SU838555A1 - Ultrasonic inspection device for moving hot metallic billets - Google Patents

Description

one

The invention relates to non-destructive testing, and more specifically to devices for ultrasonic testing of the interface between the liquid and solid phases of continuous cast metal billets.

Known devices for ultrasonic testing of hot metal,; having an emitter and receiver of ultrasonic vibrations Transmitters) fl.

However, since direct contact of the sensors with the surface of the thorn object is impossible due to the weight of the low temperature limit of their operability, an intermediate cooled body-sound duct is installed between the sensors and the product surface. Since even a small air gap between the sump and the test product prevents the passage of ultrasonic vibrations, the gap is filled with contact liquid (water, oil, molten metals or salts). In the case of using a contact liquid with a boiling point below the temperature of the object being monitored (for example, water, the acoustic connection of the sound ducts may be broken.

Closest to the invention, the technical essence is a device for ultrasonic testing of moving hot metal blanks, comprising a frame, an ultrasonic transducer attached to it, a receiver connected to it with sound guides and power elements designed to press the sound conductors to the workpiece 2.

However, the ducts in the known device are made in the form of RO.GShKOV that need to be cooled. Besides

5, the acoustic coupling of the sound ducts to the workpiece may be disrupted due to the lack of relative immobility of the workpiece and the rollers.

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The purpose of the invention is to improve acoustic communication by ensuring the relative immobility of the workpiece and the sound ducts.

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This goal is achieved by the fact that the device is provided with guides, located along the moving workpiece, in which a frame is installed by means of rollers, and a return mechanism connected to the frame.

FIG. 1 shows schematically the device, a general view; in Fig.2 a section aa in Fig. 1.

The device contains a frame 1, on which the power elements 2 -and the sound lines 3, pressed by the force elements 2 to the controlled workpiece 4, are installed. The sound-lines and arms 3 are cooled with water using installed | On their cylindrical parts, cooling devices (not shown). Brackets 5 with rollers b are also fixed on frame 1, Frame 1 can be moved on rollers b along rails 7 mounted on racks 8. Cable 9 passing through blocks 10 mounted on brackets .11, frame 1 is connected to counterweights 12, which are the return mechanism. On the racks there are stops 13. The device operates as follows.

In the initial state, the frame 1 is in the upper position, which is determined by the location of the supports 8 on the uprights 8. The sound ducts 3 are retracted from the test piece. 4, When an appropriate signal is applied, the power elements 2 press the sound lines 3 against the moving workpiece 4, providing an acoustic connection between them. Due to the frictional forces, the workpiece 4 entrains the sound lines 3, as well as the power elements 2 and the frame 1, which moves down on the rollers 6 along the guides 7. Then, by the appropriate command, the power elements 2 move the sound lines 3 away from the workpiece 4. Under the action of counterweights 12 frame 1 rises up to the stops 13, i.e. to the starting position. After this, the next cycle of the device operation begins.

Moving the frame along the guides during the control process ensures the relative immobility of the moving workpiece and the sound ducts made in the form of conical rods. The working ends of the acoustic ducts are pressed against the workpiece for the time being monitored by the power elements, ensuring reliable and stable acoustic coupling with minimal energy loss in the transition zone. The acoustic coupling does not depend on the state of the workpiece surface, since the working ends of the sound ducts have a small diameter (10 mm), therefore even with relatively small clamping forces, the entire end surface of the sound ducts is in contact with the workpiece.

In the proposed device, the relative immobility of the sound lines and sensors is also ensured. This achieves a stabilization of the acoustic coupling between them and reduces to a minimum the influence of the intermediate zone on the amplitude of the useful signal.

 The proposed device provides discrete control of the workpiece in increments of several centimeters to several meters. Measurement discontinuity satisfies requirements

 for control of a continuous-cast ingot, as with an appropriate choice of step, taking into account the existing casting speeds, the relative change of the controlled parameter

5 (TO.PERSONS of a hard shell, the depth of the liquid core) at a distance equal to the pitch is no more than 1%, which is significantly less than the permissible relative measurement error (-5%).

Q In addition to measuring the thickness of the hard shell of the ingot at the exit of the mold and controlling the absence of a liquid phase in the ingot in the vicinity of the thrust rolls, the device can be used to continuously measure the ratio of the thicknesses of the hard shell to the liquid core of the workpiece, as well as to determine when the ingot is completely cured over the cross section. Use in the device of conical sound pipes and discontinuity

controls allow to reduce heat transfer from the product to the ducts, which on the one hand reduces unwanted cooling of the workpiece, with

5 another - heating of the sound pipes.

Claims (2)

Invention Formula A device for ultrasonic testing of moving hot metal workpieces, comprising a frame, an ultrasonic emitter mounted on it, a receiver associated with it, a chimney and power elements designed to press the sound ducts to the workpiece, in order to improve by ensuring the relative immobility of the workpiece and the sound ducts, it is supplied with guides arranged along the moving workpiece, in which the frame is installed by means of rollers and connected with frame return mechanism. Sources of information taken into account in the examination. 1. Patent of Great Britain No. 1057802, 60 cl. H 4 D, 1963. 2. Patent of Great Britain No. 1271824, cl. H 4 D, 1968 (prototype). P L f3 five l ff w J. 9 n t 6