Mechanism of improved corrosion resistance of type 304L stainless steel, nitric acid grade, in nitric acid environments

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Journal of Materials Engineering and Performance; (United States)

DOI:https://doi.org/10.1007/BF02818368· OSTI ID:6873423

Kain, V; Shinde, S S; Gadiyar, H S ^[1]

---

1. BARC, Bombay (India)

Materials for critical components in nuclear fuel reprocessing plants are required to have low corrosion rates and long designed life because access for repairs is not possible. Stainless steel type 304L, nitric acid grade (NAG), is the new material suitable for such applications. It has guaranteed low corrosion rates and is not susceptible to intergranular corrosion (IGC) in nitric acid environments. The corrosion behavior of type 304L stainless steel, NAG, and type 304L stainless steel, commercial purity (CP), in nitric acid environments is investigated in detail. Studied are: microstructural mapping in the three directions, effect of sensitization heat treatment, resolution annealing and sensitization heat treatment for the as-received and cold-worked samples of the two varieties on the resultant microstructures. The anodic polarization characteristics along the three directions for both varieties in 1N HNO[sub 3] are compared. The susceptibility of both varieties to end grain corrosion in 9N HNO[sub 3] + 1 g Cr[sup +6]/liter boiling solution is assessed, and microstructural examination of the exposed sample is carried out to compared the degree of end grain corrosion. Their susceptibility to IGC due to segregation of impurity elements to grain boundaries is also compared. It is shown that controlled microstructure (fine grain size, retained cold work, and discrete precipitation at grain boundaries) along with controlled chemical composition is responsible for improved corrosion resistance of the NAG variety. The NAG variety has much less susceptibility to corrosion along the long- and short-transverse directions and, therefore, less susceptibility to end grain corrosion. The means and consequences of controlling chemical composition are also discussed.

• OSTI ID: 6873423
• Journal Information: Journal of Materials Engineering and Performance; (United States), Journal Name: Journal of Materials Engineering and Performance; (United States) Vol. 3:6; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

050800 -- Nuclear Fuels-- Spent Fuels Reprocessing
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
AUSTENITIC STEELS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CORROSION
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
DATA
EXPERIMENTAL DATA
FUEL REPROCESSING PLANTS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
IRON ALLOYS
IRON BASE ALLOYS
LOW CA
MATERIALS
NICKEL ALLOYS
NITRIC ACID
NUCLEAR FACILITIES
NUMERICAL DATA
STAINLESS STEEL-304L
STAINLESS STEELS
STEEL-CR19NI10-L
STEELS