JPS61232063A - Quality improving device for metal welding - Google Patents

Abstract

PURPOSE:To prevent a solidification crack and hydrogen embrittlement and to prevent as well the defect due to impurities by passing the line of magnetic force and current to the molten metal of a molten pool and by applying continuously the electromagnetic force in the bottom direction of the molten pool. CONSTITUTION:The welding face of welding materials 1, 2 is abutted to a V-shaped groove and magnetic poles 3, 4 and electrodes 5, 6 are assembled so that the line of magnetic force from the magnetic poles 3, 4 and the current from the electrodes 5, 6 are crossed at right angles at the molten pool estimating position. In this case the electrodes 5, 6 fix the insulating body so that the tip of the electrode comes into contact with the base metal surface with sliding vertically via electrical insulating bodies 7, 8 and pressure-fitting springs 9, 10 close to the magnetic pole, passing DC small current to coils 11, 12 and DC big current is passed to the electrodes 5, 6. A welding rod 13 is mechanically connected via a lever 16 to the speed controlling variable resistor 15 of a wire rope coiler 14 to penetrate with sliding the metal fitting 17 at the tip of the lever, to generate an arc in the space with the base metal welding face, to form the molten pool, to adjust mechanically the speed controlling variable resistor 15 of the wire rope coiler 14 and to automatically control to the following-up speed.

Description

[Detailed description of the invention] The present invention relates to a metal welding quality improvement device.

Conventional metal welding has disadvantages such as solidification cracking and hydrogen embrittlement, as well as blowholes and slag entrainment defects.

The present invention can prevent the occurrence of defects due to cracks and impurities, and it is possible to prevent the occurrence of defects due to these cracks and impurities. Continuously applies electromagnetic force by passing magnetic lines of force and current to the molten pool, promoting internal pressure and density proportional to the depth of the molten pool, fostering high-quality growth of crystal grains, preventing solidification cracking, and eliminating air bubbles and impurities, and reducing crystal grains and grains. This is a metal welding quality improvement device that is characterized by preventing hydrogen atoms from entering the field.

The NS pole of the U-shaped electromagnet is bent near the tip of the magnetic pole, so that the magnetic pole surface slides closely against the base metal surface, and a wire is wound around the magnet rod so that the magnetic pole becomes the NS pole. A line connecting the center of the NS magnetic pole to the welding line makes an angle of 45 degrees, and the NS pole is placed in a position close to the molten pool.The electrode is attached to the electromagnet rod near the magnetic pole so as to slide through an electrical insulator. The mounting position is such that the electrode surface slides closely against the base metal surface, and the lines connecting the centers of the magnetic pole and electrode intersect at right angles, maintaining a 45 degree angle left and right with the welding line, and the intersection of the two lines is on the base metal welding line. Two electrodes are installed on the base metal surface so that they match the predicted molten pool position and are brought into contact by the electromagnet's gravity, the electromagnet's attraction force, and the electrode's pressure contact spring.

The power source uses direct current, and the electrodes are connected to electric wires capable of passing low voltage and large current through an electromagnetic force control device, and the wires are capable of passing low voltage and small current. A support driving wheel and a wire lobe winding machine that follows the welding speed are installed on the opposite side of the magnetic pole, and the tip of the wire lobe is hooked at an appropriate position on the welding line extension to cause the electromagnet to follow the welding progress. The welding equipment that uses this device consists of a welder, a welding rod, a welding rod holder, and a dedicated power source.

An embodiment of the present invention for butt joint welding of steel materials will be explained with reference to the drawings. The welding surface of the welding base material L2 in FIG. The NS pole 3.4 of the electromagnet in the figure straddles the welding line, and the magnet rod is placed approximately parallel to the welding line, so that the magnetic field line from the magnetic pole 4 and the current from the electrode 5.6 are at right angles at the expected position of the molten pool. Assemble the magnetic poles 3.4 and electrodes 5.6 of the cone-shaped electromagnet so that they intersect. The electrode 5.6 is fixedly mounted near the magnetic pole via an electrical insulator 7.8 and a pressure contact spring 9.10 so that the tip of the electrode automatically contacts the base material while sliding up and down. A small DC current is passed through the electrodes 11.12 and a large DC current is passed through the electrodes 5.6. The welding rod 13 in FIG. 1 is mechanically connected via a lever 16 to the speed control variable resistor 15 of the wire lobe winder 14 in FIGS. An arc is generated between the welding surface and the welding surface to create a molten pool, and the speed control variable resistor 15 of the wire lobe winder 14 is mechanically adjusted to automatically control the following speed. The integrated electromagnet and electrode follow the progress of welding while keeping the magnetic pole surface and electrode surface in contact with the base metal surface.One end of the wire lobe 18 is connected to the wire lobe winder 14, and the other end is extended to the welding line shown in Fig. 1111. The hook is wound and pulled at an appropriate position 19 on the line, supported by the driving wheels 20 and 21, guided by the guide rail 2223, and follows the progress of welding.

A current cross-flows with the molten metal title ζ magnetic field lines in the molten pool in Figure 1, and electromagnetic force is continuously applied to metal atoms and initial crystal grains toward the bottom of the molten pool, promoting pressure and density proportional to the depth of the molten pool. This method not only promotes high-quality crystal grain growth and prevents solidification cracking, but also eliminates the cause of low-temperature cracking by discharging air bubbles and impurities and preventing water droplet atoms from entering crystal grains and grain boundaries.

In corner welding of a T-shaped joint, one magnetic pole and electrode are rotated 90 degrees using the magnetic pole rod connecting portion 241 in FIG. 3 and brought into contact with the T-shaped base metal surface. In addition, in connection welding of pipes, by attaching crescent-shaped extended magnetic poles and electrodes that match the curved outer shape of the pipe, it can function similarly to butt joint welding.

An example of welding a non-ferrous metal butt joint of the present invention will be explained with reference to Fig. #I1 and Fig. 2. Since the base material is paramagnetic, it is necessary to provide a magnetic path soft iron material 25 on the back side of the base material directly under one magnetic pole. It can guide magnetic lines of force into the molten pool and act in the same way as in steel materials, preventing the occurrence of multiple defects in non-ferrous metal welding.

In the present invention, in addition to the magnetic transformation and increase in electrical resistance in and around the molten pool, both electromagnetism flows out over a wide area. It works well and can significantly improve the quality of welding, and is especially effective when used before welding nuclear power related equipment. Welding of structurally important parts, parts that cannot be inspected, and materials that cannot be re-welded can be used as a quality assurance technique. In general welding, non-destructive inspection is not required, and this has the effect of increasing the technical reliability of welding in general.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the relative position between the present invention and the welding base material;
Fig. 2 is a 1-1 sectional view of Fig. 1 and shows an example of the use of magnetic path soft iron material for welding non-ferrous metal materials, Fig. 3 is a perspective view showing the structure of the present invention, and Fig. 4 is a detailed view of the present invention. It is an explanatory diagram.

Claims (1)

[Claims] Electromagnetic force is continuously applied to the molten metal atoms and initial crystal grains during metal welding by passing magnetic lines and current in a direction according to Fleming's left-hand rule, so that electromagnetic force is generated toward the bottom of the molten pool.
It is characterized by promoting internal pressure and density proportional to the depth of the molten pool, fostering high-quality growth of crystal grains, preventing solidification cracking, and discharging air bubbles and impurities and preventing hydrogen atoms from penetrating into crystal grains and grain boundaries. Equipment for improving the quality of metal welding.