EP 0673443 B1 19970305 - METHOD OF ANNEALING STEEL STRIP IN AN ANNEALING FURNACE WITHOUT THE FORMATION OF SOOT
Title (en)
METHOD OF ANNEALING STEEL STRIP IN AN ANNEALING FURNACE WITHOUT THE FORMATION OF SOOT
Title (de)
VERFAHREN ZUM RUSSFREIEN GLÜHEN VON STAHLBAND IN EINEM GLÜHOFEN
Title (fr)
PROCEDE DE RECUIT SANS FORMATION DE SUIE DE FEUILLARDS D'ACIER DANS UN FOUR A RECUIT
Publication
Application
Priority
- DE 4241746 A 19921211
- EP 9303334 W 19931127
Abstract (en)
[origin: WO9413843A1] When annealing steel strip in annealing furnaces, contamination often occurs in the form of carbon deposits on the surface of the steel. The use of hydrogen in the protective-gas atmosphere allows such deposits to be converted to methane. If, however, a thermodynamically determined methane-concentration limit is exceeded, soot deposits are formed. In order to avoid this, methane formed as a reaction product is removed at intervals from the dome of the furnace in a protective-gas purge cycle. The invention calls for the purge cycle to depend on the amount of CH4 formed and to be controlled by a system which measures the fixed thermodynamic values of the H2/CH4 system and compares them with permitted limits. If the measured values are above or below the respective limits, an additional purge is carried out during the hold time for a period of approximately 1 hour. This ensures optimum purging and improved product quality at reduced annealing cost.
IPC 1-7
IPC 8 full level
C21D 1/76 (2006.01); C21D 9/67 (2006.01); C21D 9/52 (2006.01); C21D 11/00 (2006.01)
CPC (source: EP US)
C21D 1/76 (2013.01 - EP US); C21D 9/67 (2013.01 - EP US); C21D 9/52 (2013.01 - EP US); C21D 11/00 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE DE FR GB IT LU
DOCDB simple family (publication)
WO 9413843 A1 19940623; AT E149575 T1 19970315; DE 4241746 C1 19940825; DE 59305669 D1 19970410; EP 0673443 A1 19950927; EP 0673443 B1 19970305; EP 0673443 B2 20010110; HR P931483 A2 19950228; HR P931483 B1 19980630; SI 9300652 A 19940630; SI 9300652 B 20020228; US 5645655 A 19970708; ZA 939267 B 19950213
DOCDB simple family (application)
EP 9303334 W 19931127; AT 94901900 T 19931127; DE 4241746 A 19921211; DE 59305669 T 19931127; EP 94901900 A 19931127; HR P931483 A 19931210; SI 9300652 A 19931210; US 48877695 A 19950608; ZA 939267 A 19931210