High-strength automobile part welding process

Abstract

The invention discloses a high-strength automobile part welding process. The process comprises the steps that S1, oil removing and cleaning are conducted; s2, melting the welding fluid; s3, welding: a conical suction pipe is connected to the laser welding equipment, the conical suction pipe moves in the welding fluid along with the lower end part of the shell, a suction pump of the laser welding equipment works to enable the conical suction pipe to extract gas in the welding fluid, a laser welding gun on the laser welding equipment irradiates a steel plate overlapping part to form a circular laser welding part, and the circular laser welding part is welded to the lower end part of the shell; linearly irradiating laser on the outer edge of the circular laser welding part; according to the welding equipment, a suction pump, a conical suction pipe and a gas guide pipe are matched with one another to extract and remove gas in welding fluid, so that the defect of air holes in welding gaps of accessories is avoided, a softened part generated by laser lap welding is reheated and quenched through laser irradiation, the hardness of the temporarily softened part is improved, and the welding quality is improved. The softened part is eliminated, so that the breakage starting from the softened part can be inhibited, and the overall quality of the weldment can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a high-strength automobile accessory welding process. Background Art

[0002] In automobile manufacturing, in order to improve the rigidity of automobile frames, reduce the weight of automobiles, and improve the collision performance of automobiles, high-strength lightweight alloy materials have become an inevitable trend. Automobile body parts are mainly connected by welding. The current welding methods mainly include tungsten inert gas arc welding, metal gas argon arc welding, stir friction welding, laser welding, electron beam welding, variable polarity plasma arc welding and other welding methods. Fusion welding methods, high-strength steel plates have a metal structure of quenched martensite as the main body. The laser welding part is tempered around, thereby generating tempered martensite, the hardness decreases, and local softening is formed. When the vehicle collides, the local The softening point becomes the starting point of the steel plate fracture of the car body. The fracture phenomenon based on the local softening point of this laser welding obviously occurs in high-strength steel plates with a tensile strength of more than 1180MPa. Due to the long-distance laser welding, the distance between the welding parts can be shortened, and multiple welding parts can be formed on the accessories. However, the formation of multiple laser welding parts on the accessories will also form multiple softening parts, increasing the risk of fracture. In addition, the gas in the welding liquid cannot be effectively removed during laser welding of automobile body accessories, and porosity defects are easily generated during welding, affecting the welding quality. It is more likely to form local softening points, affecting the strength of the automobile body welding. Summary of the invention

[0003] The present invention aims to solve the deficiencies of the prior art and provide a high-strength automobile parts welding process.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A high-strength automobile parts welding process, the steps are:

[0006] S1. Degreasing and cleaning: Before welding, use a wire brush and sandpaper to polish the groove and surrounding areas of the accessories, and then put them in a container to clean the oil and metal ions floating on the surface;

[0007] S2. Molten solder liquid: The solder is placed in the housing of the laser welding equipment, and the laser welding gun of the laser welding equipment melts the solder into solder liquid;

[0008] S3. Welding: overlap the accessory steel plates and place them in the shell. Connect a conical suction pipe to the laser welding equipment. The conical suction pipe moves in the welding liquid along with the lower end of the shell. The suction pump of the laser welding equipment works so that the conical suction pipe extracts gas from the welding liquid and discharges the gas through the air guide pipe and the suction pump. The laser welding gun on the laser welding equipment irradiates the overlapped part of the steel plates to form a circular laser welding part. The laser passes through the outer edge of the circular laser welding part and irradiates the laser in a straight line to form a quenching part on the steel plate.

[0009] S4. Post-weld cleaning: Take the welded parts out of the shell, use a hard-bristle brush to remove the welding slag from the welding parts, then immerse them in a 2%-3% potassium dichromate solution at 60℃-80℃ for 5-10 minutes, then rinse them with 40℃ hot water, and check the quality of the weld to see if there are defects such as pores, cracks, deformation, or inclusions.

[0010] In step S1, the step of cleaning the oil stains and metal ions floating on the surface of the accessories after polishing is to first place the accessories in a 93# gasoline solution container for immersion and degreasing, then clean the accessories in a 5%-10% concentration NaOH solution container, the solution temperature is required to be 40-60°C, clean for 1-3 minutes, take out the accessories, rinse with running water, and finally dry them naturally.

[0011] The linear irradiation laser is irradiated at least 3 mm from the outer edge of the circular laser welding portion.

