EQ70钢CTOD断裂韧度评估及允许值确定

采用传统方法评定EQ70钢断裂韧度CTOD值是否优良时，通常将基于英国BS7448规范测试的CTOD断裂韧度最小值与CTOD允许值δ_min进行比较，当EQ70钢CTOD断裂韧度最小值大于CTOD允许值δ_min时，则EQ70钢的CTOD断裂韧度优良，此方法局限于能够查阅到EQ70钢的CTOD允许值δ_min，但国内外规范中很少对CTOD允许值δ_min做明确规定。基于英国BS7910《金属结构缺陷可接受性评定方法指南》的失效评定曲线对EQ70钢的断裂韧度CTOD合格性进行评定，能够克服传统方法的不足。同时依据BS7910规范还可以推导出EQ70钢CTOD允许值δ_min，比传统的工程方法“母材参考法”和“类比法”具有优越性。

Assessment of EQ70 Steel CTOD Fracture Toughness and Determination of the Allowed Value

The traditional method for evaluation fracture toughness of EQ70 steel CTOD value， through the comparison of the minimum value of CTOD fracture toughness which is based on BS7448 specification test and the allowed value CTOD δ_min . When the minimum value of EQ70 steel CTOD fracture toughness is greater than the minimum allowed value δmin ， the CTOD fracture toughness value of EQ70 steel is good， this method is limited to refer to EQ70 steel CTOD allowed value of δmin， but the CTOD allowed value δmin rarely is specified in the specifications at home and abroad. The assessment of EQ70 steel fracture toughness CTOD conformity based on the failure assessment curve of BS7910 Metal Structure Defect Acceptable Guidelines evaluation method， can overcome the insufficient of traditional method. According to the BS7910 specification， EQ70 steel CTOD allowed value δmin derived is superior than those of engineering methods base metal reference methods and method of analogue.