Intergranular and general Corrosion behaviour of 17-4 PH weldments

1995 ◽  
Vol 46 (9) ◽  
pp. 534-538 ◽  
Author(s):  
K. S. Raja ◽  
K. Prasad Rao
Keyword(s):  
Corrosion Behaviour ◽  
General Corrosion

scholarly journals On the Application of Bipolar Electrochemistry to Characterise the Localised Corrosion Behaviour of Type 420 Ferritic Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 794 ◽  
Author(s):  
Yiqi Zhou ◽  
Dirk Lars Engelberg
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Pitting Corrosion ◽  
Corrosion Behaviour ◽  
General Corrosion ◽  
Full Spectrum ◽  
Nucleation Sites ◽  
Corrosion Pitting ◽  
Cathodic Region ◽  
Bipolar Electrochemistry

Bipolar electrochemistry has been applied to Type 420 ferritic stainless steel in order to determine the full spectrum of anodic-to-cathodic polarisation behaviour. The occurrence of crevice corrosion, pitting corrosion in combination with general corrosion, pitting corrosion only, general corrosion only, followed by a cathodic region has been observed. Instances of pitting corrosion initiated near chromium-rich carbides with Cr23C6, Cr3C2, and Cr7C3 identified as pit nucleation sites. The observed pit growth kinetics were independent of the electrochemical over-potential. Characterisation of the pit size distributions supports the presence of a critical dissolved volume for the transition of metastable to stable pit growth and pit coalescence.

Weight Gain and Hydrogen Absorption in Supercritical Water At 500°C of Chromium-Coated Zirconium-Based Alloys: Transverse vs Longitudinal Direction

2021 ◽  
Author(s):  
Kittima Khumsa-Ang ◽  
Stephane Rousseau ◽  
Oksana Shiman
Keyword(s):  
Weight Gain ◽  
Supercritical Water ◽  
Hydrogen Absorption ◽  
Corrosion Behaviour ◽  
Reactor Core ◽  
Neutron Cross Section ◽  
Zirconium Alloys ◽  
Longitudinal Direction ◽  
General Corrosion ◽  
Enriched Uranium

Abstract Canadian Nuclear Laboratories (CNL) has an on-going Research & Development programme to support the development of a scaled-down 300 MWe version of the Canadian Super-Critical Water Reactor (SCWR) concept. The 300 MWe and 170-channel reactor core concept uses low enriched uranium fuel and features a maximum cladding temperature of 500°C. Our goal is to test surfacemodified zirconium alloys for use as fuel cladding. Zirconium alloys are attractive as they offer low neutron cross section thereby allowing the use of low enriched fuel. In this paper, we report on the results of general corrosion experiments used to evaluate chromiumcoated zirconium-based alloys in the two chemistries (630 ug/kg O2 in both deaerated and lithiated supercritical water). These experiments were conducted in a refreshed autoclave at 500°C and 23.5 MPa. After exposure, the weight gain and the hydrogen absorption were examined. At adequate coating thickness, longitudinal and transverse coupons show similar corrosion behaviour with improved corrosion resistance compared to uncoated coupons. The measured concentrations of hydrogen absorption are higher for the transverse coupons. Alkaline treatment resulted in higher weight gains than was found in pure oxygenated supercritical water.

In-Situ Corrosion Studies on Cast Steel for a High-Level Waste Packaging in a Rock Salt Repository

1988 ◽  
Vol 127 ◽  
Author(s):  
W. Schwarzkopf ◽  
E. Smailos ◽  
R. Koster
Keyword(s):  
Electron Beam ◽  
Rock Salt ◽  
Corrosion Behaviour ◽  
Cast Steel ◽  
Maximum Temperature ◽  
High Level Waste ◽  
General Corrosion ◽  
Vertical Temperature Profile ◽  
Corrosion Studies

ABSTRACTPrevious corrosion studies performed on a number of materials have shown that unalloyed steels are promising materials for long-term resistant packagings to be used in disposal of heat-generating wastes in rock salt formations. This is the reason why those steels are the subject of more detailed investigations. This paper reports an in-situ experiment conducted in the Asse salt mine in which the influence of selected characteristics (welding, shape) of containers on the corrosion behaviour of cast steel was studied. The material was tested in NaCl brine which might intrude into an HLW borehole in an accident scenario. For this, an electron beam welded cast-steel tube was stored for 18 months in a 2-m deep heated borehole and the annular gap between the tube and the borehole wall was filled with saturated NaCl brine. The vertical temperature profile in the borehole was in the range from 90°C to 200°C; the maximum temperature occurred in the center of the heated zone and the minimum temperature in the upper parts of tube.Under the testing conditions cast steel was subjected to general corrosion at a maximum corrosion rate of 120 μm/a. Considering this magnitude of the corrosion rates, the resulting corrosion allowances are technically acceptable for a packaging having long service-lives. Pitting and crevice corrosion as well as stress-corrosion cracking did not occur in cast steel, and electron beam welding did not exert a noticeable influence on cast-steel corrosion. With these results available, cast steel continues to be considered as a promising HLW packaging material.

