SU452425A1 - Reinforcement insert - Google Patents

Description

: .. The invention relates to the field of foundry, in particular to the manufacture of blast furnace cooling plates. A known reinforcing insert with a protective layer of copper deposited on its surface to be filled with molten iron. However, in the manufacture of massive iron castings from the surface of reinforcing inserts, a protective layer of copper is washed away and steel is carburized, which leads to a decrease in the plastic properties of the metal and the operational unreliability of the casting. The preliminary coating of the reinforcing insert with a layer of steel also cannot reliably protect it from carburization due to the intense diffusion of carbon in the steel layer. In order to prevent the protective layer of copper from washing off by the flow of molten iron and to create an additional carbon diffusion barrier. in the reinforcement insert the latter is provided with a steel tape winding. Steel pipes (Art. 10) with a diameter of 60 mm and a wall thickness of 6 mm are cleaned and electrolytically coated with copper. The coating thickness is 20-45 microns. In order to compare the effect of various methods of protecting the reinforcement from carburization, pilot castings with a section of 300x260 mm and a length of 600 mm are made, in the central part of which pipes are installed. In one casting, the pipe is installed without protection, and in others with copper coating without winding and with winding of the outer surface of the pipe with steel tape 0.8-1.2 mm thick. For casting, cast iron melted in a DSP-0.5 furnace of the following composition (in wt.%) Is used: 3.20-3.28 carbon; 1.52-1.67 silicon; 0.84-0.89 manganese; 0.04-0.06 sulfur and 0.17-0.22 phosphorus. The temperature of the metal during casting is 1320-1340 ° C. After solidification of the castings, they are cut and. templates are explored. The study was carried out by means of metallographic analysis and in some cases by a radioisotope method using the isotope Cj. It has been established that in the absence of a protective coating on the pipe, the carburization depth

it was 0,8-1,7 mm, when using electrolytic copper plating it is 0,7-1,4 mm, it has a mottled character and depends on the washout of the coating. When protecting the outer part of the pipe with a 0.81, 2 mm thick steel tape, no carbonization of the pipe was found to protect the outer part of the pipe from washing out.

This is facilitated not only by the elimination of the washout of the coating, but also by the creation of gallons. Tsy additional barrier to diffusion; carbon from the tube.

Subject invention

The reinforcement insert is predominantly for reinforcing the cold plates of metallurgical aggregates coated on its surface to be filled with molten iron, a protective layer of honey, characterized in that in order to prevent the protective copper layer from flushing the molten iron and creating an additional carbon diffusion barrier into the reinforcement The latter is provided with a steel tape winding.