Title:
HEAT-TREATMENT STEEL FOR HIGH-STRENGTH SPRING
Document Type and Number:
WIPO Patent Application WO/2007/114491
Kind Code:
A1
Abstract:
A heat-treatment steel for springs which is to be subjected to cold coiling, can
combine sufficient atmospheric strength with coilability, and has a tensile
strength of 2,000 MPa or higher. Through a heat treatment after spring formation,
the steel can heighten performances required of springs. The heat-treatment
steel for high-strength springs is characterized by containing, in terms of
mass%, 0.4-0.9% C, 1.0-3.0% Si, 0.1-2.0% Mn, and 0.1-1.0%, excluding 0.1%, V,
the amount of N being 0.007% or less and the remainder being iron and unavoidable
impurities. It is further characterized in that after the heat treatment, a subsequent
extraction residue analysis gives results which satisfy the relationship [amount
of V present in filtrate resulting from filtration through 0.2-µm filter
(mass%)]≥[amount of V contained in steel (mass%)]Œ0.4.
Inventors:
HASHIMURA, Masayuki (12 Nakamachi, Muroran-sh, Hokkaido 50, 0508550, JP)
橋村雅之 (〒50 北海道室蘭市仲町１２番地新日本製鐵株式会社 室蘭製鐵所内 Hokkaido, 0508550, JP)
OCHI, Tatsurou (12 Nakamachi, Muroran-sh, Hokkaido 50, 0508550, JP)
越智達朗 (〒50 北海道室蘭市仲町１２番地新日本製鐵株式会社 室蘭製鐵所内 Hokkaido, 0508550, JP)
橋村雅之 (〒50 北海道室蘭市仲町１２番地新日本製鐵株式会社 室蘭製鐵所内 Hokkaido, 0508550, JP)
OCHI, Tatsurou (12 Nakamachi, Muroran-sh, Hokkaido 50, 0508550, JP)
越智達朗 (〒50 北海道室蘭市仲町１２番地新日本製鐵株式会社 室蘭製鐵所内 Hokkaido, 0508550, JP)
Application Number:
JP2007/057625
Publication Date:
October 11, 2007
Filing Date:
March 29, 2007
Export Citation:
Assignee:
NIPPON STEEL CORPORATION (6-3 Otemachi 2-chome, Chiyoda-ku Tokyo, 71, 1008071, JP)
新日本製鐵株式会社 (〒71 東京都千代田区大手町二丁目６番３号 Tokyo, 1008071, JP)
HASHIMURA, Masayuki (12 Nakamachi, Muroran-sh, Hokkaido 50, 0508550, JP)
橋村雅之 (〒50 北海道室蘭市仲町１２番地新日本製鐵株式会社 室蘭製鐵所内 Hokkaido, 0508550, JP)
OCHI, Tatsurou (12 Nakamachi, Muroran-sh, Hokkaido 50, 0508550, JP)
新日本製鐵株式会社 (〒71 東京都千代田区大手町二丁目６番３号 Tokyo, 1008071, JP)
HASHIMURA, Masayuki (12 Nakamachi, Muroran-sh, Hokkaido 50, 0508550, JP)
橋村雅之 (〒50 北海道室蘭市仲町１２番地新日本製鐵株式会社 室蘭製鐵所内 Hokkaido, 0508550, JP)
OCHI, Tatsurou (12 Nakamachi, Muroran-sh, Hokkaido 50, 0508550, JP)
International Classes:
C22C38/00; C21D9/52; C22C38/12; C22C38/60; F16F1/02; C22C38/00; C21D9/52; C22C38/12; C22C38/60; F16F1/02
Attorney, Agent or Firm:
AOKI, Atsushi et al. (SEIWA PATENT & LAW, Toranomon 37 Mori Bldg. 5-1,Toranomon 3-chom, Minato-ku Tokyo 23, 1058423, JP)