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1 – 10 of 750Guirong Yang, Zhaoxia Pan, Zhenghai Zhang, Wenming Song, Ying Ma and Yuan Hao
This study aims to investigate the initial corrosion behavior in aqueous solution of 20# seamless steel under (CO2/aqueous solution) gas–liquid two-phase stratified flow…
Abstract
Purpose
This study aims to investigate the initial corrosion behavior in aqueous solution of 20# seamless steel under (CO2/aqueous solution) gas–liquid two-phase stratified flow conditions.
Design/methodology/approach
The initial corrosion behavior was studied through the weight loss methods, scanning electron microscopy with energy-dispersive x-ray spectroscopy and x-ray diffraction.
Findings
The corrosion rate of 20# steel obviously increases with the increasing gas pressure at different corrosion time when the CO2 pressure is less than 0.11 MPa, and the increase of corrosion rate tends to be steady when the pressure exceeds 0.11 MPa. With the increase of CO2 pressure, the corrosion products changed from flocculent to acicular, granular and scaly. A four-stage model for the growth of the corrosion product layer was proposed, namely, the diffusion reaction stage, the local film formation stage, the complete film formation stage and the densification stage of the product film.
Originality/value
A four-stage model for the growth of the corrosion product layer on the pipe wall surface under this condition was proposed, namely, the diffusion reaction stage, the local film formation stage, the complete film formation stage and the densification stage of the product film. The growing process and densification mechanism of corrosion products layer were discussed.
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Hongyu Liu, Yingxue Teng, Jing Guo, Qinghe Xiao, Miao Wang, QiHang Pang and Shengli Li
This paper aims to explore the transformation process and transformation mechanism of carbon steel under the marine environment.
Abstract
Purpose
This paper aims to explore the transformation process and transformation mechanism of carbon steel under the marine environment.
Design/methodology/approach
In this paper, the transformation and rust layers corrosion products on 0Cu2Cr carbon steel with different cycles coupon test was investigated and deeply explored by scanning electron microscope, energy dispersive spectrometer, X-ray diffraction.
Findings
The results showed that the thickness of rust layers grew from 71.83 µm to 533.7 µm with increasing duration of corrosion. The initial corrosion product was γ-FeOOH, then part of the γ-FeOOH continued growing, and under the capillary action, the other part of the γ-FeOOH transformed to α-FeOOH.
Originality/value
To the best of the authors’ knowledge, this paper puts forward for the first time a new viewpoint of the development of corrosion products of low-carbon steel in two ways. This discovery provides a new idea for the future development of steel for marine engineering.
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Balázs Illés, Barbara Horváth, Attila Géczy, Olivér Krammer and Karel Dušek
The aim of this paper is to present a review of the tin whisker growth phenomena. The study focuses mainly on whisker growth in a corrosive climate when the main inducing factor…
Abstract
Purpose
The aim of this paper is to present a review of the tin whisker growth phenomena. The study focuses mainly on whisker growth in a corrosive climate when the main inducing factor of the whisker growth is oxidation. The tin whisker phenomenon is still a big challenge in lead-free reflow soldering technology. Modern lead-free alloys and surface finishes with high tin content are considered to be possible sources of whisker development, also the evolution of electronic devices towards further complexity and miniaturization points to an escalation of the reliability risks.
Design/methodology/approach
The present work was based on a worldwide literature review of the substantial previous works in the past decade, as well as on the results and experience of the authors in this field.
Findings
The effect of corrosion on tin whisker growth has been under-represented in reports of mainstream research; however, in the past five years, significant results were obtained in the field which raised the corrosion phenomena from being a side effect category into one of the main inducing factors. This paper summarizes the most important findings of this field.
Practical implications
This literature review provides engineers and researchers with a better understanding of the role of corrosion in tin whisker growth and the current challenges in tin whisker mitigation.
Originality/value
The unique challenges and future research directions about the tin whisker phenomenon were shown to highlight rarely discussed risks and problems in lead-free soldering reliability.
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Guirong Yang, Wenming Song, Fuqiang Wang, Ying Ma and Yuan Hao
This paper aims to investigate the corrosion rate, surface morphology and composition of corrosion products of 20# seamless steel in aqueous CO2 solution under stratified…
Abstract
Purpose
This paper aims to investigate the corrosion rate, surface morphology and composition of corrosion products of 20# seamless steel in aqueous CO2 solution under stratified gas-liquid two-phase flow condition. The development of a corrosion products layer has also been discussed.
