Effect of Annealing and Aging Treatment on Pitting Corrosion Resistance of Fine-Grained Mg-8%Al-0.5%Zn Alloy

JOM ◽  
2019 ◽  
Vol 71 (12) ◽  
pp. 4758-4768 ◽  
Author(s):  
Gajanan M. Naik ◽  
S. Narendranath ◽  
S. S. Satheesh Kumar ◽  
Sandeep Sahu
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Aging Treatment ◽  
Fine Grained ◽  
Pitting Corrosion Resistance ◽  
Zn Alloy

scholarly journals Improvement of Pitting-Corrosion Resistance of Ultrafine-Grained 7475 Al Alloy by Aging

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 360
Author(s):  
Ewa Ura-Bińczyk
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Al Alloy ◽  
Subsequent Aging ◽  
Fine Grained ◽  
Transmission Electron ◽  
Pitting Corrosion Resistance ◽  
Ultrafine Grained ◽  
Ultrafine Grained Microstructure

The effect of aging on the resistance to pitting corrosion of ultrafine-grained 7475 aluminium (Al) alloy processed by hydrostatic extrusion (HE) is studied. Differences in the microstructure were investigated using secondary electron (SEM) and transmission electron microscopy (TEM). Corrosion tests were performed in 0.1 M NaCl, and characterization of corroded surface was performed. The results of this work show that the pitting susceptibility of ultra-fine grained 7475Al is related to the distribution of MgZn2 precipitates. After HE, the formation of An ultrafine-grained microstructure at the grain boundaries of ultrafine grains is observed, while subsequent aging results in the formation of MgZn2 precipitates in the grain interior. Grain refinement increases susceptibility to localized attack, while the subsequent aging improves the overall corrosion resistance and limits the propagation of corrosion attack.

Influences of Aging Precipitation on Corrosion Resistance of 18Cr-18Mn-2Mo-0.77N HNS

2009 ◽  
Vol 79-82 ◽  
pp. 1013-1016 ◽  
Author(s):  
Zu Rui Zhang ◽  
Hua Bing Li ◽  
Zhou Hua Jiang ◽  
Zhen Li ◽  
Bao Yu Xu
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Volume Fraction ◽  
Aging Treatment ◽  
High Nitrogen ◽  
Aging Precipitation ◽  
Pitting Corrosion Resistance ◽  
Nitrogen Steel ◽  
The Matrix ◽  
Nose Temperature

Influences of aging precipitation of Cr2N and Chi (χ) phases on the resistance to pitting corrosion and intergranular corrosion of 18Cr-18Mn-2Mo-0.77N high nitrogen steel (HNS) as a type of fundamental and structural materials were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) pattern and electrochemical methods. Intergranular, cellular Cr2N and χ phases precipitate gradually along grain boundaries and inward grains. The volume fraction of precipitation presents a C-curve with a nose temperature of 850°C during 2h aging treatment. The solution-treated (ST) HNS exhibits the highest pitting corrosion potential because of high nitrogen content in steel, and especially no precipitation. The pitting corrosion resistance of aged HNS decreases because of the formation of aging precipitation which results in the depletion of Cr and Mo in the matrix. The pitting corrosion potentials firstly decrease then increase as the same tendency as the amount of precipitation expect 850°C and 900°C. Double loop electrochemical potentiokinetic reaction (DL-EPR) results show that the change tendency of IGC susceptibility is well consistent with the amount of precipitation of aged HNS for 2h at various temperatures. With prolonging the aging time at 850°C, aged HNS presents more obviously intergranular sensitization due to the formation of aging precipitation which results in the depletion of Cr and Mo.

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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