Crack Initiation and Crack Propagation of Pre-corroded Ni-16Cr Alloy in 4.5%NaCl Aqueous Solution

Abstract

-This paper examines the characteristics of corrosion fatigue of a Ni-16Cr alloy workpiece soaked in 4.5%NaCl aqueous solution for a period of one week, followed by corrosion fatigue testing in the same aqueous solution. Corrosion, corrosion fatigue crack initiation mechanisms, crack surface morphology and fractographic analysis are discussed and compared to results from a workpiece fatigued in ambient laboratory air. Experimental results reveal susceptibility to surface pits in the Ni-16Cr alloy workpiece in a 4.5%NaCl aqueous solution, a result that is supported by morphology and fractographic analysis.