[0012] The beneficial effects of the present invention are as follows: the welding equipment of the present invention utilizes a suction pump, a conical suction pipe and an air guide tube to cooperate with each other to extract the gas in the welding liquid, so that no porosity defects will appear in the gaps of the accessory welding, and the softened part produced by the laser lap welding is reheated and quenched by laser irradiation to increase the hardness of the temporarily softened part, and the softened part is eliminated, thereby being able to suppress the rupture starting from the softened part, thereby improving the overall quality of the weldment. DETAILED DESCRIPTION

[0013] The present invention will be further described below in conjunction with embodiments:

[0014] A high-strength automobile parts welding process, the steps are:

[0015] S1. Degreasing and cleaning: Before welding, use a wire brush and sandpaper to polish the groove and surrounding areas of the accessories, and then place them in a container to clean the oil stains and metal ions floating on the surface; first place the accessories in a 93# gasoline solution container for immersion and degreasing, and then clean the accessories in a 5%-10% concentration NaOH solution container. The solution temperature is required to be 40-60℃, and the cleaning should be 1-3 minutes. Take out the accessories and rinse them with running water, and finally air dry them naturally.

[0016] S2. Molten solder liquid: The solder is placed in the housing of the laser welding equipment, and the laser welding gun of the laser welding equipment melts the solder into solder liquid;

[0017] S3. Welding: overlap the accessory steel plates and put them into the shell. Connect a conical straw to the laser welding equipment. The conical straw moves in the welding liquid along with the lower end of the shell. The suction pump of the laser welding equipment works so that the conical straw extracts the gas in the welding liquid and discharges the gas through the air duct and the suction pump. The laser welding gun on the laser welding equipment irradiates the overlapped part of the steel plates to form a circular laser welding part. The outer edge of the circular laser welding part is irradiated with a linear laser. The linear irradiation laser irradiates at least 3mm from the outer edge of the circular laser welding part. In the above, a quenched portion is formed on the steel plate, and a softened portion based on heat input during quenching is formed around the quenched portion; after a laser beam is irradiated to the overlapped portion to form a circular laser welded portion, the softened portion formed around the circular laser welded portion is cross-cut to form a linear quenched portion, thereby hardening the softened portion around the circular laser welded portion, so that the quenched portion can be formed by linearly irradiating the outer edge of the laser overlap welded portion to divide the softened portion, and the softened portion is eliminated, thereby suppressing cracking starting from the softened portion;

[0018] S4. Post-weld cleaning: Take the welded parts out of the shell, use a hard-bristle brush to remove the welding slag from the welding parts, then immerse them in a 2%-3% potassium dichromate solution at 60℃-80℃ for 5-10 minutes, then rinse them with 40℃ hot water, and check the quality of the weld to see if there are defects such as pores, cracks, deformation, or inclusions.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0021] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrated; it can be mechanically connected, electrically connected, or able to communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

Claims

1. A high-strength automobile parts welding process, characterized in that: The steps are: S1. Degreasing and cleaning: Before welding, use a wire brush and sandpaper to polish the groove and surrounding areas of the accessories, and then put them in a container to clean the oil and metal ions floating on the surface; S2. Molten solder liquid: The solder is placed in the housing of the laser welding equipment, and the laser welding gun of the laser welding equipment melts the solder into solder liquid; S3. Welding: overlap the accessory steel plates and place them in the shell. Connect a conical suction pipe to the laser welding equipment. The conical suction pipe moves in the welding liquid along with the lower end of the shell. The suction pump of the laser welding equipment works so that the conical suction pipe extracts gas from the welding liquid and discharges the gas through the air guide pipe and the suction pump. The laser welding gun on the laser welding equipment irradiates the overlapped part of the steel plates to form a circular laser welding part. The laser passes through the outer edge of the circular laser welding part and irradiates the laser in a straight line to form a quenching part on the steel plate. S4. Post-weld cleaning: Take the welded parts out of the shell, use a hard-bristle brush to remove the welding slag from the welding parts, then immerse them in a 2%-3% potassium dichromate solution at 60℃-80℃ for 5-10 minutes, then rinse them with 40℃ hot water, and check the quality of the weld to see if there are defects such as pores, cracks, deformation, or inclusions.

2. A high-strength automobile parts welding process according to claim 1, characterized in that: In step S1, the step of cleaning the oil stains and metal ions floating on the surface of the accessories after polishing is to first place the accessories in a 93# gasoline solution container for immersion and degreasing, then clean the accessories in a 5%-10% concentration NaOH solution container, the solution temperature is required to be 40-60°C, clean for 1-3 minutes, take out the accessories, rinse with running water, and finally dry them naturally.

3. A high-strength automobile parts welding process according to claim 2, characterized in that: The linear irradiation laser is irradiated at least 3 mm from the outer edge of the circular laser welding portion.