Supervisor:
Southwest Ordnance Industry Bureau
Organizer:
Chongqing Ordnance Industry Society
Chongqing University of Technology
Chongqing University of Technology
Research on stress corrosion cracking of 2195 Al Li alloy in 30% HNO3
| DOI: | 10.11809/bqzbgcxb2023.08.041 |
| Keywords: | Al Li alloy; dilute nitric acid; stress corrosion; finite element method; cracking |
| Abstract: | As a new structural material of liquid missile propellant storage tank, the compatibility between Al Li alloy and the propellant needs to be solved urgently under long term wet storage conditions. For this reason, this paper carries out stress corrosion cracking research on 2195 Al Li alloy for storage tanks. Firstly, four point bending method is used to investigate the stress corrosion performance of 2195 Al Li alloy in 30% HNO3 medium, and conducts an in depth analysis of the alloy surface corrosion morphology, focusing on the intergranular crack growth behavior initiated from the corrosion pit. Subsequently, based on the experimental results, the finite element method is used to explore the stress and strain evolution process during the initiation and propagation of stress corrosion cracks. The results show that the stress corrosion sensitivity of 2195 Al Li alloy gradually decreases with the increase of external load deflection in dilute nitric acid, and large corrosion pits and intergranular corrosion appear on the surface. When the degree of corrosion increases to a certain extent, the weakening of the intergranular strength can easily cause intergranular crack propagation. The crystal spalling during the corrosion crack growth is determined by the intergranular strength and crystal deformation, and the intergranular strength can be used as an index to measure the resistance of Al Li alloy to stress corrosion cracking. |
| Published: | 2023-08-28 |
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