Marine-grade Aluminum Shipbuilding Welding Process
5083 aluminum alloy is a high magnesium alloy with good strength, corrosion resistance and machinability among non-heat treatable alloys. The surface is beautiful after anodizing. Arc welding performance is good. Excellent corrosion resistance makes 5083 alloy widely used in maritime applications such as ships, as well as automobiles, aircraft welding parts, and subway and light rail. If you choose 5083 aluminum equivalent, 5383 aluminium is one choice.
Almost various welding methods can be used to weld aluminum and aluminum alloys, but aluminum and aluminum alloys have different adaptability to various welding methods, and various welding methods have their own applications.
Gas welding and electrode arc welding methods are simple in equipment and easy to operate. Gas welding can be used for repair welding of aluminum sheets and castings that do not require high welding quality.
Electrode arc welding can be used for repair welding of aluminum alloy castings. The inert gas shielded welding (TIG or MIG) method is a widely used welding method for aluminum and aluminum alloys. Aluminum and aluminum alloy sheets can be welded by tungsten electrode alternating current argon arc welding or tungsten electrode pulse argon arc welding. Aluminum and aluminum alloy thick plates can be processed by tungsten helium arc welding, argon-helium mixed tungsten arc welding, gas metal arc welding, and pulse metal arc welding.
Preparation before welding
1. Cleaning before welding: When welding aluminum and aluminum alloys, the oxide film and oil stains on the welding joint of the workpiece and the surface of the welding wire should be strictly removed before welding.
There are two cleaning methods: chemical cleaning and physical cleaning. Chemical cleaning has high efficiency and stable quality, and is suitable for cleaning welding wires and small-sized workpieces produced in batches. There are two methods: dipping method and scrubbing method.
Mechanical cleaning is often used when the workpiece is large in size, has a long production cycle, or is contaminated after multi-layer welding or chemical cleaning. After cleaning, if the storage time is too long (such as more than 24 hours), it should be reprocessed.
2. Backing plate: The strength of aluminum alloy is very low at high temperatures, and liquid aluminum has good flow properties. The weld metal is prone to collapse during welding. In order to ensure penetration without collapse, backing plates are often used during welding to support the molten pool and nearby metal. The backing plate can be graphite plate, stainless steel plate, carbon steel plate, copper plate or copper rod, etc. An arc-shaped groove is opened on the surface of the backing plate to ensure that the weld seam is formed on the opposite side.
3. Preheating before welding: Thin and small aluminum parts generally do not need to be preheated. Preheating before welding can be performed when the thickness is 10mm ~ 15mm. According to different types of aluminum alloys, the preheating temperature can be 100℃ ~ 200℃. Preheating can reduce deformation of weldments and reduce defects such as pores.
Post weld cleaning
The residual flux and welding slag left in and around the weld after welding will destroy the passivation film on the aluminum surface and sometimes corrode the aluminum parts, so they should be cleaned up. Workpieces with simple shapes and general requirements can be cleaned by simple methods such as hot water rinsing or steam blowing.
For aluminum parts with high requirements and complex shapes, wash them with a hard-bristled brush in hot water, and then soak them in a chromic anhydride aqueous solution or potassium dichromate solution at about 60°C to 80°C with a concentration of 2% to 3% for 5-10 minutes. Then rinse and wash in hot water, dry in an oven, or blow dry with hot air, or dry naturally.
Haomei Aluminum is a professional marine grade aluminum sheet manufacturer. Welcome to leave message below to inquire 5083 and 5052 h32 aluminum sheet specifications.
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