SU1066718A1 - Nonstick material for foundry - Google Patents

Abstract

The use of products of combustion of technological gases of titanium-magnesium production of the composition, wt.%: Silicon dioxide 15-20 Aluminum oxide 1-2 Iron oxide 0.6-1.5 Manganese oxide. 0.3-1.0 Chromium oxide 0.1-0.5 Titanium dioxide The rest as a nonstick material for foundry.

Description

3

05

X

The invention relates to a foundry industry, namely to non-stick materials for the manufacture of molding and core sands, anti-stick coatings, and pastes. It is known to use as a nonstick material for coating casting molds and volcanic ash rods consisting of silicon oxides, aluminum, titanium and iron 1.

This coating does not provide castings with a clean surface, since volcanic ash has a low melting point and low refractoriness. A nonstick material containing oxides of aluminum, iron, calcium, magnesium, titanium, and water 2 is known.

The said non-stick material contains a large amount of iron oxides (4-16%), which leads to a decrease in its chemical inertness and refractoriness, as a result of which its fusion and invariance are reduced. In addition, the nonstick material does not allow for the production of steel castings with a clean surface, especially when using alloyed steel grades.

Also known nonstick material - garnet ZZ, containing, in May. %

Silicon dioxide 33.05 Aluminum oxide 17.96 Iron oxide33.05

Titanium dioxide 3.57 Manganese oxide 5.60 Chromium oxide 0.26

 Magnesium oxide 3.74

Calcium Oxide 2.50

Sodium oxide +

potassium oxide 0.10

However, this non-stick material has a low refractoriness and the large amount of iron and manganese oxides contained in it (38.65%) leads to an increase in its chemical activity, as a result of which hard-to-segregate chemical burns form on the surface of castings made of carbon and alloyed grades. Calcium and magnesium oxides contained in garnet enhance the formation of steel castings.

The purpose of the invention is to increase the chemical inertness of the antiburning coatings, molding and core mixtures, improving their antiburning properties and the quality of the surface of castings, as well as expanding the range of antiburning materials for the foundry industry.

. This goal is achieved by using the combustion products of the process gases of titanium-magnesium production of the composition, wt.%: Silica 15-20 Aluminum oxide 1-2 Iron oxide 0.6-1.5 Manganese oxide 0.3-1.0 Chromium oxide 0.1 -0.5

Titanium dioxide Else as a nonstick material for foundry.

The products of combustion of titanium-magnesium production gases (PSTG) are obtained in the form of ashes with a fraction of up to 20 mm when burning process gases in a furnace, the material is not aggressive, is stored and shipped in paper bags.

PSTG containing about 80% titanium dioxide and about 15-20% silicon dioxide have a melting point of about 1840 ° C. In the system titanium dioxide - silicon oxide, no chemical compounds are formed that contribute to the formation of chemical burns. When interacting with liquid steel, it is possible to form chemical compounds,, forming eutectics with a melting point of 1580-1630 K. The melting point of eutectics containing oxides of titanium and iron is 423-473 K higher than the melting point of the resulting filament in the FeO- SiOi when using margalite coatings containing a large amount of SiO Foil, which promotes the formation of a chemical burn when using conventional marshalite coatings, forms two low-melting eutectics; one with vustite, whose melting point is 1450 K, and the other with tridymite, whose melting point is 1451 K.

In the system FeO-TiO - SiOg there are no ternary chemical compounds. Consequently, in the interaction of liquid steel with non-stick material p

PSTG does not form complex chemical compounds that promote the formation of chemical burns. Thus, PSTG can be used in non-stick paints, molding compounds and dry bulk coatings.

As a binder in a coating containing PSTG, the following can be used: sulphite-yeast mash, sulphite liquor, as well as starch, dextrin, molasses, various resins and other known binding materials. Bentonites and molding clays of various grades, groups, grades and classes can be used as stabilizers, as well as high molecular weight stabilizers: corboxymethylcellulose, polyvinyl alcohol,; polyvryl butylate, polyacrylate amide.

The compositions and properties of nonstick coatings obtained with nonstick materials (1) not known (2) are given in table. 1 and 2.

As can be seen from the table. 2, the nonstick coating, in which high titanium dioxide content PSTG is used (up to 80%), satisfies the requirements imposed on nonstick coatings. The nonstick coating based on PSTG has good sedimentation stability, covering power and abrasion resistance. There are no smudges on the surface of the painted forms and rods, a uniform layer of sufficient thickness is obtained.

The proposed coating with nonstick material has high antiburning properties. The surface quality of castings made using molds and cores shortened by this coating is better than those coated with garnet coating.

PSTG is well combined with other anti-burn materials: iron-free zircon concentrate of grade C 54 (PCT USSR 655-70), powdered disten-sillimanite concentrate of the brand KDS-P (TU-4824-30774), dust-like quartz, etc.

The compositions and properties of nonstick coatings, in which PSTG is used in combination with powdered kyanene-sillimanite (1) and zircon (2) concentrates, are given in Table. 3 and 4.

As can be seen from the table. 3 and 4, the technological and nonstick properties of coatings with combined refractory materials comply with the requirements of production in the manufacture of steel castings.

Thus, the proposed nonstick material can be used in combination with other refractory materials.

Milled PSTG can be used in the composition of molding and core mixtures with various bonding materials: oil shale. loy, sulfite-yeast brew, liquid glass, etc.

The compositions and properties of the mixtures using additives nonstick material according to the invention (1) and the known (2) are given in table. 5 and 6.

0

As can be seen from the table. 6, the proposed material provides the best technological and anti-burn properties of the mixture.

Fine PSTG can

5 to use as a dry nonstick coating of rods. A vibropum layer is used for coating. The rods on the suspension are lowered into a container, mounted on an electromechanical vibrostand, with finely divided. PSTG, then the container is closed with a lid. The processing time is 2 minutes, the oscillation amplitude is 1.2 mm, and often 5 ta to 80 Hz.

For these tests, PSTG were selected, including, if possible, average and upper values

0 component ingredients.

The penetration depth of the proposed dry nonstick material into the core is 3.4-3.6 mm with the indicated parameters. With the use of these rods, cast iron castings are made, the surface of which is clean, without burns.

The implementation of the invention improves the antiburning properties

0 molding and core sands, nonstick coatings and pastes, improve the surface quality of castings and expand the range of nonstick materials for foundry

5 production. Economic efficiency is 2-3 p. on 1 ton, pour.

Table 1

The waste product of the combustion of technological gases of titanium-magnesium production

Ground pomegranate concentrate Bentonite

Sulfite yeast brew Technical soap Water

52.0 2.0 4.0 0.5

41.5

Table

Ground products of combustion of technological gas and titanium and magnesium production

Young pomegranate concentrate Sulfite yeast brew (CJ) Shale resin (GTP)

Compressive strength raw, kgf / cm

Gas permeability, units Humidity,%

Tensile strength of dry, kgf / cm

Anti-stick properties

Table 5

10.0 3.6 2.0

Table 6

0.17

70

3.6

6.0 pa no

Burner and glassy piercing film

Claims (2)

The use of products of combustion process gases titanium-magnesium production composition, wt.%: Silicon dioxide 15-20 Aluminum oxide 1-2 Ferrous oxide 0.6-1.5 Nitrate manganese. 0.3-1.0 Chromium oxide · 0.1-0.5 Titanium dioxide Else as ^ nonstick material for foundry. one 1066718 2