Influence of Microstructural Constituents and Applied Thermomechanical Processes on Corrosion Behaviour of Aluminum Alloys Produced with Twin Roll Casting (TRC) Technique

2014 ◽  
Vol 794-796 ◽  
pp. 181-186 ◽  
Author(s):  
Cemil Işıksaçan ◽  
Mert Günyüz ◽  
Onur Birbaşar ◽  
Cengiz Konya ◽  
Murat Dündar
Keyword(s):  
Free Surface ◽  
Aluminum Alloys ◽  
Corrosion Behaviour ◽  
Corrosion Mechanism ◽  
General Corrosion ◽  
Corrosion Performance ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Thermomechanical Processes ◽  
Twin Roll

Aluminum alloys produced with Twin Roll Casting (TRC) technology still necessitate to be thoroughly investigated in some areas. Corrosion mechanisms operating under special conditions with the contribution of unique features of the microstructure are among those. Materials produced with TRC have unique features inherently generated due to the solidification path of the material during casting. Contrary to the very fine particles at the locations close to the free surface, centerline segregation (CLS) occurring at the mid-plane of the thickness have different morphological and compositional features than rest of the microstructure. While, unless directly exposed, it has almost no contribution to the general corrosion behavior of the alloy, some manufacturing processes generation new free surfaces in the material for CLS to be exposed to the corrosive media can be harmful for overall general corrosion performance of the alloy. It differentiates itself in corrosion behaviour with its compositional and morphological features than rest of the microstructure. Hence, influence of CLS on corrosion behaviour of two different alloys in 3000 and 8000 series employed for heat exchangers and packaging applications, respectively, are studied in the present study. Since CLS does not disappear with rolling passes but only changes its morphology, samples were taken at appropriate thickness of the downstream process that allow corrosion tests to be conducted at the cross section of the samples. Metallographical preparation techniques were used to reveal the CLS. Samples were dipped in to the HCl-NaCl containing test solution to observe the progress of corrosion in the matrix and heavily populated CLS areas during the course of test. Open-circuit potential (OCP) measurements were carried out on the rolled free surface, quarter plane and mid plane of the samples after milling the surface of the samples. Different samples produced with compositional and thermomechanical processing route variants were used. Results show that composition of the alloy and applied thermomechanical processes influence the corrosion characteristics of CLS and accordingly the overall corrosion performance. Other important finding is the contribution of manufacturing method to corrosion mechanism whether if it reveals the CLS by creating new free cross sectional surfaces.

The Corrosion Behaviour of Mg Alloy AZ91D/TiCp Metal Matrix Composite

2005 ◽  
Vol 488-489 ◽  
pp. 705-708 ◽  
Author(s):  
Suqiu Jia ◽  
Shu Sheng Jia ◽  
Guangping Sun ◽  
Jun Yao
Keyword(s):  
Metal Matrix ◽  
Corrosion Behaviour ◽  
Galvanic Corrosion ◽  
General Corrosion ◽  
Az91d Alloy ◽  
Alloy Matrix ◽  
Electrochemical Tests ◽  
Alloy Az91d ◽  
The Matrix ◽  
Carbide Particles

The corrosion of a magnesium-based MMC, comprising a AZ91D alloy matrix and 5 vol% titanium carbide particles has been studied in saline environments, using immersion and electrochemical tests. Corrosion was localized initially and developed subsequently into general corrosion , the local corrosion rate of AZ91D/TiCp being faster than diecast AZ91D due to the formation of less protective corrosion products. Galvanic corrosion for AZ91D/TiCp, due to coupling of the matrix and reinforcement, was more severe than diecast AZ91D.

scholarly journals Comparative Study on the Corrosion Behaviour of welded and un-welded Mild Steel in Agitated Media of Distilled Water 0.5mol, 0.3mol of Sodium Sulphate (Na2SO4) Solution

2020 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Comparative Study ◽  
Mild Steel ◽  
Corrosion Behaviour ◽  
Research Work ◽  
Sodium Sulphate ◽  
General Corrosion ◽  
Distilled Water ◽  
Experimental Conditions ◽  
Analytical Instruments ◽  
Materials Used

The research work was based on the comparative study of the corrosion bebaviour of the mild steel using agitated distilled water with 0.5 mol and 0.3 mol of Na2SO4 solution. The materials used for the research work are welded and un-welded mild steel. The mild steel materials were obtained at the Foundry shop of the Ajaokuta Steel Company Limited. The mild steel materials were analyzed using the SPECTRO Analytical Instruments at the Foundry shop of the company. These experiments were performed using 0.5mol and 0.3mol of Na2SO4 in different agitated media of distilled water .The samples used for general corrosion studies were 10mm and 4mm mild steel thickness. These materials were cut into specimen sizes to 2cm by 2cm). Twenty -eight (28) specimens each were prepared for the 10mm and 4mm mild steel materials the samples were ground and polished on the emery papers which removed rust particles on the test materials. The specimens were exposed for days for over fifty –four (54) days, with an interval of 3days. It was observed that welded materials have higher corrosion rate than the un-welded materials when subjected to experimental conditions. The corrosion rates values were used to plot graphs against time of exposure.

