RU2106947C1 - High-frequency current welding method - Google Patents

Abstract

FIELD: high-frequency welding. SUBSTANCE: method involves arranging parts to be welded in equally spaced relation so that constant welding gap is defined between them; directing high-frequency current and closing welding circuit; feeding molten additive agent into welding gap. As a result part edges are further heated. EFFECT: increased efficiency by reduced deformation due to welding and provision for high-rate welding of parts of any thickness. 1 dwg

Description

 The invention relates to welding, and more particularly to welding using high frequency currents (HD).

 A known method of high-frequency welding (British Patent N 1151348, CL B 23 K 11/00), which implements the welding process using a high heating frequency. During the process, filler material is used, for which a triangular bar of the same metal as the workpiece is continuously fed into the welding zone, into the corners between the workpieces. The latter are preliminarily reduced to each other without a gap, the high-frequency current is supplied by means of contacts to the workpiece parts, and the heating under alloying of the filler metal is provided by an induction wire.

 The process is technologically complex. Welding thus extended metallurgical semi-finished products is impractical, because devoid of the known advantages that high-frequency welding will give. The productivity of the process is low, because it is very difficult to hold the weld pool at high welding speeds. It is difficult and not always possible to ensure high quality of welding during such a process (there is no metal emission characteristic of a high frequency of pressure welding that removes scale, dirt, etc. defects from the welded surfaces from the welding zone. All the dirt rolls into the seam. The method is also difficult to perform and constructively. The solution of Japanese Patent No. 49-153343) is known.

 "The method of continuous welding of metal sheets", which consists in obtaining a T-joint from 3 initial billets. To do this, the blanks forming the "surface" of the profile are brought at an angle to each other, a blank "rib" is introduced into the gap between them. High frequency current is applied.

 With this circuit, the “rib” is in the worst conditions, so its edges are preheated by an inductor connected in parallel with the current-carrying contacts.

 In this method, optimal conditions are not created for obtaining the required quality of welding. The method is power (after the parts are warmed up, current is supplied and crimped).

 This circumstance introduces restrictions on the thickness of the welded parts. In addition, the process is economically unprofitable and structurally difficult due to the fact that two processes take place here: contact and induction heating, therefore, two sources are required (the current is supplied to two parts, and the third is heated by an inductor).

 A known method of welding metals by fusion [1], according to which the filler material is fed into the gap between the edges to be welded in molten form, and the edges are additionally heated by the heat of the molten metal.

 This method, as closest to the claimed, is selected as a prototype.

 The aim of the invention is to enable welding using high frequency currents by non-force method, to ensure welding of metal of any thickness, to obtain high quality weld, reduce deformation and contamination of the weld by converting the welding process into a high-frequency process. Another objective of the invention is to obtain manufacturability and environmentally friendly and resource-saving welding process.

 This goal is achieved by the fact that in the method of welding with high-frequency currents, including the installation of parts with a constant gap, closing the welding circuit by feeding filler material into the gap, passing the high-frequency current and filling the gap while heating the parts, according to the invention, the filler material is fed into the gap in molten form, due to which carry out additional heating of the edges.

 The process is not a force (does not require compression), because the gap is filled with molten metal. The method is contact, such a process can be welded any thickness. The method does not require additional power sources.

 In our case, only two parts are heated; flows along the edges of the parts, closing on the molten metal filling the gap, because of this the process becomes adjustable in modes, which affects the quality of the seam. In the proposed method, there is no convergence angle, the circuit goes through the electrode, current c. hours flows only on surfaces facing each other, and since the surfaces are the same, equal currents flow, providing the same heating.

 The method is highly efficient and environmentally friendly.

 The drawing shows a schematic diagram of a specific implementation of the method.

 The drawing shows the welded parts 1, molten filler material 2, current leads 3 to the RF source.

 Example. Material with a thickness of 10 mm is set equidistantly with respect to each other at a constant distance of 0.5 cm from each other. Welding current is supplied including To fill the gap using molten metal electrode with a diameter of 3 mm, continuously supplied to the welding zone. Supply current c. hours equal to 200 A, supplied from a current source with a capacity of 250 kW, frequency 440 kHz.

 To hold the bath, you can use gaskets, for example, ceramic.

 Using the invention allows to significantly increase the characteristics of the welding current, to make the welding process technological, cost-effective and environmentally friendly. Parts can be welded at high speed (10-15 times higher than in arc welding). You can cook elements of any thickness. The method makes it possible to significantly reduce welding deformation.

 Heating the edges directly during high-frequency welding can save energy and reduce deformations by heating a smaller volume of metal, as well as increase productivity.

 Welding is carried out in one pass. You can also cook brands and pipes.

Claims (1)

 A method of welding with high-frequency currents, in which the parts are installed with a constant gap, the welding circuit is closed by feeding filler material into the gap, a high-frequency current is passed and the gap is filled with simultaneous heating of the edges, characterized in that the filler material is fed into the gap in molten form, due to which additional heating of the edges is carried out.