Comparative Stress Corrosion Cracking Behavior of Austenitic Iron-Base and Nickel-Base Alloys

Traditionally the stress corrosion resistance of austenitic iron-base and nickel-base alloys in chloride environments has been compared in the laboratory using the boiling magnesium chloride test.^1-4  This test has invariably demonstrated that increasing the nickel content of the austenitic alloys increases their resistance to stress corrosion cracking (SCC). More recently, questions have arisen regarding the suitability of the magnesium chloride test in ranking alloys in terms of their stress corrosion resistance to chloride environments. It has been noted⁵  that significant additions of silicon (>2%) to Fe-Cr-Ni alloys increase their resistance to stress corrosion in boiling magnesium chloride, but that this increase is barely detectable in tests using sodium chloride solutions at elevated temperatures. The tests described in the present paper were carried out to determine the effect of increasing nickel content on the stress corrosion behavior of austenitic iron-base and nickel-base alloys in chloride environments other than boiling...