course of subsequent cooling and, finally, subjecting the so worked metal to a normalizing at a temperature lower than 1100.degree. C. (A) and to a tempering at a temperature below the Ac.sub.1 point.