Like other metal materials, stress corrosion cracking of magnesium alloy anode materials only occurs under tensile stress. The SCC rate increases with the increase of tensile stress. Compressive stress can improve the stress corrosion resistance of magnesium alloy. Long term application of 30% - 50% yield strength constant stress on magnesium alloy can inhibit stress corrosion cracking of magnesium alloy, but when the material is in this stress state for a long time, stress corrosion cracking will still occur.
The stress corrosion cracking caused by constant load stress corrosion test is more serious than that caused by constant deformation test. The dead load increases with the decrease of cross-section area, and the constant bending decreases with the decrease of corrosion area. The results show that the strain rate is an important factor affecting the stress corrosion cracking of magnesium alloy.
The pre deformation of magnesium alloy has an important influence on its stress corrosion sensitivity. With the increase of pre deformation, the fracture rate of magnesium alloy increases. It is well known that the stress corrosion sensitivity of cast magnesium alloy is lower than that of wrought magnesium alloy. The effect of cold working on stress corrosion cracking of magnesium alloy is bidirectional.
Some studies show that cold rolling can reduce the stress corrosion resistance of magnesium alloy, and some studies show that forming can improve the stress corrosion resistance of magnesium alloy. The experimental results on the effect of cold working on stress corrosion behavior are contradictory, but the influence of microstructure and residual stress cannot be excluded.
In the process of assembly at room temperature, magnesium alloy will produce residual stress, especially in the assembly process of stress corrosion sensitive magnesium alloy, the residual stress caused by assembly deformation is very large, which will increase the sensitivity of stress corrosion cracking of magnesium alloy.
Shandong Linyi Bosi conductive materials Co., Ltd. is a high-tech enterprise specializing in the production of MMO flexible anode, conductive polymer flexible anode and titanium coated anode, mainly providing cathodic protection technology, engineering design, installation and technical services. Tel: 0539 3712117, 15588026668.