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Article
Publication date: 27 September 2018

Xuequn Cheng and Xiao Mei Zuo

The purpose of this paper is to study the electrochemical behavior of 690 alloy with corrosion products in simulated pressurized water reactor (PWR) primary water environment.

Abstract

Purpose

The purpose of this paper is to study the electrochemical behavior of 690 alloy with corrosion products in simulated pressurized water reactor (PWR) primary water environment.

Design/methodology/approach

This paper opted for a laboratory study using simulation of high temperature and high pressure environment immersion testing. The electrochemical behavior was studied by potentiodynamic polarization, electrochemical impedance spectroscopy, scanning Kelvin probe microscopy (SKP). Moreover, the corrosion products were analyzed by X-ray photoelectron spectroscopy.

Findings

The results demonstrated that the particle majority in the 690 alloy corrosion products subsequent to high temperature and high pressure immersion testing were mainly oxides of Fe and Ni, which protected the matrix. As the immersion testing duration increased, the corrosion potential of the 690 alloy apparently increased, and the corrosion current density de'creased, while the corrosion resistance Rf increased gradually along with the density. The SKP demonstrated that the EKP increased by nearly 400 mV from −0.42 to −0.03 V following the immersion testing, indicating that the corrosion product film played an apparent protective role on the substrate.

Originality/value

This paper provides a theoretical basis for the corrosion behavior and inhibition mechanism of 690 alloy in PWR primary water environment.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 29 January 2024

Meigui Yin, Lei Zhang and Longxiang Huang

The purpose of this paper is to study the effect of surface salt spray duration on the fretting wear and electrochemical corrosion behaviors of Inconel 690 alloy.

Abstract

Purpose

The purpose of this paper is to study the effect of surface salt spray duration on the fretting wear and electrochemical corrosion behaviors of Inconel 690 alloy.

Design/methodology/approach

A high-temperature steam generator was applied to salt spray test samples, a fretting wear rig was used to realize the damage behavior tests, an electrochemical workstation was applied to analysis the changes of each sample’s corrosion dynamic response before and after fretting wear.

Findings

The thickness of the oxide film that formed on sample surface was increased with the salt spray duration, and somewhat it could act as lubrication during the fretting wear process; however, the corrosive chloride would accelerate the fretting mechanical damage behavior.

Originality/value

In a salt steam spray condition, the fretting tribo-corrosion behaviors of Inconel 690 alloy surface was studied.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Content available
Article
Publication date: 1 October 2002

86

Abstract

Details

Anti-Corrosion Methods and Materials, vol. 49 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 4 July 2016

Chuan Liu, Ying Luo, Min Yang and Qiang Fu

The purpose of this paper is to clarify the effect of material hardening model and lump-pass method on the thermal-elastic-plastic (TEP) finite element (FE) simulation of residual…

Abstract

Purpose

The purpose of this paper is to clarify the effect of material hardening model and lump-pass method on the thermal-elastic-plastic (TEP) finite element (FE) simulation of residual stress induced by multi-pass welding of materials with cyclic plasticity.

Design/methodology/approach

Nickel-base alloy and stainless steel, which are used in J-type weld for manufacturing the nuclear reactor pressure head, can easily harden during multi-pass welding. The J-weld welding experiment is carried out and the temperature cycle and residual stress are measured to validate the TEP simulation. Thermal-mechanical sequence coupling method is employed to get the welding residual stress. The lumped-pass model and pass-by-pass FE model are built and two materials hardening models, kinematic hardening model and mixed hardening model, are adopted during the simulations. The effects of material hardening models and lumped-pass method on the residual stress in J-weld are distinguished.

Findings

Based on the kinematic hardening model, the stresses simulated with the lumped-pass FE model are almost consistent with those obtained by the pass-by-pass FE model; while with the mixed hardening material model, the lumped-pass method has great effect on the simulated stress.

Practical implications

A computation with mixed isotropic-kinematic material seems not to be the appropriate solution when using the lumped-pass method to save the computation time.

Originality/value

In the simulation of multi-pass welding residual stress involved in materials with cyclic plasticity, the material hardening model should be carefully considered. The kinematic hardening model with lump-pass FE model can be used to get better simulation results with less computation time. The results give a direction for welding residual stress simulation for the large structure such as the reactor pressure vessel.

Details

Engineering Computations, vol. 33 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 6 February 2019

Da-Hai Xia and Jing-Li Luo

Corrosion is considered as one of the issues that threaten the safe operation of steam generator (SG) tubing. Some sulfur-related specie can cause corrosion degradation of SG…

Abstract

Purpose

Corrosion is considered as one of the issues that threaten the safe operation of steam generator (SG) tubing. Some sulfur-related specie can cause corrosion degradation of SG tubing. Sulfur-induced corrosion of SG alloys in high temperature and high-pressure water is one of the most complicated processes. The purpose of this study is to study the effect of reduced sulphur on passive film properties of steam generator (SG) tubing.

Design/methodology/approach

In this paper, the effects of reduced sulfur on passive film properties of SG tubing were reviewed from the aspects of thermodynamic calculations and experimental.

Findings

Thermodynamic calculations are mainly presented by E-pH diagrams, volt equivalent diagrams and species distribution curves. The stability of sulphur species highly depends on temperature, solution pH, and electrochemical potential. Experimental data indicated that reduced sulfur species can interact with the passive film, which led to changes in film thickness, film structure, semiconductivity and pitting growth rate.

