EP 0156545 A2 19851002 - Heat treatment with an autoregulating heater.
Title (en)
Heat treatment with an autoregulating heater.
Title (de)
Wärmebehandlungsverfahren mittels selbstregulierender Heizvorrichtung.
Title (fr)
Procédé de traitement thermique au moyen d'un dispositif chauffant auto-régulateur.
Publication
Application
Priority
US 58671984 A 19840306
Abstract (en)
Apparatus and process for selectively heat treating at least a portion of an article in the field with autoregulated heating. The autoregulated heating is provided by a heater including at least a first magnetic material disposed along the portion of the article to be heat treated. The first magnetic material has a magnetic permeability which sharply changes at temperatures at or near the autoregulating (AR) temperature thereof. The changes in permeability result in corresponding changes in the skin depth of the first magnetic material and, hence, the heating produced therein responsive to a.c. current passing therethrough. By maintaining the a.c. current constant in amplitude and frequency, the first magnetic material and the portion of the article are regulated at substantially the AR temperature of the first magnetic material. By selecting the first magnetic material to have AR temperature substantially corresponding to the temperature at which metal anneals, tempers, hardens, softens, stress relieves or the like, heat treating at an autoregulated temperature is achieved. The autoregulated heater can be incorporated into the article or can be applied to the article thereafter, in each case permitting in field heat treating. Autoregulated heating can also be achieved by any of various multilayer structures to provide desired autoregulation effects.
IPC 1-7
IPC 8 full level
C21D 9/50 (2006.01); C21D 1/34 (2006.01); C21D 1/40 (2006.01); C21D 9/08 (2006.01); C21D 11/00 (2006.01); H05B 3/00 (2006.01); H05B 3/12 (2006.01); H05B 6/00 (2006.01); H05B 6/02 (2006.01); H05B 6/10 (2006.01)
CPC (source: EP)
C21D 1/34 (2013.01); C21D 9/08 (2013.01); C21D 11/00 (2013.01)
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI NL SE
DOCDB simple family (publication)
WO 8504069 A1 19850912; AT E56476 T1 19900915; CA 1265419 A 19900206; DE 3579605 D1 19901018; EP 0156545 A2 19851002; EP 0156545 A3 19870513; EP 0156545 B1 19900912; JP H0656793 B2 19940727; JP S61501355 A 19860703
DOCDB simple family (application)
US 8500368 W 19850306; AT 85301501 T 19850305; CA 475792 A 19850305; DE 3579605 T 19850305; EP 85301501 A 19850305; JP 50132785 A 19850306