Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions.

Bo Sun,Qiang Feng,Tianyuan Ye,Mumeng Wei,Jinghua Yao

doi:10.3390/ma8095290

Abstract

This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH)3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss), degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e., dissolved oxygen (DO) and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet.

Highlights

B10 copper-nickel alloy is widely used in the condenser tubes of various ships, heat exchangers of coastal power plants and piping systems of seawater desalination equipment owing to its outstanding resistance to corrosion, in flowing seawater.Copper-nickel will gradually replace copper to become the mainstream piping material
B10 copper corrosion raterate under oxygenated stirring and and stationary conditions over time
On the premise that the other test conditions were fixed, B10 alloy alloy corrosion rate was markedly higher under oxygenatedstirring stirringconditions conditionsthan than the the stationary corrosion rate was markedly higher under thethe oxygenated stationary conditions

Summary

Introduction

B10 copper-nickel alloy (which contains 90% copper and 10% nickel) is widely used in the condenser tubes of various ships, heat exchangers of coastal power plants and piping systems of seawater desalination equipment owing to its outstanding resistance to corrosion, in flowing seawater. Copper-nickel will gradually replace copper to become the mainstream piping material. Many studies have been carried out on copper-nickel alloy, such as corrosion behavior under various environmental conditions, extension of lifecycle, and improvement of corrosion resistance [1,2,3,4,5,6]. Parvizi et al studied the behavior and protection mechanism of the alloy under differing flow velocities, temperatures, pH values, compositions of seawater, and many other factors [8].

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Conclusion