Originality/value

The state-of-the-art discussed in this paper gives basis for resolving engineering problems regarding with sulfur-induced corrosion.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 22 May 2009

Hosni M. Ezuber

The purpose of this paper is to evaluate the effect of seawater temperature on the corrosion behaviour of 90‐10 cupronickel alloys. Also, to investigate the effect of thiosulphate…

Abstract

Purpose

The purpose of this paper is to evaluate the effect of seawater temperature on the corrosion behaviour of 90‐10 cupronickel alloys. Also, to investigate the effect of thiosulphate additions (one of the major sulphide oxidation products in seawater) on the alloy corrosion rate in seawater.

Design/methodology/approach

Potentiodynamic polarization measurement (DC) was used to estimate the corrosion rate of the cupronickel alloy in seawater with and without thiosulphate species (50‐650 ppm).

Findings

It was observed that the cupronickel alloy suffered accelerated corrosion as the seawater temperature was raised from 25 to 50 or 80°C. The increase in the corrosion rate was found to correspond well with the negative shift in the free corrosion potential. Thiosulphate addition was found to depend on the test temperature. At 25°C, thiosulphate activated the alloy dissolution rate and the higher were the thiosulphate concentrations, the higher was the corrosion rate. At 50 or 80°C, however, thiosulphate promoted the dissolution rate at early stages, but seemed to interfere with the surface film formation later on, producing a black film that effectively decreased the alloy corrosion rate. At higher potentials, however, the film became non‐protective, leading to accelerated corrosion once again.

Originality/value

This paper explains the corrosion behaviour of 90‐10 cupronickel alloys in seawater as a function of test temperature and thiosulphate additions.

Details

Anti-Corrosion Methods and Materials, vol. 56 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 27 October 2023

Junyu Shi, Shengli Ling, Yinjie Kuang, Yonggang Tong, Yongle Hu and Dunying Deng

The purpose of this paper is to reveal the effect of microstructure on the corrosion behavior of CoCrNi alloy in 3.5 Wt.% NaCl solution.

Abstract

Purpose

The purpose of this paper is to reveal the effect of microstructure on the corrosion behavior of CoCrNi alloy in 3.5 Wt.% NaCl solution.

Design/methodology/approach

The as-cast CoCrNi alloy was prepared by arc melting, and the cold-rolled and annealed alloys were prepared by processing the as-cast alloy.

Findings

The experimental results showed that a protective passivation film was formed on the surfaces of these CoCrNi MEA, and the stability and compactness of alloys increased in the sequence of cold-rolled, as-cast and annealed CoCrNi alloys. The annealed CoCrNi alloys had the best pitting resistance.

Originality/value

This study proposes the effect of the microstructure of CoCrNi alloy on corrosion resistance.

Details

Anti-Corrosion Methods and Materials, vol. 70 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 January 2014

Panagiotis Spathis

– The purpose of this work was to study the cracking susceptibility of a 7017 aluminium alloy, after anodising under various conditions.

Abstract

Purpose

The purpose of this work was to study the cracking susceptibility of a 7017 aluminium alloy, after anodising under various conditions.

Design/methodology/approach

Slow strain tests in dry air, laboratory air and sodium chloride solution were employed. Anodic oxide films were produced with various applied current densities and thicknesses, in horizontal or vertical orientation of the coatings, at the free corrosion potential and also at various anodic or cathodic potentials. For the interpretation of the results, a metallographic study of the specimens before and after straining to failure was carried out using a scanning electron microscope.

Findings

The behaviour of anodic coatings was found to depend very much on the anodising conditions. The coatings reduced the ductility of the alloy in dry air but can actually increase the ductility in laboratory air and in 3.5 per cent sodium chloride solution. In most cases, the ductility of coated specimens was greater in 3.5 per cent NaCl solution than in dry air, possibly due to crack blunting by the aggressive environment. Anodic coatings moved the free corrosion potential of the alloy in the noble direction and both the anodised and the bare alloy generally suffered a reduction in ductility at potentials anodic or cathodic to the free corrosion potential, the fall being more rapid for the anodised alloy.

Research limitations/implications

The mechanism causing the increased ductility of coated specimens in 3.5 per cent NaCl solution than in dry air remains yet to be confirmed.

Practical implications

The selection of suitable anodic coatings for the protection of aluminium alloys against stress corrosion cracking depends on the anodising conditions.

Originality/value

The paper provides information regarding the influence of anodising conditions on the anticorrosive properties of electrolytically prepared anodic coatings on aluminium alloys.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Content available
Article
Publication date: 29 April 2014

95

Abstract

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 3
Type: Research Article
ISSN: 0003-5599

Article
Publication date: 14 September 2022

Tingyun Ming, Qunjia Peng, Yaolei Han and Tao Zhang

This paper aims to understand the effect of water jet cavitation peening (WJP) on stress corrosion cracking (SCC) behavior of alloy 600 and alloy 182 in high temperature water.

Abstract

Purpose

This paper aims to understand the effect of water jet cavitation peening (WJP) on stress corrosion cracking (SCC) behavior of alloy 600 and alloy 182 in high temperature water.

Design/methodology/approach

Surface and cross-section morphology, grain boundary microstructure, residual stress and strain distribution, hardness and surface roughness in water jet cavitation peened alloy 600 and alloy 182 were characterized.

Findings

A superior stress corrosion cracking resistance was obtained in 600MA, which can be attributed to the formation of the ultrafine grain layer and the higher magnitude residual compressive stress.

Originality/value

Relationship between WJP-induced microstructure and stress state change and SCC susceptibility was conducted. It could provide a theoretical basis for developing application of WJP in nuclear power plants.

Details

Anti-Corrosion Methods and Materials, vol. 69 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

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