Design/methodology/approach
The following methods were used: weight loss method, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction.
Findings
The corrosion rate curve presents an irregular zigzag change trend with a gradual increase in time. The peak value of the corrosion rate appears when the corrosion time is 4 h and 8 h. The corrosion products layer is composed of two sub-layers: the inner dense layer that is about 6 µm thick and the outer loose layer that is about 9 µm thick when the corrosion time is 8 h. The main corrosion product are FeCO3 and Fe2O3.
Originality/value
The atomic ratio of Fe/C/O is relatively stable for the inner dense layer, but changes in thickness for the outer loose layer. There is a densification stage after a loose corrosion products layer forms, and it is periodic.
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The complexity of atmospheric corrosion, further compounded by the effects of climate change, makes existing models inappropriate for corrosion prediction. The commonly used…
Abstract
The complexity of atmospheric corrosion, further compounded by the effects of climate change, makes existing models inappropriate for corrosion prediction. The commonly used kinetic model and dose-response functions are restricted in their capacity to represent the non-linear behaviour of corrosion phenomena. The application of artificial intelligence (AI)-driven machine learning algorithms to corrosion data can better represent the corrosion mechanism by considering the dynamic behaviour due to changing climatic conditions. Effective use of materials, coating systems and maintenance strategies can then be made with such a corrosivity model. Accurate corrosion prediction will help to improve climate change resilience of the social, economic and energy infrastructure in line with the UN Sustainable Development Goals (SDGs) 7 (Affordable and Clean Energy), 9 (Industry, Innovation and Infrastructure) and 13 (Climate Action). This chapter discusses atmospheric corrosion prediction in relation to the SDGs and the influence of AI in overcoming the challenges.
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The purpose of this paper is to predict the life of a corroding metallic structure in seawater so that uncertain and unpredictable failures of a structure, leading to accidents…
Abstract
Purpose
The purpose of this paper is to predict the life of a corroding metallic structure in seawater so that uncertain and unpredictable failures of a structure, leading to accidents, can be prevented.
Design/methodology/approach
Pitting has been known to show a large scatter in the measurable parameters such as corrosion rate, maximum pit depth, time to perforation and so on. Scatter results from the influence on pit development on metal surface heterogeneity and from variations in the corrosive environment over time. All these facts suggest that randomness is an inherent and unavoidable characteristic of pitting corrosion over time, so that stochastic models have been developed to formulate pit depth as a function of parameters influencing the process. Since chloride penetrates the passive film of the metal surface, Cl ion distribution into the metal has been mapped by finite element method (FEM).
Findings
The maximum pit depth which decides the onset of perforation or leakage has been modeled by the following equation: d=36.31(ΔE)0.68×(Δt)0.35. Cl ion distribution within a pit and outside has been modeled for better understanding of pit initiation which till today is not fully understood.
Practical implications
Perforation and leakage of a tank, container, or pipeline occur when the depth of pitting reaches the section thickness of the material of which the metallic structures are made. The pitting corrosion is localized and occurs at any spot or site where electrochemical conditions (ΔE Equation (9)) are prone to pitting. This leads to unpredictable failures of the structures which may look polished and undamaged under naked eyes. In most metallic structures, pitting may be present at some spots, but failures occur only when the depth predicted by the model Equation (9) reaches the section thickness of the material. Thus, determining pipe to soil potential gives a guide to go for maintenance before pit depth reaches the material thickness, and thereby unpredictable failure can be prevented. Second, the map generated by FEM showing Cl distribution throws much information and light on movement of Cl ions from passive layer into the pit, which leads to its growth. This helps scientists and researchers to understand the mechanism and gives much insights on finding new methods for protection of structures.
Social implications
The work will guide the engineers and researchers to prevent unpredictable failures of structures leading to accidents and human and property loss and prevent environment pollution from spilling of oil from tank and pipeline.
Originality/value
This is an original work based on several laboratory-generated simulated experimental data.
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Lei Fu, Hui Li, Li Lin, Qingyuan Wang, Qi Fan, Xinjie Huang, XiuLan Li, Sheng Lai and Lifei Chen
Most supersonic aircraft were manufactured using 2A70 aluminum alloy. The purpose of this paper is to study the corrosion mechanism and fatigue behavior of an aircraft in a…
Abstract
Purpose
Most supersonic aircraft were manufactured using 2A70 aluminum alloy. The purpose of this paper is to study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue.
