EP 0184115 B1 19890222 - SURFACE-TREATED STEEL STRIP HAVING IMPROVED WELDABILITY AND PROCESS FOR MAKING
Title (en)
SURFACE-TREATED STEEL STRIP HAVING IMPROVED WELDABILITY AND PROCESS FOR MAKING
Publication
Application
Priority
JP 25235584 A 19841129
Abstract (en)
[origin: EP0184115A1] A surface-treated steel strip having improved weldability is provided, comprising a metallic Cr layer deposited on a steel strip to a weight of 50 to 150 mg/m<2>, a metallic Sn layer deposited on the chromium layer to a weight of 50 to 400 mg/m<2>, and a chromate coating layer deposited on the Sn layer and consisting essentially of 3 to 15 mg/m<2> of metallic Cr and 3 to 15 mg/m<2> of hydrated Cr oxide calculated as elemental Cr. The surface-treated steel strip is made by subjecting the cleaned surface of a steel strip to chromium electrodeposition, rinsing the Cr-deposited strip, subjecting the strip to tin electrodeposition in an acidic bath containing 1.5 to 10 grams per liter of Sn ion at a pH of lower than 0.5, rinsing the Sn-deposited strip, and subjecting the strip to chromate treatment in a chromate bath containing up to 50 grams per liter of CrO3 and sulfuric acid, a sulfate or fluoride at a current density of at least 10 A/dm<2>, thereby forming a chromate coating layer consisting essentially of metallic Cr and hydrated Cr oxide.
IPC 1-7
C25D 5/12; C25D 3/04; C25D 3/30; C25D 11/38; C25D 7/06; B32B 15/18
IPC 8 full level
C25D 3/30 (2006.01); C25D 5/10 (2006.01); C25D 5/12 (2006.01); C25D 5/26 (2006.01); C25D 11/38 (2006.01)
CPC (source: EP KR US)
C25D 3/30 (2013.01 - EP); C25D 5/12 (2013.01 - EP KR US); C25D 11/38 (2013.01 - EP US)
Designated contracting state (EPC)
BE DE FR GB IT NL
DOCDB simple family (publication)
EP 0184115 A1 19860611; EP 0184115 B1 19890222; AU 5036685 A 19860605; AU 559801 B2 19870319; CA 1273600 A 19900904; CN 1006694 B 19900207; CN 85109305 A 19860806; DE 3568356 D1 19890330; JP H052744 B2 19930113; JP S61130500 A 19860618; KR 860004165 A 19860618; KR 900001829 B1 19900324; ZA 859071 B 19860730
DOCDB simple family (application)
EP 85114989 A 19851126; AU 5036685 A 19851126; CA 496616 A 19851129; CN 85109305 A 19851128; DE 3568356 T 19851126; JP 25235584 A 19841129; KR 850008916 A 19851128; ZA 859071 A 19851127