RU2289496C1 - Method of friction welding with displacement of blank materials (versions) - Google Patents

Abstract

FIELD: mechanical engineering; welding.

SUBSTANCE: invention can be used to produce permanent butt joints in manufacture of skeleton-and-panel structures, housings, different tanks and shells. According to invention, parts of blanks to be welded are installed tightly to each other along line of connection. Welding tool is used consisting of two functional parts: housing with support bead and working rod installed in housing for removal and adjustment of axial displacement. Butt joint of blanks to be welded is sealed by rotating support bead at force 2-5 times less than that required for material of this thickness. Tacking is carried out by driving rotating working rod through depth equal to 0.2-0.5 of thickness of material to be welded at translational movement of rod. Weld is formed by driving rod through full depth of welding at building welding force. Method can be used in welding of longitudinal and closed girth joints.

EFFECT: improved conditions of forming weld joints, quality and strength characteristics owing to decrease of wedging force.

4 cl, 7 dwg

Description

The invention relates to a technology for the production of permanent joints of parts end-to-end by friction welding with a rotating welding tool. The invention can be used in various fields of engineering in the manufacture of frame-panel structures, cases, various tanks and shells.

There are many known methods of friction welding, based on plasticizing the metal released by the welding tool excited by the welding tool rotating between the parts to be joined together with thermal energy and mechanically mixing it with the formation of an integral tight welded joint, for example, A.S. USSR No. 106972, class In 23 K 20/12, 1956, A.S. USSR No. 195846, class In 23 K 20/12, 1967, US Pat. RF №2126738 class In 23 K 20/12, 1995, US Pat. RF №2196030, class In 23 K 20/12, 2001, US Pat. ЕВП No. 1314508, cl. In 23 K 20/12, 2003, US Pat. ЕВП No. 1314509, cl. B 23K 20/12, 2004, з. Japan No. 3261431, class B 23K 20/12, 2001

For example, in RF patent No. 2126738, a method of friction stir welding is described, in particular for joining stamped assembly profiles, in which the elements to be welded (workpieces) are installed along the line of their joining. Welding is carried out by rotating the welding tool with a working rod (probe with a finger) made of a material harder than the material of the welded elements, which generates frictional heat and ensures the formation of a plasticized zone in the material of the adjacent elements, while the outer surface of the probe finger is threaded, providing enhanced flow of plasticized material in the horizontal and vertical direction by applying pressure to it, directed m perpendicular to the connected surfaces of the elements while ensuring the flow of plasticized material along the working rod in the vertical direction and allowing solidification of the material behind the probe.

The disadvantage of this method is the increase in the initial assembly gap under the influence of proppants arising from the movement of the rotating welding tool along the welded joint, above the optimum value, especially when welding at speeds of more than 12 m / h, which leads to a deterioration in the conditions of formation of the weld and reduce it quality and strength characteristics.

The closest in technical essence can be considered the method according to US Pat. EPO No. 1310320, class In 23 K 20/12, 2000, which describes the method of friction welding by friction with a rotating tool with preliminary fixation of the joined structural elements with tack welds, in which the welded workpieces are installed along the line of their connection closely to each other using tack welds, they are introduced into the initial section of the junction of the rotating welding tool and move the welding tool along the junction of the welded workpieces to obtain a weld. At the same time, the tack joints are made so that technological protrusions arranged along the line of the connected elements are arranged on the end sides of the elements to be joined, the ends of these protrusions are grabbed, and then a friction joint is made with a rotating tool, starting mainly from the ends of the protrusions. After welding, the technological protrusions are removed.

The use of such a welding method also does not exclude an increase in the assembly gap in comparison with the initial one, and hence, deterioration in the quality and strength characteristics of the welded joint.

The objective of these inventions is to create a method of friction welding with the achievement of a technical result in the form of improving the conditions for the formation of a welded joint, increasing its quality and strength characteristics by reducing the wedging force.

