How to avoid deformation by laser welding thin parts

For the deformation of general welded components, it is not necessary to correct it. Only when the deformation generated after welding exceeds the technical requirements, it should be corrected

The main cause of welding deformation is the shrinkage of the welded joint; The essence of correction is to create a new deformation to offset the deformation that has already occurred; The main methods of correction are mechanical method and heating method.

Mechanical correction method
1. Hand hammer forging (knocking): Use an iron hammer to manually knock and deform the welded workpiece. To prevent damage to the workpiece, it is generally necessary to pad iron (preferably soft metal material), which is the simplest correction method.
2. For thin welded parts, rolling equipment such as a "flattening machine" can be used to roll the weld seam and surrounding area to achieve the purpose of correction; Without equipment, heavy vehicles such as large trucks and forklifts on site can be used for wheel pressing according to actual conditions.
3. For simple, medium and small welding components, a jack (hydraulic or screw) can be used for correction.
4. For welding parts with high stiffness and strength, a press (hydraulic press, hydraulic press, pneumatic press) can be used for correction.
5. Special straightening equipment (such as roller presses) can be used for straightening profiles.


Heating correction method
6. The heat source of the heating correction method is mainly flame heating, and the main factors that determine the heating correction effect are: heating position, heating temperature, and the shape of the heating zone; The key to success or failure is the correct selection of heating position, which is generally judged by experience for simple components; For complex components, repeated testing is necessary to find the optimal heating position. The determination of heating temperature is usually visually measured, and can also be measured using commercially available thermometers (meters). The heating temperature generally does not exceed 800 ℃ (cherry red).

• Silvano

  : 7. Point heating: It refers to heating a point on the metal surface, with a diameter of about 10-20mm and a distance of 50-150mm between the points. After heating a point, immediately use a soft hammer to hit the hot spot. When hitting a thin plate, a pad iron should be added on the back and water should be added to cool it (wet cloth can also be wiped). It is mainly suitable for correcting the wavy deformation of the thin plate. 8. Strip heating: Heat the surface of the workpiece into a strip shape, with the bandwidth and strip density determined by the deformation amount. It is suitable for thick plates, structures with large deformation and rigidity (such as beams, columns, etc.). 9. Triangular heating (wedge heating): the heating area is triangular, and the shrinkage at the bottom of the triangle is greater than that at the top, which is applicable to members with large stiffness and deformation, such as bending deformation. 10. Point heating, strip heating, and triangular heating can be organically and flexibly applied, achieving twice the result with half the effort for corrective work. 11. Overall heating: Suitable for situations with large quantities and small weldments, consider using overall heating to provide mechanical correction (strike while the iron is hot) and slow cooling, which is very practical for materials with strong quenching properties.

• Silvano

  : Correction of heating by other heat sources 12. For weldments with no surface requirements, Arc welding with welding rod and gas shielded metal arc welding with consumable electrode can be used to weld at the position requiring heating for correction. 13. For components with surface requirements, tungsten argon arc welding can be used to correct the parts that need to be heated without adding wires (the base material does not melt). I hope it can help you