SU1748981A1 - Electrode coating composition - Google Patents

Abstract

Use: welding of non-critical structures in alternating and direct current. The essence of the invention: the composition of the electrode coating contains, in wt%: Me 7.8-10, flux, AN-348A 88.8-91.4, aluminum powder 0.8-1.2. It is applied to the rod by dipping. 1 tab.

Description

The invention relates to the field of welding, namely to electrode coatings of a multi-alloy mixture for the manufacture of thin-coated electrodes by dipping and can be used for welding non-critical steel structures instead of electrodes with a stabilizing coating.

Formulations of stabilizing coatings are known, such as a chalk coating, on the top of the A-1 electrodes. MT, VIAM-25, developed for the manufacture of electrodes based on wire Sv-08 by dipping with a coating ratio of 1-2%. The coating includes chalk and liquid glass (soda). Increased productivity is achieved by introducing titanium dioxide and manganese ore into the composition of the coating.

The stabilizing chalk coating contains 100 parts by weight of chalk and 17–20% sodium liquid glass (dry residue to the weight of chalk). The main purpose of the coating is to increase the stability of the welding arc. Due to the large spattering losses and waste, the low rate of electrode melting, the impossibility

conduct high-current welding electrodes with such a coating have low productivity. To improve the performance of stabilizing electrodes, to improve the formation of a seam, small amounts of titanium dioxide, manganese ore, which form a small amount of low-melting slag (A-1, MT, T-2, VIAM-25 electrodes) are introduced into the coating,

The disadvantage of these coatings is that due to the large losses on burnout and spraying, the electrodes have low productivity, the small thickness of the coating does not provide sufficient protection of the weld pool and arc gap from the influence of atmospheric air, therefore the mechanical properties of the weld metal are low and practically do not differ on the properties of the weld metal welded with bare wire. Many welding works during welding of inappropriate structures and surfacing works are performed with high-quality electrodes, which leads to the loss of scarce ferroalloys used to manufacture these electrodes and creates

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deficiency in electrodes where they are really needed.

The aim of the invention is the development of the composition of the electrode coating for the manufacture of electrodes by dipping, not containing scarce materials, providing an increase in the quality of the welded joint when welding non-critical structures made of steel with alternating and direct current.

The goal is achieved by the fact that the composition of the electrode coating is made of the following components, wt.%:

FluusAN-348A88,8-91,4

Marble, Mel 7,8-10,0

Aluminum powder 0,8-1.2

Liquid sodium

glass density 1,34-55

- (dry residue 22% from

weight of dry mix).

The flux components of AN-348A are slag-forming, CaCO3-slag- and gas-forming, aluminum powder is a deoxidizing agent. When the ratio of components changes, the quality of the weld deteriorates, the slag crust separability, pores and undercuts appear. Therefore, this ratio of homemade products is optimal.

The AN-348A flux and marble (chalk) are pre-ground in a ball mill, sieved through a sieve 04 of GOST 6613-73, mixed in the specified ratios with the powder. After adding liquid glass, the coating components are thoroughly mixed. The consistency of the mixture makes it possible to obtain electrodes with a one-time dipping method with a coating ratio of 12–14% (for an electrode diameter of 3 mm). After refining, the electrodes are dried in an oven with a temperature of 200 ° C for 1 hour.

Testing of samples from steel St 3 for static stretching in accordance with the requirements of GOST 6996-66 (samples type XII, butt joint welding) showed that the tensile strength is not less than 380 MPa, destruction occurs

base metal When welding with electrodes with a diameter of 3 mm, the current is 100-105 A, the melt ratio is 7.8-8.0 g / A.h, the deposition rate is 7.35-7.45

g / A.h, loss factor of 5.7-6.6%.

The use of this coating for the manufacture of electrodes makes it possible to exclude the use of deficient ferroalloys (ferromanganese and carbonate) as a deoxidizing agent.

ferrosilicon), whose content in high-quality electrodes reaches 15-20%. Electrodes with the specified coating provide the mechanical properties of the welded joint at the level of the e-38 electrodes (380 MPa).

Electrodes provide greater penetration depth, which allows butt welding for sheet material with a thickness of up to 4 mm without edge cutting. In case of violation of equal thickness of the coating, the arc wanders. Welding was performed on specimens of steel V ST 3 GOST 380-71. When testing the strength of a welded joint, the tensile strength is within 375-380 MPa for cases where the coating components

within specified limits.

With the deterioration of the technological properties of the electrodes when the composition of the coating changed beyond the specified limits, the welded samples were not subjected to the test for static stretching.

The results of the evaluation of the quality of the electrodes are given in the table.

Claims (1)

The invention The composition of the electrode coating containing honey, aluminum, which is characterized by the fact that, in order to improve the quality of the welded joint in the manufacture of electrodes by dipping for welding non-critical steel structures on constant and alternating current, the composition additionally contains flux AN-348A in the following ratio of components, McJt yu Flux AN-348A88.8-H-91.4 Mel7.8-10.0 Aluminum (powder) 0.8-1.2. i Continuation of the table