ISO 20728 is a safety standard on corrosion of metals and alloys. An alloy is a mixture of chemical elements of which at least one is a metal. ISO 20728 specifies a method for the determination of resistance to stress corrosion cracking (SCC) of magnesium alloys intended for use in structural applications (such as magnesium front end, gearbox and clutch housing units, steering column parts, shift actuators, valve covers, and housings, brackets, and intake manifold blades, electronic devices, power tools, and medical equipment). The method allows the determination of the resistance to SCC as a function of the chemical composition, the method of manufacture, and heat treatment of magnesium alloys.
ISO 20728 is applicable to cast and wrought magnesium alloys in the form of castings, semi-finished products, parts, and weldments and covers the method of sampling, the types of specimens, the loading procedure, the type of environment, and the interpretation of results. ISO 20728 allows assessment of the relative performance of materials and products in environments containing chlorides or sulphates.
ISO 20728 on determining the resistance of magnesium alloys to stress corrosion cracking is relevant to:
Stress corrosion cracking of magnesium alloys is sensitive to microstructural orientation with respect to the stress axis. In testing SCC resistance, it is necessary to consider the way the specimens are prepared from cast or wrought alloy so that orientation-dependent SCC resistance can be assessed. ISO 20728 is associated with hydrogen evolution and the generation of often very soluble corrosion products. Tests may be conducted under constant load, constant strain, or by the slow strain rate technique with evaluation criteria for stress corrosion cracking resistance appropriate to the chosen loading method. Overall, ISO 20728 is useful as it assists in determining the resistance of magnesium alloys to stress corrosion cracking which can help you in your business.
EN ISO 20728:2018
ISO 20728:2018