SU789641A1 - Composition for electrochemical polishing of steels - Google Patents

Description

The invention relates to the electrochemical treatment of metals, in particular to the polishing of steels that have homogeneous (X18H10T) and heterogeneous (55C2, 5512, 55C2G9HS, ZOHH2MF2, etc.) structures. A number of dressings are known for polishing various steels containing sulfuric and phosphoric acids and a mixture of organic additives Mi p1. Closest to the invention is a well-known solution for electrochemical polishing of steels (carbonaceous and semi-rritic steels) containing phosphoric and sulfuric acids, alkali metal chloride (potassium chloride) and an organic additive, for example, inhibitor I-1B C. However, the known solutions are not sufficiently ()) effective in polishing steel grades that have a heterogeneous and H (4ogenic structure (Table 1). The purpose of the invention is to improve the quality of steel polishing. The goal is achieved hem, which as an organic additive solution contains melamine n / or hexamethylenetetraamine and ethylene glycol with the following ratio of components, g / l: Phos (| yuric acid1O17-1356 Sulfuric acid367-734 Melamine and / or hexamethylenetetraamine1-2O Ethylene glycochemide, O1-2O alkali metal chloride, 5-2O With this as lorida alkaline metal solution contains atri or potassium chlorides. Polishing is recommended to be carried out at a temperature of 15–7 ° C and about 1 h (x; tons of 10–10 A / dm for 3–15 min. potassium sodium), adsorbed on the anode, contribute to the creation of an active-passive state, which is necessary for high-quality electrochemical polishing.

At the same time, melamine and / or hexamethylene tetraamine, ethylene glycol, which are adsorbed on the surface of the metal covered with an anodic semiconductor oxide film, increase the energy barrier and the activation energy of the process. These surfactants of a different nature are selectively adsorbed on various structural components and crystallographic planes of the metal, which leads to the healing of oxide film defects. The oxide film becomes more perfect, which contributes to the passivation of the steel surface.

But to create an active-passive state, activation of the surface is required, which is achieved by introducing chlorine anions (potassium chloride or sodium) into the solution. The halogenidion introduced into the lattice of the passivating oxide increases the rate of dissolution of passive iron due to the facilitation of the transfer of charges and matter through the surface oxide.

The presence of a complex additive (melamine and / or brine hexamethylenetetraamine, ethylene glycol, potassium chloride or sodium) in solution leads to a significant

HbHvi kinematic effects that contribute to the fact that the combined effect of organic and inorganic substances on anodic dissolution is

more effective than the action of each separately. This is explained by the synergism that enhances the effect of surfactants during co-adsorption, due to the interaction of molecules of simultaneously simultaneously introduced substances with each other.

In addition, the introduction of a surfactant reduces the surface tension, thus facilitating the process of oxygen evolution, the presence of chlorine ions increases the conductivity of the solution.

The substances used (melamine, hexamethylenetetraamine, ethylene glycol, potassium chloride or sodium) are non-flammable, non-combustible.

TOXIC, well soluble in water and in the proposed solution.

/

The solution does not require the use of foam. extinguisher

In tab. 1 shows the results of comparative tests on the quality of polishing of steels having a heterogeneous structure in the known and proposed solutions (temperature 4СЯС, density

current 90 A / dm and duration 9 min)

The invention is illustrated by the examples presented in table. 2

Phosphoric acid, (sp. In. 1,695 g / cm)

Sulfuric acid

(beats in. 1,835 g / cm)

Melamine Hexamethylenetetramine

Ethylene glycol Sodium Chloride Potassium Chloride

steel grade

1017 1356 1186.5 1186.5 734 367-550.5 550.5

ten

1O

20

ten

ten

20

0.01

1010

20

0.5

Х18Н10Т Х18Н10Т Х18Н10Т Х18Н1ОТ

57896416

As can be seen from the tables, proposed, primary grades of steel in a wide

This solution can significantly (operating temperature range and rotate the quality of polishing of current bones).

Rq Roughness

after polishing,

μm n, Q, ishoci

corresponds to that 6

according to GOST 2789-.73) 1,5O (0,5O) Metal removal, g / cm 2,92 (2.30) Steel grade Relative 18.1 (73) smoothing,%

Reflective

36 (78) ability. % Note 1186.5 1186.5 1186.5 1186.5 550.5 55О, 5 550.5 550.5 1О - - Х18Н10Т Х18Н10Т ЗОХН2МФ2 55С2

Table 1

1.57 (0.68) 2.2 (1.35) 55C2

44 (88) 41 (54) The values in parentheses are for the proposed solution containing phosphoric acid (1186.5 g / l), sulfuric acid (550.5 g / l), hexamethylenetetraamine (5 g / l), ethylene glycol. (2 g / l) and potassium chloride (10 g / l). 3.55 (3.13) 3, О1 (2.82) 55С2Г55Г2 29.9 (61.14) 13.7 (38.6) Table 2 1356 1О17 1186.5 550.5 55С2Г

steels as an organic abob & KR it contains a mixture of malamna and / W19

Alkali chloride

metal0,5-20

Claims (2)

Claim 1. A solution for electrochemical polishing of steels containing phosphoric and sulfuric acids, an alkali metal chloride and an organic additive "characterized in that" for the purpose of improving the quality of polishing of steel as an organic additive, it contains a mixture of melamine and / or non-nitrates, g / l: Phosphoric acid Sulfuric acid Melamine and / or hexamethylenetetraamine Ethylene glycol Alkali metal chloride 1017-1356 367-734 1-20 _ 0.01-20 0.5-20. ¹⁰ Continuation of the table. 2 5 6 7 8 9 10 eleven 40 thirty 40 40 70 fifteen 40 110 110 110 110 210 ¹⁰ 110 9 9 9 9 fifteen 3 9 .1.25 1.3 1.31 1,52 D 71 1.35 1.35 0.58 0.67 1,0 .0.75 0.62 1.14 0.64 V6 V 6 6 V 6 V6 V6 V 6 Ch 8 ST7 V7 V7 Hg8 HT7 97 53 48,4 23.7 50.7 63.7 15.6 52.7 45.1 44.6 39,4 49.4 142.3 3.6 42,4 5.02 4.95 4.38 5.49 9.49 1,2 4.7 100 100 86 38 60 46 76 242 238 238 226 235 225 242 69 68.5 68.5 64 67 66 ⁶⁹ 2. A solution of pop. 1 characterized in that as the alkali metal chloride it contains sodium or potassium chlorides.