CN105033438B - A welding method for aluminum-steel composite parts and aluminum-steel composite parts - Google Patents

Abstract

The welding method of the aluminum-steel composite part ensures that enough temperature is generated during welding by reasonably setting the surface roughness, the pressure, the revolution, the stretching speed and the cooling speed, so that the metal at the welding surface generates plastic deformation, an aluminum-steel combination area with enough thickness is formed at the welding seam after welding, and the defects of bubbles, cracks and the like are not generated at the welding seam, so that the tensile strength at the welding seam is greater than that at the aluminum matrix. After welding is finished, the welding surface is locally heated, so that residual stress at the welding seam can be removed, and the connection strength at the welding seam is improved.

Description

A welding method for aluminum-steel composite parts and aluminum-steel composite parts

technical field

The invention relates to a welding method for an aluminum-steel composite part and the aluminum-steel composite part, belonging to the technical field of friction welding technology.

Background technique

In the prior art, for the joining of dissimilar metals such as steel and aluminum, fusion welding is usually used, or mechanical connection methods such as rivets are used, or adhesive bonding is used.

When fusion welding is used, because the heat input to the welding part is too large, it is easy to form fragile intermetallic compounds at the joint surface between steel and aluminum, which reduces the joint strength between steel and aluminum. Under long-term use, especially Under the action of torque, the weld is prone to breakage, resulting in structural failure.

When glue is used for bonding, the bonding force between steel and aluminum often fails to meet the requirements, and the glue may further reduce the bonding force between steel and aluminum due to aging.

When joining by mechanical methods such as rivets, there are problems that the shape of the product will be affected by the riveting, or fatigue fracture will occur due to the long-term use of the riveted parts.

To sum up, how to provide a solidly bonded aluminum-steel composite part is an unresolved technical problem in the prior art.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the technical problem that the production method of steel-aluminum composite parts in the prior art makes the joint between steel and aluminum not firm, so as to propose an aluminum-steel joint that can make the joint between steel and aluminum firm. Production methods for composite parts.

For this reason, the present invention provides a kind of welding method of aluminum-steel composite parts, it is characterized in that, comprises the following steps:

Plate or block aluminum parts with a surface roughness of Ra1.6-Ra6.3, and cylindrical steel parts are used. The thickness of aluminum parts is not less than 9mm, and the diameter of steel parts is not less than 20mm;

Fix the steel parts and aluminum parts, and make the plate surface of the aluminum part and the end face of the steel part align and contact to form a welding surface, and apply a force to the steel part and perpendicular to the welding surface on the aluminum part or The component of the force, so that the force or the component of the force produces a pressure of 280-380KN on the welding surface;

Keep the pressure on the welding surface, and rotate the steel part relative to the aluminum part at 300-500 rpm. After 3-5s, stop the rotation of the steel part. During the rotation of the steel part, use The steel part gradually penetrates into the aluminum part at a speed of 0.8-1mm/s, and joins with the aluminum part in a plastically deformed state to form an aluminum-steel composite part;

Cool the aluminum-steel composite to room temperature at a cooling rate of 200-300°C/min to complete welding.

It also includes the step of surface treating the welded surfaces of the aluminum and steel parts to control the surface roughness of the aluminum and steel parts.

Steel parts and aluminum parts are rotationally joined in an inert gas atmosphere.

After the steel parts stop rotating, continue to maintain the above pressure on the welding surface, and the pressure holding time should not be less than 10s.

After welding, heat the welding surface locally to 200-250°C and keep it warm for 1-2h.

The welding surface of the selected aluminum part has a circular truncated hole groove, the depth of the hole is 1-2mm, and the selected steel part has a circular truncated boss on the welding surface, and the clamp formed by the busbar of the boss and the central axis of the boss The angle is 3-5° larger than the angle formed by the generatrix of the slot and the central axis of the slot. When welding, align the central axis of the slot and the boss.

The included angle formed by the generatrix of the circular truncated boss and the central axis of the boss is 83-88°.

The included angle formed by the generatrix of the frustum-shaped hole and the central axis of the hole is 80-85°.

The present invention also provides an aluminum-steel composite part, including a plate-shaped or block-shaped aluminum part, and a cylindrical steel part welded and fixed to the plate surface of the aluminum part, the aluminum part and the steel part The parts are welded and fixed by any of the welding methods described above.

