HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME
[Object] Provided is a high-strength steel sheet having excellent bendability and a method for manufacturing the steel sheet. [Solution] A high-strength steel sheet has a chemical composition containing, by mass%, C: 0.04% to 0.20%, Si: 0.6% to 1.5%, Mn: 1.0% to 3.0%, P: 0.10% or less, S: 0.030% or...
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Main Authors | , , |
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Format | Patent |
Language | English French German |
Published |
16.09.2020
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Subjects | |
Online Access | Get full text |
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Summary: | [Object] Provided is a high-strength steel sheet having excellent bendability and a method for manufacturing the steel sheet. [Solution] A high-strength steel sheet has a chemical composition containing, by mass%, C: 0.04% to 0.20%, Si: 0.6% to 1.5%, Mn: 1.0% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 0.10% or less, N: 0.010% or less, one, two, or all of Ti, Nb, and V in an amount of 0.01% to 1.0% each, and the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 50% or more of ferrite, in which an average grain diameter at a position located 50 µm from a surface of the steel sheet in a thickness direction is 3000 × [tensile strength TS (MPa)] -0.85 µm or less, a C content in precipitates having a grain diameter of less than 20 nm formed in steel is 0.010 mass% or more, and a amount of precipitated Fe (an amount of Fe precipitated in a form of cementite) is 0.03 mass% to 1.0 mass%, and an arithmetic average roughness Ra of 3.0 µm or less. |
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Bibliography: | Application Number: EP20160878470 |