RU2219522C2 - Device to test welds in strips or wires - Google Patents

Abstract

FIELD: equipment testing quality of welds for multicyclic fatigue. SUBSTANCE: device to test welds in strips or wires has frame carrying system of rotary bending rollers arranged in staggered order and coupled to drive of their rotation. System of rotary bending rollers arranged in staggered order is equipped with mechanism adjusting their positions and transmitter of sagging of specimen of strip or wire welded into closed endless structure, supporting rollers to position given closed endless structure are mounted on both sides of system of rotary bending rollers arranged in staggered order. Revolution counter is put on shaft of one supporting roller, another roller is coupled to tension mechanism carrying transmitter of tension force. EFFECT: raised productivity and authenticity of process testing specimens of welds of strips or wires. 1 dwg

Description

 The invention relates to the field of metal welding and can be used in the development of welding modes and quality control of welded joints.

 Modern technological processes of continuous rolling of strips or wire provide for butt welding of the ends of rolls of strips or wire, without interrupting the rolling or drawing process, and welded joints are rolled or dragged together with strips or wire.

 Considering that in this case, welded joints are subjected to repeated bending and tension, the necessary condition for successful metal processing is the strength and ductility of welded joints, ensuring uninterrupted passage of joints through metallurgical units. In this case, the quality of welded joints cannot be checked by non-destructive testing methods due to the high performance of the units (docking takes 1 minute and there is no necessary pause to stop for quality control), joint defects made by butt contact welding are not detected on a moving strip by known non-destructive testing methods . Therefore, the development of optimal welding conditions is carried out on prototypes to identify the optimum ratio of the parameters of the mode with quality control by methods that destroy the welded joint, in particular kinks and tensile tests.

 It is known, cited as an analogue of the present invention - the method, the test of a welded joint with a bend of 60-180 degrees (see A.S. Gelman. Butt welding of a tape of tool steels // Welding production, 1956, 1, p. 4-7) . The disadvantage of these tests is the need for additional hardness measurements at the junction and peri-butt area to identify their ductility and confirm the possibility of cold rolling strips.

 The closest, from existing analogues, the prototype of the proposed invention - the method is a known method of testing welded specimens for bending with kink (see I.P. Nikonov, D.D. Ostrov. Properties of welded joints from hot-rolled electrical steel // Welding production , 1969, 12, pp. 34-36), in which the compound is subjected to repeated alternating bending and determine the number of cycles to failure.

 A disadvantage of the known method described as a prototype is that the bending is done manually and it takes a lot of time to test the welding technology when testing a series of samples, especially close to the optimal mode, when a large number of bends are necessary before breaking. In addition, laboratory studies of the weldability of metals should be as close as possible to the operating conditions, in this case, the conditions for the passage of welded joints through a metallurgical unit with tension and kinks, and with the known method it is impossible to identify the complex effect of bending and tension on the reliability of the welded joint.

 However, this becomes possible when using a special device developed by the authors of the present invention to implement the inventive method, a device that has no analogues either in domestic or in world practice, since information about such a device was not found in either the technical or patent literature.

 The task of the claimed invention, both in terms of the method and the device, is to bring the test of the welded joint as close as possible to the actual conditions of its use.

 The technical effect achieved in this case is an increase in the productivity of the testing process of samples of welded joints of strips or wires, an increase in the quality of tests due to the simultaneous impact of alternating bends and tension on the samples. Thus, it is possible to test one welded joint or at the same time a series of samples welded in modes with the same or different parameters.

 The task with achieving the desired effect is achieved by the fact that in the method of testing samples of a welded joint of a strip or wire by repeatedly alternating bending and determining the number of cycles until the welding quality is destroyed, the samples of strips or wire are section-welded into a closed endless lash, and testing of thus formed samples produced on a special device containing a bed with a system of bending rollers mounted on it, arranged in a checkerboard pattern and connected drive their rotation. In this case, the roller system is equipped with a mechanism for adjusting their position and a deflection sensor for the whip of samples. The device is also equipped with supporting rollers on both sides of the bending rollers, on the shaft of one of which a revolution counter is installed, and the tension mechanism is connected to the other with a tension force sensor.

 The inventive method is as follows.

 Closed endless lash is welded from samples of a strip or wire with a selection of different welding modes, after which it is tested on the claimed device.

 The drawing shows a device for testing samples of welded joints of strips or wire.

 The device comprises a frame 1, a system of staggered bending rollers mounted on it 2, connected with a drive for rotating them 3 and a deflection adjustment mechanism 4, a deflection sensor 5, supporting rollers 6 installed on both sides of the bending rollers, on one of which a revolution counter is installed 7, and a tension mechanism 8 connected to another roller with a tension force sensor 9.

 The device operates as follows.

 A welded closed lash 10 is installed between the previously bent bending rollers 2 and placed on the rollers 6. The deflection adjustment mechanism 4 reduces the bending rollers 2, controlling their position on the deflection sensor 5. A load or a set of weights is established on the tension mechanism 8, controlling the tension force on the sensor 9 Next, turn on the rotation drive 3 and repeatedly pass the welded lash 10 through the bending rollers 4 until one of the joints breaks. The revolution counter 7 determines the number of bends of each welded joint. After visual inspection of the remaining welded joints, it is concluded that the testing of this whip is continued, for which purpose the welded joint is re-welded or the whip welded in the mode with another combination of parameters is set.

 Thus, the task of the proposed invention is solved - increasing the productivity of the test process of welded samples with simultaneous exposure to multiple bends and tension.

Claims (1)

A device for testing samples of a welded joint containing a bed with a system of staggered rotating bending rollers connected to a drive for rotating them mounted on it, while a system of staggered rotating bending rollers is equipped with a mechanism for adjusting their position and a deflection sensor for strip or wire samples welded in a closed endless structure, and on both sides of the system of staggered rotating bending rollers installed sub rzhivayuschie rollers for placement of the closed endless structure, the shaft of one of the support rollers is mounted revolution counter and the other connected with the tensioning mechanism equipped with a tension force sensor.