The welding method of the aluminum-steel composite provided by the invention has the following advantages:

1. The welding method of aluminum-steel composite parts provided by the present invention ensures that sufficient temperature is generated during welding by reasonably setting surface roughness, pressure, rotation speed, penetration speed and cooling speed, so that the metal at the welding surface is produced Plastic deformation, and form an aluminum-steel bonding zone of sufficient thickness at the weld after welding, and no defects such as bubbles and cracks at the weld, so that the tensile strength of the weld is greater than that of the aluminum matrix. Local heating of the welding surface after welding can remove the residual stress at the weld and improve the connection strength at the weld.

2. The welding method of the aluminum-steel composite part provided by the present invention is to preform a circular truncated hole groove on the plate surface of the aluminum part, and form a circular truncated boss at the welding end of the steel part, and simultaneously place the circular truncated boss The angle between the busbar and the central axis of the boss is set to be 3-5° larger than the angle between the busbar and the central axis of the circular truncated hole. On the one hand, the circular platform is aligned with the hole to form a steel part before welding. Provide positioning with the aluminum parts. On the other hand, the steel parts extend into the aluminum parts during welding, and the steel parts and the aluminum parts form a welding joint surface on the surface of the circular table, which increases the joint area and improves the steel parts. In addition, the pre-formed hole can also reduce the amount of overflow of the aluminum part from the welding area.

3. The aluminum-steel composite part provided by the present invention is prepared by the above method, so it has very high peel strength, stable combination of aluminum and steel, and long service life.

Description of drawings

In order to make the content of the present invention more easily understood, the present invention will be described in further detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

Fig. 1 is the structural representation before welding of aluminum parts of the present invention and steel parts;

Fig. 2 is the structural representation of the aluminum-steel composite part of the present invention after turning;

The reference signs in the figure are represented as: 1-steel parts; 2-aluminum parts; 3-cylinders; 31-blind holes; 4-round bases; Department; 43-round protrusion.

detailed description

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings.

Example 1

This embodiment provides a welding method for aluminum-steel composite parts, comprising the following steps:

S1: Use plate-like aluminum parts with a surface roughness of Ra1.6 and cylindrical steel parts with a surface roughness of Ra1.6. The thickness of the aluminum part is 9mm, the diameter of the steel part is 20mm, and the aluminum part is 1060 Pure aluminum, steel parts are 304 stainless steel;

S2: Fix the aluminum parts and steel parts, and make the plate surface of the aluminum part and the end face of the steel part align and contact to form a welding surface, and apply a force to the steel part and perpendicular to the welding surface on the aluminum part The force or the component of the force, so that the force or the component of the force produces a pressure of 280KN on the welding surface;

S3: Keep the pressure on the welding surface, and make the steel part rotate relative to the aluminum part, the rotation speed is 300 rpm, stop the rotation of the steel part after 5s, and make the steel part rotate during the rotation of the steel part. The parts are gradually inserted into the aluminum parts at a speed of 1mm/s, and are joined with the aluminum parts in a plastically deformed state to form an aluminum-steel composite part, wherein the pressure is maintained for 10s after stopping the rotation;

S4: Cool down the aluminum-steel composite part to room temperature at a cooling rate of 200°C/min to complete welding.

S5: After the welding is completed, loosen the aluminum-steel composite part and place it in the heating device, locally heat the welding surface to 200°C, and keep it warm for 2 hours.

The aluminum-steel composite parts produced by the above welding method include cylindrical steel parts and plate-shaped aluminum parts welded to the end faces of the cylindrical steel parts. The peel strength of the aluminum-steel composite parts is shown in Table 1. .

Example 2

S1: Use plate-like aluminum parts with a surface roughness of Ra1.6 and cylindrical steel parts with a surface roughness of Ra5.6. The thickness of the aluminum parts is 10mm, and the diameter of the steel parts is 21mm;

S2: Fix the aluminum parts and steel parts, and make the plate surface of the aluminum part and the end face of the steel part align and contact to form a welding surface, and apply a force to the steel part and perpendicular to the welding surface on the aluminum part The force or the component of the force, so that the force or the component of the force produces a pressure of 320KN on the welding surface;

S3: Keep the pressure on the welding surface, and make the steel part rotate relative to the aluminum part, the rotation speed is 400 rpm, stop the rotation of the steel part after 3s, and make the steel part rotate during the rotation of the steel part. The parts are gradually inserted into the aluminum parts at a speed of 0.8mm/s, and joined with the aluminum parts in a plastically deformed state to form an aluminum-steel composite part, wherein the pressure is maintained for 11s after stopping the rotation;

S4: Cool down the aluminum-steel composite part to room temperature at a cooling rate of 250°C/min to complete welding.

S5: After the welding is completed, loosen the aluminum-steel composite part and place it in the heating device, locally heat the welding surface to 220°C, and keep it warm for 1.2h.

