METHOD FOR DETERMINATION OF PERMISSIBLE CURRENT FOR GRAPHITIZED ELECTRODES IN ELECTRIC ARC STEEL MELTING FURNACE Russian patent published in 2001 - IPC

FIELD: electrothermics, applicable in use of graphitized electrodes in an electric arc steel melting furnace. SUBSTANCE: the method consists in determination of physico-mechanical parameters of graphitized electrodes, resistivity ρ_a for a standard group inclusive, determination of criterion Kl characterizing the permissible load-carrying capacity of the standard group of electrodes, construction of dependence of the permissible current on criterion Kl, characterizing the permissible load-carrying capacity of the standard group of electrodes, determination of criterion Kl characterizing the permissible load-carrying capacity of the group of electrodes under test. Measured additionally for the group of electrodes under test are breaking strength σ_r, thermal conductivity λ, modulus of elasticity E_⊥, coefficient of thermal expansion α_⊥, and criterion Kl characterizing the permissible load-carrying capacity of electrodes is found by formulas: Kl₁ = 0,353σ_r/E_⊥-0,28α_⊥-0,085ρ_a+0,0063λ-0,294 for electrodes, 500 to 610 mm in diameter, Kl₂ = 0,140σ_r/E_⊥-0,14α_⊥-0,0425ρ_a+0,0047λ-5,6 for electrodes, 350 to 450 mm found by the value of Kl₁ or Kl₂ on the graph of permissible current versus Kl, characterizing the permissible load-carrying capacity of the group of electrodes under test. EFFECT: enhanced reliability and accuracy of determination of permissible load for graphitized electrodes with different physico-technical indices of native and foreign manufactures. 1 dwg, 3 tbl