Stress Cracking

Stress cracking refers to the brittle cracking phenomenon that occurs in materials such as plastics, metals, or glass under a constant stress below their short-term strength, due to the synergistic action of environmental media (e.g., chemical solvents, oils, detergents). In foreign trade, this term is commonly encountered in quality disputes involving plastic products, pipes, containers, automotive parts, and electronic enclosures. Usage scenarios include: contract quality clauses specifying resistance to stress cracking, customer complaints about products cracking during transportation or use, and suppliers providing environmental stress cracking resistance (ESCR) test reports. Note: Stress cracking differs from ordinary mechanical fracture in that its cracks usually show no significant plastic deformation and may occur delayed; it differs from 'aging cracking' in that stress cracking requires the simultaneous presence of stress and a medium, whereas aging cracking is mainly caused by light, heat, and oxygen. Foreign trade practitioners should specify test standards (e.g., ASTM D1693, ISO 22088) in orders and retain samples and test reports to handle claims.