Design/methodology/approach
For this purpose, the aluminum alloy samples were subjected to pre-corrosion and alternating corrosion-fatigue experiments. The failure mechanisms of corrosion and corrosion fatigue were analyzed using microscopic characterization methods of electrochemical testing, X-ray diffraction and scanning electron microscopy. Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life.
Findings
The results showed that the corrosion damage caused by the corrosive environment was gradually connected by pitting pits to form denudation pits along grain boundaries. The deep excavation of chloride ions and the presence of intergranular copper-rich phases result in severe intergranular corrosion morphology. During cyclic loading, alternating hardening and softening occurred. The stress concentration caused by surface pitting pits and denudation pits initiated fatigue cracks at intergranular corrosion products. At the same time, the initiation of multiple fatigue crack sources was caused by the corrosion environment and the morphology of the transient fracture zone was also changed, but the crack propagation rate was not basically affected. The polarization curve and impedance analysis results showed that the corrosion rate increases first, decreases and then increases. Fatigue failure behavior was directly related to micro characteristics such as corrosion pits and microcracks.
Originality/value
In this research, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. To study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, the Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life.
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C. Pusarla, A. Dasgupta, M.G. Pecht and A. Christou
This paper presents an application of the physics‐of‐failure design philosophy to flip‐chip bonds in a microelectronic package. The physics‐of‐failure philosophy utilises…
Abstract
This paper presents an application of the physics‐of‐failure design philosophy to flip‐chip bonds in a microelectronic package. The physics‐of‐failure philosophy utilises knowledge of the life‐cycle load profile, package architecture and material properties to identify potential failure mechanisms and to prevent operational failures through robust design and manufacturing practices. The potential failure mechanisms and failure sites are identified in this paper for flip‐chip bonds, and an approach is presented to prevent the identified potential failure mechanisms by design. Finally, quality conformance issues are discussed to ensure a robust manufacturing process and qualification issues are addressed to evaluate the reliability of the designed flip‐chip bond.
Abstract
Purpose
The purpose of this paper is to investigate the effect of chloride along with NO2 on the atmospheric corrosion of bronze using exposure tests.
Design/methodology/approach
Surface tension tests and electrochemical impedance measurements together with scanning electron microscopy (SEM) with energy dispersive atomic X‐ray, and X‐ray diffraction are used to characterize the corrosion behavior.
Findings
The results of the weight loss measurements show that the whole corrosion kinetics can be described approximately by: ΔW=atb; the synergistic effect of chloride and NO2 is observed clearly, though no nitrate existed in the corrosion products.
Originality/value
A new catalyst theory has been suggested in this paper, i.e. that NO2 acts as a catalyst during the corrosion process when significant quantities of chloride also are present.
Guangwei Liang, Zhiming Gao, Cheng-Man Deng and Wenbin Hu
The purpose of this study is to reveal the effect of nano-Al2O3 particle addition on the nucleation/growth kinetics, microhardness, wear resistance and corrosion resistance of…
Abstract
Purpose
The purpose of this study is to reveal the effect of nano-Al2O3 particle addition on the nucleation/growth kinetics, microhardness, wear resistance and corrosion resistance of Co–P–xAl2O3 nanocomposite plating.
Design/methodology/approach
The kinetics and properties of Co–P–xAl2O3 nanocomposite plating prepared by electroplating were investigated by electrochemical measurements, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Vickers microhardness measurement, SRV5 friction and wear tester and atomic force microscopy.
Findings
A 12 g/L nano-Al2O3 addition in the plating solution can transform the nucleation/growth kinetics of the plating from the 3D progressive model to the 3D instantaneous model. The microhardness of the plating increased with the increase of nano-Al2O3 content in plating. The wear resistance of the plating did not adhere strictly to Archard’s law. An even and denser corrosion product film was generated due to the finer grains, with a high corrosion resistance.
Originality/value
The effect of different nano-Al2O3 addition on the nucleation/growth kinetics and properties of Co–P–xAl2O3 nanocomposite plating was investigated, and an anticorrosion mechanism of Co–P–xAl2O3 nanocomposite plating was proposed.
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