The aluminum-steel composite parts produced by the above welding method include cylindrical steel parts and plate-shaped aluminum parts welded to the end faces of the cylindrical steel parts. The peel strength of the aluminum-steel composite parts is shown in Table 1. .

Example 3

S1: Use plate-like aluminum parts with a surface roughness of Ra6.3 and cylindrical steel parts with a surface roughness of Ra4.6. The thickness of the aluminum parts is 13mm, and the diameter of the steel parts is 23mm;

S2: Fix the aluminum parts and steel parts, and make the plate surface of the aluminum part and the end face of the steel part align and contact to form a welding surface, and apply a force to the steel part and perpendicular to the welding surface on the aluminum part The force or the component of the force, so that the force or the component of the force produces a pressure of 380KN on the welding surface;

S3: Keep the pressure on the welding surface, and make the steel part rotate relative to the aluminum part, the rotation speed is 500 rpm, stop the rotation of the steel part after 4s, and make the steel part rotate during the rotation of the steel part. The parts are gradually inserted into the aluminum parts at a speed of 0.9mm/s, and joined with the aluminum parts in a plastically deformed state to form an aluminum-steel composite part, wherein the pressure is maintained for 12s after stopping the rotation;

S4: Cool down the aluminum-steel composite part to room temperature at a cooling rate of 300°C/min to complete the welding.

S5: After the welding is completed, loosen the aluminum-steel composite part and place it in the heating device, locally heat the welding surface to 250°C, and keep it warm for 1h.

The aluminum-steel composite parts produced by the above welding method include cylindrical steel parts and plate-shaped aluminum parts welded to the end faces of the cylindrical steel parts. The peel strength of the aluminum-steel composite parts is shown in Table 1. .

Example 4

S1: Use plate-like aluminum parts with a surface roughness of Ra6.3 and cylindrical steel parts with a surface roughness of Ra4.6. The thickness of the aluminum parts is 13mm, and the diameter of the steel parts is 23mm; The frustum-shaped hole is preformed on the welding surface, and the depth of the hole is 1.5mm; the frustum-shaped boss is formed on the welding surface of the steel part, and the angle between the busbar of the frustum-shaped boss and the central axis of the boss is 83°; The angle between the busbar of the slot and the central axis of the slot is 80°;

S2: Fix the aluminum parts and steel parts, and make the plate surface of the aluminum part and the end face of the steel part align and contact to form a welding surface, and apply a force to the steel part and perpendicular to the welding surface on the aluminum part The force or the component of the force, so that the force or the component of the force produces a pressure of 380KN on the welding surface;

S3: Keep the pressure on the welding surface, and make the steel part rotate relative to the aluminum part, the rotation speed is 500 rpm, stop the rotation of the steel part after 4s, and make the steel part rotate during the rotation of the steel part. The parts are gradually inserted into the aluminum parts at a speed of 0.9mm/s, and joined with the aluminum parts in a plastically deformed state to form an aluminum-steel composite part, wherein the pressure is maintained for 12s after stopping the rotation;

S4: Cool down the aluminum-steel composite part to room temperature at a cooling rate of 300°C/min to complete the welding.

S5: After the welding is completed, loosen the aluminum-steel composite part and place it in the heating device, locally heat the welding surface to 250°C, and keep it warm for 1h.

The aluminum-steel composite parts produced by the above welding method include cylindrical steel parts and plate-shaped aluminum parts welded to the end faces of the cylindrical steel parts. The peel strength of the aluminum-steel composite parts is shown in Table 1. .

Example 5

S1: Use plate-like aluminum parts with a surface roughness of Ra1.6 and cylindrical steel parts with a surface roughness of Ra6.3. The thickness of the aluminum parts is 10mm, and the diameter of the steel parts is 21mm; The welding surface is preformed with a circular truncated hole, and the depth of the hole is 1mm; the welding surface of the steel part is formed with a circular truncated boss, and the angle between the busbar of the circular truncated boss and the central axis of the boss is 87°; the circular truncated boss The angle between the busbar of the slot and the central axis of the slot is 82°;

S2: Fix the aluminum parts and steel parts, and make the plate surface of the aluminum part and the end face of the steel part align and contact to form a welding surface, and apply a force to the steel part and perpendicular to the welding surface on the aluminum part The force or the component of the force, so that the force or the component of the force produces a pressure of 320KN on the welding surface;

S3: Keep the pressure on the welding surface, and make the steel part rotate relative to the aluminum part, the rotation speed is 400 rpm, stop the rotation of the steel part after 3s, and make the steel part rotate during the rotation of the steel part. The parts are gradually inserted into the aluminum parts at a speed of 0.8mm/s, and joined with the aluminum parts in a plastically deformed state to form an aluminum-steel composite part, wherein the pressure is maintained for 11s after stopping the rotation;

S4: Cool down the aluminum-steel composite part to room temperature at a cooling rate of 250°C/min to complete welding.

