DEVICE FOR DETERMINING UNIFORMITY OF MECHANICAL PROPERTIES OF ARTICLES OF THEIR METAL AND DETECTION IN THEM OF ZONES WITH ABNORMAL HARDNESS Russian patent published in 2019 - IPC G01N27/82 

FIELD: physics.

SUBSTANCE: invention relates to control of physical properties of articles and materials, and can be used for detection of zones with hardness anomalies and other physical and mechanical properties of surface of steel sheets, rails, pipes and rods. Proposed device comprises roller conveyor to displace in controlled process, demagnetiser, working clearance compensation system and set of at least two electromagnetic transducers (ET) each including at least one working coil and case. Each ET is an assembly of at least two working coils (WC) wound on U-shaped cores, wherein the lines connecting the poles of each core are oriented parallel to each other in such a way that the variable magnetic field generated by the coils is closed through the control object (CO) or along, or across rolling direction. Frequency F of the maximum in the spectrum of the magnetic field generated by the ET is selected from the relationship: F≤0.8×Fc, where Fc is the frequency at which change of inductance of WC at changeover of ET to CO changes direction from positive (inductance at approach increases) to negative (inductance at approach falls). Gap compensation system further comprises a compressed air supply system to the ET, wherein each ET additionally comprises at least one hole made in the ET bottom (from the monitoring object side) and serving for air outlet from the ET bottom and creation of the air cushion in the space between the CO and ET, and area S of bottom of ED satisfies the condition: S≥5,000/P, where S – area of ET bottom in mm², P is the air pressure at the inlet of the ET, in bars, wherein the sole is matched with the CO. Each ET additionally comprises a device for its pressing to a controlled object with a given force, which provides stabilization of the gap between the CO and the ET at a given value.

EFFECT: high reliability, fast operation, efficiency and accuracy of determining uniformity of mechanical properties of metal articles in conditions of their in-line production.

7 cl, 5 dwg