scholarly journals Passivity and Semiconducting Behavior of a High Nitrogen Stainless Steel in Acidic NaCl Solution

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yanxin Qiao ◽  
Xiang Cai ◽  
Jie Cui ◽  
Huabing Li
Keyword(s):  
Stainless Steel ◽  
Manganese Oxides ◽  
Chloride Ions ◽  
Passive Films ◽  
Molybdenum Oxides ◽  
Nacl Solution ◽  
High Nitrogen ◽  
Pitting Corrosion Resistance ◽  
The Stability ◽  
Corrosive Environments

The passivity and semiconducting behaviors of a high nitrogen-containing nickel-free stainless steel (HNSS) in 0.05 mol/L H2SO4+ 0.5 mol/L NaCl have been investigated. Results indicated that HNSS offered excellent pitting corrosion resistance in corrosive environments. Three corrosion potential values were observed in potentiodynamic polarization response, indicating the existence of an unstable system. The current transient and Mott-Schottky plots demonstrated that the stability of passive films decreased with the increase of applied potentials. The angle resolved X-ray photoelectron spectrometric results revealed that the primary constituents of passive films formed in 0.05 mol/L H2SO4+ 0.5 mol/L NaCl solution were composed of iron oxides, manganese oxides, Cr2O3, and Cr(OH)3. Meanwhile, it indicated that molybdenum oxides did not exist in the oxide layer, but chloride ions were present in the passive films.

Pitting Susceptibility and Semiconducting Properties of Passive Films of 18Cr-18Mn-2Mo-0.9N High Nitrogen Austenitic Stainless Steel

2009 ◽  
Vol 79-82 ◽  
pp. 993-996 ◽  
Author(s):  
Hua Bing Li ◽  
Zhou Hua Jiang ◽  
Zhen Li ◽  
Zu Rui Zhang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Ph Value ◽  
Chloride Ions ◽  
Passive Films ◽  
High Nitrogen ◽  
Ph Values ◽  
Pitting Corrosion Resistance ◽  
Semiconducting Properties

The effects of pH value and chloride ions concentration of the solution on pitting susceptibility and semiconducting properties of passive films formed on 18Cr-18Mn-2Mo-0.9N high nitrogen austenitic stainless steel (HNSS) were investigated using potentiodynamic polarization and capacitance measurement methods, respectively. The anodic polarization curves show that HNSS exhibits excellent pitting corrosion resistance in the solution with different pH values and chloride ions concentration, and the pitting corrosion resistance of HNSS decreases a little with decreasing the pH value or increasing the chloride ions concentration of the solution. The passive films formed on HNSS in the solution with pH values ranging from 1 to 9 or chloride ions concentration from 3.5 wt% to 20 wt% NaCl behave as n-type semiconductors. With increasing the pH value or decreasing the chloride ions concentration, the shallow donor and deeper donor densities decrease and the flat bland potential decreases, and the thickness of space charge layer increases. The deeper donor increases and then the second positive slope of straight linear region disappears with decreasing the pH value or increasing the chloride ions concentration of the solution, which can be attributed to the formation of Cr6+ is depressed.

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.

Effect of tempering treatment on pitting corrosion resistance of modified cast CA6NM stainless steel in 3.5 % NaCl solution

2021 ◽  
Author(s):  
Vinda Puspasari ◽  
Mukhlis Agung Prasetyo ◽  
Arini Nikitasari ◽  
Efendi Mabruri ◽  
Moch. Syaiful Anwar
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Nacl Solution ◽  
Pitting Corrosion Resistance ◽  
Tempering Treatment

scholarly journals Use of ZnAl-Layered Double Hydroxide (LDH) to Extend the Service Life of Reinforced Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1769 ◽  
Author(s):  
Celestino Gomes ◽  
Zahid Mir ◽  
Rui Sampaio ◽  
Alexandre Bastos ◽  
João Tedim ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Layered Double Hydroxide ◽  
External Solution ◽  
Chloride Ions ◽  
Nacl Solution ◽  
The Stability ◽  
Ph Range ◽  
Double Hydroxide ◽  
Corrosion Of Steel ◽  
Steel Rebars

This work investigated the use of ZnAl-layered double hydroxide (LDH) intercalated with nitrate or nitrite ions for controlling the corrosion of steel in reinforced concrete. The work started by analyzing the stability of the powder in the 1–14 pH range and the capacity for capturing chloride ions in aqueous solutions of different pH. The effect of the ZnAl-LDH on the corrosion of steel was studied in aqueous 0.05 M NaCl solution and in mortars immersed in 3.5% NaCl. It was found that the LDH powders dissolved partially at pH > 12. The LDH was able to capture chloride ions from the external solution, but the process was pH-dependent and stopped at high pH due to the partial dissolution of LDH and the preferential exchange of OH– ions. These results seemed to imply that ZnAl-LDH would not work in the alkaline environment inside the concrete. Nonetheless, preliminary results with mortars containing ZnAl-LDH showed lower penetration of chloride ions and higher corrosion resistance of the steel rebars.

The Influence of Cold Working on Semiconducting Properties of Passive Film and Pitting Corrosion Resistance of High Nitrogen Austenitic Stainless Steel

2011 ◽  
Vol 415-417 ◽  
pp. 784-788
Author(s):  
Li Wei Xu ◽  
Hua Bing Li ◽  
Qi Feng Ma ◽  
Zhou Hua Jiang ◽  
Dong Ping Zhan
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Cold Rolling ◽  
Passive Film ◽  
Pitting Corrosion ◽  
High Nitrogen ◽  
Pitting Corrosion Resistance ◽  
Semiconducting Properties ◽  
Rolling Deformation

The effect of cold working on semiconducting properties of passive film and pitting corrosion resistance of 19Cr-18Mn-2Mo-0.9N high nitrogen austenitic stainless were investigated by anodic polarization, AC impedance and capacitance measurement methods. With increasing the cold rolling deformation ranging from 0% to 60%, the passive region of high nitrogen austenitic stainless steel decreases, and the corrosion potential, EIS radius and polarization resistance all decreases. The Mott-Schottky result indicates that the pitting corrosion resistance deteriorates with increment of cold rolling deformation. The results show that the passive films formed on high nitrogen austenitic stainless steel with different cold rolling deformation behave as n-type semiconductors. With increasing the cold rolling deformation grade, the donor density (ND) increases, but the thickness of the space-charge layer (W) decreases. The decreasing of the thickness of space-charge layer with increment of cold rolling deformation is attributed to the inceasing defect which deteriorates the stability of the passive film.

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