ISO 7539-2 is an international standard and a part of the ISO 7539 series that discusses the preparation and use of bent-beam specimens for the corrosion of metals and alloys. Corrosion is a type of oxidisation whereas rusting is a part of corrosion. If an alloy contains ferrous metal (iron), it will rust.
ISO 7539-2 covers procedures for designing, preparing and using bent-beam test specimens for investigating the susceptibility of metal to stress corrosion. The term “metal” as used in this part of ISO 7539 includes alloys.
Bent-beam 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 cast material, wire or rod, or for machined specimens of circular cross-section. They can also be used for parts joined by welding.
Since the preparation of the specimens and the apparatus used for stressing them are both simple and inexpensive, bent-beam specimens are especially suitable for multiple testing and atmospheric stress corrosion tests. Bent-beam specimens are usually tested under nominally constant strain conditions but nominally constant load conditions may be employed. In either case, local change of curvature in the specimen when cracking occurs results in changing conditions during crack propagation. The “test stress” is taken as the highest surface tensile stress existing at the start of the test.
ISO 7539-2 on bent-beam specimens applies to:
Corrosion is a type of oxidisation whereas rusting is a part of corrosion. If an alloy contains ferrous metal (iron), it will rust. The bent-beam specimen is designed for determining the stress-corrosion behaviour of alloy sheets and plates in a variety of environments. The bent-beam specimens are designed for testing at stress levels below the elastic limit of the alloy.
ISO 7539-2 provides you with the principle in which the test consists of applying bending stress to a beam specimen of rectangular or circular section and exposing the stressed specimen to a specified test environment. ISO 7539-2 helps you in the bent-beam specimens which are used only for testing at stress levels below the elastic limit since the formulae used for calculating stress in bent beams apply only within the elastic range.
ISO 7539-2 provides you with comprehensive guidance useful throughout the process of production.
ISO 7539-2:1989