Influences of Mo substitution by W on the precipitation kinetics of secondary phases and the associated localized corrosion and embrittlement in 29% Cr ferritic stainless steels

2006 ◽  
Vol 418 (1-2) ◽  
pp. 211-217 ◽  
Author(s):  
Chan-Jin Park ◽  
Myung-Kyu Ahn ◽  
Hyuk-Sang Kwon
Keyword(s):  
Stainless Steels ◽  
Localized Corrosion ◽  
Secondary Phases ◽  
Precipitation Kinetics ◽  
Ferritic Stainless Steels ◽  
Kinetics Of

Corrosion Evaluation of Ferritic Stainless Steels for Automotive Exhaust Applications

CORROSION ◽  
10.5006/3319 ◽  
2019 ◽  
Vol 75 (11) ◽  
pp. 1276-1280
Author(s):  
Y. Emun ◽  
H.S. Zurob ◽  
J.R. Kish
Keyword(s):  
Stainless Steels ◽  
Localized Corrosion ◽  
Bench Mark ◽  
Neutral Salt ◽  
Automotive Exhaust ◽  
Metallographic Examination ◽  
Ferritic Stainless Steels ◽  
Corrosion Evaluation ◽  
Corrosion Susceptibility ◽  
Salt Fog

This study compares the localized (exterior) corrosion susceptibility of chromized steel to bench-mark ferritic stainless steels for automotive exhaust applications. Continuous near-neutral salt fog exposure (ASTM B117) was used for this purpose. Corrosion susceptibility was determined using mass loss measurements coupled with a post exposure metallographic examination. Complementary potentiodynamic polarization measurements were made in the bulk salt solution to help interpret the relative performance. The elevated Cr content provided by the chromizing surface treatment provides comparable corrosion resistance to the more highly alloyed ferritic stainless steels studied. The major factor affecting localized corrosion susceptibility is the formation of rust deposits, which act as effective pit-like corrosion initiation sites.

Effect of Humidity on the Corrosion Kinetics of Ferritic Stainless Steels Subjected to Synthetic Biogas

2011 ◽  
Vol 696 ◽  
pp. 417-422 ◽  
Author(s):  
Piyorose Promdirek ◽  
Gobboon Lothongkum ◽  
Yves Wouters ◽  
Somrerk Chandra-ambhorn ◽  
Alain Galerie
Keyword(s):  
Partial Pressure ◽  
Stainless Steels ◽  
Carbide Formation ◽  
Partial Pressure Of Oxygen ◽  
Weight Changes ◽  
Fuel Gas ◽  
Ferritic Stainless Steels ◽  
Corrosion Kinetics ◽  
The Stability ◽  
Kinetics Of

Ferritic stainless steels have nowadays been used as materials for interconnectors in solid oxide fuel cells (SOFCs) at intermediate temperatures (800°C). Their degradation in contact with dry synthetic biogas used instead of other fuel gas has already been studied. In such biogas atmosphere, humidity may play an important role. The objective of this study is therefore to understand the effect of H2O on the corrosion kinetics of the ferritic stainless steels type AISI441 (18CrTiNb) under synthetic biogas (70%CH4and 30%CO2) mixed with 3%H2O. The thermodynamic analysis by FactSage was used to determine the partial pressure of oxygen and the activity of carbon in the humid biogas. The results showed that the partial pressure of oxygen is in the range 10–24.8to 10–21.2bar for temperatures between 600-800°C and that the formation of solid carbon can occur in these conditions. This was not different compared with the conditions in dry biogas. These conditions lead to the stability of some important oxides such as Cr2O3and Cr-Mn spinel and to carbon deposition and/or carbide formation. The surface morphology of 441 subjected to humid biogas showed oxide scale composed mainly of Cr2O3topped with Cr-Mn spinel. Some carbide such as Cr7C3was found in chromia scale. Kinetic experiments under both dry and humid biogas at temperatures between 600 and 800°C showed linear weight changes. Arrhenius law was followed and the rate-determining steps were identified as parallel oxidation and carburization limited by oxide-gas interface reactions.

Initiation of Localized Corrosion of Ferritic Stainless Steels by Using the Liquid-Phase Ion Gun Technique

2016 ◽  
Vol 164 (2) ◽  
pp. C1-C7 ◽  
Author(s):  
Jun-Seob Lee ◽  
Takashi Kawano ◽  
Tomohiro Ishii ◽  
Yuichi Kitagawa ◽  
Takayuki Nakanishi ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Stainless Steels ◽  
Localized Corrosion ◽  
Ferritic Stainless Steels

scholarly journals Influence of Nb stabilization on the recovery and recrystallization kinetics of a ferritic stainless steel with soft magnetic properties for automotive applications

