Some Case Histories of Stress Corrosion Cracking Of Austenitic Stainless Steels Associated With Chlorides

Abstract

Some 22 case histories of stress corrosion cracking in Types 302, 304, 316, 321, and 347 stainless steels are presented. These occurred in water, steam, brines, and miscellaneous solutions. In each case, either the chloride content was high initially, or conditions were such that chlorides could concentrate. Usually the temperature was quite hot. Often the environment was acid and in most cases it seemed likely that air was present. Microexamination always revealed transcrystalline cracks which usually had a characteristic branching growth. In each case it was concluded that internal tensile stresses in combination with concentrated chlorides caused the cracking. Some means of avoiding cracking are pointed out. Following the case histories the results of some laboratory tests are presented which show that resistance to cracking increases with nickel content, and that large additions of nickel bring about a major improvement. Inconel, which is at the high nickel end of this series of alloys is considered immune to this type of stress corrosion cracking. 3.5.8