SU944733A1 - Paste for correcting deffects on working surface of chill mould - Google Patents

Description

(5) PASTE FOR CORRECTION OF DEFECTS ON THE WORKING SURFACE OF COKILEES

one

The invention relates to foundry, in particular, to paste compositions for correcting defects on the working surface of chill molds, in particular, high-grade cracks.

A heat-insulating coating for chill molds containing talc, water glass, salt and water is known.

The coating is sprayed onto the surface of the chill mold every 1 to 5 fillings and serves to insulate the entire working surface of the chill mold ft.

However, this coating is not able to correct the defects of the chill molds.

The known paste is used to correct the defects of the molds, containing 65% of quartz flour, 35% of refractory clay and liquid glass to a thickness of putty 2J.

However, this composition is used only for repairing small cracks.

and the presence of 5% clay leads to cracking of the paste, which impairs the presentation of the castings and reduces the resistance of the paste.

The closest in technical essence and the achieved result to the invention is a coating for chills, consisting of 2% refractory clay, 23 ground talcum powder, 1.2 borax, C% liquid glass and 7P water 3.

This composition is not capable of correcting the defects of the chill molds and serves only as a protective coating. The coating has a low adhesive ability and does not provide the required quality of the surface of the castings and the resistance of the molds.

The aim of the invention is to improve the quality of the surface of castings and to increase the resistance of the molds and the adhesiveness of the paste.

This goal is achieved by the fact that the paste for correcting defects on the working surface of the chill molds, including talc, refractory clay, water glass and water, additionally contains iron dust and salt with the following ratio of ingredients, weight ..:

20-25

3-5 15-20

3-10

5-10 Else

The presence of cast iron dust and table salt in the proposed composition increases the refractoriness of the coating and brings its thermophysical properties closer to the properties of chill molds, which improves the operating conditions of the chill molds.

In addition, the combination in the composition of the paste of iron dust and salt within the specified ratio

Talc

Fire clay

Cast Iron Dust Cooking Salt Liquid Glass Bug Water

++ 7334

It also makes it possible to increase the elasticity of the paste, to increase its refractoriness and adhesive ability, as well as the mechanical strength during solidification, which is necessary both when applying the paste and to increase its durability during operation after solidification from the heat of the chill mold.

The manufacture of the paste is carried out as follows.

Talc is added to the measured amount of liquid glass and mixed, then 5-10% of water is added and thoroughly mixed. AT

5. The resulting solution is added refractory clay, cast iron dust and salt. After the addition of each component, the composition is thoroughly mixed until a homogeneous

20 masses. Thereafter, water is added to a pasty state.

The metal paste is applied to the defective surface by hand with a spatula until a uniform layer is obtained.

25 The compositions and properties of the proposed and known pastes are given in Tables 1 and 2.

Table 1

23 18 20 23 25 27

Adhesive paste ability, on a 5-point scale

Increase the service life of chill molds, times

Surface roughness of castings, R,

Presentation of castings on a 5-point scale

The durability of the paste, the amount of pouring

As can be seen from the table. 2, the optimum composition of the paste is composition 3.

The proposed paste is a good means for sealing the defects of chill molds; it adheres well to the surface of the chill mold, thereby improving the presentation of castings under conditions of operating chills.

The proposed paste has a linear expansion coefficient approximately the same with the material of the working surface of the wall of the metal of iron or steel (, 11.0-10 1 / ° C). Due to the same linear expansion during operation, the paste does not crack, does not pour out and protects the damaged surface of the mold from further damage.

The implementation of the invention will improve the quality of the surface at 3, 0

3.0

2.0 2.5

2.5

40

80 itQ

40

35-37 35-37 35-37 35-37 35-37

Fat (RZ. - 40), increase the resistance of the chill molds 2.5 - 3 times and increase the adhesiveness of the paste.

Claims (1)

Invention Formula The paste for correcting defects on the working surface of the chill molds, including talc, refractory clay, liquid glass and water, is characterized in that, in order to improve the quality of the surface of the castings and increase the durability of the chill molds and adhesion of the paste, it additionally contains iron dust and salt when the ratio of ingredients, weight: Talc20-25 Fireproof clay3-5 7 9t 7338 Cast iron Svarika A. A. Cover the foundry of 15-20 forms. M., Mechanical Engineering, Cooking 1977, p. 119. salt -5-102. Chill casting. Help Liquid glass 5-10s allowance. M., Mechanical Engineering, 19b7, Water Rest. 9. Sources of information, 3. Cast Iron Handbook, taken into account when examining M., Mashinostroenie, 1978, p. 503.