2013 ◽  
Vol 66 (2) ◽  
pp. 159-163
Author(s):  
Nicolas Meyer ◽  
Marc Mantel ◽  
P.E. Dubois ◽  
Muriel Veron ◽  
Yves Brechet ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Stainless Steels ◽  
Fuel Injection ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Ferritic Stainless Steels ◽  
Engine Efficiency ◽  
Deformed State ◽  
Kinetics Of ◽  
Interesting Solution

Usually niobium is added in ferritic stainless steels to avoid chromium carbides precipitation and then to improve corrosion resistance and to avoid embrittlemet. This study shows that a low Nb stabilization makes recrystallization nucleation much faster and prevents incomplete recrystallization. A qualitative interpretation, based on interaction with precipitates, is proposed and explains the main features of the softening kinetics as well as the microstructures obtained. Above a specific magnetizing frequency, the deformed state led to smaller losses than the recrystallized state. These results are believed to be attributed to a grain size effect. This leads to soft magnetic properties that makes 17%CrNb ferritic stainless steels a very interesting solution for the market of electromagnetic injection. Improving response-time of fuel injection valves is a great challenge for automotive industry in order to enhance car engine efficiency and to limit noxious gas emission.

scholarly journals Data on the Corrosion Resistance and Polarization Behaviour of Lean Austenitic and Ferritic Stainless Steels in Neutral Chloride Media

2019 ◽  
Vol 35 (3) ◽  
pp. 1138-1142
Author(s):  
Roland Tolulope Loto
Keyword(s):  
Corrosion Resistance ◽  
Stainless Steels ◽  
Microscopic Analysis ◽  
Localized Corrosion ◽  
Ferritic Stainless Steels ◽  
Anodic Passivation ◽  
Chloride Attack ◽  
316L Steel ◽  
Polarization Behaviour ◽  
Corrosion Pits

Stainless steels are extensively applied in diverse industries due to their exceptional corrosion resistance. The corrosion resistance of alloy stainless steels (316L austenitic and 430Ti ferritic stainless steel) was studied in neutral chloride solutions with chloride concentrations of 1%, 2%, 3%, 4%, 5% and 6%. Their general and localized corrosion resistance were compared and discussed in addition to their passivation characteristics. Corrosion rate results obtained showed 430Ti exhibited slightly greater general resistance to chloride attack compared to 316L. Further investigation showed 316L steel exhibited higher resistance to localized corrosion attack to its resilient passive film. 430Ti exhibited cathodic and anodic passivation compared to 316L which only exhibited anodic passivation. Optical microscopic analysis showed the presence of small, superficial corrosion pits on 316L steel compared to 430Ti, which exhibited deep corrosion pits.

scholarly journals Precipitation kinetics of Cu-rich particles in super duplex stainless steels

2021 ◽  
Author(s):  
Vahid A. Hosseini ◽  
Kjell Hurtig ◽  
Daniel Gonzalez ◽  
James Oliver ◽  
Nicklas Folkeson ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Duplex Stainless Steels ◽  
Precipitation Kinetics ◽  
Super Duplex Stainless Steels ◽  
Kinetics Of

scholarly journals Corrosion Susceptibility and Allergy Potential of Austenitic Stainless Steels

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4187
Author(s):  
Lucien Reclaru ◽  
Lavinia Cosmina Ardelean
Keyword(s):  
Stainless Steels ◽  
Raw Materials ◽  
Austenitic Stainless Steels ◽  
Steel Structure ◽  
Austenitic Steels ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Secondary Phases ◽  
Chemical Test ◽  
Nickel Release

Although called stainless steels, austenitic steels are sensitive to localized corrosion, namely pitting, crevice, and intergranular form. Seventeen grades of steel were tested for localized corrosion. Steels were also tested in general corrosion and in galvanic couplings (steels–precious alloys) used in watchmaking applications. The evaluations have been carried out in accordance with the ASTM standards which specifically concern the forms of corrosion namely, general (B117-97, salt fog test), pitting (G48-11, FeCl3), crevice (F746-87) and intergranular (A262-15, Strauss chemical test and G108-94, Electrochemical potentiodynamic reactivation test). All tests revealed sensitivity to corrosion. We have noticed that the transverse face is clearly more sensitive than the longitudinal face, in the direction of rolling process. The same conclusion has been drawn from the tests of nickel release. It should be pointed out that, despite the fact that the grade of steel is in conformity with the classification standards, the behavior is very different from one manufacturer to another, due to parameters dependent on the production process, such as casting volume, alloying additions, and deoxidizing agents. The quantities of nickel released are related to the operations involved in the manufacturing process. Heat treatments reduce the quantities of nickel released. The surface state has little influence on the release. The hardening procedures increase the quantities of nickel released. The quantities of released nickel are influenced by the inclusionary state and the existence of the secondary phases in the steel structure. Another aspect is related to the strong dispersion of results concerning nickel release and corrosion behavior of raw materials.

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