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.

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.

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.

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.

OUTOKUMPU FORTA H500

Alloy Digest ◽  
2018 ◽  
Vol 67 (2) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Physical Properties ◽  
Nitrogen Content ◽  
Tensile Properties ◽  
Work Hardening ◽  
Research Centre ◽  
High Nitrogen Content ◽  
High Nitrogen

Abstract Forta H500 is an austenitic stainless steel in which manganese replaces some of the nickel. Its high-nitrogen content adds strength. Grades Forta H800 and H1000 can be derived from the same composition by changing the degree of work hardening. This datasheet provides information on physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming and joining. Filing Code: SS-1278. Producer or source: Outokumpu Stainless AB, Avesta Research Centre.

scholarly journals Testing of intergranular and pitting corrosion in sensitized welded joints of austenitic stainless steel

10.30544/274 ◽  
2017 ◽  
Vol 23 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Bore V. Jegdic ◽  
Biljana Bobić ◽  
Milica Bošnjakov ◽  
Behar Alić
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Pitting Corrosion ◽  
Heat Affected Zone ◽  
Intergranular Corrosion ◽  
Chromium Concentration ◽  
Pitting Corrosion Resistance

Pitting corrosion resistance and intergranular corrosion of the austenitic stainless steel X5Cr Ni18-10 were tested on the base metal, heat affected zone and weld metal. Testing of pitting corrosion was performed by the potentiodynamic polarization method, while testing of intergranular corrosion was performed by the method of electrochemical potentiokinetic reactivation with double loop. The base metal was completely resistant to intergranular corrosion, while the heat affected zone showed a slight susceptibility to intergranular corrosion. Indicators of pitting corrosion resistance for the weld metal and the base metal were very similar, but their values are significantly higher than the values for the heat affected zone. This was caused by reduction of the chromium concentration in the grain boundary areas in the heat affected zone, even though the carbon content in the examined stainless steel is low (0.04 wt. % C).

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