S5: After the welding is completed, loosen the aluminum-steel composite part and place it in the heating device, locally heat the welding surface to 220°C, and keep it warm for 1.2h.

The aluminum-steel composite parts produced by the above welding method include cylindrical steel parts and plate-shaped aluminum parts welded to the end faces of the cylindrical steel parts. The peel strength of the aluminum-steel composite parts is shown in Table 1. .

Example 6

S1: Use plate-like aluminum parts with a surface roughness of Ra1.6 and cylindrical steel parts with a surface roughness of Ra1.6. The thickness of the aluminum part is 9mm, the diameter of the steel part is 20mm, and the aluminum part is 1060 Pure aluminum, steel parts are 304 stainless steel; pre-formed circular truncated holes on the welding surface of aluminum parts, the depth of the holes is 2mm; formed circular truncated bosses on the welding surface of steel parts The included angle between the busbar and the central axis of the boss is 88°; the included angle between the busbar and the central axis of the circular truncated slot is 85°;

S2: Fix the aluminum parts and steel parts, and make the plate surface of the aluminum part and the end face of the steel part align and contact to form a welding surface, and at the same time ensure that the central axis of the hole and the boss are aligned. For aluminum The component exerts a force or force component perpendicular to the welding surface toward the steel component, so that the force or force component produces a pressure of 280KN on the welding surface;

S3: Keep the pressure on the welding surface, and make the steel part rotate relative to the aluminum part, the rotation speed is 300 rpm, stop the rotation of the steel part after 5s, and make the steel part rotate during the rotation of the steel part. The parts are gradually inserted into the aluminum parts at a speed of 1mm/s, and are joined with the aluminum parts in a plastically deformed state to form an aluminum-steel composite part, wherein the pressure is maintained for 10s after stopping the rotation;

S4: Cool down the aluminum-steel composite part to room temperature at a cooling rate of 200°C/min to complete welding.

S5: After the welding is completed, loosen the aluminum-steel composite part and place it in the heating device, locally heat the welding surface to 200°C, and keep it warm for 2 hours.

The aluminum-steel composite parts produced by the above welding method include cylindrical steel parts and plate-shaped aluminum parts welded to the end faces of the cylindrical steel parts. The peel strength of the aluminum-steel composite parts is shown in Table 1. . The welding method of the aluminum-steel composite parts in the embodiment 1-3, by reasonably setting the surface roughness, the pressure, the number of rotations, the penetration speed, and the cooling speed, it is ensured that sufficient temperature is generated during welding, so that the metal at the welding surface Produce plastic deformation, and form an aluminum-steel bonding zone of sufficient thickness at the weld after welding, and no bubbles, cracks and other defects occur at the weld, so that the tensile strength of the weld is greater than that of the aluminum matrix. Local heating of the welding surface after welding can remove the residual stress at the weld and improve the connection strength at the weld.

The welding method of the aluminum-steel composite part in the embodiment 4-6 is deformed on the basis of the method described in the embodiment 1-3, as shown in Figure 1, the welding surface of the aluminum part is preformed into a frustum-shaped Hole slot, the depth L1 of the hole slot is 1-2mm, the welding end of the steel part forms a circular platform-shaped boss, the width L2 of the boss is basically equal to the depth L1 of the hole slot, and the included angle β between the busbar of the boss and the central axis of the boss is 83-88°, the angle α between the busbar of the hole slot and the central axis of the hole slot is 80-85°, and it is necessary to ensure that the angle between the busbar of the frustum-shaped boss and the central axis of the boss is smaller than that of the busbar of the frustum-shaped slot and the hole The included angle of the central axis of the groove is 3-5° larger, and when welding, the central axis of the hole groove and the boss are aligned. The frustum-shaped hole is preformed on the surface of the aluminum part, and the frustum-shaped boss is formed on the welding end of the steel part. The included angle between the bus bar and the central axis of the hole is set to be 3-5° larger. On the one hand, the round table is aligned with the hole to provide positioning for the steel and aluminum parts before welding. On the other hand, the welding When the steel part extends into the aluminum part, the steel part and the aluminum part form a welding joint surface on the surface of the round table, which increases the joint area and improves the welding strength between the steel part and the aluminum part. In addition, the preformed The slots also reduce the amount of aluminum spillage from the weld area.

