SU1362584A1 - Method of arc welding with consumable electrode with short closing of arc gap - Google Patents

Abstract

This invention relates to a 1 -S short arc arc welding technology. . 1 ((CG) arc gap and can be used in all fields of mechanical engineering. The purpose of the invention is to improve the quality of welded joints and process performance while reducing the consumption of electricity and welding materials. To achieve the goal in conducting the arc welding process with arc short circuit welding the gap in the short-circuit period, the welding current is reduced at the time of the formation of a neck on the electrode to a minimum value that does not violate the process stability. The moment of formation of the cervix is determined by the increase in voltage on the arc during the fault time. The method practically eliminates splashing and ensures good weld formation. The energy consumption is up to 32%, and the welding wire is up to 12%, 1 Ill. i (L with O) N3 SL 00 4

Description

The invention relates to methods for arc welding with a fusion electrode in a protective gas environment and can be used in shipbuilding, mechanical engineering and other industries.

The aim of the invention is to improve the quality of welded joints and process performance while reducing the consumption of electricity and welding materials.

The drawing shows the change in voltage and arc current at various points in the formation and destruction of the jumper neck during the charging process with arc short-circuits.

The method is carried out as follows.

During steady arc burning (1g.d.) (drawing) a drop is formed. The arc gap is reduced. In this case, the voltage drop across the arc and the magnitude of the welding current practically do not change. At the moment of the start of a short circuit (t, cs), the drop touches the surface of the weld pool and the arc gap closes. The arc goes out. The voltage decreases sharply and the current in the circuit increases. As the current increases, the pinch effect increases, which leads to the formation of a neck at the moment t2 of the short-circuit. and helps to accelerate the transition drops in the bath.

So that the thinned neck does not overheat the passage w, it does not get destroyed by it with an explosion at the same time, i.e. at the time of the formation of the neck, reduce the welding current to the magnitude of L. 3 min (moment 1 3 short-circuit).

The value of L. m.s.nn is determined from the formula

1k.z.min 1.78 10

Ed

Vg-VK.

V ,,,

where e is the potential gradient of the arc column; d is the diameter of the electrode wire; Vg is the voltage drop across the arc; Aq.a. is the sum of the cathode and anodic voltage drop;

Y „is the feed rate of the electrode wire when welding in a CO2 environment. For example, at У „4.53 (m / s), d 1.2 mm, 1 km of 215 A.

The moment of neck formation is fixed by an increase in arc voltage during the arc short circuit time. After breaking the jumper at time t4 k.z. uve0

five

0

five

0

five

0

five

0

The current is reduced to a magnitude of 1cv. Then the cycle repeats from a steady arc. The cycle of current change during a short circuit of an arc gap allows one to prevent a gas-dynamic shock caused by electromagnetic forces during the formation of a jumper between the electrode metal drop and a spring bath, to limit the current flowing through the formed jumper of the liquid metal, and when the neck is formed a sharp decrease in the welding current to a value of 1k.z. mines to exclude its overheating, which ensures the elimination of spattering and improvement of the quality of welding, as well as increased productivity due to the exclusion of works on cleaning the welds.

In addition, the limitation of short-circuit currents saves energy consumption.

Example. Welded in the medium: Ar 80%; CO2 is 20% of standard wire 0 1.2 mm of the brand SV1OH19N11M4F with a current of 180-200 A, arc voltage of 19-20 V by a serial automatic from a current source of the type VDU-504 UZ with a microprocessor-based controller K1-20.

At the time of formation of the neck current 1K.C. limited to the level of 215-220 A. (1k.zmin). The signal at the beginning of the limit, i.e. the appearance of a jumper neck was fixed by increasing the voltage on the arc during a short circuit to 2.3 V.

The process was stable, the formation of the seam is good. The method virtually eliminates splashing, ensures good formation of the weld. The energy saving in this example is 32%, and the welding wire is 12%.

Claims (1)

Invention Formula The method of arc welding with a short-circuit arc arc welding electrode, in which a welding current is reduced during a short circuit and its subsequent increase, characterized in that, in order to improve the quality of welded joints, process performance, reduce power consumption and welding materials by eliminating splashing, the welding current is reduced to the minimum short-circuit current at the time of the jumper jaw formation, and its subsequent increase one after the break. and I