We specialize in OEM customized large-scale structural parts manufacturers. Specializes in laser cutting, plasma cutting, bending, welding, stamping and machining. Provide customized metal products for welding frames/brackets for machinery, wind power, nuclear power, pumps, construction, ships, excavators, construction machinery, motors, gas tanks, pressure tanks, mineral equipment, automobiles and various industries /Base/Column/Cabinet/Hardware.
| Welding parts product description |
| product: |
OEM customized welding parts |
| Welding method: |
Gas shielded welding, argon arc welding or customized |
| application: |
Wind power, nuclear power, pumps, construction, ships, excavators, construction machinery, motors, gas tanks, pressure tanks, mineral equipment, automobiles, etc. |
| Product advantages: |
We have 12 years of experience in the manufacture of large structural parts, with accurate dimensions, firm welding, no deformation, no welding slag, wide application range, low price and high quality |
| Material: |
Steel, S355, S355J2G3, ST52, ST52-3, Q345, Q235, NM360, Hardox 400, Hardox 500, SS304, SS316 .. or according to customer requirements. |
| drawing |
Specification drawing software: PDF, Solid work, ProE, JPG, Auto CAD |
| Production equipment: |
laser cutting (<= 20mm), plasma cutting, welding machine, lathe, drilling machine, grinder, deep hole drilling, large CNC vertical lathe, CNC gantry milling, CNC floor boring, etc........ |
| Process technology: |
Process technology: technical review through technical customization-blanking-pair spot welding-inspection-welding forming-annealing-surface treatment-CNC processing-inspection, etc. |
| Quality: |
Strict material inspection, precise size control, promotion of quotation and delivery guarantee, 100% quality control. |
| Packing: |
steel pallets, wooden pallets, wooden boxes, according to customer requirements. |
MOQ: |
1 piece |
| Current major markets: |
the United States, Australia, Canada, Germany |
Production time: |
1-2 weeks |
1. **Oxide Film:** A dense, high-melting-point (approximately 2050ºC) AlO oxide film rapidly forms on the aluminum surface, while aluminum's melting point is only about 660ºC. This oxide film hinders metal fusion and easily leads to inclusions.
2. **High Thermal Conductivity:** Aluminum has a high thermal conductivity, requiring a more concentrated heat source and greater heat input during welding; otherwise, it is prone to incomplete penetration.
3. **High Tendency to Hot Cracking:** Aluminum has a high coefficient of linear expansion and a large shrinkage rate during solidification, easily generating significant internal stress and welding deformation, leading to hot cracking.
4. **Hydrogen-Induced Porosity:** Liquid aluminum can dissolve a large amount of hydrogen, while solid aluminum is almost insoluble. During the solidification process of the molten pool, hydrogen cannot escape in time, forming pores. Moisture is the main source of hydrogen.
5. **No Color Change:** Unlike steel, aluminum does not turn red during heating, making it difficult for operators to judge the heating temperature and easily leading to weld burn-through. 6. Alloy Element Loss: Low-boiling-point alloying elements in some aluminum alloys (such as magnesium and zinc) are easily evaporated and lost at high temperatures, affecting the chemical composition and performance of the weld.
II. Pre-welding Preparation (Key to Successful Welding) Pre-welding preparation is the most crucial step in ensuring the quality of aluminum alloy welding, accounting for over 50% of its importance.
1. Material Selection and Matching
· Base Metal Identification: Identify the aluminum alloy grade (e.g., 5-series 5A06, 6-series 6061). Non-heat-treatable aluminum alloys (e.g., 1-series, 3-series, 5-series) have better weldability; heat-treatable aluminum alloys (e.g., 2-series, 6-series, 7-series) have poorer weldability and are prone to cracking.
· Welding Wire Selection:
· Principle: Generally, welding wires with similar chemical composition or strength to the base metal are selected.
• Commonly used grades: ER4043 (good versatility, good crack resistance, good flowability), ER5356 (high strength, used for 5-series and 6-series base metals, but not heat resistant).
• Special aluminum alloy welding wire must be used; other materials cannot be substituted.
2. Cleaning (Crucial!)
• Mechanical cleaning: Use a stainless steel wire brush (specifically for aluminum, avoid cross-contamination) or a louvered brush to grind the area to be welded and both sides of the bevel for at least 20-30mm until a metallic luster is exposed. Note: Brush marks should be along the weld direction to avoid pressing the oxide film into the base metal.
• Chemical cleaning: For products with high requirements, acetone or a special aluminum alloy cleaner can be used to remove oil stains, followed by rinsing with clean water.
• Drying: Welding should be performed immediately after cleaning; the drying time should not exceed 4 hours. If the environment is humid, it is recommended to lightly heat the bevel with a flame or heat gun to remove moisture.
3. Beveling Preparation
* Due to the high fluidity of molten aluminum, a smaller blunt edge and a larger beveling angle are usually required to prevent burn-through and collapse.
* Select the beveling type (I-shape, V-shape, U-shape, X-shape) according to the plate thickness. Thick plates must be beveled to ensure full penetration.
4. Tooling and Fixtures
* Use appropriate tooling and fixtures to fix the workpiece and effectively control welding deformation.
* Pay attention to the conductivity and heat dissipation of the fixtures to avoid false contact or excessive heat dissipation.
