SU448106A1 - Protective gas mixture - Google Patents

Description

This invention relates to the field of shielded gas welding.

A known protective gas mixture consisting of 80% Ar + 15% CO2 + 5% Os ensures high quality of weld metal and a significant reduction in spatter during welding with jet transfer of electrode metal.

In the absence of jet transfer, the welding process in this mixture practically does not differ from welding in CO2 and is characterized by intensive sputtering of the electrode metal and the rough-scaly formation of the weld surface. This significantly impairs the appearance of the product being welded and, as a result, narrows the range of application of protective gas mixtures.

The reduction of the critical current to obtain the jet transfer of metal is achieved by the fact that ozone in the amount of 0.00001-0.1% is introduced into the composition of the mixture, and the remaining components are taken in the following ratio,%:

Carbon dioxide5-40

Oxygen0,01 - 10

Argon Else

The proposed gas mixture, while retaining all the positive qualities of the known mixture, makes it possible to obtain a jet transfer of metal at a lower value of the welding current and, therefore, to perform small-section welds without splashing. The presence of low concentrations of ozone in the mixture helps to improve the atmosphere in the welding shop. In addition, ozone, which gives a gas mixture a specifically pleasant smell, can quickly detect its leakage.

The mixture is prepared by mixing pure gases from cylinders (ozone is obtained using a laboratory ozonizer), using welding rod Sv-08G2S with a diameter of 1.6 and 2.0 mm.

Experimental welding showed that the use of the proposed mixture allows to obtain a steady jet transfer of the electrode metal for a wire with a diameter of 1.6 mm at a welding current of 300 a, and for a wire with a diameter of 2.0 mm at a current of 350 a. Under the same conditions of welding in a mixture of Ar + 25% CO2 + 5% Oa, the critical current was 350 a and 400 a, respectively.

Technological tests of the proposed mixture showed that it provides good formation of welds in all tested modes. When welding on currents above the critical, the surface of the seams is smooth, comparable to the surface of the seams made under flux. Arc burning in this case is soft, spattering is completely absent. rm; The subject matter of the invention Protective gas mixture for electric arc welding containing argon, carbon dioxide and oxygen, characterized in that, 4 in order to ensure the jet transfer of the electrode metal, having introduced ozone in the composition of the Mixture in an amount of 0.00001 to 0.1% the remaining components are taken in the following ratio,%: Carbon dioxide 5-40 Oxygen 0.01-10 Argon Else.