Methods of corrosion testing used for development and commercial exploitation of new shipbuilding steels and alloys. Review. Part II. Corrosion cracking and field marine tests

Abstract

The review describes methods of stress corrosion cracking (SCС) tests that implement various conditions for samples loading: at a constant static load or deformation, at a constant or increasing load of samples with a previously grown fatigue crack, with a slow strain rate. Such tests shall be carried out to determine the resistance of shipbuilding materials to be used in loaded ship structures in contact with seawater. Brief descriptions of the mechanism of stress corrosion cracking of steels and alloys are given. The necessity to carry out bench tests of steels and their welded joints, as well as models simulating individual units and elements of structures, is indicated. At this stage, conditions are ensured as close to operating conditions as possible due to exposure in various climatic zones of the world’s oceans (variations in temperature, chloride concentration, amount of dissolved oxygen, degree of biofouling, and their simultaneous impact). It is shown that during verification field tests (final stage) new materials promising for operation in marine conditions pass the final evaluation of corrosion resistance in the form of elements of ship structures and systems in the conditions of ship operation.