Search
Filters

51316-7170-Effect of Temperature on the Crevice Corrosion Resistance of Austenitic Stainless Steels

Resistance of S30400 and S31600 SSs to chloride-induced crevice corrosion was assessed in a wide range of temperatures and chloride concentrations. Repassivation potential of S30400 SS decreased with increasing chloride & temperatures from 0 to 60ºC, and it a constant value in the range from 60 to 90ºC regardless of chloride.

 

Product Number: 51316-7170-SG
ISBN: 7170 2016 CP
Author: Martin Rodriguez
Publication Date: 2016
$0.00
$20.00
$20.00

The crevice corrosion repassivation potential of austenitic 304 and 316 stainless steels was determined by the Potentiodynamic-Galvanostatic-Potentiodynamic (PD-GS-PD) method. The alloy specimens contained 24 artificially creviced spots formed by two ceramic washers (crevice formers) wrapped with a thick PTFE tape. Crevice corrosion tests were performed in 0.1 mol/L and 1 mol/L NaCl solutions at temperatures between 0 and 90ºC and in CaCl2 5 mol/L solution at temperatures between 10 and 90°C.Abundant pits in the crevice corroded regions of 304 stainless steel were observed. In 0.1 and 1 mol/L NaCl solutions pits coalescence was detected and pit diameter increased as temperature increased. In 5 mol/L CaCl2 solutions smaller pits were observed regardless the testing temperature. A lower pit density in the crevice corroded regions was found in 316 stainless steel showed when compared to 304 stainless steel. Crystalline type of attack which resembles the type of damage observed in crevice-corroded Ni-Cr-Mo alloys was observed along with pits in 316 stainless steel at temperatures below 60ºC.In the tested conditions 316 stainless steel was significantly most resistant to chloride-induced crevice corrosion than 304 stainless steel due to the 2.5% molybdenum addition. The repassivation potential decreased linearly with increasing temperatures and it showed the usual linear decrease with the logarithm of chloride concentration for the two tested steels. According to the localized acidification model there is a minimum potential value below which localized corrosion is not expected regardless the chloride concentration and temperature. These minimum potential values were established for the tested alloys based on measurements of the crevice corrosion repassivation potential and the corrosion potential in the acidified crevice-like solution. These values were -0.431±0.015 VSCE for 304 stainless steel and -0.397±0.015 VSCE for 316 stainless steel. A comparison was made of the crevice corrosion resistance of austenitic 304 and 316 stainless steels and that of the more resistant super-austenitic 254SMO and 654SMO and super-duplex 2507 stainless steels which were previously tested.

 

Keywords: downloadable, S30400, S31600, temperature, chloride, localized corrosion, Galvele

The crevice corrosion repassivation potential of austenitic 304 and 316 stainless steels was determined by the Potentiodynamic-Galvanostatic-Potentiodynamic (PD-GS-PD) method. The alloy specimens contained 24 artificially creviced spots formed by two ceramic washers (crevice formers) wrapped with a thick PTFE tape. Crevice corrosion tests were performed in 0.1 mol/L and 1 mol/L NaCl solutions at temperatures between 0 and 90ºC and in CaCl2 5 mol/L solution at temperatures between 10 and 90°C.Abundant pits in the crevice corroded regions of 304 stainless steel were observed. In 0.1 and 1 mol/L NaCl solutions pits coalescence was detected and pit diameter increased as temperature increased. In 5 mol/L CaCl2 solutions smaller pits were observed regardless the testing temperature. A lower pit density in the crevice corroded regions was found in 316 stainless steel showed when compared to 304 stainless steel. Crystalline type of attack which resembles the type of damage observed in crevice-corroded Ni-Cr-Mo alloys was observed along with pits in 316 stainless steel at temperatures below 60ºC.In the tested conditions 316 stainless steel was significantly most resistant to chloride-induced crevice corrosion than 304 stainless steel due to the 2.5% molybdenum addition. The repassivation potential decreased linearly with increasing temperatures and it showed the usual linear decrease with the logarithm of chloride concentration for the two tested steels. According to the localized acidification model there is a minimum potential value below which localized corrosion is not expected regardless the chloride concentration and temperature. These minimum potential values were established for the tested alloys based on measurements of the crevice corrosion repassivation potential and the corrosion potential in the acidified crevice-like solution. These values were -0.431±0.015 VSCE for 304 stainless steel and -0.397±0.015 VSCE for 316 stainless steel. A comparison was made of the crevice corrosion resistance of austenitic 304 and 316 stainless steels and that of the more resistant super-austenitic 254SMO and 654SMO and super-duplex 2507 stainless steels which were previously tested.

 

Keywords: downloadable, S30400, S31600, temperature, chloride, localized corrosion, Galvele

Also Purchased
Picture for Crevice Corrosion on Super Duplex—Effect of Potential on Critical Crevice Corrosion Temperature
Available for download

51313-02763-Crevice Corrosion on Super Duplex—Effect of Potential on Critical Crevice Corrosion Temperature

Product Number: 51313-02763-SG
ISBN: 02763 2013 CP
Author: Anne Britt Høydal
Publication Date: 2013
$20.00
Picture for Effect of Temperature to Crevice Corrosion of Austenitic and Duplex Stainless Steel in Deepwater
Available for download

51312-01361-Effect of Temperature to Crevice Corrosion of Austenitic and Duplex Stainless Steel in Deepwater

Product Number: 51312-01361-SG
ISBN: 01361 2012 CP
Author: Jing Wang
Publication Date: 2012
$20.00