(19)
(11) EP 0 136 810 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
26.11.1986 Bulletin 1986/48

(43) Date of publication A2:
10.04.1985 Bulletin 1985/15

(21) Application number: 84305806

(22) Date of filing: 24.08.1984
(84) Designated Contracting States:
DE FR IT

(30) Priority: 07.09.1983 GB 8323995

(71) Applicant: UNITED KINGDOM ATOMIC ENERGY AUTHORITY
 ()

(72) Inventors:
  • Duncombe, Edward
     ()
  • Thomson, Alexander
     ()
  • Evans, Robert Arthur
     ()

   


(54) Temperature control during annealing


(57) Temperature control at a weld (52) between a tube (51) and tube plate (53) having heat input from an inductive heating probe (50) to effect annealing of the weld is performed with the aid of a signal generating receptor coil (54) coupled with the probe (50). The signal from the coil (54) experiences a characteristic change when the temperature of the weld reaches the required annealing temperature and this signal is used to control the heat input to the weld. The receptor coil can be inside the tube (51), outside the tube (51), embracing a number of similar tubes (51) or may be inside an adjacent tube (51). At the anneal, the materials of the tube and weld reach their Curie point which brings about a permeability change. The invention also has application to annealing a braze between a ferritic repair tube and a ferritic tube in a tube plate as can arise during the repair of shell and tube heat exchangers used in nuclear systems.






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