RU2609120C2 - Protective coating for surface from sticking of molten metal splashes - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention can be used in welding by consumable electrode as protective agent for surface of welded articles and process equipment. Protective coating is produced on basis of electrochemically synthesized, activated aqueous catholyte solution, which, by changing structure of water, provides synergetic interaction of components of coating on molecular and ion levels, which improves operational characteristics of given coating. Protective coating contains following component ratio, wt%: electrochemically activated catholyte 50, neonol 10, diethylene glycol 28, polypropylene glycol 12.

EFFECT: produced non-stick film has good wettability to contaminated metal surface, low corrosion activity to metals.

1 cl, 1 tbl

Description

The invention "A protective coating for a surface against sticking of splashes of molten metal" relates to mechanical engineering, energy, and construction and can be used in technological processes where metal is used for welding with a consumable electrode, as protective agents for the surface of welded products and technological equipment.

When welding products, a significant amount of welding spatter adheres firmly to the surface of the base metal and welding tool material, which impairs the appearance and performance of the finished metal structure, is an unacceptable defect for complex and high-quality products and can cause a fire, and also takes a lot of time to physical spray removal.

Spray protection is partially solved by the technological application of solutions: careful selection of welding electrodes and wire, more precise adjustment of welding equipment, selection of the optimal mode and angle of welding, and a number of others. All these methods require time and material costs and do not always lead to the desired result. The most optimal and cost-effective is the use of special protective agents that prevent the adhesion of splashes on the surface. The choice of tool is very important - the quality of the weld should not deteriorate, the protective coating should be well removed from the metal surface and not impair adhesion during subsequent painting.

Known coating for surface protection against adhesion of splashes of molten metal, patent RU 2134186, publ. 08/10/1999, class B23K 35/365, containing, g per 1 liter of water: sulphite-alcohol stillage - 50-80, soap - 30-40 and soda ash - 15-20, abrasive waste - 30-60. The disadvantage of this coating is its reduced protective properties, as well as the presence of a fermentation process during storage.

The closest analogue in the set of essential features and the achieved technical result is the coating disclosed in patent RU 2268127, publ. January 20, 2006, class B23K 35/36, containing, g per 1 liter of water: sulphite-alcohol stillage concentrate in an amount of 200-220 g and glycerol 120-150 g per 1 liter of water. However, this coating has low technological properties, expressed in poor wettability of surfaces contaminated with fats and oils.

The technical result is reliable protection of the welded surfaces of the product, technological equipment from sticking of molten metal splashes during welding due to the formation of a non-stick film, with good wettability to a contaminated metal surface, with low corrosion activity to metals, which, after welding, is well removed from the metal surface and does not impair adhesion during subsequent painting.

This goal is achieved in that the protective coating for the surface from adhesion of molten metal splashes is created on the basis of an electrochemically synthesized, activated, aqueous, catholytic solution, which, due to a change in the structure of water, provides synergies between the components of the coating at the molecular and ion levels, which leads to an improvement performance characteristics of the coating in terms of wettability, adhesion, protection of welded surfaces, reduced corrosion activity and stability awns storage solution.

This TMS concentrate contains, by weight. %:

- Electrochemical activated catholyte with ORP ϕ≤ -300 mV and pH≥11.5 - 50

- Neonol - 10

- Diethylene glycol - 28

- Polypropylene glycol - 12

A protective coating based on the proposed composition is prepared in a reactor with a capacity of 1 m ³ equipped with an anchor stirrer and a thermometer. Getting the product is carried out at an ambient temperature of 15-28 ° C. An electrochemical activated catholyte is poured into the reactor, which is obtained in a diaphragm-type flow electrolyzer (STEL-10N-120-01), the calculated amount is 500 kg, 100 kg of Neonol are added to the solution in turn, after stirring and dissolving 280 kg of diethylene glycol are added, then with continuous stirring Polypropylene glycol is added - 120 kg. The resulting solution is well mixed until all components are completely dissolved and the homogeneous composition is poured into plastic cans or barrels. The stabilization of the resulting solution is ensured by the hydroxyl groups of the electrochemical activated catholyte having an ORP of ϕ≤ -300 mV and a pH≥11.5.

Physico-chemical properties of the protective coating are shown in table 1.

To determine the effectiveness of protecting the surface of products and technological equipment from sticking of molten metal splashes, we tested this coating in the welding section of the assembly shop of the engineering plant. The tests were carried out during manual and semi-automatic welding.

The protective coating was applied on the surface of the welded products in various ways: by spraying or by simple brush application. The applied coating spreads well, wets the surface and forms an even layer of protective film. After 5 minutes exposure, welding of products from St3 and 10KHSND steels was carried out. At the end of welding work, metal sprays that have fallen into the protective layer are easily removed with a metal brush or rags. After the welding operation, the residual layer of the protective coating is easily removed from the surfaces with a damp rag. As tests have shown, a cleaned welded surface does not have traces of corrosion and does not adversely affect the adhesion of paints and varnishes, which ensures the quality of subsequent painting of products.

Thus, the protective coating provides reliable protection of the surfaces to be welded and technological equipment from sticking of splashes of molten metal during welding due to the formation of a non-stick film. The protective coating has good wettability to a metal surface and reduced corrosion activity to metals. This coating is fireproof, as it is water-based, does not contain solvents, which reduces the formation of vapors and the risk of fire during welding. The protective coating provides cost-effectiveness in use, the remains of the product can simply be washed off with water after use or removed with a rag, the working solution has a long shelf life.

Claims (2)

A coating for protecting the surface from sticking of splashes of molten metal, characterized in that it contains an electrochemically activated catholyte having a pH ≥ 11.5 and a redox potential of ϕ≤ -300 mV, neonol, diethylene glycol and polypropylene glycol in the following ratio of components, wt.% : electrochemically activated catholyte  fifty neonol  10 diethylene glycol  28 polypropylene glycol  12