Stress Corrosion Cracking of Iron and Nickel Base Alloys in Sulfate Solutions at 289 C

CORROSION ◽  
1973 ◽  
Vol 29 (11) ◽  
pp. 442-450 ◽  
Author(s):  
DAVID A. VERMILYEA

Abstract Stress corrosion cracking (SCC) of iron and nickel base alloys in aqueous solutions at 289 C (552 F) has been studied using a straining electrode apparatus. Cracking susceptibility decreases in the order sensitized stainless steel, cold worked stainless steel containing martensite, sensitized Inconel 600, annealed stainless steel, and annealed or cold worked Inconel 600 and alloy AL 326. High cracking susceptibility usually occurs when conditions result in the development of thick reaction products. Acid conditions and chromium depletion favor thick reaction products and enhance susceptibility.

CORROSION ◽  
1969 ◽  
Vol 25 (1) ◽  
pp. 15-22 ◽  
Author(s):  
A. W. LOGINOW ◽  
J. F. BATES

Abstract In certain applications, stress corrosion cracking of austenitic stainless steels has occurred when these steels are subjected to tension stresses (residual and applied) and are exposed to hot chloride solutions. Although stress corrosion cracking can be prevented by treatments to relieve residual stresses and by control of the environment, such procedures are expensive and not always reliable. An extensive study was therefore undertaken to develop a steel that would-be inherently resistant to stress corrosion cracking. The results of the study, conducted on stressed specimens of experimental steels immersed in a boiling 42% magnesium chloride solution, showed that carbon and nickel improved the stress corrosion resistance of annealed steels, and? nickel and silicon increased the resistance of cold-worked steels. It was also found that nitrogen decreased the resistance of annealed steels whereas phosphorus and molybdenum decreased the resistance of cold-worked steels. Manganese, copper, chromium, sulfur, and aluminum had little or no effect on stress corrosion resistance. This study resulted in the formulation of a steel composition containing 18% chromium, 18% nickel, 2% silicon, and 0.06% carbon, with low phosphorus and molybdenum contents. This steel was melted in an electric furnace; and1 its, stress corrosion, corrosion, and mechanical properties were determined. Test results show that the new steel (called USS 18-18-2 stainless steel) is much more resistant to stress; corrosion cracking than currently available austenitic stainless steels. Furthermore, the resistance of this steel is better than that of a 20% chromium, 34% nickel alloy that is being marketed; for its resistance to stress corrosion cracking.


Author(s):  
E. A. Kenik ◽  
M. G. Burke

Radiation-induced segregation (RIS) and associated irradiation-assisted stress corrosion cracking (IASCC) of austenitic alloys may be a major factor in limiting component lifetimes in water-cooled nuclear reactors. There are some similarities between radiation-induced sensitization/IASCC and thermally-induced sensitization/intergranular stress corrosion cracking. Both processes are associated with chromium depletion at grain boundaries. Segregation to boundaries in a neutron irradiated type 316 stainless steel has been investigated with both energy-dispersive X-ray spectrometry (EDXS) and parallel detection electron energy loss spectrometry (PEELS).All specimens were from the same heat of cold-worked type 316 stainless steel. Both unirradiated control material and material irradiated at ∼300°C to a range of fluences 0.3 - 5 × 1026 neutrons/m2 (E>0.1 MeV) were available. The mass of irradiated material was minimized by mechanically polishing 3-mm-diam. disks to ∼75 μm thickness prior to electropolishing. However, the specific radioactivity of the specimens, which increased with neutron fluence, limited the application of EDXS to the unirradiated and the lowest fluence irradiated materials.


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