Laser welding seam post-processing method
By performing standstill treatment and mechanical impact treatment of welds after laser welding, deformation and performance problems caused by residual tensile stress in the welds are solved, and the corrosion resistance and mechanical properties of the materials after welding are significantly improved.
Patent Information
- Application Number
- CN202411913583.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-03-28
AI Technical Summary
After laser welding, there is a large residual tensile stress in the weld, which can easily lead to deformation and cracking of the welded parts, and the corrosion resistance and mechanical properties of the materials after welding are poor.
A laser welding weld post-treatment method is adopted, including standstill treatment and weld mechanical impact treatment. The standstill treatment can stabilize the grain arrangement and dislocation, while the mechanical impact treatment uses the hard impact head to perform mechanical impact of constant pressure and frequency, releasing residual tensile stress.
Effectively release residual tensile stress generated during laser welding, reduce the risk of material deformation and cracking, and improve the corrosion resistance and mechanical properties of the material after welding.
Smart Images
Figure CN119710165A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of laser welding, in particular to a laser welding weld post-processing method. Background Art
[0002] Laser welding is a welding method that uses a high-energy-density laser beam as a heat source. The focused laser beam bombards the weldment, generating heat to melt the workpiece and form a weld.
[0003] After laser welding, due to the uneven temperature distribution on the weld surface and the thermal expansion and contraction of the metal, large residual tensile stresses will be generated. These residual tensile stresses can easily cause deformation, cracking and other problems in the weld during use. At the same time, the grains in the weld and heat-affected zone will become coarser during laser welding, and the welding slag and burrs generated by laser welding will reduce the corrosion resistance and mechanical properties of the material after welding.
[0004] At present, chemical treatment and heat treatment methods are mainly used for weld post-treatment, which have strict requirements on the treatment environment. In addition, post-treatment methods such as ultrasonic impact, shot peening, and laser impact have high equipment costs and difficult process control. Therefore, in response to the above problems, the present invention proposes a laser welding weld post-treatment method. Summary of the invention
[0005] The purpose of the present invention is to provide a laser welding weld post-processing method to solve the problems raised in the above background technology.
[0006] To achieve the above object, the present invention provides a laser welding weld post-processing method, comprising the following steps:
[0007] Step 1: Static treatment of the weld after laser welding;
[0008] Step 2: Perform at least one mechanical impact treatment on the weld after the static treatment in step 1.
[0009] Preferably, the standing time t of the standing treatment in step one is 0 min to 15 min, for example, it can be 30s, 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min or 15 min, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
[0010] Preferably, in step 2, the mechanical impact treatment of the weld is performed using a hard impact head, starting from one end of the weld and performing mechanical impact with constant pressure and frequency until the other end of the weld; the impact trajectory of the impact and the impact circle formed by each impact are continuous along the weld.
[0011] Preferably, in the step 2, the weld is subjected to mechanical impact treatment, and the process parameters include impact pressure p, impact frequency f, impact head size diameter d, and impact overlap ratio η.
[0012] Preferably, in the mechanical impact treatment of the weld in step 2, the process parameter of the impact pressure p is 0.25MPa-12MPa, for example, 0.25MPa, 0.5MPa, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa, 10MPa,
[0013] 11MPa or 12MPa, etc., but are not limited to the listed values, and other unlisted values within the numerical range are also applicable.
[0014] Preferably, in the mechanical impact treatment of the weld in step 2, the process parameter adopted for the impact frequency f is 2 Hz to 20 Hz, for example, it can be 2 Hz, 3 Hz, 4 Hz, 5 Hz, 6 Hz, 7 Hz, 8 Hz, 9 Hz, 10 Hz, 11 Hz, 12 Hz, 13 Hz, 14 Hz, 15 Hz, 16 Hz, 17 Hz, 18 Hz, 19 Hz or 20 Hz, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
[0015] Preferably, in the mechanical impact treatment of the weld in step 2, the process parameter used for the impact head size diameter d is 3mm to 10mm, for example, it can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc., but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.
[0016] Preferably, in the mechanical impact treatment of the weld in step 2, the impact overlap rate η adopts the area overlap rate or diameter overlap rate of the impact circle, and the adopted process parameters are 50% to 95%, for example, it can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
[0017] The impact overlap rate η is calculated by formula (1) or formula (2):
[0018]
[0019] Among them, S1 and S2 are the areas of two adjacent impact circles, S is the area of the overlapping part of S1 and S2; d1 and d2 are the lengths of the diameters of two adjacent impact circles, and d is the length of the overlapping part of d1 and d2.
