THIN STEEL SHEET FOR PRESS FORMING - JFE Steel Corporation

Title:

THIN STEEL SHEET FOR PRESS FORMING

Document Type and Number:

Japanese Patent JP3476495

Kind Code:

B2

Abstract:

PURPOSE: To provide a thin steel sheet for press forming in which press formability is not impaired, image clarity after coating is excellent and star marks are hardly generated.
CONSTITUTION: The surface condition is matched with the following conditions (1)-(3) and also (4) and/or (5). (1) The average waviness (Wca) of the ruggedness on both surface of the steel sheet is ≤0.6μm. (2) The average roughness (Rz) based on ten points for the ruggedness of the surface that is in contact with a punch is ≥10μm. (3) The average roughness (Ra) for the ruggedness of the surface that is in contact with a die is ≥0.4μm and the area ratio of the flat part is ≥40%. (4) In an arbitrary position on the surface of the steel sheet that is in contact with the punch, a recessed part having the depth of ≥10μm from the center face is one or more within the square of 200μm×200μm. (5) The variation range of the height of the protruded parts on the surface of the steel sheet that is in contact with the punch is 20% or below than the average height of the protruded parts.

Inventors:

Makoto Nakanaka
Toshiyuki Kato
Mitsuhiro Sato

Application Number:

JP6396293A

Publication Date:

December 10, 2003

Filing Date:

March 23, 1993

Export Citation:

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