SU1366338A1 - Method of thermit welding - Google Patents

Abstract

The invention relates to welding production, in particular, to thermite welding of reinforcement of building structures under installation conditions. The aim of the invention is to increase the productivity and quality when welding building structures in assembly conditions. A sleeve 2 of refractory material, such as graphite, is mounted on the elements to be welded 1, so that its end abuts against the bottom of the mold 4 mounted on the elements to be welded. At the bottom of the form pour a layer of flux and thermite mixture. After the thermite reaction has passed and the melt is divided into slag and metal, the sleeve is removed outside the weld pool 14. Welding of the reinforcement rods according to this method reduces the time for preparatory operations, which increases the welding performance. Slag inclusions in the weld are also reduced. 5 il. S (L oo a 05 oo s o

Description

one

The invention relates to welding production, in particular, to thermite welding of reinforcement of building structures under installation conditions.

The aim of the invention is to increase productivity and quality during welding of building structures in assembly conditions.

FIG. 1 shows the preparatory welding stage of the proposed method with welded elements in the form of rods in FIG. 2, a stage of the proposed method of welding rods after conducting a thermite reaction, separating the melt formed into metal and slag and removing the sleeve beyond the weld pool; in fig. 3 - the same, with the output of the sleeve beyond the limits of the liquid slag on phi1. 4 shows the preparatory stage of welding with elements to be welded in the form of a rod and a plate; FIG. 5 shows the stage of welding a rod and a plate after carrying out a thermite reaction with the sleeve being brought out of the liquid slag,

On the elements to be welded, for example, rods 1, a sleeve 2 of a refractory material, for example, a graph, is installed detachable along the length. The inner diameter of the sleeve is 1-2 mm greater than the diameter of the rods 1 covered by it. Parts of the sleeve are fastened with wire twists or spring rings 3,

A split form 4 is mounted on the rods x 1 so that the end of the sleeve 2 abuts against the bottom 5 of the form 4. The form 4 is held together by a collar 6 and fixed to the rod with the stop 7.

When welding the rod with the plate, the sleeve 2 is mounted on the rod until the end of the sleeve contacts the plate (Fig. 4).

At the bottom 5 of the mold 4, a layer of flux 8 is poured, used for arc welding of carbon steels, for example, grade AN-348 or OCC-4. Any other flux of a similar class is possible.

Instead of a layer of flux, flux washers 9 can be used, which is a spinner; it is a compressed flux on an inorganic bond, for example, from liquid glass (Fig. 4).

The amount of flux used as a bulk layer or washer.

3663382

should be such that the molten flux adjoins the side surface of the end part of the sleeve 2 and covers the entire bottom 5 of the form 4 with a layer thickness of 1.0-1.5 mm. Between the form 4 and the sleeve 2, thermite mixture 10 is poured. Form 4 is closed with a composite crush: - which has an opening

10 12 for the exit of gases and the possibility of mixing; sleeve 2,

Thermite mixture 10 is ignited by one of the known methods. After passing the thermite reaction, forming a melt and dividing it into molten slag 13 and molten metal to form a weld pool 14 in the cavity 15 of the mold 4, the sleeve 2 leaves the weld pool 14 to stop 2 The stop 16 is installed in the rod to be welded in a position determined by the dimensions of the form and the elements to be welded, the volume of the weld pool and the amount of protrusion of the rods 1.

25 Sleeve 2 can be removed from the weld pool 14 so that its end face is above the surface of the weld pool (Fig. 2), or, if the rods allow,

30 D the surface of the liquid slag 13 (Fig. 3). In the latter case, the service life of the sleeve increases, since the likelihood of its damage is eliminated when the hard slag is peeled off. During the period of the thermite reaction, the heat released through the sleeve 2 is transferred to the welded elements 1. They heat up depending on the amount of the thermite mixture 10

 is 800-1100 ° C. Therefore, as soon as the movement of the sleeve 2 begins, the superheated metal of the weld pool 14 comes into contact with the heated elements 1 to be welded.

The surfaces of the rods are sub-melted, which subsequently leads to the joint crystallization of the metal of the weld pool 14 and the metal of the 1x weld elements with a minimum amount of slag inclusions, resulting in a high-quality weld joint.

35

45

50

During the thermite reaction, the released heat melts the layer of flux 8 or flux washers 9, the melted flux covers the bottom 5 of the form 4, wets the side surface of the end part of the sleeve 2 and beyond; /

JO

but-

sixteen

17

12

figure 1

/ "

(puaZ

fyal

sixteen

.S

/ "

Claims (1)

Claim 10 Method of thermite welding, in which the zone of the welded joint is protected from slagging, the form is welded onto the parts to be welded, it is covered with a thermite mixture and carried out 15 thermite reaction, characterized in that, in order to increase productivity and quality when welding building structures under installation conditions, protection 2Q is performed by installing a sleeve of refractory material on the elements to be welded with the possibility of its movement along the axis of one of the elements and after passing the thermite reaction and separating the resulting melt into slag and metal lead the sleeve outside the weld pool. figs! - "Ζ23> figure 2