The method of welding metal strips overlap

 

(57) Abstract:

The method can be used for consolidation of the rolls on the endless rolling mills in the steel and engineering industries. On facing each other, the ends of the bands perform evenly spaced depressions depth not exceeding the thickness of the strip and the ratio of the areas of the cross-section troughs and separated protrusions 1<S RR/Sinvoice2. Combine the tabs of the end of one strip with the depressions of the other end of the strip. Heat the weld metal volume to a temperature not higher than the temperature of phase transitions. By precipitation deform this volume simultaneously over the entire area of the welded connection to the width of one lane. Increases strength of a welded joint is not only due to the diffusion of education total grains, but at the expense of tensile shear ledges of the base metal of the strip ends. 3 Il.

The invention relates to the welding of metal and can be used for consolidation of the rolls, making long belt traction tool on the endless rolling mills, etc.

According to GOST 2601-84 known welding pressure, which is carried out at temperatures below Dania necessary plastic deformation of the connected parts.

As disadvantages of this method it can be noted that for each material you need to know to set and adjust a combination of parameters such as the degree, speed and temperature of deformation and strength of a welded joint on the shift is determined by the contact area of the articulating surfaces and the nature of relationships formed at the boundary [1].

There is a method of welding the ends of the strips overlap [2], the essence of which is that during the welding pressure by using drive, the inlet zone of the welding electric current to heat the metal, the seam is unrolled in the direction of the width of the strip to its thickness.

The main and very important disadvantage of this method is that, according to [1], when the roll welding diffusion processes in the area of the connection do not have time to develop so much to change the structure of the connection zone due to insufficient duration of the interaction under pressure connected surfaces. When this happens only gripe surfaces and welded connection has low durability and can be used only as a transport.

The closest analogue is the welding method SMU method, on the contact surfaces of the welded bands perform evenly spaced depressions, before welding combine the resulting projections of the end of one strip with the depressions of the other end of the strip. Then heat up the weld metal volume method for electrical resistivity and produce joint deformation of the ends of the strips.

The present invention is to provide a method of welding metal strips overlap, providing ravnopravnosti welded joints and base metal bands.

The problem is solved as follows.

Side surfaces of the ends of the welded strips facing each other, in the direction of the width of the bands perform evenly spaced depressions with a depth not more than half the thickness of the strip with the ratio of the areas of the cross-section troughs and separated protrusions 1 < SRR/Sinvoice2. Then combine the tabs of the end of one strip with the depressions of the other end of the strip. The method of electrical resistance heat weld metal volume to a temperature not higher than the temperature of phase transformations and by precipitation deform this volume simultaneously over the entire area of the welded connection to the thickness of odnoy sizes and precipitated simultaneously combined volume of bands over the entire area of the welded connection, allows addition of diffusion with the formation of common beans to increase the strength of the welded joint due to the tensile shear ledges of the base metal bands.

The choice of parameters of projections and depressions is defined by the following considerations.

The depth of the depressions should be no more than half the thickness of the strip, on the basis of ensuring the total thickness of the solid metal compound is not less than the thickness of the strip. The shape of projections and depressions may be different and determined by technological reasons and tools for their implementation.

The ratio of the areas of cross-sections of the depressions and protrusions must be larger than 1 in order to ensure that the combination of depressions and protrusions with guaranteed clearance. The condition of the ratio of these areas is less than 2 due to the fact that the joint upsetting of the ends of the bands in the welding process, it is a guarantee fill with metal side ledges, gaps and create a continuous contour of the welded connection.

Heating the deformable volume to a temperature not higher than the temperature of phase transformations excludes changes in the structure and, consequently, the mechanical properties of the welded joint compared with the base metal bands.

At f is shown in Fig. 2 - the same, with a triangular trapezoidal protrusions and depressions of Fig. 3 shows a weld joining the strip ends after heating and precipitation.

The method is as follows.

At the ends of the bands perform evenly spaced Dina depth not exceeding the thickness of the strip with the ratio of the areas of their cross-sections to areas of cross-sections separating them protrusions 1 < SRR/Sinvoice2. Then combine the tabs of the end of one strip with the depressions of the other end of the strip. After being welded to the volume of down current from the welding transformer and heat up the volume to a temperature not higher than the temperature of phase transformations metal bands. Further, by precipitation deform this volume simultaneously over the entire area of the welded connection to the width of one lane. Within the volume of the weld zone to form a continuous contour welding, as shown in Fig. 3. Thanks to the strength of the welded joint tensile provided not only by formed by diffusion of common beans in contour welding, but also due to the tensile shear ledges of the base metal of the strip ends.

Example

For welding of the ends of the strips 4 mm thick steel of ZOGGS monm;

- the width of the protrusions 1.0 mm;

the number of protrusions is not less than 4;

- heating temperature of the weld zone is not higher than 760oC.

The proposed method of welding metal strips overlap should be used in the metallurgical and engineering industries for the enlargement of the rolls, in the manufacture of long tape pulling tool, such as the traction unit of the downhole pump unit.

Sources of information:

1. Karakozov E. C. welding of metals by pressure. M: Engineering. 1968, S. 147.

2. Mechanical equipment cold rolling. Edited by CL. - Corr. An SSSR, Leningrad Chimica. M: Engineering. 1972, S. 379.

3. FR 2598643 A, 20.11.87.

The method of welding metal strips overlap when facing each other, the surfaces of the joined ends of the bands perform evenly spaced depressions in the direction of the width of the bands, combine educated projections of one strip with the depressions of the other strip, heat welded volume method for electrical resistivity and produce deformation of the connection zone, wherein the ratio of the areas of the cross-section troughs and separated protrusions are selected from the ratio above the temperature of the phase transitions of the welded metal, and the deformation produced by precipitation simultaneously over the entire area of the welded connection to the width of one lane.

 

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