Frishauf, Holtz, Goodman & Chick, P.C.
High tensile strength hot-rolled steel sheet and method for manufacturing the same
A high tensile strength hot-rolled steel sheet comprises 0.04 to 0.09% C, 0.1% or less Si, 0.5 to 1.5% Mn, 0.02% or less P, 0.01% or less S, 0.1% or less Al, 0.001 to 0.008% N, and 0.01 to 0.15% Ti, by mass %, the content of ingredient there each satisfying the equation (1), and the ferritic grain size &agr; (&mgr;m) satisfying the equation (2):[C]+7&times;[Si]+0.1&times;[Mn]+[P]+14&times;[S]+1.75&times;[Al]+23&times;[N]+[Ti]+18&times;[O]+7&times;[Cu]+18&times;[Sn]+7&times;[Mo]+1.7&times;[Cr]+70&times;[B]+7&times;[Ca]+14&times;[Zr]+14&times;[V]+7&times;[Nb]&lE;2&#8195;&#8195;(1)3&lE;&agr;&lE;60&times;[Ti]+8&#8195;&#8195;(2)where, [X] denotes the content (mass %) of element X. This hot-rolled steel sheet has excellent workability, high magnetic permeability and high magnetic flux density in a strong magnetic field, and has 490 MPa or higher strength, and is suitable for large electric equipment such as a rotor of generator.
NKK Corporation
C C C Y C C C C H C
C22C C22C C21D Y02P C21D C22C C22C C22C H01F C21D
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Yoshimasa Akira Hiroshi Tadashi Toru Satoshi Hiroyasu Sadanori Takeshi
Funakawa Hiura Nakata Inoue Inazumi Ishijima Kikuchi Imada Nakahara