PROCEDURE FOR ELECTRO-MAGNETIC CHECK OF QUALITY OF THERMAL TREATMENT OF FERRO-MAGNETIC ITEMS AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2011 - IPC G01N27/80 

FIELD: metallurgy.

SUBSTANCE: procedure for electro-magnetic check of quality of thermal treatment of ferromagnetic rods consists in exposing to alternate magnetic field, in reversal magnetisation of rods in hysteresis cycle, and in determination of values of parametres required for assessment of quality of thermal treatment of rods. Set peak value of electric voltage induced in coils and hardness of rods are chosen as these parametres. Checked sections of rods enveloped with coils are exposed to effect of alternate magnetic field. Reversal magnetisation of checked sections of the rods is carried out during not less, than 10-12 hysteresis cycles. Set peak value of voltage on each coil is measured at reaching major hysteresis loop; hardness of rods as indicator of quality of their thermal treatment is found by preliminary determined correlation dependence of rod hardness and set peak values of voltage at outputs of coils. Also, here is disclosed the device for non-destructive check of quality of ferromagnetic rods thermal treatment.

EFFECT: increased accuracy, reliability and efficiency of check of rods with non-uniform characteristic of hardness along their length.

4 cl, 3 dwg