Effect of Temperature and Chloride Content on the Stress Corrosion Cracking Susceptibility of 304 Stainless Steel Welded Joints Treated by Ultrasonic Impact Treatment

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Gang Ma ◽  
Xiang Ling
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Welded Joints ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Chloride Ion ◽  
Chloride Content ◽  
304 Stainless Steel ◽  
Effect Of Temperature ◽  
Ultrasonic Impact Treatment

Effect of temperature and chloride content on the stress corrosion cracking (SCC) susceptibility of 304 stainless steel welded joints treated by ultrasonic impact treatment (UIT) is investigated in this study. High tensile weld residual stress is an important factor contributing to SCC. UIT can produce compressive stresses on the surface of welded joints that negate the tensile stresses to enhance the SCC resistance of welded joints. In the SCC testing, the specimens were immersed in sodium chloride solution at the temperatures of 200 °C–280 °C in the range of sodium chloride solution from 50 g/L to 200 g/L. During the testing, treated specimens show good SCC resistance with different temperature and consistency of chloride ion. The results show that the SCC susceptibility of 304 stainless steel welded joints reduces with increase of temperature and decrease of chloride ion consistency. The surface roughness of sample after UIT was investigated by portable surface roughness tester. The results reveal that surface of the samples becomes rougher than the original plate with the increase of the impact duration, which contribute to the pitting corrosion of treated specimens. And, the level of pitting corrosion is reduced with increase of temperature.

Effect of Ultrasonic Impact Treatment on the Stress Corrosion Cracking of 304 Stainless Steel Welded Joints

2008 ◽  
Author(s):  
Gang Ma ◽  
Xiang Ling
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
304 Stainless Steel ◽  
Ultrasonic Impact Treatment

High tensile weld residual stress is an important factor contributing to stress corrosion cracking (SCC). Ultrasonic impact treatment (UIT) can produce compressive stresses on the surface of welded joints that negate the tensile stresses to enhance the SCC resistance of welded joints. In the present work, X-ray diffraction method was used to obtain the distribution of residual stress induced by UIT. The results showed that UIT could cause a large compressive residual stress up to 325.9MPa on the surface of the material. A 3D finite element model was established to simulate the UIT process by using a finite element software ABAQUS. The residual stress distribution of the AISI 304 stainless steel induced by UIT was predicted by finite element analysis. In order to demonstrate the improvement of the SCC resistance of the welded joints, the specimens were immersed in boiling 42% magnesium chloride solution during SCC testing, and untreated specimen cracked after immersion for 23 hours. In contrast, treated specimens with different coverage were tested for 1000 hours without visible stress corrosion cracks. The microstructure observation results revealed that a hardened layer was formed on the surface and the initial coarse-grained structure in the surface was refined into ultrafine grains. The above results indicate that UIT is an effective approach for protecting weldments against SCC.

Effect of Ultrasonic Impact Treatment on the Stress Corrosion Cracking of 304 Stainless Steel Welded Joints

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Xiang Ling ◽  
Gang Ma
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
304 Stainless Steel ◽  
Ultrasonic Impact Treatment

High tensile weld residual stress is an important factor contributing to stress corrosion cracking (SCC). Ultrasonic impact treatment (UIT) can produce compressive stresses on the surface of welded joints that negate the tensile stresses to enhance the SCC resistance of welded joints. In the present work, X-ray diffraction method was used to obtain the distribution of residual stress induced by UIT. The results showed that UIT could cause a large compressive residual stress in access of 300 MPa on the surface of the material. A 3D finite element model was established to simulate the UIT process by using the finite element software ABAQUS. The residual stress distribution of the AISI 304 stainless steel induced by UIT was predicted by finite element analysis. In order to demonstrate the improvement of the SCC resistance of the welded joints, the specimens were immersed in boiling 42% magnesium chloride solution during SCC testing, and untreated specimen cracked after immersion for 23 h. In contrast, treated specimens with different impact duration were tested for 1000 h without visible stress corrosion cracks. The microstructure observation results revealed that a hardened layer was formed on the surface and the initial coarse-grained structure in the surface was refined into ultrafine grains. The above results indicate that UIT is an effective approach for protecting weldments against SCC.

scholarly journals Kinetics of Pitting Dissolution of Austenitic Stainless Steel 304 in Sodium Chloride Solution

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
M. Saadawy
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Chloride Ion ◽  
Corrosion Current ◽  
Stainless Steel 304 ◽  
Kinetics Of Dissolution ◽  
Austenitic Stainless Steel 304 ◽  
Kinetics Of

The effect of addition of chloride ion on the corrosion of stainless steel 304 in Na2SO4 solution under constant ionic strength conditions at 30°C was studied using potential-time and potentiodynamic polarization techniques and it was found that the addition of chloride ion reduces the growth of protective passive film on the surface and increase corrosion current. The kinetics of dissolution in sodium chloride solution (0.05–0.5M) at 30°C was also studied and the kinetic rate equation was derived and was found to verify the following relationship: CCl− where .

Corrosion Protection of AISI 304 Stainless Steel Filters by a Surface Treatment

2005 ◽  
Vol 498-499 ◽  
pp. 93-97
Author(s):  
L. De Micheli ◽  
Isolda Costa
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Sodium Chloride ◽  
Corrosion Protection ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
304 Stainless Steel ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Protection Method

In this study a corrosion protection method was used with AISI 304 SS filters and its effect on their corrosion resistance was evaluated in a sodium chloride solution (0.5 mol/L). The corrosion resistance of the surface treated filters was investigated at increasing temperatures, from 22 oC to 100 oC. It was found that the treatment improved the corrosion resistance of the filters at all temperatures tested. The film formed was maintained on the filters surface during the whole period of test (3 weeks). Surface analysis of untreated and treated filters, after corrosion tests, supported the indication of the beneficial effect of the corrosion protection treatment evaluated in this study.

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