一、前言应力腐蚀断裂是石油化工容器主要失效形式之一。而应力腐蚀抗力最薄弱之处则是焊接区,其中尤以熔合线处为最甚。近年来,许多容器开罐检查证明,不少裂纹就是从熔合线处发生或发展的。因此,评定焊接区各部位(包括熔合线处)抗应力腐蚀的断裂韧性是容器选材、设计和安全性评定的重 I. Introduction Stress corrosion cracking is one of the main failure modes of petrochemical containers. The weakest point of stress corrosion resistance is the welding area, especially at the fusion line at the worst. In recent years, many containers have been opened for inspection to prove that many cracks occur or develop from the fusion line. Therefore, assessing the fracture toughness of stress corrosion resistance at various locations in the weld zone (including the weld line) is critical for design, design, and safety of the container