The Relative Stress-Corrosion Susceptibility of Titanium Alloys in the Presence of Hot Salt

2009 ◽  
pp. 31-31-22
Keyword(s):  
Titanium Alloys ◽  
Stress Corrosion ◽  
Relative Stress ◽  
Corrosion Susceptibility

A New Solution Potential Measurement for Predicting Stress Corrosion Performance of 2219 Aluminum Alloy Products

CORROSION ◽  
1969 ◽  
Vol 25 (5) ◽  
pp. 199-207 ◽  
Author(s):  
R. L. HORST ◽  
E. H. HOLLINGSWORTH ◽  
W. KING
Keyword(s):  
Stress Corrosion ◽  
Chloride Solution ◽  
Corrosion Performance ◽  
Electrochemical Test ◽  
Potential Measurement ◽  
2219 Aluminum Alloy ◽  
Simple Measurement ◽  
Corrosion Susceptibility ◽  
H2o2 Solution ◽  
Mechanism Of The Reaction

Abstract A new electrochemical test for predicting the stress corrosion performance of 2219 alloy products in the T851 and T87 tempers is described. The test requires only a simple measurement of solution potential of an unstressed specimen in a mixture of absolute methyl alcohol and carbon tetrachloride. It is rapid, requiring less than an hour and has the outstanding advantage of providing differences of nearly 200 millivolts between borderline and resistant conditions of stress corrosion susceptibility, as contrasted to differences of less than 20 millivolts in conventional NaCl-H2O2 solution. The test offers an attractive possibility for evaluating stress corrosion performance of 2219 products quickly as an alternate or supplement to the conventional 30-day alternate immersion exposure in 3½% sodium chloride solution. The mechanism of the reaction between 2219 and this organic electrolyte suggests that a similar test can be developed for other aluminum alloys.

Effect of Long-Term Service Exposure on the Localized Corrosion and Stress Corrosion Cracking Susceptibility of Type 347 Stainless Steel

CORROSION ◽  
10.5006/2612 ◽  
2017 ◽  
Vol 74 (3) ◽  
pp. 350-361 ◽  
Author(s):  
K. Ravindranath ◽  
N. Tanoli ◽  
B. Al-Wakaa
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Localized Corrosion ◽  
X Ray Diffraction ◽  
Degree Of Sensitization ◽  
Corrosion Susceptibility ◽  
Service Exposure

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.

The Effects of Microstructural Variations on Stress-Corrosion Cracking Susceptibility of Ti-8Al-1Mo-1V Alloy on Marinized Gas Turbines

1967 ◽  
Author(s):  
W. P. Danesi ◽  
R. A. Sprague ◽  
M. J. Donachie
Keyword(s):  
Titanium Alloys ◽  
Stress Corrosion ◽  
High Temperatures ◽  
Stress Corrosion Cracking ◽  
Gas Turbines ◽  
Effective Means ◽  
Corrosion Cracking ◽  
Corrosion Testing ◽  
Time Operation ◽  
Long Time

Salt can cause titanium alloys to crack, and if long-time operation of titanium hardwares in salt atmospheres is expected, effective means must be found to eliminate or control this tendency. The authors describe in detail their stress-corrosion testing of titanium alloys, and the results are plotted in a number of tables. Figures show stress-versus-temperature charts at different high temperatures, and the microstructure of the alloy after testing is illustrated. The results of the tests are evaluated and a brief summary is given.

Intergranular Corrosion and Stress Corrosion Cracking of Sensitised AA5182

2006 ◽  
Vol 519-521 ◽  
pp. 641-646 ◽  
Author(s):  
Alison J. Davenport ◽  
Yudie Yuan ◽  
Rajan Ambat ◽  
Brian J. Connolly ◽  
Martin Strangwood ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Intergranular Corrosion ◽  
Corrosion Cracking ◽  
Critical Factors ◽  
Phase Precipitation ◽  
Β Phase ◽  
Grain Boundary Plane ◽  
Corrosion Susceptibility ◽  
Variable Precipitation

AA5182 (Al-4.5 wt% Mg) can become susceptible to intergranular corrosion (IGC) with time at moderately elevated service temperatures owing to precipitation of Mg-rich β-phase at grain boundaries, which can lead to stress corrosion cracking (SCC). The IGC and SCC susceptibility of AA5182 was found to depend strongly on sensitisation heat treatments. AFM and TEM studies demonstrated that the degree of precipitation and thus susceptibility to attack for a boundary can be related to its crystallographic misorientation. Low angle boundaries (<20°) are most resistant to attack as they do not show β-phase precipitation. However, higher angle boundaries show highly variable precipitation and corrosion susceptibility: critical factors are the grain boundary plane and precipitate/matrix crystallographic relationship.

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