SCC can not develop if one succeeds in removing one of the following three prerequisites from the corrosion system:
All remedies must be oriented to this requirements.
Selection of materials that are SCC resistant, i.e. determining semi-finished product production, manufacturing processes, and heat treatments that prevent the development of structures that promote SCC. Heavily soiled materials such as free-machined materials (with impurities as chip breakers).
This is especially true for corrosion types that involve hydrogen creation.
The highest possible material strength should not be used, neither through loading or production (e.g. shaping, heat treatment). For example, in Cr steels, hardness above 30 HRC is an indicator for possible SCC-sensitivity.
Inciting compressive internal stresses at the surface, such as through shot peening or rolling. Using chipping procedures with set parameters (e.g. chipping rate, chip depth, tool geometry, cool cutting media), for which compressive stresses have been verified after chipping. No changes to procedures or parameters without verification of comparable compressive stresses in the surface being machined.
Experience has shown that grinding will create tensile stresses in surfaces. For this reason, grinding should, if possible, be avoided in systems that are prone to SCC.
Certifying and monitoring auxiliary materials during manufacture (e.g. cutting fluid, cleaning and etching baths, etc.). Special caution with auxiliary materials with halogen compounds such as chlorine. If in doubt, these products should be certified in suitable SCC tests.
Experience has shown that the following combinations of processing bath and material require special caution:
bronzing/burnishing baths with hardened and case-hardened steel parts
hot perchloroethylene degreasing baths with high-strength Ti alloys
Rinsing baths contaminated with chloride combined with parts made from high-strength Al alloys and (martensite) Cr steels.
In every case, sensitive parts (such as parts made from case-hardened steels such as gears and shafts) should be sufficiently shot peened on all surfaces that are to be treated with a bath.
Suitable realistic corrosion systems (material, loads/sample shape, media) must be selected in order to verify SCC risks. Defining the characteristic (e.g. crack growth rate, time to crack initiation, time to fracture) is important for selecting a test for SCC-sensitivity. For example, SCC testing of Ti alloys frequently requires nicked or cracked samples, with the crack growth speed and crack image as criteria.
Hollow spaces should be avoided as early as the design phase. In rotor parts such as disks and spacers, these are conical lugs in which corrosive media can collect during standstill or under the influence of centrifugal force.
In blind holes, the hole and threads must be sufficiently sealed against operating fluids. It must be ensured that no corrosive remnants (e.g. from galvanic baths or etching and cleaning baths) remain in the threaded blind holes, which might later react with other fluids during operation (such as condensation water) and form dangerous electrolytes.
Selection of suitable coatings, such as organic lacquers and inorganic coatings (Al powder-filled lacquer with a ceramic binder, enamel, metallic coatings). Cathodic protective effects are desirable, since they provide corrosion protection of the base material even if the coating is damaged all the way through.
The surfaces should be as smooth an clean as possible. Contaminants that can change the corrosion behavior (e.g. cell action), such as may be deposited during manufacturing or repair procedures (e.g. smeared tool material, remnants of peening material), must be avoided or safely removed.