Corrosion of metals and alloys � Test method for measuring the stress corrosion crack growth rate of steels and alloys under static-load conditions in high-temperature water

2021 ◽  
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Crack Growth Rate ◽  
Stress Corrosion ◽  
Crack Growth ◽  
Static Load ◽  
Test Method ◽  
High Temperature Water ◽  
Load Conditions ◽  
Temperature Water

Environment Induced Cracking of Turbine Disc Steel: Effect of Organic Acids on Corrosion Fatigue of 3.5NiCrMoV Steels in High Temperature Water

2007 ◽  
Vol 345-346 ◽  
pp. 999-1002
Author(s):  
W.Y. Maeng
Keyword(s):  
Growth Rate ◽  
Acetic Acid ◽  
High Temperature ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Growth Rates ◽  
High Temperature Water ◽  
Turbine Disc ◽  
Crack Growth Rates ◽  
Temperature Water

Organic acids (acetic and formic acid) are produced by the decomposition of ETA (Ethanol Amine, C2H7NO) used as pH controller of secondary water in nuclear power plants. Corrosion Fatigue (CF) tests (R=0.2, 0.1Hz) were conducted to evaluate the effect of acetic acid on the CF crack growth rate in high temperature water at 150°C. Acetic acid significantly influenced the environmental cracking behavior of turbine disc steels in high temperature water. The CF crack growth rates of turbine disc steels increase as the organic acid concentration increase to a critical saturation pH value (~pH 4). Beyond the saturation value of pH, the CF crack growth rates decrease significantly. The higher CF crack growth rate of the higher pH solution in water of intermediate content range (pH 4~pH 5) of acetic acid is due to the higher content of H+ enhancing the reduction reactions. Crack tip blunting prevents the CF cracks from growing with increasing rate in the solution of organic acid concentrations beyond the critical value.

Crack Branching and Its Effect on Environmentally Assisted Cracking in High Temperature Water Environments

2010 ◽  
Author(s):  
Zhanpeng Lu ◽  
He Xue ◽  
Tetsuo Shoji
Keyword(s):  
High Temperature ◽  
Stress Corrosion ◽  
Crack Growth ◽  
Stress Corrosion Cracking ◽  
Crack Tip ◽  
Corrosion Cracking ◽  
Crack Growth Behavior ◽  
Crack Branching ◽  
High Temperature Water ◽  
Temperature Water

Crack kinking or branching has been observed in laboratory stress corrosion cracking tests and in some components suffering from stress corrosion cracking in nuclear power plant coolants. There are several types of crack branching: i.e., macroscopic multiple branching cracks, local crack branching or the combination of both. Crack branching affects the crack tip stress/strain distribution in terms of stress intensity factor and crack tip strain rate, and consequently affects crack growth behavior. The crack tip mechanical fields in some typical crack branching systems are quantified using empirical, analytical and numerical simulation methods. The effect of crack branching is less significant in contoured double cantilever beam specimens than in compact tension specimens for the same size and configuration of branched cracks. The applications of the analysis results to some observed crack branching phenomena of austenitic alloys in high temperature water environments are discussed based on the theoretical crack growth rate formulation.

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