Title:
HOT DIP GALVANNEALED STEEL SHEET AND ITS PRODUCTION
Document Type and Number:
Japanese Patent JP3149801
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To improve the image clarity of a steel sheet after coating and the flaking resistance of plating coating by forming Al-contg. Fe-Zn alloy plating film having specified surface roughness on a dead-soft steel having a specified compsn.
SOLUTION: The compsn. of a steel is, by weight, ≤0.004% C, 0.03 to 0.13% Si, 0.05 to 0.4% Mn, 0.007 to 0.02% P, 0.018 to 0.05% Ti, 0 to 0.02% Nb, 0.005 to 0.1% Al, 0 to 0.005% B, and the balance Fe with inevitable impurities. On at least one side of a steel sheet produced from the steel having this compsn., Fe-Zn alloy plating film contg. 0.18 to 0.5% Al is formed. The surface roughness of this plating film is regulated to ≤1μm by arithmetic average roughness (Ra), and the number of the peaks of troughs is regulated to 320 to 600/25.4mm. Furthermore, it is preferable that the steel sheet before the plating is retained in the temp. range of 600 to 500°C for 20 to 60sec in a reducing atmosphere composed of hydrogen and nitrogen and in which the dew point is regulated to -20 to -40°C.
Inventors:
Masahiko Hori
Tamotsu Toki
Hiroshi Takebayashi
Tamotsu Toki
Hiroshi Takebayashi
Application Number:
JP30168196A
Publication Date:
March 26, 2001
Filing Date:
November 13, 1996
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
C23C2/02; C22C38/00; C22C38/14; C23C2/06; C23C2/28; C23C2/40; (IPC1-7): C23C2/28; C22C38/00; C23C2/02
Attorney, Agent or Firm:
Morio Mori (1 outside)