Effect of ammoniacal sea water on material properties of copper–nickel alloy

Abstract

Abstract A low nickel copper alloy commonly used in the plumbing/drainage pipelines on ships was investigated under slow strain rate conditions in air, and in solution containing 3·5%NaCl + 10%MgCl2, with and without 1% ammonia. The tests were conducted at ambient temperature (28 ± 1°C) at strain rates corresponding to a crosshead speed of 5·76 × 10-5cm min-1, without a passivation current. The results obtained did not show any significant deterioration in the mechanical properties of the alloy in the tests conducted in air or in solution without ammonia. However, with the introduction of 1% ammonia, a reduction in the material strength and a change in the mode of failure were observed. This paper discusses the results obtained in the present investigation and in particular the load bearing capacity of the material and the modes of failure in Cu–Ni alloys exposed to sea water.