The Rare Earth In The Preparation Of Copper-nickel Alloy Condenser

Copper-nickel alloy condenser tube is an important basis material in the areas of electric power, ship-building,petrol chemicals and ocean engineering industry. These industrial areas will be greatly improved by developping a new copper-nickel alloy condenser tube with high corrosion resistance. A new BFe10-1-1-Re alloy with addition of rare earth element Re was studied in present paper. Annealed microstructures of BFe 10-1-1 alloys were observed by OM and TEM. Mechanical properties in the room temperature were tested by tension test and Vickers hardness test. By static corrosion test, SEM and XRD, the corrosion behavior of BFe10-1-1 alloy and the mechanism of its corrosion resistance were investigated in the polluted seawater environment. The main experimental results were obtained as follows: Due to addition of proper amount of Re, the dendrite segregation of the above alloy was reduced, the grains were refined, the grain boundaries were cleaned and the microstructures became more homogeneous; With addition of proper amount of Re, the plasticity of BFel0-1-1 alloy was greatly improved, which enhanced its workability and facilitated producing coiled tubes and pipes with large diameter. While the strength and hardness of this alloy were reduced slightly, but still satisfied the ASTM B111-2003 standard; By adding proper amount of Re, the corrosion resistance of BFe10-1-1 alloy was improved obviously, because that a compact oxide film was formed in the surface of the alloy. These chemical compounds distributed homogeneously are bonded with the matrix alloy firmly and prevent the alloy from further corrosion.