scholarly journals CHARACTERIZATION OF CHROMIUM NITRIDE PRECIPITATION IN THE HEAT AFFECTED ZONE OF THE SUPERDUPLEX STAINLESS STEEL UNS S32750: AN EXPERIMENTAL AND NUMERICAL ANALYSIS

2021 ◽  
Vol 27 (2) ◽  
pp. 57-62
Author(s):  
PAOLO FERRO ◽  
Alberto Fabrizi ◽  
Franco Bonollo ◽  
Jan-Olof Nilsson
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Stainless Steels ◽  
Heat Affected Zone ◽  
Chromium Nitride ◽  
Chromium Nitrides ◽  
Pitting Corrosion Resistance ◽  
Superduplex Stainless Steel ◽  
Nitride Precipitation

It is well known that pitting corrosion resistance of duplex and superduplex stainless steels strongly depends on microstructural characteristics such as ferrite/austenite proportion, presence of intermetallic phases and elemental partitioning between the austenite and ferrite phases. In particular, during the welding operation, very fine chromium nitrides may precipitate within ferrite grains of the heat affected zone drastically reducing the corrosion resistance of welded joints of duplex and super duplex stainless steels. However, due to their small size and low distribution, analyzing the chemical composition and crystallography of chromium nitrides is quite difficult and only a restricted number of advanced techniques of investigation may discriminate their signal from the surrounding matrix. This work is aimed at supporting the microstructural characterization of a welded joint of a superduplex stainless steel by means of a field-emission gun scanning electron microscope. Sub-micron chromium nitride precipitates, identified within the ferritic grains of the heat affected zone, are recognized to be the main reason for the reduced pitting corrosion resistance of the analyzed welded joints. The results are supported by a multi-pass welding process numerical simulation aimed at estimating the cooling rates promoting chromium nitride precipitation in the heat affected zone. 

Effect of Rare Earth on the Inclusions and Pitting Resistance of Ferrite Stainless Steel

2012 ◽  
Vol 531 ◽  
pp. 47-50
Author(s):  
Xiao Liu ◽  
Jian She Li
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Anodic Polarization ◽  
Electrochemical Methods ◽  
Polarization Curves ◽  
Metallographic Examination ◽  
Pitting Corrosion Resistance

The anodic polarization curves of 430 ferrite 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 430 ferrite 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 430 ferrite 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 430 ferrite stainless steels.

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.

The Effect of Alloying Cu on Pitting Corrosion Resistance of Copper-Bearing Ferritic Stainless Steel

2008 ◽  
Vol 569 ◽  
pp. 197-200 ◽  
Author(s):  
Wei Zhang ◽  
De Ning Zou ◽  
Hong Hong Yao ◽  
Jun Yang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Antibacterial Properties ◽  
Ferrite Matrix ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Pitting Corrosion Resistance ◽  
Effect Of Alloying

Copper is a well-known alloying element which is used to improve the resistance to general corrosion of stainless steels. Our previous experiments show that the increase of copper content can acquire the excellent antibacterial properties and can also increase the tendency to cold formability of the ferritic stainless steels. However, the effect of alloying Cu on the resistance to localized corrosion has not been clarified sufficiently. In order to understand the effect of copper on pitting corrosion resistance of the ferritic antibacterial stainless steel, the electrochemical experiments were carried out and the anodic polarization curves were performed in 3.5% NaCl solution for two kinds of steels. The results reveal that the ε-Cu phase in ferrite matrix diminishes pitting corrosion resistance of the antibacterial stainless steel in the chlorides medium. It is connected with the poor passive behavior of the ε-Cu phase inclusions.

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).

scholarly journals Chromium Nitride Precipitation Behavior in Weld Heat-affected Zone of High Nitrogen Stainless Steel.

2002 ◽  
Vol 42 (12) ◽  
pp. 1391-1398 ◽  
Author(s):  
Makoto Ogawa ◽  
Kazuo Hiraoka ◽  
Yasuyuki Katada ◽  
Masayuki Sagara ◽  
Susumu Tsukamoto
Keyword(s):  
Stainless Steel ◽  
Heat Affected Zone ◽  
Chromium Nitride ◽  
Precipitation Behavior ◽  
High Nitrogen ◽  
High Nitrogen Stainless Steel ◽  
Nitride Precipitation ◽  
Weld Heat

ATI 436S Alloy

Alloy Digest ◽  
2013 ◽  
Vol 62 (3) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Heat Treating ◽  
Ferritic Stainless Steels ◽  
Pitting Corrosion Resistance ◽  
Forming Characteristics

Abstract ATI 436S is a ferritic stainless steel stabilized with titanium. It is superior to ATI Type 409 and 430 in general and pitting corrosion resistance. The ATI 436S alloy exhibits machining, welding, and forming characteristics similar to those of other stabilized, ferritic stainless steels. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1139. Producer or source: Allegheny Ludlum.

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