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.

scholarly journals The Pitting Corrosion Behavior of the Austenitic Stainless Steel 308L-316L Welded Joint

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1258
Author(s):  
Jinshan He ◽  
Shiguang Xu ◽  
Wenxin Ti ◽  
Yaolei Han ◽  
Jinna Mei ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Statistical Analysis ◽  
Austenitic Stainless Steel ◽  
Passive Film ◽  
Pitting Corrosion ◽  
Welded Joint ◽  
Weld Zone ◽  
Electrochemical Tests ◽  
Pitting Corrosion Resistance

The pitting corrosion resistance of the austenitic stainless steel 308L-316L welded joint was investigated by electrochemical tests. It is found that the weld zone was the most critical for pits to initiate in the welded joint due to relatively instable passive film with few Mo and inhomogeneous passive film induced by multiple (Mn, Al, and Si) oxides and continuous network of 13.94 vol.% δ ferrites. By statistical analysis, 53.8% pits initiated at (Mn, Al, and Si) oxides, 23.0% in austenite, and 23.2% at interface between ferrite and austenite. In addition, heat-affected zone was prone to have pitting corrosion compared with the base metal since residual strain was much higher in the region.

Influences of Nitrogen Content and Aging Precipitates on Pitting Corrosion Resistance Properties of High Nitrogen Austenitic Stainless Steel

2013 ◽  
Vol 448-453 ◽  
pp. 102-106
Author(s):  
Zu Rui Zhang ◽  
Zhen Ye Zhao ◽  
Chun Zhi Li ◽  
Zhou Hua Jiang ◽  
Hua Bing Li
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Nitrogen Content ◽  
Pitting Corrosion ◽  
Corrosion Potential ◽  
High Nitrogen ◽  
Pitting Corrosion Resistance ◽  
The Matrix ◽  
Nose Temperature

This study is concerning the influences of nitrogen content and aging precipitates on pitting corrosion resistance properties of high nitrogen austenitic stainless steel (HNS) through potentiodynamic polarization method. The microstructure of aged HNS is analized by scanning electron microscopy (SEM). The main results obtained are as follow: the formation of intergranular, cellular Cr2N and intermetallic χ precipitates makes the depletion of Cr and Mo in the matrix and deteriorates the resistance to pitting corrosion in aged specimens. Cr2N starts to precipitate in the form of lamellar structure to cellular precipitates, the pitting corrosion drops to about 0 VSCE. HNSs perform the same tendency that the pitting corrosion potential firstly decreases then increases and reduce to the minimum value at nose temperature. All the pitting corrosion potential of HNS-B aged for 2h at different temperature presents more than that of HNS-A. The pitting corrosion resistance is mainly controlled by nitrogen content before great precipitates of cellular Cr2N and intermetallic χ phase rich in Cr and Mo. It is also mainly controlled by the content and the type of precipitates after great precipitates of cellular Cr2N.

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 Rare Earth on the Inclusions and Pitting Resistance of Austenitic Stainless Steel

2013 ◽  
Vol 718-720 ◽  
pp. 29-32 ◽  
Author(s):  
Xiao Liu ◽  
Yu Bo
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Austenitic Stainless Steel ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Anodic Polarization ◽  
Austenitic Stainless Steels ◽  
Metallographic Examination ◽  
Pitting Corrosion Resistance

The anodic polarization curves of 21Cr-11Ni austenitic stainless steels with various RE contents in 3.5% NaCl neutral solutions have been measured by electrochemical methods. The effect of RE on pitting corrosion resistance of 21Cr-11Ni stainless steels has been studied by the metallographic examination. The results show that sulfide and other irregular inclusions are modified to round or oval-shaped RE2O2S and RES after adding RE to 21Cr-11Ni stainless steesl. RE makes sulfide, and other irregular inclusions change to dispersed round or oval-shaped RE inclusions, effectively inhibits the occurrence of pitting corrosion, thereby enhancing the corrosion resistance of 21Cr-11Ni austenitic stainless steels.

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