RU2252120C1 - Coating for protecting surface against splashes of melt metal at electric arc fusion welding - Google Patents

Abstract

FIELD: single-pass welding by means of consumable electrode in carbon dioxide medium for protecting manufacturing equipment and surfaces of welded parts against splashes of melt metal.

SUBSTANCE: coating contains next ingredients, g per 1l of water: sulfite-alcohol mash, 100; barium, 30-40.

EFFECT: lowered content of phosphorus in metal of welded joint, reduced quantity of hard-to-trap splashes.

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Description

The invention relates to single-pass metal welding by a consumable electrode in carbon dioxide, and in particular to coatings for protecting the surface of welded products and processing equipment from splashes of molten metal.

Known coating for protecting a metal surface from splashes of molten metal, containing the following components (in%): aluminum powder - 4 ... 10; dextrin - 4 ... 10; Marshalite - 62 ... 64 water - 26 ... 30 (see ed. St. USSR No. 273350, 23 K 35/36, 1970).

The described coating has low technological properties, expressed in an increase in the phosphorus content in the weld metal.

The closest in technological essence is a coating to protect the surface from adhesion of splashes of molten metal, containing the following components, g per 1 liter of water: sulphite-alcohol stillage - 60 ... 110; soap - 25-45; soda ash - 15 ... 25; kaolin 25-50 (see ed. St. USSR No. 923784, 23K 35/36, 1980).

A disadvantage of the known coating is the increase in its application of the phosphorus content in the weld.

The task is to develop a coating composition that ensures a decrease in the phosphorus content in the deposited metal.

This object is achieved by the fact that barium is introduced into the coating to protect the surface from splashes of molten metal during fusion welding containing water, sulfite-alcohol stillage concentrate, with the following components, g per 1 liter of water:

sulphite-alcohol bard 100

barium 30-40

The inventive coating is characterized by the presence of the following significant distinguishing features (content of components g per 1 liter of water):

a) sulfite-alcohol bard 100

b) barium 30-40

Studies on patent and scientific and technical literature have revealed a number of technical solutions for a similar purpose, however, feature (b) is missing. From this we can conclude that the proposed coating meets the eligibility conditions of the invention: “novelty” and “inventive step”, and numerous laboratory tests have shown its high technological properties.

The coating components perform the following functions:

1) sulfite-alcohol bard - protective functions;

2) barium - reduces the phosphorus content in the weld metal.

The transition of phosphorus from molten weld metal to slag with the participation of barium is described by the following reactions:

[P] + 2O ₂ = PO ₄

2 [P] + 5 [O] = (P ₂ O _{5) SHL}

2Р + 8О + 3Ва = Ва ₃ ( _{РО 4} ) _2shl

Three coating compositions were made from these components. The table shows the results of a chemical analysis of the weld metal (phosphorus content) and the amount of hard to remove spatter (welding wire Sv-08G2S, diameter 1.6 mm; welding current 300 A; welding samples were made of St3 steel).

For comparison, the characteristics of known coatings are given.

Table 1 Coating Known by A.S. No. 273350 Known by A.S. No. 9237840 Proposed (barium content, g) thirty 35 40 The phosphorus content,% 0.019 0.016 0.014 0.013 0.012 Hard to remove spray% 3.8 2.1 2.1 1.9 1.9

Claims (1)

A coating to protect the surface from splashes of molten metal during fusion welding, containing water, sulphite-alcohol stillage, characterized in that barium is introduced into it with the following components, g per 1 liter of water: sulphite-alcohol bard 100 barium 30-40