Method of arc welding

 

(57) Abstract:

Usage: for arc welding of butt joints with narrow cutting edges. The inventive when welding in a narrow groove opening angle of the edges is performed in 25 - 30o. The welding process are the burner at an angle with an inclination relative to the vertical axis in 20-30oand the root of the weld is performed by decreasing the welding current and voltage of the welding mode subsequent layers of the seam. The width of the gap is 2-3 mm 5 table.

The invention relates to welding, in particular, to a method of arc welding of butt joints with narrow cutting edges, and can be used in all sectors of the economy, which uses automatic or semi-automatic welding connections of any steel thickness up to 70 mm in the lower position using standard equipment.

Known methods of welding in shielding gas consumable electrode in a narrow groove [1,2,3]

The disadvantages of the methods include: the need to use special equipment (expensive and scarce), lack of reliability of welding methods.

The closest to predate less than 30o. Arc pressure on the molten metal is adjusted so that the width of the arc on the surface of the weld pool was smaller than the size of the gap in the junction, i.e., when performing a method for welding modes of the proposed method minimum value of gap width is 5.5 mm [2]

The disadvantage of this method is the increased size of the cross-sectional area of the weld, the complex process of reproduction method (regulation of arc pressure on the molten metal) and the use of special equipment for its implementation.

The aim of the invention is to increase the productivity in the manufacture of welded steel constructions any brands up to 70 mm thickness by reducing the cross-sectional area of the weld and reduce the width of the gap; reducing consumption of welding materials, energy, improving weld quality by reducing the flatness (warp details).

This objective is achieved in that before welding perform in any way the seam one-way sealing edges with a metal thickness of up to 35 mm and two-way when the metal thickness up to 70 mm, the width of the gap is 2 to 3 mm, the weld root perform at St. the seam and, welding torch have an angle with an inclination relative to the vertical axis 20 of the 30o. In addition, the proposed method of arc welding performed on standard equipment. The method is as follows.

Collect details, prepared by the proposed method, stir in the cutting arc, perform root weld on the low modes. Then perform the filling of the cutting at the optimum welding conditions. To perform this welding method used standard equipment.

Comparative analysis of the proposed solutions with the prototype shows that the claimed method of arc welding differs from the known reduction of the width of the gap, which is 2 to 3 mm, which allows to significantly reduce the cross-sectional area of the weld, therefore, to improve the performance of welding, to reduce the consumption of welding materials, electricity, and will simplify the welding process (no need to adjust the arc pressure on the molten metal), using standard equipment. Thus, the claimed method meets the criteria of the invention of "novelty."

Analysis of the known welding methods showed that when following the main pairs of the arch, and the Assembly) will increase the quality of connections by reducing warping of parts. This allows to make a conclusion on the conformity of the proposed technical solution the criterion of "substantial differences".

Example. Was welding arc welding in carbon dioxide product from sheet steel St 70 mm thick with bevel edges 25o(total angle) made mechanical gouging. Material consumable electrode welding wire رق-HTMT a diameter of 1.4 mm, the Parameters of welding conditions shown in table. 1.

Welding performed from welding rectifier VS-300 semi-automatic And-547 on the hard external characteristic. The result is a high-quality suture (PL. 2), lack of penetration was no.

The proposed solution allows you to:

1. To increase productivity in the manufacture of welded structures of large thickness by reducing the cross-sectional area of the weld (see tab. 3), reducing the complexity of cleaning the surface of articles from molten metal splashes.

2. To reduce the consumption of welding materials, electricity up to 42% compared with the prototype while improving the quality of welded joints (increased strength properties, impact strength, reduced shrinkage).

In table. 4 shows the optimal the economic impact by reducing consumption of welding materials, electricity, improving the quality of welded joints, the complexity of the preparation for welding, welding and strip from molten metal splashes.

In the laboratory welding was tested welding method in the following modes (table. 5).

Method of arc welding of butt joints in steel thickness up to 70 mm in the narrow groove with an included angle of less than 30owhere arc excite in section, and the welding process lead to the optimal mode, wherein, with the aim of improving productivity, reducing cost and improving quality, the gap width between the edges take is equal to 2

3 mm, welding lead angle of forward inclination relative to the vertical axis 20

30oat the root of the weld is performed by reducing the optimal values of current and voltage from 20 to 25%

 

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