[0020] Compared with the prior art, the beneficial effects of the present invention are:
[0021] The method of the present invention uses simple equipment, has low process control difficulty, and has good post-weld treatment effect. The method of the present invention is used for post-processing of laser welding welds, which can effectively release the residual tensile stress generated during laser welding or processing, reduce the risk of material deformation and cracking, and improve the corrosion resistance and mechanical properties of the material after laser welding. Therefore, the present invention has high practicality and economy. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 A post-processing method flow chart of a laser welding weld post-processing method; DETAILED DESCRIPTION
[0023] Example 1
[0024] See also Figure 1 This embodiment provides a technical solution for a laser welding weld post-processing method, comprising the following steps:
[0025] Step 1: Static treatment of the weld after laser welding;
[0026] Step 2: Perform a mechanical impact treatment on the weld after the static treatment in step 1.
[0027] The process parameter used for the standing time t of the standing treatment is t=5min.
[0028] The process parameter used for the impact pressure p is p=1 MPa.
[0029] The process parameter adopted for the impact frequency f is f=9 Hz.
[0030] The process parameter adopted for the impact head size diameter d is d=5mm.
[0031] The impact overlap rate η adopts the overlap rate of the diameter of the impact circle, and the adopted process parameter is η=80%, that is, the center distance between the impact circles of two adjacent impacts is 1mm.
[0032] When performing mechanical impact treatment on the weld, a hard impact head is used to perform mechanical impact with constant pressure and frequency from one end of the weld until the other end of the weld; the impact trajectory of the impact and the impact circle formed by each impact are continuous along the weld; the specific landing point of the impact head is in the middle of the weld.
[0033] The laser welding weld obtained by the post-treatment method provided in this embodiment is subjected to failure load and tensile strength tests by a universal material testing machine. Compared with the weld that has not been post-treated by this method, the tensile strength is increased by no less than 25Mpa, and the comprehensive performance of the weld is improved by 5% to 30%. The degree of lattice refinement is observed by electron microscope scanning, and the effect is better than that of the laser welding weld that has not been post-treated by this method. This method fully releases the residual tensile stress, effectively improves the lattice structure of the weld, removes defects such as burrs and oxide scale on the weld surface, and improves the corrosion resistance and mechanical properties of the material after laser welding.
[0034] Example 2
[0035] See also Figure 1 , the standing time t described in step 1 can be adjusted within the range of 0min to 15min. Within this range, the longer the standing time t is, the more stable the arrangement and dislocation of the grains are, and the more sufficient the stress release is, but at the same time it will increase the degree of hardening of the weld, which is not conducive to impact plastic deformation. Therefore, the standing time t can be adjusted in a targeted manner according to the material properties of the actual weldment material and the specific conditions of the actual working environment. For example, it can be 30s, 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min or 15min, etc., but it is not limited to the listed values, and other values not listed within the numerical range are also applicable.
[0036] Example 3
[0037] See also Figure 1 , the impact pressure p described in step 2 can be adjusted within the range of 0.25MPa to 12MPa. Within this range, the greater the impact pressure p, the smoother the weld toe impact, but at the same time it will affect the surface smoothness and cause deformation. Therefore, the impact pressure p can be adjusted in a targeted manner according to the material properties of the actual weldment material and the specific conditions of the actual working environment. For example, it can be 0.25MPa, 0.5MPa, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa, 10MPa, 11MPa or 12MPa, etc., but it is not limited to the listed values, and other values not listed within the numerical range are also applicable.
[0038] Example 4
[0039] See also Figure 1, the impact frequency f described in step 2 can be adjusted within the range of 2Hz to 20Hz. Within this range, the larger the impact frequency f, the more complete the release of residual tensile stress, and the more thorough the removal of defects such as burrs and scales on the weld surface, but at the same time it will affect the surface smoothness and cause deformation. Therefore, the impact frequency f can be adjusted in a targeted manner according to the material properties of the actual weldment material and the specific conditions of the actual working environment. For example, it can be 2Hz, 3Hz, 4Hz, 5Hz, 6Hz, 7Hz, 8Hz, 9Hz, 10Hz, 11Hz, 12Hz, 13Hz, 14Hz, 15Hz, 16Hz, 17Hz, 18Hz, 19Hz or 20Hz, etc., but it is not limited to the listed values, and other values not listed within the numerical range are also applicable.
