SU595067A1 - Method of making reinforced castings - Google Patents

Description

(54) METHOD FOR MAKING REINFORCED CASTINGS

I

The invention relates to the field of ferrous metallurgy, in particular to the foundry industry, to the manufacture of refrigerated blast furnace stoves.

A known method of manufacturing refrigeration plates is by reinforcing them with pipes that are covered with protective sheaths 1.

The disadvantage of this method is the significant carburization of the tubes in the casting nroness and the improvement of thermal conductivity between the casting and the tube.

A method is also known to manufacture refrigeration plates for blast furnaces, in which, in order to reduce the carburization of pipes, when casting slabs, a layer of iron powder 2 is applied to the marshalite coating before pouring metal.

The disadvantage of this method is the deterioration of the thermal conductivity between the casting and the reinforcement, with its pipe, due to the fact that the marshalite coating has a low thermal conductivity. The result of a deterioration in thermal conductivity is an increase in the temperature of the working surface of the cold plates, increased wear and growth of cast iron. In addition, this method does not efficiently reduce the depth of carburizing of the reinforcement due to cracking, flaking

and washout marshalite coating in place with iron powder. Carburization of pipes leads to loss of ductility nx) i premature exit nz stro refrigerating

plates

The aim of the invention is to increase the effective thermal conductivity between the spud and the pipe, reducing the carburization of the cooled pipes.

This is achieved by the fact that before applying the metal powder on the reinforcing tubes nx the inner cavities are filled with a magnetically hard material, for example a cobalt alloy. When this occurs, reliable fixing of the underlayer of the metal powder on the surface is cooled, the tubes are magnetically charged, and there is no need to use refractory, TIN-TOBoro mantle, and their coatings, which increases the effective tenloconductivity between the casting and the tube i reduces the carbonization of the coolant and their tubes. When pouring h} tuna into the iolite of the form, it is a magnetically solid material, filled the tube cavity of the undium, the accumulator

part of the heat of liquid iron reduces the contact time of the liquid with, which significantly reduces the carburization of the cooling pipes.

A reduction in the carburization of the cooling tubes provides for an increase in their plasticity and an increase in the service life of the cooling plates.

The verification of the method of manufacturing reinforced castings was carried out under the conditions of the foundry workshop of the pilot production plant of the Institute for Casting. Six workpieces of 600X500X250 mm dimensions are cast with cooling pipes of steel 20060X6 mm inserted into the central part. In three castings, a marshalite coating was first applied to the cooling tubes, and then a layer of iron powder PZH-1K with a thickness of 0.8-1.0 mm was applied.

In three other castings, shot of a Komol cobalt alloy of the “Komol” grade is poured into the pipes, and a layer of 0.8–1 mm thick iron powder PZH-1K is applied to the surface of the pipes.

The casting is carried out with iron of grade Ж4Х- 0.6 at a temperature of 1320-1330 ° С. Samples are cut from the central part of the castings and metallographic studies and studies of the effective thermal conductivity between the cast iron and the pipe are carried out using the radial heat flux method in a cylindrical sample from an axial internal electric heater.

The research results are summarized in the table.

Studies show that the proposed method reduces the carburization of cooling pipes by 2.5 times, increases the effective thermal conductivity between the casting and the pipe, and thereby increases the service life of the cooling plates of blast furnaces by 1.5-1.7 times.

Claims (2)

Invention Formula A method of manufacturing reinforced castings, mainly refrigeration plates of blast furnaces, comprising applying a protective coating in the form of metal powder onto reinforcing pipes, installing them in a casting mold and pouring the metal, in order to reduce carburizing the reinforcing pipes and improving the efficiency of the heat sink, before applying the metal powder on the reinforcing pipes, their internal cavities are filled with a hard magnetic material, for example cobalt power. Sources of information taken into account in the examination 1. USSR author's certificate jY 276339, cl. In 22D 19/02, 1970. 2. Application 2000679, cl. In 22D 19/02, 04.03.74, according to which a decision was made to issue an author's certificate.