Sources and scope for this page: Industry convention — no single governing standard (conventional usage, definitions vary between sources), covering the definition of stress-corrosion cracking. No independent source check is recorded for this page: the content rests on the sources listed and on the working shown on the page. How sources, methods and updates are recorded.
Definition
Neither the stress nor the chemical alone would cause failure. Together they crack the part, often at a stress well below yield and in a chemical that has no effect on unstressed specimens.
Amorphous plastics are highly susceptible: polycarbonate, acrylic and PEI crack at press fits and threads after cleaning with a solvent. In metals, austenitic stainless cracks in chloride environments at elevated temperature, which is why duplex and super-austenitic grades exist.
Common misuse
Designing from a chemical compatibility table alone. Those ratings assume an unstressed specimen; stress makes a chemical that is rated acceptable fail in practice.