SU841868A1 - Method of working welded connections - Google Patents

Description

The invention relates to welding, in particular to methods for treating welded joints, and may find application in various parts of the machine industry in the manufacture of welded structures. A known method of treating welded joints, including plastic deformation of the weld metal by forging, and subsequent artificial aging. However, this method is characterized by the complexity of the technological process. The closest to the present invention is the method of welding welded joints i, which performs a plastic deformation of the weld metal and heat affected zone rollers The disadvantages of the method of processing welded joints is the instability of the geometric dimensions, namely, the uneven thickness of the metal la in the deformation zone and the degree of reduction of the seam length, as well as different parts of stepenushireni seam length. For example, after plastic deformation of the longitudinal seam of the cylindrical shell by rolling the roller, a change in diameter along the seam length occurs. For shell rings, the perimeter and diameter become larger than in the middle part. The mechanical properties of the compound after rolling, due to the unevenness of the degree of reduction of the weld along the length, have a considerable scatter. The instability of the geometrical parameters of the product is explained by the fact that during the rolling process, the stress – strain pattern in the deformation zone varies along the seam, and the plastic flow of the metal has a different direction. Thus, at the beginning of rolling, the metal flow occurs predominantly to the sides of the seam and back, pulled out from under the rollers, in the middle part of the seam length the metal flows in 3 directions and in the thickness direction, and at the end of the seam - forward and to the side of the seam With an increase in the degree of compression of the seam as well as during the rolling of compounds in the heated state, shear plastic deformations of the metal increase, and the instability of the geometrical parameters of the product simultaneously increases. The purpose of the invention is to improve the quality of the welded joint. This goal is achieved due to the fact that simultaneously with the rolling of the weld seam and the heat-affected zone, a compressive load is applied to the welded joint in the direction of the longitudinal axis of the weld in the area equal to the width of the zone, plastic deformation from welding. Fig. 1 shows a rolling pattern of a welded joint, at the ends of which longitudinal compressive forces are applied at the width of the plastic deformation zone; in fig. 2 is a diagram of a change in the geometrical dimensions of a welded product after rolling without application of longitudinal compressive forces at the ends of the seam; in fig. 3 is a diagram of the change in the geometrical dimensions of a welded product after rolling with the application of longitudinal compressive forces at the ends of the seam in an area equal to the width of the plastic deformation zone. The dashed lines indicate the geometric size of the compound prior to rolling. The method is carried out as follows. The welded product 1 is placed between the rollers 2, then at the ends of the seam in the area equal to the width 2B of the zone of plastic deformation from the weld, a longitudinal compressive load Pjj is applied. With the efforts of the compression, PPROKOTTSI nz rollers create the necessary: the degree of compression of the seam. Welded product can move relative to the rollers with speed, or plastic seam can be deformed when the rollers move and the product is stationary. seam rollers with the same scheme of stress-strain state of metal in the deformation zone along the seam length. The plastic flow of the metal along the seam flows to the side of the seam 84 and in the direction of the mass, resulting in a higher quality of the treatment, the welded product. . The length 1 of the product also does not change. Plastic deformation of the weld metal with the application of longitudinal compressive forces at the ends of the weld ensures uniform mechanical properties of the joint along the length of the weld. After the end of the rolling process, the welded section is freed from the reduction force of the RPRS, as follows: Crimping rollers, and from longitudinal compression loads E. ... .Example. The tests were carried out on welded specimens with a thickness of 2 mm, a length of 500 mm, and a width of 250 mm from an AMGbM alloy with longitudinal butt welds made by argon-arc welding with a non-melting electrode using ShGb filler wire. Welded samples rolled in a rolling machine between two rollers, without heating and with preheating. The preheat temperature of the deformation zone is 400-420 ° C. The degree of compression of the seam in both cases is 30% and is provided by applying a compressing force to the rollers of the rolling machine. Welded specimens are fixed in a special device (frame), which is equipped with a removable support silo device, before rolling the seam. After securing the specimen in the fixture, longitudinal compressive forces are applied to the ends of the welded joint at the ends equal to the width of the deformation zone. Longitudinal compression forces are monitored. The width of the 3oiibi deformation zone of the welded specimen in the steady-state region is determined by testing. During plastic deformation of the seam by rolling with rollers at room temperature, the width of the deformation zone in the steady-state region is within 28–30 mm, and during deformation with heating, 39–41 mm, respectively. The magnitude of the longitudinal compressive force is taken so that the local contact stresses at the ends of the sample at the locations of the stops are 0.4-0.6 of the yield strength of the material5 corresponding to the considered rolling temperature of the product. Simultaneously applying longitudinal compressive forces to the welded specimen seam rollers rolling machine. The longitudinal compressive forces applied over the weld seams create, in the process of plastic deformation of metal by seam with rollers, the same pattern of stress-strain state of the metal in the deformation zone along the length of the seam. The plastic flow of metal along the weld length proceeds to the side of the weld and in the thickness direction, as a result of which the processing quality of the welded product, increases. The table shows the values of changes in the size of the specimen uiurene, as well as changes in their thickness to the axis of the seam in three sections, namely, rolled in without applying longitudinal compressive forces at the ends of the seam

Laminated with application of longitudinal compressive forces at 8, in the middle and at the end of the specimen. Data is presented when the joints are rolled in a heated state without application of longitudinal compressive forces and with application of longitudinal compressive forces at the ends of the joint in an area equal to the width of the center of The tables show that the geometrical dimensions of the rolled samples with the application of longitudinal compressive forces, namely the magnitude of the broadening Д В and the magnitude of the thickening of the metal in the deformation zone have a stable character along the length of the seam. Sample length does not change. Plastic deformation of the weld metal with the application of longitudinal compressive forces at the ends of the weld also provides uniform mechanical properties of the joint along the length of the weld.

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At the beginning

In the middle of the Invention-1sh formula. A method for treating welded joints in which plastic deformation of the weld metal and dewlaps of the Yoy zone is carried out by rolling rollers, so that, in order to improve the quality of the welded joint, simultaneously with the rolling of the weld and the round area A compressive load is applied to the welded joint in the direction of the longitudinal direction1, 4 of the reference seam axis in a section with a width equal to the width of the zone of plastic deformation from welding. Sources of information taken into account during the examination 1.A.Article certificate of the USSR No. 3.36373, cl. C 21 D 9/50, 1971. 2, Sagalevich V.M. Methods for eliminating welding deformations and stresses. M., Mechanical Engineering, 1974, p. 24-55 ..

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Claims (1)

Claim A method of treating welded joints, in which plastic deformation of the weld metal and the weld zone is performed by rolling with rollers, which means that, in order to improve the quality of the welded joint, a compressive load is applied to the welded joint in the direction the longitudinal axis of the weld in a section with a width equal to the width of the zone of plastic deformation from welding.