SU1201348A1 - Solution for chemical smoothing of stainless steel - Google Patents

Abstract

MECHANICAL POLISHING STAINLESS STEEL SOLUTION containing phosphoric, nitric, hydrochloric and sulfosalicylic acids, a surfactant and water, characterized in that, in order to improve the quality of the polished surface, it additionally contains glycerin, ethylene diamine-tetraculate, and disodium salt. , benzyl alcohol, and as a surfactant a mixture of triethanolamine, ethylene glycol and ethoxylated potassium alkyl phosphate (Oxyphos) in the following ratio, wt.%: osphoric acid 25-35 Nitric acid 4-6 Solic acid 4-5 Sulfosalicylic acid 0.3-0.5 Glycerin1-2 Disodium solo ethylenediaminetetrai acetic acid (Trilon B) 0.5-1.0 (L C Benzyl alcohol 0.045- 0.1 Surface-active .e substance-mixture: 0.005-0.015 triethanolamine 0.015-0.017 etyl glycol 0.001-0.01 OXYFOS 1 hE Water Residual Sl9 4 00

Description

1 The invention relates to the chemical treatment of metals, in particular to the chemical polishing of stainless steels, and can be used in medical, instrument-making and other areas of industry. The purpose of the invention is to improve the quality of the polished surface. Example. Samples of austenitic stainless steel with a size of 50x20x1 mm are degreased in an alkaline solution, washed in water and immersed for 1-3 minutes in a solution with a temperature of 80-85 ° C, with the following prepared: calculated amounts of HC1 (1, 18 g / cm and HNOj ( g / cm2) are mixed, the mixture of acids is kept at room temperature until slightly yellow (5-10 minutes) and then added to the aqueous solution, the concentration of which is 39%. Estimated amounts of sulfosalicylic acid are subsequently added to the mixture of acids thus obtained, Trilon B, glycerol and surfactants. After chemical polishing (CP), the samples are washed with water and neutralized in a solution of NaOH (70 g / l) for 5 minutes at 70 ° C, washed with water and dried. A composition of the following composition, wt.%, is taken as the surfactant: Phosphorus-containing surfactant (Oxyphos) 0.1-3.0 Triethanolamine 4-10-10.0 Ethylene glycol 10.0-12.0 Water 2.0-30.9 Benzyl alcohol Up to 100 The quality criterion for the polished surface is the appearance of the sample, the reflection coefficient and the surface roughness parameter. The reflection coefficient is measured on a FB-2 gloss meter. The standard is a silver mirror, the reflection coefficient of which is assumed to be equal to 100%. The roughness parameter is measured on a model 208 profilometer. By the metal removal rate, we mean the removal (thickness of the surface layer) of the metal passing into the electrolyte solution per unit time; micron / min dimension An increase in the removal rate makes it possible to reduce the processing time of the metal surface, which is necessary to achieve the same roughness at 482 with the same absolute value of the removal of the surface layer. The advantage of the proposed solution in comparison with the known one is a greater removal rate, which makes it possible to reduce the processing time by a factor of 3. The polishing process should be carried out at 80-85 ° C 1-3 MiiH. The process of chemical polishing of steel in the proposed solution can take place at a lower temperature and / or shorter processing time than in the known. The results of chemical polishing of samples of steel grade 12X18H9T in the proposed and known electrolytes are given in Table. 1. The results of chemical polishing of samples of steel grade 12X18H9T in the proposed electrolyte with concentrations of electrolyte ingredients above and below the suggested interval are given in Table. 2. Introduction to the known mixture of acids, additives of Trilon B allow increasing the polishing ability and the rate of steel dissolution due to the formation of complexes with the products of the dissolution of the main components of steel (iron and chromium). The introduction of glycerol improves the smoothing process of the surface due to an increase in the viscosity of the solution and speeding up the process of forming a viscous film on the surface of the sample to be polished. The use of this surfactant composition allows improving the quality of the polished surface due to the adsorption of each of the components of this composition on the surface-active centers of the polished steel sample and, consequently, accelerated dissolution of the microprotrusions. The use of the proposed solution for CP stainless steel, mainly 12X18H9T, allows a greater degree of reduction of the roughness parameter of the treated surface (to R (j 0.18-0.24 mm) and increase the surface reflection coefficient (up to 40-49%) with a small metal than in the case of a known electrolyte (R 0.46 µm). Only the simultaneous presence of all of these components (Trilon B, glycerin, a mixture of surfactants) can significantly improve the quality of the polished surface: reduce

roughness parameter and increase the reflection coefficient.

 The results of the influence of additives on the process of chemical polishing of 12Kh18N9T steel are shown in Table. 3. The sortav mixture of acids by wt.% (SSC): phosZzornaya acid 30; hydrochloric acid 4.5; nitric acid 6; t 85C, time - 1 min.

The results of the influence of various surfactants on polishing of 12Kh18N9T steel (the composition of the solution in Table 39) are given in Table. four.

201348,4

Table 5 shows the results of the influence of the concentration of additives of organic compounds dissolved in the solution on the quality of chemical polishing of 5 steel 12X18H9T. The composition of the mixture of acids (wt.%): Phosphoric acid ZP, hydrochloric acid 4.5, nitric acid 6, sulfosalicylic acid 0.5, 1 min.

From the above examples, it follows that the solution for the chemical polishing of steel has several advantages over the known one.

T a to l and c a t

Phosphoric acid

Salt acid nitric acid

Sulfosalicylic acid

3,5-Dimethylpyridine Polyethylene glycol Glycerin Trilon V Blend surfactant Water

CP temperature, With HP time, min

Removal rate IU µm / min

Ra surface roughness, microns

before HP after HP

Reflection coefficient

to HP

after CP

As a surfactant mixture, the composition shown above is taken.

35 4

thirty

thirty

4.5

.five

four

6

6

,four

0.3

0.5

0.5

2.0

t.5

1.5 1.0.

00.7

0.7 0.15 0.13 0.13

0 to 100

Up to 100 To 100 80 3

85 1

80 3

5.8

5.5

3.1

Electrolyte composition and control parameter

Phosphoric acid Sol acid Acid nitric acid

C ulfos alicylic acid

Glycerol

Trilon B

Surfactant composition

Water

Temperature, HP.С

Time HP min

Metal removal, micron / min

Surface roughness Ra, micron

before HP after HP

Reflection coefficient

to HP

after CP

table 2

The electrolyte content of the examples, wt.%

I.

2

one

37 6

7

Claims (1)

SOLUTION FOR CHEMICAL POLISHING OF STAINLESS STEEL, containing phosphoric, nitric, hydrochloric and sulfosalicylic acids, a surfactant and water, characterized in that, in order to improve the quality of the polished surface, it additionally contains glycerol, disodium salt of ethylene diamine tetraacetic acid , benzyl alcohol, and as a surfactant a mixture of triethanolamine, ethylene glycol and hydroxyethylated potassium alkyl phosphate (Oxyphos) in the following ratio, wt.%: Phosphoric Acid 25-35 Nitric acid 4-6 Hydrochloric acid Sulfosalicylic acid 0.3-0.5 Glycerin 1-2 Disodium Salt,> ethylenediaminetetraacetic acid (Trilon B) 0.5-1.0 Benzyl alcohol 0.045-0.1 Surfactant-mixture: triethanolamine e type e nglycol oxyphos Water SU, „> 1201348 0.005-0.015 0.015-0.017 0.001-0.01 Else>