Comparative Methods for Measuring Degree of Sensitization in Stainless Steel

2009 ◽  
pp. 99-99-34 ◽  
Author(s):  
WL Clarke ◽  
RL Cowan ◽  
WL Walker
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sourabh Shukla ◽  
Awanikumar P. Patil ◽  
Ashlesha Kawale ◽  
Anand Babu Kotta ◽  
Inayat Ullah

Purpose Effect of grain size on degree of sensitization (DOS) was been evaluated in Nickel free steel. Manganese and nitrogen contained alloy is a Ni-free austenitic stainless steels (ASS) having type 202 grade. The main purpose of this investigation is to find the effect of recrystallization on the DOS of stainless steel after the thermo-mechanical processing (cold work and thermal aging). Design/methodology/approach In the present investigation, the deformation of 202 grade analyzed using X-ray diffraction (XRD) and microstructural testing. Optical microstructure of Ni-free ASS has been done for cold worked samples with thermally aged at 900°C_6 h. Double loop electrochemical potentiodynamic reactivation test used for findings of degree of sensitization. Findings Ni-free ASS appears to be deformed more rapidly due to its higher stacking fault energy which gave results in rapid transformation from strain induced martensite to austenite in form of recrystallized grains, i.e. it concluded that as cold work percentage increases more rapidly recrystallization occurs. XRD results also indicate that more fraction of martensite formed as percentage of CW increases but as thermal aging reverted those all martensite to austenite. So investigation gives the conclusion which suggests that with high deformation at higher temperature and duration gives very less DOS. Originality/value Various literatures available for 300 series steel related to the effect of cold work on mechanical properties and sensitization mechanism. However, no one has investigated the effect of recrystallization through thermomechanical processing on the sensitization of nickel-free steel.


2020 ◽  
Vol 173 ◽  
pp. 108742
Author(s):  
Yeganeh Kelidari ◽  
Mehrdad Kashefi ◽  
Mostafa Mirjalili ◽  
Mahla Seyedi ◽  
Thomas W. Krause

2013 ◽  
Vol 856 ◽  
pp. 60-63
Author(s):  
M. Milad ◽  
N. Zreiba

The sensitization of stainless steel type AISI304 (304SS) is evaluated as a function of pre-welding cold work and welding heat input. 304SS is cold rolled to various percentages of thickness reduction of up to 50% at ambient temperature before being TIG welded. The susceptibility of 304SS to sensitization (weld decay) is evaluated using ASTM A262, practice A and electrochemical potentiokinetic reactivation tests. The results indicate that the influence of pre-welding cold work on the degree of sensitization (DOS) is distinct and appreciable within the range of 10% to 35% CR. In addition, within this range the optimum level of cold work after which the DOS starts to decrease is found to be inversely related to the amount of welding heat input. At higher levels of cold work of ≥ 35% CR, it is found that neither the cold work nor the heat input significantly influences the amount of DOS. Microstructural investigation showed that the predominant intergranular corrosion (IGC) occurs at austenite grain boundaries and less likely at ferrite / austenite interfaces of the weld metal. Meanwhile, transgranular attack at austenite bulk matrix along the defects is rarely observed.


2006 ◽  
Vol 41 (8) ◽  
pp. 2381-2386 ◽  
Author(s):  
Regina Célia de Sousa ◽  
José Carlos Cardoso Filho ◽  
Auro Atsushi Tanaka ◽  
Ayana Cristina S. de Oliveira ◽  
Wilman Eduardo Italiano Ferreira

CORROSION ◽  
10.5006/2612 ◽  
2017 ◽  
Vol 74 (3) ◽  
pp. 350-361 ◽  
Author(s):  
K. Ravindranath ◽  
N. Tanoli ◽  
B. Al-Wakaa

The paper presents the results of a study conducted on the effects of long-term service exposure of Type 347 stainless steel (SS) on the microstructure and corrosion susceptibility. The material subjected to the study was in service in a petroleum refinery as heater tube at 620°C for 31 years. The microscopic and x-ray diffraction studies of the service-exposed specimen revealed the precipitation of chromium-rich carbides along the grain boundaries. The microstructural changes that occurred as a result of service exposure affected the ductility and toughness of the alloy. The sensitization of the alloy was assessed by scanning electron microscopy and double loop electrochemical potentiodynamic reactivation. The studies have indicated some degree of sensitization in the alloy. The service exposure resulted in a marginal increase in the susceptibility of Type 347 SS to pitting in environments containing NaCl and NaCl + H2S. Environments such as H2SO4 and K2S4O6 at the tested concentrations did not differentiate between service-exposed and solution annealed specimens for their corrosion susceptibility. Slow strain rate testing of Type 347 SS in both the service-exposed and solution annealed conditions showed susceptibility to stress corrosion cracking in environment containing NaCl + H2S, while the alloy did not show susceptibility to SCC in H2SO4 and K2S4O6. The long-term service exposure did not noticeably influence the SCC susceptibility of Type 347 SS under the tested conditions.


2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Mehmet Emin Arıkan ◽  
Rafet Arıkan ◽  
Mustafa Doruk

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.


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