ISO 7539-3 is an international standard and a part of the ISO 7539 series that discusses the preparation and use of U-bend specimens for corrosion of metals and alloys. Corrosion is a type of oxidization whereas rusting is a part of corrosion. If an alloy contains ferrous metal (iron), it will rust.
ISO 7539-3 covers procedures for designing, preparing and using U-bend test specimens for investigating the susceptibility of metal to stress corrosion. The term “metal” as used in this part of ISO 7539 includes alloys.
U-bend specimens are used to test a variety of product forms. They are used principally for sheet, plate or flat extruded material, which conveniently provides flat specimens of rectangular cross-section, but may also be employed for wire or rod, or machined specimens of circular cross-section. They can also be used for parts joined by welding.
The U-bend test is frequently used to establish whether a metal is susceptible to stress corrosion cracking in a given environment. It is used in laboratories to screen materials for susceptibility for specific applications and in service, environments to assess the risk of failure. The principal advantages of the test are its simplicity and its consequent adaptability for use in the plant. A disadvantage is that stresses cannot be quantified with accuracy and if this is desired an alternative method of stressing should be used.
ISO 7539-3 on preparation and use of U-bend specimens applies to:
Corrosion is a type of oxidization whereas rusting is a part of corrosion. If an alloy contains ferrous metal (iron), it will rust.
ISO 7539-3 provides the principles in which the test is performed under laboratory conditions by exposing the specimens to simulated service conditions. The advantage for you is to establish whether a metal is suitable for a proposed application or to assess the risk of stress corrosion cracking of metals used in existing plants under service conditions.
ISO 7539-3 provides you with comprehensive guidance useful throughout the process of production.
ISO 7539-3:1989