scholarly journals Influence of Nitrogen Content on the Corrosion Behavior of Powder Metallurgy Nickel-Free Austenitic Stainless Steel

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Weili Yu ◽  
Changhai Du ◽  
Hongren Shen ◽  
Hao He ◽  
Yong Yu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Powder Metallurgy ◽  
Austenitic Stainless Steel ◽  
Corrosion Current ◽  
N Content ◽  
Potentiodynamic Polarization Curves ◽  
Immersion Corrosion ◽  
Size Number ◽  
Current Densities ◽  
Corrosion Pits

Herein, powder metallurgy gas-solid nitriding was used to prepare a high-nitrogen Ni-free austenitic stainless steel with more than 1.0 wt.% N. Study of the microstructures and corrosion resistances of the as-prepared samples revealed that the corrosion weight loss, size, number of corrosion pits, and corrosion depth decreased as the N content increased from 1.19 to 1.37 wt.%. The self-corrosion current densities of the alloys were determined from their potentiodynamic polarization curves. The changes in the capacitive arc radius as demonstrated by the Nyquist curves were consistent with the conclusions of the immersion corrosion analysis; that is, a high N content leads to a high corrosion resistance.

scholarly journals Pitting Corrosion Behavior and Surface Microstructure of Copper Strips When Rolled with Oil-in-Water Emulsions

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7911
Author(s):  
Xudong Yan ◽  
Jianlin Sun
Keyword(s):  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Surface Defects ◽  
Interactive Effect ◽  
Rolling Direction ◽  
Corrosion Current ◽  
Surface Microstructure ◽  
Oil In Water ◽  
Current Densities ◽  
Corrosion Pits

Copper strips experience severe corrosion when rolled with an oil-in-water (O/W) emulsions lubricant. The effects of rolling reduction on the pitting corrosion behavior and surface microstructure of Cu strips were studied in detail using electrochemical measurements and electron back scattered diffraction (EBSD) analysis. It was found that the corrosion current densities of the rolled Cu strips increased with accumulated reduction, which also lowered the pitting potentials and weakened their corrosion resistances. Therefore, the corrosive tendency of Cu strips under different rolling reductions (ε) followed the order of ε0% < ε20.7% < ε50.6% < ε77.3%. The Cu surface easily reacted with chlorine, sulfur, and carbon components from O/W emulsions to generate pitting corrosion. Under the interactive effect of pitting corrosion and stress corrosion, pits expanded along the rolling direction. The aggregation of anions in surface defects, such as dislocations, metastable pits, and microcracks, further accelerated the pitting corrosion of the surface.

ATI 304B7 P/M

Alloy Digest ◽  
2015 ◽  
Vol 64 (8) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Austenitic Stainless Steel ◽  
Heat Treating ◽  
Boron Addition ◽  
Neutron Absorption ◽  
Bend Strength ◽  
Powder Metal ◽  
Type 304

Abstract ATI 304B7 P/M is a borated austenitic stainless steel of the type 304 base. Boron addition is accomplished through powder metallurgy. The uniform, fine dispersion of boron containing particles resulting from the P/M process imparts superior neutron absorption and enhanced toughness and ductility. This datasheet provides information on composition, physical properties, elasticity, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, joining, and powder metal forms. Filing Code: SS-1222. Producer or source: Allegheny Technologies Company.

Corrosion Behavior of Ceramic Dispersion Strengthened High-Cr Stainless Steel

2008 ◽  
Vol 135 ◽  
pp. 127-130
Author(s):  
Gyoung Ja Lee ◽  
Sang Hoon Lee ◽  
Sung Mo Hong ◽  
Byung Sun Han ◽  
Jin Ju Park ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Potentiodynamic Polarization ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
High Energy ◽  
Polarization Curves ◽  
Pitting Potential ◽  
Potentiodynamic Polarization Curves ◽  
High Energy Ball Mill ◽  
Energy Ball

In the present work, corrosion characteristics of ceramic dispersion strengthened (CDS) high-Cr stainless steel (SS) has been investigated. For the preparation of CDS SS with uniformly distributed reinforcements, TiC particles were mechanically activated with Cu powder by using high-energy ball mill machine, and then Cu-coated TiC particles were mixed with molten SS. Potentiodynamic polarization curves were experimentally measured on unmodified SS and CDS SS in 0.05 M NaCl solution. The values of corrosion potential Ecorr, corrosion current io, pitting potential Epit and polarization resistance Rp were quantitatively determined from the measured potentiodynamic polarization curves. From the result, it is concluded that CDS SS exhibits higher corrosion resistivity than unmodified SS.

scholarly journals Electrochemical behavior of two austenitic stainless steel biomaterials

2010 ◽  
Vol 63 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Enrico J. Giordano ◽  
Neusa Alonso-Falleiros ◽  
Itamar Ferreira ◽  
Oscar Balancin
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Passive Film ◽  
Scratch Test ◽  
Localized Corrosion ◽  
Cyclic Polarization ◽  
High Tendency ◽  
Pitting Potential ◽  
Stable Growth ◽  
Corrosion Pits

Potentiodynamic and potentiostatic polarization measurements were conducted in 0.9% NaCl solution to investigate the localized corrosion susceptibility of two austenitic stainless steel biomaterials: a low nitrogen, according to ASTM F 138 - the metallic material most widely utilized today in orthopedic applications; and a nitrogen- and niobium-bearing stainless steel, according to ISO 5832-9, which has shown a promising potential as a substitute of the F 138 steel for more severe loading applications and longer times inside the human body. The polarization tests revealed that the ISO 5832-9 steel is more corrosion resistant than the F 138. The critical pitting potential of the ISO 5832-9 steel could not be observed in the cyclic polarization curve up to the value of potential corresponding to its transpassivity. The potentiostatic scratch test confirmed the superiority of the ISO 5832-9 steel, which heal the mechanically damaged passive film at applied potential as high as 800 mV (SCE). Scanning electron microscopy (SEM) examination confirmed the presence of corrosion pits - lacelike pits - in a stable growth stage on the surface of F 138 steel and the absence of such pits in the specimens of the ISO 5832-9 steel. The higher corrosion resistance of the latter is attributed to the increased stability of the passive film and the high tendency to repassivate, which, in turn, is favored by the presence of nitrogen in interstitial solid solution in the austenite of this type of steel.

scholarly journals Strain-induced reactivation of corrosion pits in austenitic stainless steel

2017 ◽  
Vol 125 ◽  
pp. 12-19 ◽  
Author(s):  
F.A. Almuaili ◽  
S.A. McDonald ◽  
P.J. Withers ◽  
A.B. Cook ◽  
D.L. Engelberg
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Corrosion Pits
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