The difference between cable aluminum-clad steel core aluminum strand and steel core aluminum strand

The difference between aluminum-clad steel-cored aluminum strand and steel-cored aluminum strand is that their steel cores are different. The steel core of aluminum strand wire is made of galvanized steel wire. The aluminum clad steel wire in the aluminum clad steel core aluminum strand wire is a kind of bimetal wire. It uses high temperature and high pressure to continuously extrude electrical aluminum onto high-strength steel wire, so that about 8um thick aluminum-steel bond permeable layer is formed between aluminum and steel. After the steel wire coated with aluminum layer is pulled by the light bimetal synchronous deformation machine for many times, the aluminum and steel are deformed in the same proportion, making the aluminum-steel bond permeable layer more uniform and firm.

What are the characteristics of aluminum-covered steel core aluminum stranded wire relative to steel core aluminum stranded wire:

1. Mechanical and electrical characteristics

The structural size and mechanical properties of the aluminum-clad steel core aluminum strand are the same as those of the steel core aluminum strand, but the weight per unit length of the aluminum-clad steel core aluminum strand is about 5% lighter than that of the steel core aluminum strand. It follows that the horizontal wind loads of both are the same, but the vertical loads of the former are about 5% less than those of the latter.

At 20℃, the DC resistance of aluminum-clad aluminum-cored strand is about 3.2% lower than that of aluminum-cored strand. The guaranteed breaking force of the aluminum-clad steel core aluminum strand is about 5.5% lower than that of the steel core aluminum strand.

2. Corrosion resistance

Overhead wires are subjected to electrochemical corrosion in the atmosphere. In the steel core aluminum strand, the coating on the surface of the steel core contacts with the aluminum wire to form electrochemical corrosion, because the plating potential is lower than that of aluminum, the coating is quickly corroded, so that the steel core is exposed to the atmosphere and corroded. In addition, after the coating is corroded, the steel core contacts with the aluminum wire and forms electrochemical corrosion, and the potential of aluminum is lower than that of iron, resulting in corrosion of the aluminum wire.

For aluminum clad steel core aluminum stranded wire, because there is a good metallurgical combination between aluminum and steel in aluminum clad steel wire, each single wire in the stranded wire is aluminum contact, they do not exist electrochemical corrosion between different metals, which can greatly slow down the corrosion rate of wire, thereby prolonging its service life.

It can be said that corrosion resistance is the biggest advantage of aluminum-clad steel core aluminum stranded wire.