scholarly journals Application of electrochemical methods for the investigation of intergranular corrosion welded joint austenitic stainless steel 19Cr-9Ni

2011 ◽  
Vol 65 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Bore Jegdic ◽  
Ana Alil ◽  
Zlatan Milutinovic ◽  
Zoran Odanovic ◽  
Bojan Gligorijevic ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Welded Joints ◽  
Intergranular Corrosion ◽  
Significant Degree ◽  
Electrochemical Methods ◽  
Double Loop ◽  
Quantitative Evidence ◽  
Degree Of Sensitization ◽  
Electrochemical Potentiokinetic Reactivation

Sensitization degree of the austenitic stainless steel welded joints was investigated by electrochemical methods of the double loop electrochemical potentiokinetic reactivation (DL EPR) in H2SO4 + KSCN solution, and by the measurement of corrosion potential of the steel in the drop of the solution of HNO3 + FeCl3 + HCl. The welded joints were tested by X-ray radiographic method in order to check the presence of the weld defects. Grain size of the base metal and the welded joints were determined by optical microscopy. Good agreement between the results obtained by different electrochemical methods was obtained. Heat-affected zone (HAZ) of the austenitic stainless steel welded joints has shown significant degree of sensitization. The double loop electrochemical potentiokinetic method gave quantitative evidence about susceptibility of the stainless steel to intergranular corrosion.

Evaluation of the Susceptibility to Intergranular Corrosion for a Novel Cr-Mn-N Austenitic Stainless Steel Using DL-EPR

2013 ◽  
Vol 631-632 ◽  
pp. 192-197
Author(s):  
Lei Gang Zheng ◽  
Xiao Qiang Hu ◽  
Xiu Hong Kang ◽  
Dian Zhong Li
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Electrolyte Solution ◽  
Intergranular Corrosion ◽  
Xrd Analysis ◽  
Double Loop ◽  
Chromium Depletion ◽  
Electrochemical Potentiokinetic Reactivation ◽  
Epr Test ◽  
Optical Micrographs

The sensitization and intergranular corrosion (IGC) behavior of a novel Cr-Mn-N austenitic stainless steel (named as MPMD133) sensitized in the temperature range from 600 oC to 1000oC for 3 hours was investigated by the double loop electrochemical potentiokinetic reactivation (DL-EPR) test. The effects of the sensitization temperature on the susceptibility to IGC of MPMD133 were examined in the 0.5M H2SO4 +0.01M KSCN electrolyte solution. The results show that the degree of IGC increases as the sensitization temperature increasing till 900oC. Meanwhile it decreases rapidly when the sensitization temperature is elevated up to 1000oC, which is confirmed by the subsequent optical micrographs observation. The XRD analysis reveals that the precipitation of Cr23C6 leads to chromium depletion along the grain boundaries, consequently results in the susceptibility to IGC.

scholarly journals On the Role of Grain Size and Carbon Content on the Sensitization and Desensitization Behavior of 301 Austenitic Stainless Steel

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1193 ◽  
Author(s):  
Kolli ◽  
Javaheri ◽  
Kömi ◽  
Porter
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Grain Boundary ◽  
Carbon Content ◽  
Double Loop ◽  
Boundary Carbide ◽  
Self Healing ◽  
Chromium Depletion ◽  
Electrochemical Potentiokinetic Reactivation

The effect of grain size in the range 72 to 190 μm and carbon content in the range 0.105–0.073 wt.% on the intergranular corrosion of the austenitic stainless steel 301 has been investigated. Grain boundary chromium depletion has been studied directly using energy dispersive X-ray spectroscopy combined with scanning transmission electron microscopy and indirectly using double loop electrochemical potentiokinetic reactivation tests. In addition, chromium depletion has been modelled using the CALPHAD Thermo-Calc software TC-DICTRA. It is shown that the degree of sensitization measured using the double loop electrochemical potentiokinetic reactivation tests can be successfully predicted with the aid of a depletion parameter based on the modelled chromium depletion profiles for heat treatment times covering both the sensitization and de-sensitization or self-healing. Additionally, along with intergranular M23C6 carbides, intragranular M23C6 and Cr2N nitrides that affect the available Cr for grain boundary carbide precipitation were also observed.

scholarly journals Determination of Susceptibility to Intergranular Corrosion of UNS 31803 Type Duplex Stainless Steel by Electrochemical Reactivation Method: A Comparative Study

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Mehmet Emin Arıkan ◽  
Rafet Arıkan ◽  
Mustafa Doruk
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Intergranular Corrosion ◽  
Intermetallic Phases ◽  
Double Loop ◽  
Degree Of Sensitization ◽  
Hot Rolled ◽  
Standard Weight

In the present study as in our previous studies (Arikan and Doruk, 2008 and Arikan et al., 2012), similar specimens taken from a hot rolled cylindrical duplex stainless steel (DSS) bar with 22% Cr grade were solution annealed at 1050°C and then aged at 800∘C from 100 to 31622 min for sensitization treatment. Double loop electrochemical potentiodynamic reactivation and standard weight loss immersion acid tests were conducted. The solution annealed samples were found unsensitized. The samples aged for 100 min were less sensitized whereas samples aged for 316 min and more time were sensitized. The degree of sensitization (DOS) can be attributed to higher contribution of chromium and molybdenum depleted areas that result from intermetallic phases. However, especially the samples aged from 3162 to 31622 min have revealed chromium replenishment. Consequently, the degree of sensitization was lowered in comparison to the results obtained in previous studies.

scholarly journals Determination of Susceptibility to Intergranular Corrosion of UNS 31803 Type Duplex Stainless Steel by Electrochemical Reactivation Method

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Mehmet Emin Arıkan ◽  
Rafet Arıkan ◽  
Mustafa Doruk
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Intergranular Corrosion ◽  
Intermetallic Phases ◽  
Double Loop ◽  
Degree Of Sensitization ◽  
Hot Rolled ◽  
Standard Weight

Specimens taken from a hot-rolled cylindrical duplex stainless steel (DSS) bar with 22% Cr grade were solution annealed at1050∘C and then aged at725∘C from 100 to 31622 min for sensitization treatment. Double loop electrochemical potentiodynamic reactivation and standard weight loss immersion acid tests were conducted. The solution-annealed samples were found unsensitized. Those samples aged for 100 and 316 min were less sensitized whereas samples aged for 1000 min and especially those aged for 3162, 10000, and 31622 min were heavily sensitized. The degree of sensitization (DOS) can be attributed to higher contribution of chromium- and molybdenum-depleted areas resulting from intermetallic phases.

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