从75年以来,为了发展高强度钢,美国钢铁研究实验室进行了大量研究,改善了钢的断裂韧性和应力腐蚀抗力,使飞机结构件得到较大的安全可靠性。为了确定168.4～189.8公斤/毫米~2抗拉强度范围内纯度对应力腐蚀断裂特性的影响程度,制备了普通纯度和现在实验室条件下 Since 75 years, in order to develop high-strength steel, the United States Iron and Steel Research Laboratory conducted a lot of research to improve the fracture toughness and stress corrosion resistance of steel, the aircraft structure to obtain greater safety and reliability. In order to determine the degree of influence of the purity in the tensile strength range of 168.4 ~ 189.8 kg / mm ~ 2 on the stress corrosion cracking characteristics, normal purity and the current laboratory conditions were prepared