After the aluminum-steel composite part obtained by the welding method of the aluminum-steel composite part of Embodiment 1-6, an aluminum-steel composite part with a specific shape can be produced by machining, as shown in Figure 2, which is a lithium battery The aluminum-steel composite part of the positive terminal cover includes, an aluminum circular base 4, a steel cylinder 3, and the steel cylinder 3 is embedded into the base 4 from one end face of the base 4, and the base 4 The center position of the other end face is formed with a conical protrusion 41, and the edge position is formed with a circular protrusion 42. The side wall of the base 4 is formed with a circular protrusion that forms a certain angle with the radial direction of the base 4. 43. A cylindrical blind hole 31 protruding into the base 4 is formed at the center of the cylinder 3, and the inner wall of the blind hole 31 is formed with threads. The structure and shape of the above-mentioned aluminum-steel composite parts are all obtained by machining after welding the steel part and the aluminum part.

The welding method of the aluminum-steel composite part of the embodiment 1-6 that needs to be pointed out, after the steel part rotates relative to the aluminum part for a corresponding time (3-5s), it needs to be rapidly reduced to a speed of 0, and this speed reduction process must not exceed 0.15s.

Experimental example

According to the Japanese Industrial Standard JIS Z3144, the aluminum-steel composite parts obtained in Examples 1-6 were subjected to a peel strength test, and the test results are shown in the table below.

Peel strength test test result in table 1 embodiment 1-6

Example Peel strength/KN Example 1 0.53 Example 2 0.56 Example 3 0.63 Example 4 0.71 Example 5 0.76 Example 6 0.67

The above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (9)

1. a kind of welding method of aluminum steel composite members, it is characterised in that comprise the following steps：

Using surface roughness in the tabular of Ra1.6-Ra6.3 or block alumiaum article, and cylindric steelwork, alumiaum article thickness Not less than 9mm, steelwork diameter is not less than 20mm；

Fixed steelwork and alumiaum article, and the end face alignment contact of the plate face of alumiaum article and steelwork is formed solder side, to aluminium Product applies the component towards steelwork direction and vertical with solder side power or power, makes the component of the power or power to solder side Produce the pressure of 280-380KN；

The pressure suffered by solder side is kept, and steelwork is rotated relative to alumiaum article, revolution is 300-500 revs/min, through 3-5s After steelwork is stopped the rotation, steelwork is gradually extend into aluminum with the speed of 0.8-1mm/s in steelwork rotary course In part, engaged with the alumiaum article of state of plastic deformation and form aluminum steel composite members；

Aluminum steel composite members are cooled to room temperature, 200-300 DEG C/min of cooling rate completes welding.

2. the welding method of aluminum steel composite members according to claim 1, it is characterised in that also including to alumiaum article and steel The step of solder side of part is surface-treated to control alumiaum article and steelwork surface roughness.

3. the welding method of aluminum steel composite members according to claim 1, it is characterised in that steelwork and alumiaum article are in inertia Engagement is rotated in gas atmosphere.

4. the welding method of aluminum steel composite members according to claim 1, it is characterised in that after steelwork stops the rotation, Continue to keep solder side above-mentioned pressure, the dwell time is no less than 10s.

5. the welding method of the aluminum steel composite members according to claim any one of 1-4, it is characterised in that after completing welding, Solder side is locally heated to 200-250 DEG C, and is incubated 1-2h.

6. the welding method of the aluminum steel composite members according to claim any one of 1-4, it is characterised in that the alumiaum article of selection Solder side on have round table-like hole slot, hole slot depth be 1-2mm, on the solder side of the steelwork of selection have it is round table-like convex Platform, the angle that bus and the boss axis of boss are formed is bigger 3-5 ° with the angle that hole slot axis is formed than the bus of hole slot, During welding, it is directed at the axis of hole slot and boss.

7. the welding method of aluminum steel composite members according to claim 6, it is characterised in that the bus of round table-like boss with The angle that boss axis is formed is 83-88 °.

8. the welding method of the aluminum steel composite members according to claim any one of 1-4, it is characterised in that round table-like hole slot The angle that is formed of bus and hole slot axis be 80-85 °.

9. a kind of aluminum steel composite members, including tabular or bulk alumiaum article, it is and cylindric with what the plate face of alumiaum article was welded and fixed Steelwork, it is characterised in that：The alumiaum article and the steelwork are using the welding side any one of claim 1-8 Method is welded and fixed.