Title:
PRODUCTION OF HIGH TENSILE STRENGTH HOT DIP GALVANIZED STEEL SHEET AND HOT DIP GALVANNEALED STEEL SHEET
Document Type and Number:
Japanese Patent JP3752109
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To impart an excellent appearance free from unplating to a steel sheet by subjecting a steel sheet contg. specified amounts of Si, Mn and Cr to oxidation treatment and reduction at specified temp. for a specified time, moreover specifying the relation between the oxidizing time and reducing time and next executing hot dip galvanizing.
SOLUTION: Steel contg., by mass, 0.1 to 2% Si, 0.5 to 3% Mn and ≤1% Cr (including 0%), and in which the total content of Si, Mn and Cr is also controlled to 0.6 to 5% is subjected to oxidation treatment at 200 at 650°C for 5 to 100 sec and is next subjected to reduction at 600 to 650°C for 60 to 600 sec in an annealing furnace. At this time, the oxidizing time (S1) (sec) and the reducing time (S2) (sec) are allowed to satisfy the relation in the inequality of 4×(S1)-60≤(S2)≤10×(S1)+60 to suppress the surface concn. of the elements to be added at the time of the annealing. Next, the steel sheet is applied with hot dip galvanizing and is, if required, subjected to alloying treatment.
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Inventors:
Masafumi Shimizu
Hiroshi Irie
Takayuki Yamamoto
Hiroshi Irie
Takayuki Yamamoto
Application Number:
JP23144299A
Publication Date:
March 08, 2006
Filing Date:
August 18, 1999
Export Citation:
Assignee:
KABUSHIKI KAISHA KOBE SEIKO SHO
International Classes:
C23C2/02; C23C2/28; C21D1/76; C22C38/00; C22C38/18; C23C2/06; C23C2/40; (IPC1-7): C22C38/00; C21D1/76; C22C38/18; C23C2/02; C23C2/06; C23C2/28; C23C2/40
Domestic Patent References:
| JP6041708A | ||||
| JP6212383A | ||||
| JP6212384A | ||||
| JP7090529A |
Attorney, Agent or Firm:
Kyuichi Ueki
Etsushi Kotani
Etsushi Kotani