一、前言 在航空和宇航工业中,为减轻构件自重,普遍采用薄壁构件。这类构件在服役过程中产生的最为常见的损伤是表面裂纹,由于它的扩展而导致构件断裂。因此,评定这类材料抗裂纹扩展能力的大小是十分必要的。为此航空工业部制定了HB5279-84部标,提出了金属材料表面裂纹断裂韧性试验方法。根据标准规定,为获得表征材料特性 I. Introduction In the aviation and aerospace industries, in order to reduce the weight of components, thin-walled components are commonly used. The most common damage that this type of component generates during service is surface cracking, which causes the component to break due to its expansion. Therefore, the assessment of such materials, the size of the anti-crack expansion capacity is very necessary. To this end the Ministry of Aviation Industry developed a part of HB5279-84 standard, proposed metal surface crack fracture toughness test method. According to the standard, characterization of the material is obtained