Title:
MANUFACTURE OF GALVANNEALED STEEL SHEET EXCELLENT IN PLATING ADHESION AND PRESS FORMABILITY
Document Type and Number:
Japanese Patent JP3179202
Kind Code:
B2
Abstract:
PURPOSE: To provide a uniform alloying speed by effectively suppressing the reactivity of Ti-added steel with the molten zinc and to minimize the generation of Γ phase to inhibit the plating adhesion in the alloying treatment process.
CONSTITUTION: The ultra low-carbon steel having a composition consisting of, by weight, <0.01% C, ≥0.01% Ti, and 0.0004-0.002% B, and satisfying the inequalities of 0≤(Tiwt.%)-(48/12) (Cwt.%)-(48/14) (Nwt.%)-(32/48) (Swt.%)≤0.05 is hot-rolled at the hot-rolling finishing temperature of ≥820°C and ≤880°C. After pickling and descaling, the cold rolling is executed at the draft of ≤65%, and the recrystallization annealing is executed at the temperature of ≤500°C by the continuous galvanizing equipment and the hot dipping is executed by immersing the sheet in the galvanizing bath containing ≥0.1wt.% and ≤0.18wt.% Al for ≤3 seconds. Then, the galvanizing is executed by re-heating at the temperature of ≥450°C and ≤530°C, and the galvanized layer is substantially Zn-Fe alloyed.
Inventors:
Nobue Fujibayashi
Akira Yasuda
Makoto Isobe
Koji Yamato
Akira Yasuda
Makoto Isobe
Koji Yamato
Application Number:
JP25149992A
Publication Date:
June 25, 2001
Filing Date:
September 21, 1992
Export Citation:
Assignee:
Kawasaki Steel Co., Ltd.
International Classes:
C21D8/02; C21D9/46; C22C38/00; C23C2/06; C23C2/28; (IPC1-7): C23C2/06; C21D8/02; C21D9/46; C22C38/00; C23C2/28
Attorney, Agent or Firm:
Yoshio Kosugi (1 person outside)
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