SU1437173A1 - Method of arc spot welding - Google Patents

Description

4i SAE

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WITH

1. 14

The invention relates to arc welding with a fusible electrode and can be used in various areas of the industry involved in the manufacture of products and structures using spot and electrical riveting welded joints in various protective media and spatial positions.

The purpose of the invention is to improve the quality of welding by increasing the concentration of heat input to the weld point, shortening the welding cycle, reducing the consumption of welding materials and electricity.

The goal is achieved by the method of arc welding with a supply of a melting electrode, in which during the welding period the melting electrode is fixed relative to the current-carrying device, excite the arc, form a weld point, after which the arc is bent and brewed. The arcs supply the melting electrode with a shock reduction of its length to at least 1% of the diameter of the electrode.

The method is carried out as follows.

The melting electrode tucked into the welding machine is fixed relative to the current-carrying device for a given electrode overhang value, selected depending on its diameter and the required parameters of the electric rivet point), place the end of the electrode above the welding point, protect the welding zone from the ambient air and excite one of the known methods, then abruptly, by the form of an impact, the current-carrying device is brought closer to the surface of the metal being welded, which instantly reduces the length of the electrode reach and arc. In this case, a pulsed growth of the welding current occurs and a higher concentration of heat release to the resulting weld spot is provided.

Then, one of the known methods, which include arc stretching and crater sealing, completes the welding process. "

With a well-established electrical circuit for controlling the process (cycle) of welding the electrode overhang length per cycle of one point, it can be reduced

Iq

15

20 25,

thirty

40 dd

0

732

up to 1% of the diameter of the electrode. An even greater reduction in the length of the electrode overhang is dangerous by fusing the current-carrying device (mouthpiece) and fusing it with the electrode, which makes it impossible to continue welding the following points without repair work.

Normal should be considered the conditions of the arc (welding points in this method, when the total (initial) length of the electrode overhang remains part of it is equal to 3-5 electrode diameters.

At the same time, the method allows once fixed with respect to the current-carrying device to a melting device — with the electrode it is possible to successively weld several points, spending on each of them a part of the initial emission of the electrode.

Example. It is required to weld under flux by spot welding of an overlap joint with a thickness of 3 + 5 mm. The material of the base metal st.Z; flux brand AN-348; welding wire brand Sv08GA diameter 2.0 mm. Welding mode:

Source bit

electrode, mm40,0

Vybet electrode

after welding, mm 10.0

(5d,)

Speed of contraction of electrode outflow, mm / s 50.0 Amplitude of welding current per pulse, A 1800

As a result of welding, a point with a core diameter between the welded sheets of 9.0 mm was obtained. The length of the electrode remaining after welding of the electrode remained normal and equal to 5 diameters of 5 electrodes, i.e. 10.0 mm.

Example 2. It is required to weld a point connection with overlap in thickness of 1,. 0 mm in carbon dioxide. The material of the base metal st.Z; wire brand Sv08G2S with a diameter of 1.2 mm. Welding mode:

Departure departure

Electrode, mm20,0

Electrode overhang

after welding, mm 6.0

(5d,)

Cutting speed

Departure of electric power, mm / s 300

Welding amplitude

pulse current, A 1000

As a result of welding, an electric rivet was obtained with a dimeter core between the sheets being welded equal to 5.0 mm. The tip of the electrode after welding is equal to 5 electrode diameters or 6.0 mm, which is quite normal for a given welding mode.

No defects in the point joints obtained during welding both under flux and carbon dioxide were not detected.

The method can be used both for sequential welding with single points (electric rivets), and for simultaneous parallel welding with several points from one or several arc power sources connected in parallel. As a melting electrode, they can be used as solid ones.

and cored wires in the form of single or composite electrodes. In addition, the method can replace contact spot welding.

In comparison with the prototype, the proposed method provides a significant increase in the concentration of heat input in the metal being welded, thereby shortening the welding cycle, improving the quality of welded joints, reducing the consumption of welding materials from electrical energy and reducing welding deformations, and also greatly simplifying welding equipment.

Editor A.Lezhnina Tehred A.Kravchuk

Order 5829/14 Circulation 922 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Proofreader M.Vasilyeva

Claims (1)

METHOD OF ARC POINT .WELDING with the supply of a consumable electrode, in which for the period of welding the consumable electrode is fixed relative to the current-supplying device, excite the arc, form a weld point, then stretch the arc and weld the crater, characterized in that, in order to improve the quality of welding by increasing concentration of heat input to the weld point, reduction of the welding cycle, reduction of the consumption of welding materials and electricity, after arc excitation, _{Λ of the} consumable electrode is supplied with shock reduction <g 1 reduction of the length of its extension to a value of at least 1% of the diameter of the electrode. SU „, 1437173 1 . 1437