| 摘要 |
PURPOSE:To perform accelerated appreciation with reliability by using as a test solution a solution obtained by dissolving 0.05-0.3mol NH4OH for 1l water and 0.1-2mol water-soluble metallic hydroxide for 1mol NH4OH. CONSTITUTION:A solution obtained by dissolving NH4OH by 0.05-0.3mol for 1l water and water-soluble metallic hydroxide, such as NaOH, KOH, Ca(OH)2, and Ba(OH)2, by 0.1-2mol for 1mol NH4OH is used as a test solution. In this case, a test solution which does not contain NH4OH and water-soluble metallic hydroxide within the said ranges is not preferable because the thickness of a blackening film formed on the surface of a copper material is extremely small. For the accelerated appreciation of the stress-resistance corrosion cracking characteristics of the copper material by using the test solution, liquid temperature may be set within a wide temperature range, but the formatin of the blackening film is accelerated more at 50-70 deg.C. The formed blackening film is destroyed by applying known destructive strain, i.e., to 1.1-2.3X10<-3>. |
