Effects of thiosulfate on susceptibility of type 316 stainless steel to stress corrosion cracking in 3.5% aqueous sodium chloride

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Corrosion

DOI:https://doi.org/10.5006/1.3290293· OSTI ID:532997

Ashour, E A; Abd El Meguid, E A ^[1]; Ateya, B G ^[2]

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1. National Research Centre, Cairo (Egypt). Dept. of Electrochemistry and Corrosion
2. Cairo Univ. (Egypt). Chemistry Dept.

Effects of thiosulfate on stress corrosion cracking (SCC) susceptibility (S) of type 316 stainless steel were studied. Addition of sodium thiosulfate to 3.5% sodium chloride increased S of type 316 SS to SCC. A quantitative expression for S was given by: S = ((1{minus}(s(sol)/s(air))))(1{minus}(t(sol)/t(air))){sup 1/2} where s and t are the maximum stress and time to failure, respectively. Metallographic observations revealed the fracture mode changed from ductile to brittle for S > {approximately} 0.2. An increase in potential in the noble direction increased S significantly. An increase in Na{sub 2}S{sub 2}O{sub 3} concentration increased S at higher potentials but had no tangible effect around the free-corrosion potential ({approximately} 100 mV{sub NHE}). Na{sub 2}S{sub 2}O{sub 3} also shifted the pitting potential of type 316 SS to more active values and led to formation of wider and more open pits.

• Sponsoring Organization: USDOE
• OSTI ID: 532997
• Journal Information: Corrosion, Journal Name: Corrosion Journal Issue: 8 Vol. 53; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CORROSIVE EFFECTS
CRACK PROPAGATION
DUCTILE-BRITTLE TRANSITIONS
MATERIALS TESTING
PITTING CORROSION
SODIUM CHLORIDES
SODIUM COMPOUNDS
STAINLESS STEEL-316
STRESS CORROSION
THIOSULFATES