This problem is solved by the fact that in the method of friction welding with mixing of the material of the workpieces, which consists in the fact that set the welded parts of the workpieces along the line of their connection close to each other; fix the welded parts of the workpieces with tack welds, introduce a rotating welding tool into the initial portion of the joint and move the welding tool along the joint of the welded blanks to obtain a weld in accordance with the invention, before entering into the initial portion of the joint of the welding tool, consisting of two functional parts - housing with a support collar and installed in it a working rod with the possibility of removal and regulation of movement along the axis, sealed with a rotating op with a shoulder, the joint of the welded workpieces with a force of 2 ÷ 5 times less than the material required for a given thickness, and the tack weld is performed by introducing a rotating working rod to a depth equal to 0.2 ÷ 0.5 of the thickness of the material being welded, and translationally moving the rotating welding tool along the joint the welded workpieces along the entire length of the butt, while welding longitudinal welds then return the welding tool outside the received tack weld again to the beginning of the weld, introduce a rotating welding tool to the full welding depth with aniem full welding force and welding tool is translated along the entire length of the welded seam to form a weld.

In the frictional welding method according to the second embodiment, namely, that the parts to be welded are placed along the connection line close to each other, the parts to be welded are fixed with tack welds, a rotating welding tool is introduced into the initial portion of the joint and the welding tool is moved along the joint blanks for producing a weld, in accordance with the invention, before introducing a welding tool consisting of two functional parts - a housing with a support the volume and the working rod installed in it with the possibility of removal and regulation of movement along the axis, to the initial section of the junction, the joint of the welded workpieces is sealed with a rotating collar with a force of 2 ÷ 5 times less than the material required for the given thickness, and the tack joint is made by introducing a rotating working rod to a depth equal to 0.2 ÷ 0.5 of the thickness of the material being welded, and while welding closed welds, the rotating welding tool is moved along the joint of the welded workpieces until the tack is completely closed the seam, then, continuing the rotation of the welding tool and movement along the joint, gradually extend the working rod to the full welding depth with the creation of a full welding force and translate the welding tool at the full welding depth along the entire length of the welded joint, and after completely overlapping the beginning of the second welding pass the working rod is gradually raised above the level of the welded joint, and then the supporting shoulder is raised until the contact of the welding tool with the workpiece material is completely lost.

At the same time, the control of the magnitude of the welding force is carried out by the magnitude of the depth of the supporting shoulder in the workpiece material.

Further, this method (its variants) is explained in more detail using circuit drawings. Figure 1 shows a device for friction welding, figure 2, 3 - scheme for performing friction welding with a longitudinal seam, figure 4, 5 - scheme for performing friction welding with a closed seam, figure 6 - microstructure of the core of the welded joint, in figure 2 .7 - loading diagram of the welding tool butt butt welded workpieces.

Welding is performed using a friction welding device, schematically shown in figure 1. The device contains a welding tool, consisting of two functional parts - a housing 1 with a support collar 2 and a working rod 3 installed in it with the possibility of removal and regulation of movement along the axis, each of which has its own separate drive: drive 4 rotation of the welding tool, drive 5 movement a working rod along the axis of the tool and a measuring device 6 that controls the magnitude of the vertical movement of the welding tool.

The implementation of the method is as follows: install the welded parts of the workpieces along the line of their connection close to each other. Before entering the rotating welding tool into the initial section of the joint, the joints of the welded workpieces are sealed with a rotating support collar with a force 2–5 times less than the material required for a given thickness, while the force is controlled by the depth of the supporting collar l or L in the workpiece material, then introduced the rotating working rod of the welding tool end-to-end of the welded workpieces to a depth h equal to 0.2 ÷ 0.5 of the thickness of the welded material N (see Fig. 7) of the welding and the rotating welding tool is mixed along the joint of the welded workpieces or, conversely, the joint of the welded workpieces is moved along the joint of the relative welding tool.

When welding longitudinal seams (option 1 - see figure 2, 3) the movement of the welding tool relative to the workpieces (or workpieces relative to the tool) is produced along the entire length of the joint. Then, the rotating welding tool is returned outside the obtained preliminary weld again to the beginning of the weld, the working rod of the welding tool is inserted butt-to-weld the workpieces to the full depth H of the weld, and the welding tool (or workpieces) is advanced along the entire length of the welded joint.

