EP 0985054 A1 20000315 - METHOD FOR CONTINUOUS MANUFACTURE OF A STEEL BAND FOR DRAWING WITH IMPROVED SURFACE PROPERTIES
Title (en)
METHOD FOR CONTINUOUS MANUFACTURE OF A STEEL BAND FOR DRAWING WITH IMPROVED SURFACE PROPERTIES
Title (de)
VERFAHREN ZUM KONTINUIERLICHEN HERSTELLEN VON STAHLBAND MIT VERBESSERTEN OBERFLÄCHENEIGENSCHAFTEN ZUM TIEFZIEHEN
Title (fr)
PROCEDE DE FABRICATION EN CONTINU D'UNE BANDE EN ACIER POUR EMBOUTISSAGE PRESENTANT DES PROPRIETES DE SURFACE AMELIOREES
Publication
Application
Priority
- BE 9800061 W 19980428
- BE 9700459 A 19970527
Abstract (en)
[origin: WO9854371A1] The invention concerns a method for continuous manufacture of a steel band for drawing with improved surface properties, whereby a band, after being hot rolled and coiled at the end of the rolling process at a temperature ranging between 500 and 800 DEG C, and cold rolled with a reduction ratio of at least 30 % and preferably 75 %, is subjected to a heating step, then a thermal treatment hereafter called reactive annealing, for producing re-crystallisation, i.e. regeneration of the crystal lattice following deformation, and carburizing of the band at a temperature T, simultaneously or not depending on the final properties required for the band, and finally said band is cooled. The invention is characterised in that said reactive annealing is wholly or partially carried out under a gaseous atmosphere comprising at least CO and H2 in concentrations by volume corresponding to the following relationship: [ % vol H2] + 2 [ % vol CO] - 80 >/=0, at least H2O and CO2 in concentrations not more than 3 % by volume, a remainder of a neutral gas such as N2, and the carburizing temperature T ranges between 650 and 950 DEG C, and the total duration t of said reactive annealing thermal treatment is between 0.1 and 300 seconds and the carburizing rate is not less than 10<(-10)>.exp(T/100)g.cm(-2).s(-1), in which T is the carburizing temperature expressed in Kelvin's.
IPC 1-7
IPC 8 full level
CPC (source: EP)
C21D 8/0457 (2013.01); C23C 8/22 (2013.01); C21D 8/0426 (2013.01); C21D 8/0436 (2013.01)
Citation (search report)
See references of WO 9854371A1
Designated contracting state (EPC)
BE DE FR GB LU NL
DOCDB simple family (publication)
WO 9854371 A1 19981203; BE 1011178 A3 19990601; DE 69802525 D1 20011220; DE 69802525 T2 20020627; EP 0985054 A1 20000315; EP 0985054 B1 20011114
DOCDB simple family (application)
BE 9800061 W 19980428; BE 9700459 A 19970527; DE 69802525 T 19980428; EP 98916676 A 19980428