Views: 0 Author: Site Editor Publish Time: 2025-03-04 Origin: Site
To ensure the airtightness of automobile thin plate welds and enable them to pass helium or water pressure tests, corresponding measures can be taken from three stages: pre welding, welding process, and post welding, as follows:
Material selection and processing
Selecting suitable materials: Ensure that the quality and performance of automotive thin plates and welding materials (such as welding wires) meet the requirements, have good weldability and corrosion resistance. For example, selecting welding wires containing silicon, manganese and other elements can enhance the density of the weld seam.
Surface cleaning: Thoroughly remove oil stains, rust, oxide scales, and other impurities from the surface of the thin plate welding area to prevent defects such as porosity from affecting air tightness during the welding process. Chemical cleaning, mechanical polishing, and other methods can be used.
Welding equipment inspection
Equipment debugging: Conduct a comprehensive inspection and debugging of welding equipment to ensure stable operation, such as accurate and stable parameters of pulse frequency, current amplitude, etc. of pulse welding equipment.
Gas supply inspection: If gas shielded welding is used, the purity and flow stability of the shielding gas should be ensured. For example, argon gas with a purity of not less than 99.99% should be used as the shielding gas to prevent air from entering the weld and forming pores.
Optimization of welding parameters
Energy input control: Adjust the welding energy reasonably according to the thickness and material of the thin plate, such as the pulse width and peak current of pulse welding, the welding current and voltage of continuous welding, etc., to avoid burning through caused by excessive energy or incomplete fusion caused by insufficient energy.
Welding speed: Choose an appropriate welding speed to ensure good formation of the weld seam. Generally speaking, a slow welding speed may cause overheating and coarse grain size of the weld seam, affecting air tightness; If the speed is too fast, defects such as incomplete welding may occur.
Welding operation specifications
Maintain appropriate welding angle and posture: Keep the welding rod or welding gun at an appropriate angle with the surface of the workpiece to ensure good fusion of the weld and avoid defects such as undercutting and slag inclusion.
Control the shape and size of the weld seam: Ensure uniform width and height of the weld seam, smooth transition, and avoid uneven width and height of the weld seam, which affects the density of the weld seam.
Visual inspection of welds
Visual inspection: Conduct a comprehensive visual inspection of the weld seam, observe whether there are obvious defects such as cracks, pores, and undercutting on the surface of the weld seam, and promptly detect and deal with weld seams that do not meet the appearance requirements.
Dimensional measurement: Measure the width, height, and other dimensions of the weld seam to ensure that it meets the design requirements. For welds that do not meet the required dimensions, repair or repair welding shall be carried out.
Helium testing: Using the high permeability of helium gas, helium gas is filled into the interior of the welded part, and helium detection liquid is applied to the surface of the weld or a helium mass spectrometer leak detector is used to detect whether there is helium gas leakage. If helium gas leakage is detected, the leakage point is marked and repaired.
Water pressure test: Fill the welded part with water, apply a certain pressure, and maintain it for a period of time. Observe whether there is water seepage or leakage on the surface of the weld. For the parts with leakage, repair them with welding and retest until they pass.
Analyze the causes of defects: For problems found in helium testing or water pressure testing, analyze the reasons for the defects, such as improper welding parameters, operational errors, etc., and take targeted measures for improvement.
Repair welding and polishing: Repair welding shall be carried out on the defective parts, and after repair welding, polishing treatment shall be carried out to make the surface of the weld smooth and transition well with the surrounding base material. Re inspection shall be carried out until the airtightness of the weld is qualified.
Through the above comprehensive measures, the airtightness of automotive thin plate welds can be effectively ensured, enabling them to pass helium or water pressure tests smoothly and meet the quality requirements of automotive manufacturing.
If you have welding machine requirements, please contact Ms. Zhao
E-Mail: pdkj@gd-pw.com
Phone: +86-13631765713
