Electromagnetic ultrasonic detecting device and method for surface defects of cold rolled ribbed steel bar

Abstract

The invention relates to an electromagnetic ultrasonic detecting device and an electromagnetic ultrasonic detecting method for surface defects of a cold rolled ribbed steel bar. The electromagnetic ultrasonic detecting method for the surface defects of the cold rolled ribbed steel bar includes the following steps: installing an encoder on a cold rolling roller gear, installing an infrared thermometer on an outlet of an induction heating system, conducting real-time measurement for moving speed of the steel bar and surface temperature of the steel bar after inducting heating process, placing the steel bar after the heating process into an electromagnetic ultrasonic emitting prober, triggering a function generator through hardware to generate drive signals to high-frequency coils of the electromagnetic ultrasonic emitting prober, generating ultrasonic waves inside the steel bar and leak ultrasonic waves in a certain length pass through high-frequency coils of an electromagnetic ultrasonic receiving prober, collecting ultrasonic wave signals in real time, and conducting reconstruction on the defects through an electromagnetic ultrasonic signal reconstructing algorithm based on the temperature. According to the electromagnetic ultrasonic detecting device and the electromagnetic ultrasonic detecting method for the surface defects of the cold rolled ribbed steel bar, on-line non-destructive detection of the steel bar surface defects and steel bar near surface defects for the cold rolled ribbed steel bar in a condition of supersonic frequency induction heating is achieved, and the positions of the defects on surfaces or near surfaces can be determined.

Description

technical field [0001] The invention relates to a device and method for non-destructive detection of surface and near-surface defects of building steel, in particular to an electromagnetic ultrasonic detection device and method for surface defects of cold-rolled ribbed steel bars. Background technique [0002] Cold-rolled ribbed steel bar is a kind of steel bar with two or three crescent shapes formed by hot-rolled wire rod through multi-pass cold-rolling reduction, one rib pressing and internal stress relief. It is the most commonly used in civil engineering One of the steel products. According to the national standard cold-rolled ribbed steel bar surface quality and marking (GB 1499-1998), the surface of cold-rolled ribbed steel bar must not have cracks, scars and folds. The surface of the steel bar is allowed to have bumps, but it must not exceed the height of the transverse rib, and the depth and height of other defects on the surface of the steel bar must not be greate...

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Problems solved by technology

[0003] At present, the surface defect detection method of steel bars mainly adopts magnetic particle flaw detection method and piezoelectric ultrasonic detection method. Although magnetic particle flaw detection detection has high precision, it has a large detection workload and low detection efficiency. It belongs to offline detection and cannot realize online detection of steel bar production line. Piezoelectric ultrasonic testing requires couplant

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