The welding characteristics of aluminum alloy tubes

Aluminum alloy is widely used in various welding structure products because of its light weight, high strength, good corrosion resistance, non magnetic, good forming and low temperature performance, and so on, the use of aluminum alloy instead of steel plate material welding, structural weight can be reduced by more than 50%.

1. Strong oxidation capacity. The affinity between aluminum and oxygen is very easy to form alumina obstruct metal good combination, easy to cause slag.

2. Larger thermal conductivity and heat capacity. Welding involves the use of high power or energy concentrated heat sources, and sometimes warms up.

3. Tendency to crack hot. Aluminums line expansion coefficient and crystal shrinkage are about twice that of steel, which is prone to large welding deformations and stresses, and the adverse effects of certain impurities or alloy elements can lead to cracks in rigid joints.

4. Easy to form hydrogen holes. The main hydrogen holes in the welding pores of aluminum and aluminum alloys. During the rapid cooling process, the solubility of hydrogen drops sharply, at which time a large amount of supersaturated gas is precipitated, and hydrogen is too late to form pores in the weld metal. Therefore, when welding aluminum, welds have a great tendency to produce pores.

5, Burn through and collapse. When aluminum and aluminum alloys change from solid to liquid. Since there is no significant color change, it is not easy to judge the temperature of the melting pool. Welding, due to excessive temperature is not easy to detect resulting in burning or serious collapse