When welding closed welds (option 2 - see FIGS. 4, 5), a rotating welding tool is moved along the joint (or joint relative to the tool) along the entire length of the joint, holding the tool (working rod) at a depth of h = 0.2-0.5 thickness of the welded material H, until the start of welding is completely blocked. Then, after overlapping the start of welding, continuing the rotation of the welding tool and movement along the joint (relative), the working rod is gradually extended to the full depth of welding N and the entire seam passes at full depth, and after the beginning of the first welding pass is blocked, the working rod of the welding tool is gradually raised above the level the welded joint, and then, continuing the translational movement of the welding tool along the weld, raise the support collar until its contact with the material of the workpieces is completely lost.

An advantage of the new method of friction welding is the absence of a layered microstructure characteristic of joints made by the known methods considered. The microstructure of welded joints obtained in a new way, shown in Fig.6, is characterized by a high degree of homogenization; for example, when welding alloys of the Al-Mg system, the grain size of the metal of the welded core is 3-5 times smaller than the grain of the base material.

To achieve maximum effect, welding is performed with a tool in which the movable working rod 3 (Fig. 7) is made in the form of a rod of variable cross section. At the same time, the control of the magnitude of the welding force is performed by the magnitude of the deepening of the support collar 2 into the workpiece material.

Claims (4)

1. Method of friction welding with stirring the material of the workpieces, in which the welded parts of the workpieces are installed along the line of their connection close to each other, the welded parts of the workpieces are fixed with tack welds, a rotating welding tool is introduced into the initial section of the joint and the welding tool is moved along the joint of the welded workpieces to obtain a weld, characterized in that before entering into the initial section of the junction of the welding tool, consisting of two functional of the second parts - the case with a supporting collar and a working rod installed in it with the possibility of removal and regulation of movement along the axis, they are sealed with a rotating supporting collar of the joint of the welded workpieces with a force of 2 ÷ 5 times less than the material required for this thickness, and the tack joint is made by introducing a rotating working the rod to a depth of 0.2 ÷ 0.5 of the thickness of the material being welded and translationally moving the rotating welding tool along the joint of the welded workpieces along the entire length of the joint, while welding longitudinal welds then return dissolved welding tool is obtained tack weld seam to the top again, the rotating welding tool is introduced to the full depth of weld to the establishment of full welding force and welding tool is moved progressively along the entire length of the welded seam to form a weld. 2. The method of friction welding according to claim 1, characterized in that the magnitude of the force with which the joint of the welded workpieces is sealed with a rotating support shoulder of the welding tool is controlled by the amount of deepening of the trailing edge of the support shoulder of the rotating welding tool. 3. A method of friction welding with stirring the material of the workpieces, in which the welded parts of the workpieces are installed along the line of their connection close to each other, the welded parts of the workpieces are fixed with tack welds, a rotating welding tool is introduced into the initial section of the joint and the welding tool is moved along the joint of the welded workpieces to obtain a weld, characterized in that before entering into the initial section of the junction of the welding tool, consisting of two functional of the second parts - the case with a supporting collar and a working rod installed in it with the possibility of removal and regulation of movement along the axis, the joint of the welded workpieces is sealed with a rotating collar with a force of 2 ÷ 5 times less than the material required for a given thickness, and the tack joint is made by introducing a rotating working rod to a depth of 0.2 ÷ 0.5 of the thickness of the material being welded, while when welding closed welds, the rotating welding tool is moved along the joint of the welded workpieces until the start of welding is completely blocked, then Squeezing the rotation of the welding tool and movement along the joint, the working rod is gradually extended to the full welding depth with the creation of a full welding force and the welding tool is progressively moved along the entire length of the welded joint, and after the complete overlap of the beginning of the second welding pass, the working rod is first gradually raised above the level of the welded joint and then raise the support shoulder to the complete loss of contact of the welding tool with the workpiece material. 4. The friction welding method according to claim 3, characterized in that the magnitude of the force with which the joint of the welded workpieces is sealed with a rotating support shoulder of the welding tool is controlled by the amount of deepening of the trailing edge of the support shoulder of the rotating welding tool.

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