This code stipulates the basic requirements for the welding of aluminum and aluminum alloys, and is applicable to the welding process of single-layer containers and aluminium-lined containers of aluminum and aluminum alloys welded by manual tig welding or gas welding or fusion tig welding.

I. welding materials:

1. The purity of argon welding with 99.99% or more, dew point - 55 ℃ or less, and shall comply with the provisions of GB/T4842 or GB10624. When the pressure of bottled argon is 0.5mpa, it should not be used. (argon contains nitrogen content 0.04%; otherwise, light yellow or grass-green magnesium nitride and porosity will be generated on the surface of the welding seam; Otherwise, dense black spots, arc instability and large splash can be found on the surface of the molten pool; If the water content is 0.07%, the molten pool will boil and pores will be generated in the weld.

2. Manual tig welding electrode adopts cerium tungsten electrode. Electrode diameter should be according to the welding current size to choose (general than of the specifications of the welding current is required when using a bigger size of tungsten electrode), shall be the hemispherical of electrode end (hemispherical method: with a bigger size than required by the welding current specification of tungsten electrode, grinding the end into cone, vertical clamping electrode, with bigger than the requirements of the tungsten electrode used in current 20 ~ 30 a current arcing and lasts for a few seconds in the test plate, tungsten extreme head is half spherical. If the tungsten electrode is contaminated with aluminum, it must be polished or replaced. When there is slight pollution, the current can be increased to make the arc burn in the test plate for a while, which can burn off the pollutants) :

Cerium tungsten electrode diameter mm 2 2.5 3.2 4.0 5.0

(in direct connection) welding current A 100~200 170~250 200~300 350~480 500~675

(in reverse connection) welding current A 15~25 17~30 20~35 35~50 50~70

(ac) welding current A 85~160 120~210 150~250 240~350 330~460

3. When using MIG to weld aluminum alloy, as the aluminum welding wire is relatively soft, in order to avoid biting the wire, the wire feeding wheel is not allowed to use the wire feeding wheel with gear, and it is not suitable to use the push wire type; Wire feeding hose is not allowed to use a spring tube but teflon or nylon products, or because of grinding and pollution or congestion hose. MIG usually USES dc reverse polarity.

4. The main function of flux is to remove oxide film and some other impurities. When using, it can be mixed into paste with anhydrous alcohol or directly put flux powder on the groove and both sides. When welding fillet weld should choose those easy to remove slag after welding flux; Flux for aluminum-magnesium alloys should not contain sodium.

5. For phase welding of aluminum materials of different grades, when there is no specification in the drawings or the process, choose the welding wire material according to the base material with better corrosion resistance and lower strength level. When welding al - mg alloy or al - mn alloy, it is advisable to use welding wire with magnesium content or manganese content similar to or slightly higher than the base metal. The welding wire can be selected from GB/T10585 "aluminum and aluminum alloy welding wire", GB/T3190 "deformed aluminum and aluminum alloy chemical composition" and GB/T3197 "aluminum and aluminum alloy wire for welding rod".