III. Welding Process Control
1. Welding Method Selection
* TIG Welding (GTAW):
* Advantages: Concentrated heat, stable arc, high weld quality, aesthetically pleasing weld formation, particularly suitable for thin plates and small-sized workpieces.
* Key Points: Must use AC power supply, utilizing "cathode breakage" to remove oxide film. Use high-frequency arc initiation and current decay arc termination functions.
* MIG Welding (GMAW):
* Advantages: High efficiency, suitable for medium and thick plate welding. • Key: DC reverse polarity (DCEP) is typically used. Wire feed stability is crucial; a four-wheel drive wire feeder and a PTFE/nylon-lined welding torch are recommended. Pulsed MIG welding is commonly used for better heat input control, reducing spatter and deformation.
• Other: Laser welding, electron beam welding, etc., are used in specialized fields.
2. Gases and Tungsten Electrodes
• Shielding Gas: High-purity (≥99.99%) argon (Ar) must be used. For thick plate MIG welding, an Ar+He mixture can be used to increase penetration and heat.
• Gas Flow Rate: TIG welding typically uses 8-15 L/min, while MIG welding uses 20-25 L/min. Insufficient flow rate provides inadequate protection, while excessive flow rate creates turbulence.
• Tungsten Electrode: Cerium tungsten electrodes (WC-20) are recommended due to their strong electron emission capability and stable arc.
3. Process Parameter Control
* **High Current, High Welding Speed:** Due to aluminum's high thermal conductivity, a higher current is needed to ensure penetration, while a faster welding speed is required to prevent excessive heat input leading to burn-through and deformation.
* **Maintain Short Arc Length:** Especially in MIG welding, a short arc length provides better protection and stable droplet transfer.
* **Preheating:** For thick and large workpieces, moderate preheating (100-150ºC) can reduce thermal stress and prevent cracking. Avoid excessive preheating temperature, as this will degrade the base material's properties.
4. Operating Techniques
* **TIG Welding:** Maintain a 70°-80° angle between the welding torch and the workpiece, and a 10°-15° angle between the welding wire and the workpiece. Use a left-hand welding method.
* **MIG Welding:** Typically, a push-torch method is used (the welding torch is tilted backward 10°-15°) for easier observation of the molten pool and gas protection. • Arc Initiation and Termination: Use arc initiation and termination plates, or pause briefly at the arc initiation point and fill the crater at the termination point to prevent incomplete fusion at the start and cracking at the end.
IV. Post-Weld Treatment and Inspection
1. Post-Weld Cleaning
• Clean the oxide layer and spatter on the weld surface promptly with a stainless steel wire brush to make the weld aesthetically pleasing and easy to inspect.
2. Weld Inspection
• Visual Inspection: Inspect weld formation, reinforcement, undercut, surface porosity, and cracks.
• Non-Destructive Testing (NDT): Perform penetrant testing (PT), radiographic testing (RT), or ultrasonic testing (UT) according to product requirements to detect internal defects.
• Pressure Testing: For pressure vessels or pipelines, conduct hydrostatic or pneumatic pressure tests.
3. Post-Weld Heat Treatment (PWHT)
• For heat-treatable aluminum alloys (such as 6061), post-weld solution treatment followed by artificial aging may be necessary to restore joint strength. However, this is usually costly and should be determined based on design requirements. Key Summary and Key Points:
* **Pre-welding cleaning is fundamental:** Remove all oil, rust, and oxide film.
* **Correct wire matching is crucial:** The composition and properties depend on the base material; specialized welding wire is essential.
* **Method selection depends on plate thickness:** TIG for thin plates, MIG for thick plates; pulsed welding technology is a powerful tool.
* **Ensuring gas purity is paramount:** High-purity argon is key; moderate flow rate ensures adequate protection.
* **High current and high speed welding for controlled heat transfer:** High current and high speed minimize deformation and cracking.
* **Tooling and fixtures prevent deformation:** Secure fixing is essential; it controls deformation.
Following these precautions and relying on skilled operating experience are essential for consistently obtaining high-quality aluminum alloy welded products. For critical components, rigorous process qualification is recommended.
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How to send the product to me?
Answer: The method of transportation is up to you. We can also recommend a more economical transportation method for you!
For small batch products under 30 kg, express delivery (DHL, FedEX, TNT, UPS, EMS or others) is usually used.
30-500kg orders can be airlifted to your designated airport. For large or large quantities, we often use sea freight.
1. Question: Are you a factory or a trading company?
Answer: We are a professional processing factory + trading company.
2. Question: Do you make customized products?
Answer: Yes, all parts are customized according to customer's drawings or samples. If you want to manufacture any parts, please feel free to send us your drawings or samples.
3. Q: Will you be safe after we receive the drawings?
Answer: Yes, we will not disclose your design to third parties without your permission. Before you send the drawing to us, we can sign a confidentiality agreement.
4. Q: What is your minimum order quantity?
Answer: Usually we do not set the MOQ, but the price will be cheaper when the quantity is large. We are happy to provide customers with samples to ensure quality standards.
5. Ask. Do you provide samples? Is it free or extra?
If you want to check the samples first, you need to pay the sample fee, and the fee will be refunded to you after confirming the bulk order.
6. What payment terms do you accept?
Wire transfers, Western Union, Paypal, Trade Assurance are accepted, so please let us know which is convenient for you.
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