What is the difference between oxygen-free copper and low-oxygen copper

Low oxygen copper rod

Process disadvantages:

The electrolytic copper is melted while being added. The molten copper water is fully reduced without conditions. The entire melting process and the copper water discharge process cannot be isolated from oxygen, so the oxygen content is very high. In the copper melting process, the fuel is gas, and the copper liquid is affected by the gas fuel in the combustion process when the chemical changes, and the impact is mainly sulfur and hydrogen.

Process advantages:

(1) The output is high, and the output of the general small unit can reach 10-14 tons per hour.

(2) The copper rod unloading line adopts the plum blossom style, which is convenient for the wire drawing machine to pay off.

(3) The take-up weight is large, generally up to 4 tons per plate.

Low oxygen copper rod grades and characteristics:

There are three types of low-oxygen copper rods, T1, T2, T3. The low-oxygen copper rods are all hot-rolled, so they are soft rods and the code is R.

(1) T1: Use high-purity electrolytic copper as raw material (copper content greater than 99.9975%) to produce low-oxygen copper rods.

(2) T2: Use 1 # electrolytic copper as raw material (copper content greater than 99.95%) to produce low-oxygen copper rods.

(3) T3: Use 2 # electrolytic copper as raw material (copper content greater than 99.90%) to produce low-oxygen copper rods.

Because electrolytic copper with high purity and electrolytic copper with low purity (2 #) are relatively few in the market, most of them use 1 # electrolytic copper as the raw material, so the general low-oxygen copper rod grade is: T2R.

Oxygen-free copper rod

Oxygen-free copper rods are pure copper that contains no oxygen or any deoxidizer residues. But in fact it still contains a very small amount of oxygen and some impurities. According to national standards, the oxygen content in oxygen-free copper rods is lower than 0.02%, the impurities contained are lower than 0.05%, and the purity of copper is higher than 99.95%.

The production method uses electrolytic copper production, and its resistivity is lower than that of low-oxygen copper rods. Therefore, when manufacturing products with stricter resistance requirements,

Oxygen-free copper rods are more economical; the production of oxygen-free copper rods requires higher quality raw materials;

According to the oxygen content and impurity content, oxygen-free copper rods are divided into TU1 and TU2 copper rods. TU1 refers to oxygen-free copper with a copper purity of 99.99% and an oxygen content not higher than 0.001%; ​​TU2 refers to oxygen-free copper with a copper purity of 99.95% and an oxygen content not higher than 0.002%.

The difference between the two

Because the manufacturing method and manufacturing process of the low-oxygen copper rod and the oxygen-free copper rod are different, there is also a big difference between the two, and each has its own characteristics.

1. About the inhalation and removal of oxygen and its state of existence

The oxygen content of low-oxygen copper rods is generally 200 (175)-400 (450) ppm, so the oxygen intake is inhaled in the liquid state of copper, while the oxygen-free copper rods of the top-up method are the opposite. After holding for a considerable period of time, it is reduced and removed. Usually, the oxygen content of this rod is below 10-50ppm, and the lowest can reach 1-2ppm. The oxygen content in oxygen-free copper is relatively low, so this copper is superior in toughness.

Second, the difference between the amount of debris and hot rolling defects

The drawability of oxygen-free copper rods is superior to low-oxygen copper rods in all wire diameters. In addition to the above-mentioned organizational reasons, oxygen-free copper rods have less inclusions, stable oxygen content, and no defects that may be caused by hot rolling. The oxygen monitoring is not strict, and the unstable oxygen content will directly affect the performance of the rod. If the surface oxide of the rod can be compensated in the continuous cleaning of the subsequent process, it is more troublesome that a considerable amount of oxide exists in the "subcutaneous", which has a more direct effect on the wire breakage.

Third, the toughness of low-oxygen copper rods and oxygen-free copper rods are different

Both can be pulled to 0.015mm, but the low-temperature oxygen-free copper in low-temperature superconducting wire, the spacing between the filaments is only 0.001mm.

4. The process of making low-oxygen copper rods is different from that of oxygen-free copper rods

The process of making low-oxygen copper rods cannot be copied to the process of making oxygen-free copper rods. At least the annealing process of the two is different. Because the flexibility of the wire is deeply affected by the material composition and the rod making, wire making and annealing process, it cannot be said simply which soft or hard is the low-oxygen copper or oxygen-free copper.