SU801973A1 - Mixture for facine hot tops - Google Patents

Description

(54) MIXTURE FOR FACING

I

The invention relates to foundry, in particular, to lining the profits of large-sized steel ingots and castings, mainly castings with a height of up to 1050 mm, a diameter of up to 1600 mm and a thickness of up to 150 mm.

A heat-insulating mixture is known, consisting of a refractory filler, binder and heat-insulating additives 1, which requires the presence of heat-drying, and the heat-insulating properties are due to the burn-out of additives and by creating a porous mixture structure and, moreover, special equipment is needed for the production of shells .

A cold-hardening mixture is also known, containing quartz sand, furan resin, and an acid hardener.

This mixture is usually used for the manufacture of casting molds and cores and cannot be used because of its small survivability - 10-15 minutes for the manufacture of large shells weighing 300 kg, which are lined with mold or mold profit as applied to large-sized steel castings or ingots. When molding casings from such mixtures, due to low survivability, junctions and occur. discontinuity, and their installation in the form leads to collapse and erosion.

The aim of the invention is to increase the survivability of the mixture.

The goal is achieved by the fact that the mixture, including quartz sand, furan resin, benzenesulfonic acid, additionally contains silicone lacquer consisting of polyvinyl butyral, polymethyl phenylsilox, new resin and acetate, respectively, in a ratio of 2: 3: 45-2.5: 4: 54 at the following ratio of ingredients, mass. ° / o:

Furan resin2.0-3.0

Benzene sulfonic acid 0.4-0.6

Silicone varnish 0.5-1.0

Quartz sandEverything.

An organochlorine lacquer of the specified composition KO-068 is used in the mixture.

The procedure for preparing the mixture is common for cold hardening mixtures with a furan binder.

From the proposed mixture, shells were made of profits, which were used in the manufacture of the cylinder of a steam turbine made of 15H1M1FL steel with black weight of 22,500 kg.

The compositions of the mixtures and their properties are respectively given in Table. 1 and 2.

As follows from the table. 2, the optimum composition of the mixture is composition No. 3. The mixture has good survivability and a short profit hardening time.

The shell made of the proposed mixture is porous due to burnout of the resins: Mixture compositions weight. Ingredients №1 №2 №3 №4 №5 97.1 96.45 96.3 96 95.8 Quartz sand 2.0 2.52.5 2.5 3.0 Fura ova smrla 0.02 0.022 0.024 0.036 0.024 Polyvinylbugirap. Polymethylphenip0, 03 0.033 0.036 O, 054 0.036 siloxane resin, 0.45 0.495 0.54 0.81 0.54 Ethyl acegag; ..; 0.4 0.50.6 0.6 0.6 Beneolsulphonic acid

first polyvinyl butyral burns at T 200 ° C, then the furan resin burns and burns at T 400 ° C and then at polymethylphenylsiloxane resin at 800 ° C.

The implementation of the invention will allow to obtain shells for large-sized steel casting and ingots and to reduce the consumption of metal.

Table 1

Table 2 No. 6 6.51 93.8 3.21 2.5 2.7 0.016, 016 0.036 0.024 0.054 0.024 0.35 d, 81.35 0.6 0.6 0.60.6

Claims (1)

Claim The mixture for lining profits, mainly for steel large-sized steam turbine castings with a height of up to 1050 mm in diameter up to 1600 mm and a thickness of up to 150 mm, including quartz sand, furan resin and benzenesulfonic acid, characterized in that, in order to increase the survivability of the mixture, it additionally contains organosilicon a varnish consisting of polyvinyl butyral, polymethylphenylsiloxane resin and acetate in a ratio of 2: 3: 45–2.5: 4: 54, respectively, in the following ratio of ingredients, May. %: Furan resin 2.0-3.0 Benzene sulfonic acid 0.4-0.6 Organosilicon varnish 0.5-1.0 Quartz sand The rest,