Effect of flow rate on the corrosion behaviour of API 5L X80 steel in water-saturated supercritical CO2 environments

CORROSION ◽  
10.5006/3939 ◽  
2021 ◽  
Author(s):  
Jonas da Silva de Sa ◽  
Wenlong Ma ◽  
Joshua Owen ◽  
Yong Hua ◽  
Anne Neville ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Flow Rate ◽  
Corrosion Behaviour ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Rotating Shaft ◽  
Order Of Magnitude ◽  
X80 Steel ◽  
Condensed Water ◽  
Water Saturated

The effect of the water-saturated supercritical carbon dioxide flow rate on the corrosion behaviour of API 5L X80 steel at a temperature of 35 oC and pressure of 80 bar was investigated. Tests were carried out with the samples attached to a rotating shaft inside an autoclave. Results indicate that increasing the scCO2 flow rate had no significant influence on the general/localized corrosion rate under the various dynamic conditions considered. The average general corrosion rate was 0.064 mm/year, while the average measured pitting penetration rates were one order of magnitude higher. The size of the corrosion features on the surface of the samples, which were believed to provide an indication as to the size of the condensed water droplets, were much smaller than the calculated critical droplet size needed to be displaced by the flow, supporting the theory as to why flow rate had little effect on the corrosion response.

Corrosion of Carbon-Steel Containers for Heat-Generating Nuclear Waste in Brine Environments Relevant for A Rock-Salt Repository

1991 ◽  
Vol 257 ◽  
Author(s):  
E. Smailos ◽  
W. Schwarzkopf ◽  
B. Kienzler ◽  
R. KÖster
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Nuclear Waste ◽  
Rock Salt ◽  
Corrosion Behaviour ◽  
Carbon Steels ◽  
General Corrosion ◽  
Fine Grained ◽  
Corrosion Studies ◽  
Salt Brine

ABSTRACTIn previous corrosion studies, carbon steels, especially the fine-grained steel TStE355, were identified as promising materials for heat-generating nuclear waste containers acting as a barrier in a rock-salt repository. In the present study detailed investigations have been performed on fine-grained steel to determine the influence of important parameters on its corrosion behaviour in disposal-relevant salt brines. These parameters are: brine composition (Mg Cl2-rich and NaCI-rich brines), temperature (90°C, 170°C), and salt impurities, such as H2S concentrations of 25 mg/I-200 mg/I salt brine.Under the conditions of the tests used here, carbon steel was subjected to general corrosion. Pitting and crevice corrosion or stress-corrosion cracking were not observed. The increase in temperature from 90°C to 170°C strongly enhanced the corrosion rate of the steel. In the MgCl2-rich brines, considerably higher rates (37-70 μm/a at 90°C, 200-300 °m/a at 170°C) were observed than in the NaCI-rich brine (5 μm/a at 90°C, 46 μm/a at 170°C). H2S concentrations in the MgCl2-rich Qbrine of up to 200 mg/l did not influence significantly the corrosion rate of the steel. The corrosion rates determined imply corrosion allowances that are technically acceptable for thick-walled containers. In view of these results, fine-grained steel continues to be considered as a promising material for long-lived HLW containers.

General corrosion behaviour of modified 9Cr–1Mo steel weldments in acidic environments

1994 ◽  
Vol 29 (2) ◽  
pp. 143-146
Author(s):  
L. J. Berchmans ◽  
V. Kapali ◽  
S. Natarajan ◽  
V. Sivan
Keyword(s):  
Corrosion Behaviour ◽  
General Corrosion ◽  
Acidic Environments

scholarly journals Study of the Thermochemical Surface Treatment Effect on the Phase Precipitation and Degradation Behaviour of DSS and SDSS

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 165 ◽  
Author(s):  
Alisiya Biserova-Tahchieva ◽  
Jose Maria Cabrera ◽  
Nuria Llorca-Isern
Keyword(s):  
Corrosion Behaviour ◽  
General Corrosion ◽  
Secondary Phases ◽  
Phase Precipitation ◽  
Degradation Behaviour ◽  
Surface Protection ◽  
Thermochemical Process ◽  
Long Time ◽  
Plasma Carburizing ◽  
Carburizing Process

In this study, the effect of a plasma ion carburizing process to duplex and superduplex stainless steels (DSS and SDSS), at 925 °C for a long time, as thermochemical process influencing the microstructural evolution is presented. The objective is to analyse the diffusion elements’ influence on the precipitation of secondary phases after additional short thermal treatment. A comparison among the different treatments was performed after the resulting microstructures were analysed by Field Emission—Scanning Electron Microscope. Precipitation of secondary phases—sigma (σ), chi (χ), nitrides and carbides—seemed to occur during the treatments in a similar way for both steels (DSS and SDSS), although they showed a different morphology and precipitation mode. General corrosion behaviour of untreated and treated samples was investigated by potentiodynamic tests in order to prove their corrosion resistance. It was found that an improvement of the surface protection after the plasma carburizing process occurred.

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