Cathodic corrosion of stainless steel in nitric acid

Epstein, Joseph A.; Levin, I. A.; Rabinovitz, E.; Raviv, S.

doi:10.1016/s0010-938x(65)80051-8

Cited by 10 publications

(5 citation statements)

References 6 publications

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“…5) exhibits a small change with an appearance of breakdown behavior in cathodic region. This can be attributed to several reduction processes that occurred when SS is cathodically polarized in nitric acid and such reductions reactions causes cathodic dissolution [29]. And hence, such "cathodic" feature is observed.…”

Section: Electrochemical Investigation For Corrosion Assessmentmentioning

confidence: 96%

Corrosion behavior of Zr-based metallic glass coating on type 304L stainless steel by pulsed laser deposition method

Ningshen

Mudali

Krishnan

et al. 2011

Surface and Coatings Technology

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Section: Electrochemical Investigation For Corrosion Assessmentmentioning

confidence: 96%

Corrosion behavior of Zr-based metallic glass coating on type 304L stainless steel by pulsed laser deposition method

Ningshen

Mudali

Krishnan

et al. 2011

Surface and Coatings Technology

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“…For the direct dissolution experiments, electrolyte solutions were prepared by mixing nitric acid (HNO 3 , 70 wt.%; BDH Chemicals), hydrochloric acid (HCl, 38 wt.%; BDH Chemicals), and deionized water (18 MO, PURELAB flex; ELGA) to a final concentration of 0.48 M HNO 3 , 0.1 M KCl, and with HCl concentrations tested at 0.1, 0.5, and 1.0 M. The KCl increases the base conductivity of the electrolyte solution as well as aiding in the breakdown of the passivation layer. 9,10 The HCl employed in the direct dissolution experiments is used to further increase the dissolution rate of the untreated stainless steel. 11 An electrolyte of 0.48 M HNO 3 and 0.1 M KCl was used for the sensitized surface experiments.…”

Section: Electrochemical Analysis Dissolution and Metrologymentioning

confidence: 99%

Dissolvable Supports in Powder Bed Fusion-Printed Stainless Steel

Lefky

Zucker

Wright

et al. 2017

3D Printing and Additive Manufacturing

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This work demonstrates, for the first time, two approaches for dissolvable supports in powder bed fusion-printed metal parts. Expanding on our recent innovations with dissolvable supports in multimaterial direct energy deposition printing, this work brings dissolvable support capabilities to additive manufacturing systems that are limited to single-material builds. First, a direct dissolution approach is demonstrated with the supports electrochemically dissolved. While this process works, it is not self-terminating and maintaining dimensional accuracy for complex geometries is thus difficult. The second approach incorporates a sensitizing agent during the normal stress, relieving thermal annealing step to decrease the chemical stability of the top 100-200 lm of the component surface. The component is then etched under etching conditions with a high selectivity toward the ''sensitized'' surface over the base component material. This creates an etching process that self-terminates once the sensitized layer is removed. These two processes are first demonstrated using 17-4 PH stainless steel. Direct dissolution was conducted under anodic bias in a solution of HNO 3 / KCl/HCl; 120 lm of material were removed from the component's surface. For the self-terminating dissolution process, surface sensitization was done by exposing the sample to sodium hexacyanoferrate at 800°C for 6 h to carburize the top 100-200 lm of the sample. This carburization process captures the protective chromium in chromium carbide precipitates and renders the surface sensitive to chemical and electrochemical dissolution. The self-terminating etching reaction was demonstrated under anodic bias in a solution of HNO 3 /KCl. Open circuit potentials were measured at 10 s and 1 h, and polarization curves were used to identify the corrosion potential. Self-termination was verified by monitoring component diameter over time, and 120 lm of material were removed from the sensitized surface of the component. To further test the self-terminating sensitized approach, a set of 316 stainless steel interlocking rings were fabricated to demonstrate that this approach scales to large components with complex geometry. For these parts, this approach replaced 4-5 days of machining operations with a 32.5 h electrochemical bath.Opposite page: Dissolvable metal supports for Powder Bed Fusion (PBF) printed metals demonstrated with interlocking stainless steel rings. Photo credit: Owen Hildreth.

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“…Stainless steel alloys in these areas degrade as a result of auto-catalytic oxidation (low oxygen and pH) and produce small pits in the affected material [16]. This type of corrosion is the most dangerous form of corrosion in nuclear fuel manufacturing facilities, since it often occurs in strong acid mediums (hydrochloric, nitric, and sulfuric) and goes undetected until the damage is irreparable [17]. Figure 1 illustrates the chemical mechanism of SCC by way of chloride ion interference on the surface of a stainless steel alloy.…”

Section: Introduction 11 Corrosion In the Nuclear Manufacturing Industry Overviewmentioning

confidence: 99%

“…(g) + 2H + (aq) + 2Cl -(aq)  N 2 (g) + H 2 O (l) + Cl 2 (g)(17) This secondary reaction explains the additional chloride oxidation thatPierce et al (2007) did not discover during their research and the reason why additional chloride was removed during the lab simulations. The formation of nitrous oxide occurred at a rate of 2.0 moles of nitric oxide per mole of nitrous oxide.…”

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confidence: 96%

Reducing chloride corrosion of stainless steel in the nuclear fuel manufacturing industry : an electrochemical-environmental perspective

Spence¹

2021

Preprint

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Chloride extraction from nitric acid is an important technique for reducing corrosion of stainless steel. However, there has been a limited amount of research conducted in this area. Pumping ozone-enriched air through nitric acid is a corrosion reduction method that is widely used in the nuclear fuel manufacturing industry, including the Blind River Refinery (BRR), to purge chlorine gas out of the acid. However, this method has been shown to produce significant environmental impacts. Overall, it is an inconsistent and cost-deficient method for reducing chloride corrosion of stainless steel in nitric acid mediums below 7.2M (37.0% volume). This thesis builds on existing literature and demonstrates that oxidizing chloride ions in nitric acid using oxygen, nitric oxide and nitrous oxide is an efficient and cost-effective chloride extraction method for the case study (BRR). It was shown that the level of chloride extraction from nitric acid increased significantly when the acid strength was elevated above 8.4M (42.0%volume) and sparged with various oxidants. The most effective oxidants at this nitric acid strength were: oxygen, ozone, nitric oxide and nitrous oxide. Nitric oxide and nitrous oxide can be produced by sparging 43.0% nitric acid with air or sparging 43.0% nitric acid with NOx fumes. In terms of the BRR case study, it was shown that using operational-specific combinations of these methods can drastically reduce the environmental impacts associated with their chloride removal process; significantly increase the level of chloride extraction; reduce energy consumption and operating costs by as much as 54.0%; and reduce material requirements by as much as 80.0%.

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Cathodic corrosion of stainless steel in nitric acid

Cited by 10 publications

References 6 publications

Corrosion behavior of Zr-based metallic glass coating on type 304L stainless steel by pulsed laser deposition method

Corrosion behavior of Zr-based metallic glass coating on type 304L stainless steel by pulsed laser deposition method

Dissolvable Supports in Powder Bed Fusion-Printed Stainless Steel

Reducing chloride corrosion of stainless steel in the nuclear fuel manufacturing industry : an electrochemical-environmental perspective

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