Title:
機械構造用熱間圧延線材・棒鋼およびその製造方法
Document Type and Number:
Japanese Patent JP4018905
Kind Code:
B2
Abstract:
Steel wire rods and bars for machine structural use having, in the as-hot-rolled state, the same cold workability as conventional steel wire rods and bars subjected to softening annealing after hot rolling, and a production method thereof are provided. The hot-rolled wire rods and bars usable for machine structural use without annealing comprise, in terms of mass%, C: 0.1 to 0.5%, Si: 0.01 to 0.5%, Mn: 0.3 to 1.5% and the balance of Fe and unavoidable impurities and if desired, comprise strengthening elements, wherein the microstructure of steel is composed of ferrite and pearlite, the ferrite grain size is No. 11 or more as defined in JIS G 0552, a granular carbide having an equivalent-circle diameter of 2 mu m or less and an aspect ratio of 3 or less is contained in an area ratio of 5 to 40%, and the steel wire rods and bars have a tensile strength TS (MPa) /= -23 x Ceq + 75 (wherein Ceq = C + Si/7 + Mn/5 + Cr/9 + Mo/2).
Inventors:
Kiichiro Tsuchida
Koji Tanabe
Koji Adachi
Seiji Ito
Koji Tanabe
Koji Adachi
Seiji Ito
Application Number:
JP2001573058A
Publication Date:
December 05, 2007
Filing Date:
April 04, 2001
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C22C38/00; C21D8/06; C22C38/04; C22C38/18; C22C38/32; C21D7/13; C21D9/573
Domestic Patent References:
| JP2213416A | ||||
| JP11124655A | ||||
| JP62164823A | ||||
| JP5171262A |
Attorney, Agent or Firm:
Takashi Ishida
Jun Tsuruta
Hiroshi Kamematsu
Masaya Nishiyama
Jun Tsuruta
Hiroshi Kamematsu
Masaya Nishiyama