SU1215846A1 - Protecting and lubricating composition for casting steel - Google Patents

Description

one

This invention relates to ferrous metallurgy, in particular to compositions of protective lubricating mixtures for continuous casting of billets and casting of steel into molds.

The purpose of the invention is to improve the surface quality of castings.

As a protective and lubricating components in the mixture, tcarcarbon and graphite are used, the total content of which within the proposed limits provides for obtaining good thermal insulation properties of the mixture with a minimum thickness of the layer on the metal mirror. The increase in the content of graphite in the mixture of more than 10% leads to the carburization of the metal, especially when used in conjunction with high-carbon pyrocarbon even when the latter is given to the mixture at the lower (70%) limit. The lower limit of the graphite content (5%) is due to the minimally necessary addition of graphite to the mixture while co-giving it to the mixture of high-carbon pyrocarbon at the upper limit (75%) in order to preserve its thermal insulation properties.

The fluoropolymer used in the proposed composition is a spack-forming component, ensuring that the required melting temperatures (1050-1150 s) and viscosity (0.03-0.10 N. s / m) of the protective lubricant mixture are required. When the content in the mixture of fluorspar less than 15%

65 70

3 5

32 25

2158462

a lumpy, viscous slag is formed, which helps reduce the surface quality of the cast billet. Increase of fluorspar content

5 over 25% is undesirable from the point of view of economy ..

In tab. 1 shows the compositions of the proposed proposed (2-4) and known (6) industrial lubricants,

10 as well as compositions (1.5) in which the content of the components is higher and lower than the suggested limits.

In tab. 2 shows the physical properties of slag melts.

15 tested mixtures (Table 1) as well. the results of testing these mixtures under industrial conditions during continuous casting of 40X and 20X steels on a three-strand caster into crystallizers with a cross section of mm. The mixture consumption was 0.5 kg per ton of steel.

As follows from the data given in Table 2, the properties of the proposed 25 protective lubricants of the mixture are superior to those of a known composition and provide cast billets with a smaller amount (5 times) of surface

30 defects in the form of slag, which contributes to reducing cast rejects.

Thus, the surface quality of cast billets is enhanced by the higher assimilation 35 capacity of the speck from the proposed

mixtures with respect to non-metallic inclusions

Table 1

75 10 15

80

12

eight

50 20 10 20

Contact angle, hail

Interfacial tension, N / m

Viscosity at ISSO C, H.C / M

Cast billets rm

Amount of slags per 1 running meter, pcs

Metal scrap for slags after cleaning the surface,%

119 0.760

0.3 660

22

1.7 0.1

119 0.74

0.1 450

table 2

121 0.734

0.03 450

120112110

0.7400,8500,852

0,050,40,5

4506601300

103

14

Not

0.2

1.0 0.8

Claims (1)

PROTECTIVE-LUBRICANT MIXTURE FOR CASTING STEEL, including pyrocarbon, graphite, fluorspar, characterized in that, in order to improve the surface quality of cast billets, the mixture contains components in the following ratio, wt.%: Pyrocarbon 70-75 Graphite 5-10 Fluff stitch 10-25 Yu SP cx> > 1215846 ² lumpy viscous slag is formed, which contributes to · a decrease in the surface quality of the cast billet. The increase in the content of fluorspar 5 over 25% is undesirable from the point of view of economy .. In the table. 1 shows the test compositions of the proposed (2-4) and known (6) lubricating lubricant mixtures, 10 as well as compositions (1.5), in which the content of the components is higher and lower than the proposed limits. In the table. 2 presents the physical properties of slag melts of 15 tested mixtures (table 1), as well. the results of testing these mixtures under industrial conditions during the continuous casting of steels 40X and 20X on a three-strand continuous casting machine in crystallizers20 with a cross section of 220 * 220 mm. The consumption of the mixture was 0.5 kg per 1 ton of steel. As follows from the data in Table 2, the properties of ^{25 of} my protective-lubricating mixtures exceed the similar characteristics of the known composition and provide cast billets with less (5 times) surface 30 defects in the form of slags, which helps to reduce casting waste. Thus, the surface quality of cast billets is improved due to the higher assimilating ability of the shaft from the proposed mixture with respect to non-metallic inclusions.