[0040] Example 5
[0041] See also Figure 1 , the impact head size diameter d in step 2 can be adjusted within the range of 3mm to 10mm. Within this range, the larger the impact head size diameter d, the larger the weld toe radius after impact, the more complete the residual tensile stress release, and the more thorough the removal of defects such as burrs and scales on the weld surface, but at the same time it will affect the surface smoothness and cause deformation. Therefore, the impact head size diameter d can be adjusted in a targeted manner according to the material properties of the actual weldment material and the specific conditions of the actual working environment. For example, it can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc., but it is not limited to the listed values. Other values not listed within this numerical range are also applicable.
[0042] Example 6
[0043] See also Figure 1 , the impact overlap rate η described in step 2 can be adjusted within the range of 50% to 95%. Within this range, the larger the impact overlap rate η, the more obvious the post-processing effect of the local weld will be, but at the same time it will affect the post-processing efficiency and the overall post-processing effect of the weld. Therefore, the impact overlap rate η can be adjusted in a targeted manner according to the material properties of the actual weld material, the length of the weld to be processed and the specific conditions of the actual working environment. For example, it can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%, etc., but it is not limited to the listed values, and other values not listed within the numerical range are also applicable.
[0044] Example 7
[0045] See also Figure 1When the weld is mechanically impacted in step 2, the impact head can be placed not only in the center of the weld but also at the weld toe. The residual tensile stress of the laser welded weld is mainly concentrated at the weld toe. Therefore, the impact head placement can be adjusted in a targeted manner according to the specific conditions of the actual weld, especially the weld width and the impact head size diameter.
[0046] Example 8
[0047] See also Figure 1 When performing mechanical impact treatment on the weld in step 2, multiple or reciprocating impact treatments can be performed to improve the post-processing effect of the weld. According to the specific conditions of the actual weld, especially the width and length of the weld, the number of mechanical impact treatments on the weld can be increased in a targeted manner, or reciprocating impact treatments can be performed on the weld toes on both sides of the weld.
[0048] The embodiments described above are only descriptions of the preferred modes of the present invention, which are used to help understand the methods and core ideas of the present invention, and are not intended to limit the scope of the present invention. The above are only preferred implementation modes of the present invention. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements, modifications or changes can be made, and the above technical features can be combined in an appropriate manner. These improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should all be regarded as the protection scope of the present invention.
Claims
1. A laser welding weld post-processing method, characterized in that: The post-processing method comprises the following steps: Step 1: Static treatment of the weld after laser welding; Step 2: Perform at least one mechanical impact treatment on the weld after the static treatment in step 1.
2. The post-processing method according to claim 1, characterized in that: The standing time t of the standing treatment in step 1 is 0 min to 15 min.
3. The post-processing method according to claim 1, characterized in that: The mechanical impact treatment of the weld in step 2 uses a hard impact head to perform mechanical impact with constant pressure and frequency from one end of the weld until the other end of the weld; the impact trajectory of the impact and the impact circle formed by each impact are continuous along the weld.
4. The post-processing method according to claim 3, characterized in that: In the mechanical impact treatment of the weld in step 2, the process parameters include impact pressure p, impact frequency f, impact head size diameter d, and impact overlap ratio η.
5. The post-processing method according to claim 4, characterized in that: In the mechanical impact treatment of the weld in step 2, the process parameter of the impact pressure p is 0.25MPa~12Mpa.
6. The post-processing method according to claim 4, characterized in that: In the mechanical impact treatment of the weld in step 2, the process parameter of the impact frequency f is 2 Hz to 20 Hz.
7. The post-processing method according to claim 4, characterized in that: In the mechanical impact treatment of the weld in step 2, the process parameter used for the impact head diameter d is 3 mm to 10 mm.
8. The post-processing method according to claim 4, characterized in that: In the mechanical impact treatment of the weld in step 2, the impact overlap rate η adopts the area overlap rate or diameter overlap rate of the impact circle, and the adopted process parameters are 50% to 95%; The impact overlap rate η is calculated by formula (1) or formula (2): Among them, S1 and S2 are the areas of two adjacent impact circles, S is the area of the overlapping part of S1 and S2; d1 and d2 are the diameter lengths of two adjacent impact circles, and d is the length of the overlapping part of d1 and d2.