A Modified Double Loop EPR Technique for Detection of Sensitization in Cast Stainless Steel

Reichert, David L.; Stoner, G. E.

doi:10.1149/1.2086454

Cited by 27 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The scan potential was loaded from the open circuit potential to relative potential +300 mV SCE , with scan rate of 100 mV min −1 , then return to open circuit potential with the same scan rate, to measure the activation current density peak (maximum current density in the anodic scan, I a ) and the reactivation current density peak (maximum current density in the cathodic scan, I r ). The DOS was calculated using the ratio the two current densities as below:

DOS false(%) = \frac{I_{r}}{I_{a}} \times 100 %

…”

Section: Methodsmentioning

confidence: 99%

“…There are several methods to evaluate the degree of sensitization (DOS) to IGC of stainless steels. Double loop electrochemical potentiokinetic reactivation (DL‐EPR) technique has been successfully employed on AISI 304(L), 316(L), 321, and 403 SS . The DL‐EPR technique is based on the fact that when a sensitized specimen is kept at passive potential, the passive film formed on the Cr‐depleted region along the grain boundaries is defective compared to that formed on the grain interior.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Aging Precipitation Behavior of 316LN + Nb SS at 750 °C and Its Influences on Intergranular Corrosion Resistance

Peng

Zhou

Ye³

et al. 2018

steel research int.

View full text Add to dashboard Cite

The precipitation behavior of Nb-containing 316LN stainless steel with different aging time at 750 C are investigated by scanning electron microscope and transmission electron microscope. The degree of sensitization (DOS) of aged Nb-containing 316LN SS to intergranular corrosion (IGC) are determined by double loop electrochemical potentiodynamic reactivation (DL-EPR) technique. The precipitation sequence and the preferred nucleation sites for secondary precipitates (Z-phase, χ-phase, η-phase, σ-phase, M 23 C 6 ) are summarized. Z-phase is the priority phase in Nb-containing 316LN SS, and it precipitates uniformly in austenite matrix. Therefore, Z-phase has no observable effect on IGC due to the absence of Cr-depleted regions along grain boundaries. With Nb element addition, the precipitates of χ-phase, ηphase, and σ-phase are accelerated, while M 23 C 6 incubation time is significantly delayed relative to Nb free SS. The DOS increases considerably with increasing aging time and no self-healing process be observed even after aging for 1000 h, which is well consistent with the increase trend of precipitates.

show abstract

DOS false(%) = \frac{I_{r}}{I_{a}} \times 100 %

…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Aging Precipitation Behavior of 316LN + Nb SS at 750 °C and Its Influences on Intergranular Corrosion Resistance

Peng

Zhou

Ye³

et al. 2018

steel research int.

View full text Add to dashboard Cite

show abstract

“…The peak current density during reactivation can be used as a measure of the DOS as shown in Figure 17. Reichert and Stoner (1990) have developed a modified DL-EPR technique to be used for cast stainless steel. Figure 17 Schematic diagram of the simplified EPR test for AISI type 304 SS and 304L SS (Majidi & Streicher, 1986).…”

Section: Simplified Epr Techniquementioning

confidence: 99%

Electrochemical techniques for estimating the degree of sensitization in austenitic stainless steels

Parvathavarthini

Mudali

2014

Corrosion Reviews

View full text Add to dashboard Cite

The thermal exposure of austenitic stainless steels in the temperature range of 500°C-800°C results in the precipitation of chromium-rich M 23 C 6 carbides along the grain boundaries and concomitant chromium depletion. When chromium level falls below 12% at such depleted zones, the material is said to be sensitized. When the sensitized material is exposed to corrosive media, intergranular corrosion (IGC) and intergranular stress corrosion cracking take place. ASTM standard A262-13 is available for detecting the susceptibility to IGC. However, the extent of chromium depletion of shop-fabricated or field-constructed components is required to determine the presence or absence of sensitization for critical applications. In this review, various electrochemical techniques that can be employed to assess the degree of sensitization (DOS) in austenitic stainless steels are critically reviewed. Techniques such as electrochemical potentiokinetic and potentiostatic reactivation with recent modifications for the accurate estimation of the DOS are analyzed. The possibility of using AC impedance technique and electrochemical noise technique for assessing the DOS is also presented. The merits and demerits of each technique and areas where further research should be focused are presented in this review.

show abstract

“…Reichert and Stoner 50 have developed a modified double loop EPR technique to be used for cast stainless steel. They have suggested that there should be a significant increase in the I r /I a value corresponding to the increase in DOS.…”

Section: Electrochemical and Ndt Techniquesmentioning

confidence: 99%

Influence of metallurgical variables on sensitisation kinetics in austenitic stainless steels

Dayal¹,

Parvathavarthini²,

Raj³

2005

International Materials Reviews

View full text Add to dashboard Cite

Austenitic stainless steels are the most favoured construction materials for various components required in chemical, petrochemical, fertiliser and nuclear industries. However, these steels are prone to sensitisation. In the sensitised condition, the steels are quite susceptible to intergranular corrosion and intergranular stress corrosion cracking in chloride and caustic environments resulting in the premature failure of the fabricated components during precommissioning and service periods. The topic of sensitisation has been of interest in studies worldwide. The studies included mechanism of sensitisation, test methods, data generation, and influence of several variables and protection methods. This article covers a review of important contributions to this topic with special emphasis on the influence of metallurgical variables. The present state of understanding is discussed in the following areas: mechanisms, test methods, sensitisation diagrams, influence of chemical composition, cold work and grain size, low temperature sensitisation, modelling and laser surface treatment. The need for further investigation in certain areas is highlighted.

show abstract

A Modified Double Loop EPR Technique for Detection of Sensitization in Cast Stainless Steel

Cited by 27 publications

References 0 publications

Aging Precipitation Behavior of 316LN + Nb SS at 750 °C and Its Influences on Intergranular Corrosion Resistance

Aging Precipitation Behavior of 316LN + Nb SS at 750 °C and Its Influences on Intergranular Corrosion Resistance

Electrochemical techniques for estimating the degree of sensitization in austenitic stainless steels

Influence of metallurgical variables on sensitisation kinetics in austenitic stainless steels

Contact Info

Product

Resources

About