JPS5934472B2 - Manufacturing method for cooling hardware used in melting furnaces, etc. - Google Patents

Description

[Detailed Description of the Invention] This invention securely prevents cracking, destruction, etc. caused by the encased pipe inhibiting the shrinkage of the encased casting when casting cooling hardware that encloses a pipe for cooling. The present invention relates to a device that prevents the above problems and makes it possible to manufacture sound cooling hardware.

As is well known, cooling hardware made of cooling steel pipes cast in cast iron is used in melting furnaces, especially blast furnaces, etc. Recently, the use of cooling hardware has increased, and the wear resistance of these hardware has been improved. In order to achieve this, there is a growing trend to use special wear-resistant materials such as high hardness Nihard, high Cr cast iron, Cr-Mo cast iron, high Mn cast steel, or white pig iron in place of conventional ordinary cast iron.

However, when steel pipes are integrally cast with these materials,
The drawback is that the casting shrinks significantly after casting, and the cast steel pipe obstructs this shrinkage, often leading to the destruction of the cast hardware.

Incidentally, if we show the shrinkage rates of ordinary cast iron and the above-mentioned high Cr cast iron, 25% Cr cast iron 000 (contains 0.05% of C2.5%, Si2.0%, P-8, and 0.05% each) In both cases (% by weight), the value □ is 000.

As mentioned above, even when a pipe (steel pipe) is cast with a material having a high shrinkage rate, the present invention is capable of alleviating the inhibition of shrinkage of the casting by the cast pipe, thereby preventing cracks and fractures caused by the shrinkage inhibition. It was made with the purpose of preventing the above-mentioned problems, and therefore, its characteristic feature is that when manufacturing integrally cast cooling hardware containing a cast pipe, it is possible to prevent By providing an extensible part and integrally casting the casting, the shrinkage that occurs during solidification of the casting can be absorbed and the residual stress in the casting can be reduced.

In order to describe the present invention in detail, the conventional manufacturing method for cooling hardware will first be described with reference to the explanatory diagram in FIG. ′
The pipe 1 is integrally cast into a cast metal 3 with the pipe 1 projecting outward, and a coolant such as water is introduced from one end 2 of the pipe 1 and discharged from the other end 2'. be.

However, in the case of cooling hardware having such a structure, when the pipe is cast by encasing the pipe as described above, if the material of the encasing casting 3 has a large shrinkage rate as described above, the encasing pipe 1 may cause the casting 3 to be The shrinkage during cooling was inhibited, often leading to cracking and destruction.

On the other hand, in the present invention, as explained in FIG. 2, the cooling pipe 1 is divided in the middle, at three straight points in the figure, and both pipe ends 1' at the divided portions.

An appropriate gap 4 is provided between the pipes 1' and a short pipe 5 that is fitted onto the outside of the pipe 1 is slidably connected to the pipe 1 as a cast pipe. It is cast as a cast iron.

The one shown in Fig. 3I uses a bellows pipe 5' to form the extendable part, whereas the one shown in Fig. 2 uses a short pipe 5 to form the extendable part. , ■ in the same figure uses a flexible tube 5'.

Therefore, in the present invention, as described above, an expandable part is provided in advance at a necessary position such as the middle of a cast pipe, and the cast pipe is integrally cast with the cast pipe. The expandable part contracts in accordance with the shrinkage, and does not inhibit the shrinkage of the casting, so it is possible to reliably prevent cracking, destruction, etc., and provide a sound cooling hardware, compared to conventional cooling hardware castings. Nihard, high Cr cast iron, Cr-Mo cast iron, high Mn cast steel, white pig iron, etc. can be actively used as wear-resistant materials that have been difficult to use. The cooling hardware manufactured in this way is also effective in reducing internal stress generated by heating and cooling during use due to the presence of its expandable parts, which improves lifespan and safety. It's connected.

As described above, the manufacturing method of the present invention has various advantages, and is applicable not only to cooling hardware for blast furnaces (stave coolers), but also to cooling hardware for other melting furnaces and reduction furnaces, such as cooling hardware for reduced iron manufacturing equipment, etc. The industrial value of the present invention is significant.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional cooling hardware, FIG. 2 is a sectional view of a cooling hardware obtained by the method of the present invention, and FIG. 3 is an explanatory view of another embodiment of the extensible part of the present invention. 1... Casting pipe, 3... Casting, 4.5... Expandable part, 4,5'...
...Stretchable part, 4゜5''...Stretchable part.

Claims (1)

[Claims] 1. When manufacturing integrally cast cooling hardware that includes a cast pipe, a retractable part is provided in advance at a required position in the middle of the pipe, and the cast pipe is integrally cast. A method for producing cooling hardware used in melting furnaces, etc., which absorbs the shrinkage that occurs during solidification of the casting and reduces residual stress in the casting.