In order to evaluate the corrosion of copper which is used as an absorber vessel material in the absorption refrigeration cycle, electrochemical measurements of copper in the condition of a thin-solution layer, which is 1mm in thickness, of concentrated aqueous solution of lithium bromide in argon atmosphere were made. As a result, values of corrosion rate in the condition of a thin-solution layer were 3 to 6 times larger than in the immersed condition regardless of whether there was an

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... r or not. This difference seems to be due to the following reason. As the argon gas phase above the solution contained a little air (oxygen), the oxygen concentration was higher in the condition of a thin-solution layer than in the immersed condition. Therefore, the values of free corrosion potential in the condition of a thin-solution layer became more noble than in the immersed condition, and cathodic diffusion limit current density in the condition of a thin-solution layer increased, compared with that in the immersed condition.