Sol–gel coatings for pitting corrosion resistance of AA 2024-T3 aluminium alloy

2007 ◽  
pp. 52-62
Author(s):  
Y. Sepúlveda ◽  
E. González ◽  
M.A. Páez ◽  
C.M. Rangel ◽  
P. Skeldon ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Pitting Corrosion ◽  
Sol Gel ◽  
Pitting Corrosion Resistance ◽  
Aa 2024

Effect of severe plastic deformation by ECAP on corrosion behaviour of aluminium alloy AA 7075

2016 ◽  
Vol 81 (2) ◽  
pp. 55-61 ◽  
Author(s):  
M. Ilieva ◽  
R. Radev
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Equal Channel Angular Pressing ◽  
Pitting Corrosion ◽  
Corrosion Behaviour ◽  
Chloride Concentration ◽  
Chloride Ions ◽  
Angular Pressing ◽  
Pitting Corrosion Resistance ◽  
Aa 7075

Purpose: The present study compares the corrosion behaviour of overaged AA 7075 before and after equal channel angular pressing ECAP in two media, containing chlorides, in order to answer the question how grain refinement of aluminium alloys influences their corrosion properties.Design/methodology/approach: The effect of equal channel angular pressing ECAP on corrosion behaviour of aluminium alloy AA 7075 was studied in two water solutions, containing chloride ions: 1) 0.01 M Na2SO4 with addition of 0.01%Cl-, and 2) 3g/l H2O2 and 57g/l NaCl. The changes in electrochemical characteristics, provoked by grain size refinement after equal channel angular pressing ECAP, were found using potentiodynamic polarisation. Steady state potential, corrosion potential, corrosion current density; breakdown (pitting) potential of overaged and deformed by equal channel angular pressing ECAP aluminium alloy AA 7075 were measured.Findings: In the environment with lower chloride concentration equal channel angular pressing ECAP process led to increase in pitting corrosion resistance and in the medium with higher chloride concentration - to decrease in pitting corrosion resistance. That way grain refinement does not demonstrate a uni-directional influence on corrosion resistance of AA 70775.Research limitations/implications: The results suggest the possibility for development of materials having the same chemical composition but with different corrosion resistance to different environments.Originality/value: The paper presents the corrosion behaviour of ultrafine-grained aluminium alloy AA 7075 and the influence of the chloride ions concentration in the corrosion medium on this behaviour.

NIROSTA 4429

Alloy Digest ◽  
2000 ◽  
Vol 49 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Pitting Corrosion ◽  
Intergranular Corrosion ◽  
Heat Treating ◽  
Low Carbon ◽  
High Nitrogen ◽  
Temperature Performance ◽  
Pitting Corrosion Resistance

Abstract Nirosta 4429 is a low-carbon, high-nitrogen version of type 316 stainless steel. The low carbon imparts intergranular corrosion resistance while the nitrogen imparts both higher strength and some increased pitting corrosion resistance. It is recommended for use as welded parts that need not or cannot be annealed after welding. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-787. Producer or source: ThyssenKrupp Nirosta.

Pitting Corrosion of Biomedical Titanium and Titanium Alloys: A Brief Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Yu-Wei Cui ◽  
Liang-Yu Chen ◽  
Xin-Xin Liu
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Potential Temperature ◽  
Growth Stages ◽  
Factors Affecting ◽  
Ti Alloys ◽  
Pitting Corrosion Resistance ◽  
Superior Mechanical Properties ◽  
Good Biocompatibility ◽  
Main Factors

Abstract:: Thanks to their excellent corrosion resistance, superior mechanical properties and good biocompatibility, titanium (Ti) and Ti alloys are extensively applied in biomedical fields. Pitting corrosion is a critical consideration for the reliability of Ti and Ti alloys used in the human body. Therefore, this article focuses on the pitting corrosion of Ti and Ti alloys, which introduces the growth stages of pitting corrosion and its main influencing factors. Three stages, i.e. (1) breakdown of passive film, (1) metastable pitting, and (3) propagation of pitting, are roughly divided to introduce the pitting corrosion. As reviewed, corrosive environment, applied potential, temperature and alloy compositions are the main factors affecting the pitting corrosion of Ti and Ti alloys. Moreover, the pitting corrosion of different types Ti alloys are also reviewed to correlate the types of Ti alloys and the main factors of pitting corrosion. Roughly speaking, β-type Ti alloys have the best pitting corrosion resistance among the three types of Ti alloys.

scholarly journals The role of alloyed strontium in the microstructures and alkaline electrochemistry of Mg–5Al–4Sn alloys

RSC Advances ◽  
2020 ◽  
Vol 10 (57) ◽  
pp. 34387-34395
Author(s):  
Le Van Sy ◽  
Phan Minh Quoc Binh ◽  
Bhajan Lal ◽  
Quy Bau Nguyen ◽  
Tran Van Hung ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Die Casting ◽  
Pitting Corrosion Resistance

The development of Mg–5Al–4Sn–xSr alloys with α-grain reduction, refined precipitates and pitting corrosion resistance by die casting.

scholarly journals Pitting Corrosion Resistance and Repassivation Behavior of C-Bearing Duplex Stainless Steel

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 930 ◽  
Author(s):  
Hanme Yoon ◽  
Heon-Young Ha ◽  
Tae-Ho Lee ◽  
Sung-Dae Kim ◽  
Jae Hoon Jang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Galvanic Corrosion ◽  
Dual Phase ◽  
Corrosion Resistant ◽  
Grain Sizes ◽  
Α Phase ◽  
Pitting Corrosion Resistance ◽  
Corrosion Pits ◽  
Pit Initiation

The effects of C-substitution for part of the N content, on the pitting corrosion resistance and repassivation tendencies of duplex stainless steels (DSSs) were investigated. For this investigation, normal UNS S32205 containing N only (DSS-N) and the C-substituted DSS (DSS-NC) were fabricated. Microstructural analyses confirmed that the two DSSs had dual-phase microstructures without precipitates, and they possessed similar initial microstructure, including their grain sizes and phase fractions. Polarization and immersion tests performed in concentrated chloride solutions revealed that the DSS-NC was more resistant against stable pitting corrosion and possessed a higher repassivation tendency than the DSS-N. Furthermore, the corrosion pits initiated and propagated to a less corrosion resistant α phase. Polarization tests and corrosion depth measurements conducted in an HCl solution indicated that the DSS-NC exhibited lower galvanic corrosion rate between the α and γ phases than the DSS-N. Therefore, the growth rate of pit embryo was lowered in the DSS-NC, which shifted the potentials for the stable pit initiation and the pit extinction to the higher values.

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