MANUFACTURE OF HIGH TENSILE STEEL WITH SUPERIOR HYDROGEN EMBRITTLEMENT RESISTANCE

• Main Authors: NANUN MICHIHIKO, MIYAMOTO KATSUYOSHI
• Format: Patent
• Language: English
• Published: 16.11.1982
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PURPOSE:To manufacture the titled high tensile steel by working a steel contg. a specified amount each of C, Si, Mn, V, N and one or more among Al, Ti and Nb at a relatively low temp. in the austenite range, quenching the worked steel to form a martensite or bainite structure, and tempering it. CONSTITUTION:To a steel are added, by weight, 0.02-0.4%C, 0.01-1.5% Si, 0.2-2% Mn, 0.03-0.5% V, 0.002-0.03% N and one or more among <0.05% Al, <0.08% Ti and <0.2% Nb. This steel is worked by >=50% at <=1,200 deg.C in the austenite temp. range, and forced to be cooled from at temp. above the Ar3 transformation point to a temp. below the Ar1 transformation point to form a structure of martentite, bainite or a mixture thereof. It is then tempered at 300- deg.C- the Ac1 transformation point.