Oxygen-free copper is pure copper that does not contain oxygen or any residues of deoxidizers. But in fact still contains very small amounts of oxygen and some impurities. According to the standard, the content of oxygen is not more than 0.003%, the total content of impurities is not more than 0.05%, and the purity of copper is more than 99.95%.
Mechanical properties: tin bronze performance and tin content and organization. α-phase area, Sn content increases, σb and plasticity are increased, in about 10% Sn neighborhood, the best plasticity, in the 21 ~ 23% Sn neighborhood σb maximum. δ-phase (Cu 3l Sn 8) hard and brittle, with the increase of δ-phase, σ b initially increased, and then also decreased sharply. The tin content of industrial alloys ranges from 3 to 14%, and deformation alloys contain less than 8% tin and contain phosphorus, zinc or lead.
Chemical composition
Lead (Pb) ≤ 0.003
Zinc (Zn) ≤ 0.003
Iron (Fe) ≤ 0.004
Phosphorus (P) ≤ 0.002
Bismuth (Bi) ≤ 0.001
Antimony (Sb)≤0.002
Sulfur (S) ≤ 0.004
Tin (Sn)≤0.002
Nickel (Ni)≤0.002
Arsenic (As) ≤ 0.002
Oxygen (O) ≤ 0.002
Copper + silver (Cu + Ag) ≥99.97
Total impurity %≤0.03
Corrosion resistance: tin bronze in the atmosphere, water vapor and seawater has a high chemical stability, corrosion resistance in seawater than copper, brass excellent. Therefore, those exposed to seawater, sea breeze and the atmosphere of ships and mining machinery, widely used tin bronze castings. But hydrochloric acid and nitric acid strongly corrode tin bronze. Tin bronze corrosion in sodium alkali solution is serious; in ammonia solution and methanol solution corrosion is also relatively strong.
According to the oxygen content and impurity content, oxygen-free copper is divided into one and two oxygen-free copper. One oxygen-free copper purity of 99.97%, the oxygen content of not more than 0.003%, the total impurity content of not more than 0.03%; two oxygen-free copper purity of 99.95%, the oxygen content of not more than 0.003%, the total impurity content of not more than 0.05%.
