SU998064A1 - Welding flux for electric slag welding of alloyed steels - Google Patents

Description

The invention relates to welding materials, in particular, to the composition of the flux for electroslag welding (ESW) or smelting (ESR) of alloyed steels.,

The flux for ESW must meet the following requirements: to ensure a quick and easy start of the electric jointing process and to maintain its steady passage, especially when the slag bath is shallow and the welding electrode feed rate is high: to ensure satisfactory formation of the weld surface; to form slag which is easily separated from the surface of the weld; have a high boiling point.

Known fluxes (ESW) alloyed steels based on CaF, CaO ij.

Known flux for ESW and ESR of alloyed steels containing calcium fluoride, silica at the following ratio of components, wt.%:

Alumina 30-40

Silica.2

Fluoride

calcium 60-70

This flux. meets the largest number of requirements for fluxes for ESR and ESW; normal load

The process has a reasonable and stable process, a moderate rate of floating and ingot, minimal oxidative HocTbf, good wetting of non-metallic C 23 inclusions.

However, due to the further development of the ESR and ESW processes, the flux becomes a deficit, and its cost

10 is pretty high. In addition, when using this flux for ESW consumable electrodes, the welding seam is not strong enough, especially when welding invertar heads to the consumable electrodes of steel grades ShH-15 and ShH-15SG, and the welding time is significant.

The purpose of the invention is to reduce the cost of the welding process and increase

20 quality weld.

This goal is achieved by the fact that the flux for electroslag welding of alloyed steels containing calcium fluoride and alumina additionally contains waste gas cleaning of ESR furnaces in the following ratio of ingredients, wt.%:

Fluoride

calcium4-50

thirty

Alumina1-20 dry gas cleaning waste30-95 Dry gas cleaning waste from ESR heaps has the following chemical composition, weight,%: AljrOs- 25-29, CaO - 3-5, SIO / j 1-3, С and F-i- Else. In large metallurgical shops specializing in the production of steel by electroslag remelting, a large amount of dust evacuated from the operating volume of the crystallizer 16 along with gases accumulates in the gas exhaust system. Testing was carried out on a steel column-type apparatus A-550-U-3 when welding consumable electrodes with a cross section of 370-370 mm made of steel grade, 1ShH-15 ST with carbon steel steel inventory heads. Electric welding of consumable electrodes with an inverter head is carried out as follows. After laying on the roller table of the electrode and the inverter head, the forming device is installed in the place of formation of the weld. A consumable welding electrode is fixed in the electrode holder and centered; its relative to the ends of the welded products. Clean metal chips are poured on the lower forming unit and the welding electrode is lowered until it comes into contact with it. An ignition mixture mixed with flux ANF-b is poured on the chip around the bottom end of the electrode. At the same time, a mixture of flux ANF-b is prepared with waste gas cleaning of the ESR-10G furnaces. A part of the C-50% mixture is poured around the lower end of the welding electrode onto the ignition mixture. Then voltage is applied to the electrode. An electric arc arises between the bottom end of the electrode and the chips, the chips burn off, the ignition mixture melts, and a liquid bath forms, which shunts the electrode. The working flux gradually melts, forming a liquid slag bath in which the remelting process of the consumable welding electrode begins. The depth of the slag bath is regulated by adding the rest of the flux. Upon completion of welding, the bumming electrode is removed from the slag bath and removed. The effect of the flux composition on the process, j welding consumable electrodes with i-ner tary heads (compositions 1-3 - s. / Content of waste dry gas cleaning of ESR furnaces (proposed), part 4 - known) is given in the table.

95

The use of dry gas cleaning dust as an additive to fluxes ANf-6 and ANF-1P showed that when welding consumable electrodes made of Steel ShH-15 and ShH-15SG with inverter heads at the ESW installation, the welding seam is more qualitative than on known fluxes . There were no welds in the lower part of the weld, the seam across the entire height of the welding was smooth, without gulfs and overlaps. The time of welding the juice was due to a more rapid induction of the slag bath and the stabilization of the remelting process of the consumable welding electrode.

At the same time, the use of dry gas cleaning waste in an amount of less than 30%

25 Good, no cooks

practically did not give the advantage of quickly setting the slag bath and stabilizing the remelting process. The use of dry gas cleaning wastes: more than 95% of the total mass of the flux made it difficult to initiate the arc and induce the slag bath due to sintering of dust and the formation of a crust on the surface of the slag bath. So with a flux using 50% dust, the process stabilized in 8 minutes, and with a dust content of 25% in only 14 minutes. With a total duration of welding in the first case, 25 minutes, in the second - 35 minutes.

Claims (2)

The results of the testing showed that, in comparison with the known composition (composition 4), welding performed on the proposed flux yielded positive results. The ESW process was stabilized more quickly, the total welding time was shorter, and the best weld was obtained. Thus, the application of the proposed flux with the content of waste gas dry cleaning of ESR furnaces will reduce the cost of the ESW process and improve the quality of the weld as compared with known fluxes. Claims of the invention Welding flux for electroslag welding of alloyed steels containing calcium fluoride and clay in the form of q reducing the cost of the welding process and improving the quality of the weld, it introduces waste gas cleaning of ESR furnaces with the following ratio of ingredients , wt.%: Fluoride concentrations 4-50 Alumina1-20 Dry gas waste. cleaning- 30-95 Sources of information, taken into account in the examination 1. Techniques for electrical welding of metals and alloys by fusion. Ed. B.Ye.Patona, Mechanical Engineering, 1974, p. 364-365, 2. Authors certificate of the USSR 356080, cl. In 23 K 35/362, 11.02.71 (prototype).