An experimental device for on-line detection and control of welding temperature of high-frequency straight seam welded pipes

Abstract

The invention discloses an online detection and control experimental device for the welding temperature of an electric resistance welding steel pipe. The online detection and control experimental device is mainly characterized in that the side, facing a high-frequency generator, of the upper portion of a rack is perpendicularly connected with one end of a supporting rod; connecting pieces are connected to the supporting rod at intervals in a sleeving manner; the top of each connecting piece is further provided with an upper screw hole communicating with a middle through hole, wherein a set screw is arranged in the upper screw hole; a connecting lug is arranged below each connecting piece, and a colorimetric temperature measurement device is installed on each connecting piece through the corresponding connecting lug; one set of temperature measuring assembly is composed of one connecting piece, the corresponding set screw, the corresponding colorimetric temperature measurement device, a corresponding bolt and a corresponding nut on the supporting rod, and three to six sets of temperature measuring assemblies are arranged. Each colorimetric temperature measurement device is connected with a computer through a signal line, and the computer is also connected with the high-frequency generator and an output device of the high-frequency generator through a signal line to from a closed-loop control system. According to the online detection and control experimental device for the welding temperature of the electric resistance welding steel pipe, the phenomenon that the temperature for welding the vertex of a V-shaped opening angle is directly measured is avoided, the influences of mist generated by cooling liquid on measurement of the welding temperature are reduced, the welding temperature is accurately controlled, and the quality of the welding pipe is ensured.

Description

technical field [0001] The invention relates to an experimental device for on-line detection and control of the welding temperature of ERW steel pipes. Background technique [0002] High-frequency straight seam welded pipe (Electric Resistance Welding, referred to as ERW) is a form of resistance welding. After the hot-rolled plate is formed by a forming machine, the steel coil is deformed into a smooth cylindrical tube blank. When the high-frequency current passes through When the V-shaped opening angle load circuit of the tube blank is loaded, due to its strong skin effect and proximity effect, the high-frequency current is forced to be highly concentrated on the heating edge of the tube blank, and then the welding zone is rapidly heated to the welding state by thermal energy. Under the action of the extrusion force of the extrusion roller, the melted two edges of the tube blank are fused together, and the effect of welding is achieved after cooling to form a steel pipe. I...

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Problems solved by technology

If the welding temperature is too high, it is easy to overheat the weld and form perforation; if the welding temperature is too low, the weld cannot be penetrated, or desoldering and skipping occur, which will affect the quality of the weld and cause waste of raw materials

In the traditional production process of high-frequency welded pipes, the welding temperature is realized by manual observation and adjustment of the output power of high-frequency power supply or welding speed, so the quality of welded pipes is affected by many human factors, and its stability is difficult to guarantee

At present, some scholars have also studied the welding temperature directly to the V-shaped opening angle vertex by using a colorimetric thermometer. However, in the actual production workshop of the welded pipe factory, due to the mist generated by the coolant, the high temperature in the welding area and the relative position of the roll and the tube blank are limited. And other comprehensive factors, there will be a deviation between the measured welding temperature and the actual welding temperature at the top of the V-shaped opening angle

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