核监测用断裂韧性Charpy尺寸试样的合理设计

预制疲劳裂纹侧槽Charpy尺寸试样是一种经济、方便的评价核压力容器用钢弹塑性断裂韧性的单试样方法。本文就几种常用压力容器用钢详细研究了侧槽相对深度对断裂韧性及相应的稳定裂纹扩展量的影响,并和满足GB2038要求的大尺寸试样的试验结果进行了对比。研究结果表明,采用预制疲劳裂纹、侧槽相对深度为30%的Charpy尺寸试样及三点弯曲试验曲线上最大载荷前的能量,可以偏安全地评价裂纹开始扩展时材料的弹塑性断裂韧性,建立了核监测用断裂韧性试验Charpy尺寸试样的合理设计。此外,还研究了侧槽的拘束效应和对试样的加厚作用,对试验结果进行了理论解释。

The Reasonable Design of Charpy-size Specimen for Fracture Toughness Test in Nuclear Surveillance

Pre-cracked and side-grooved Charpy-size specimen is an economical and convenient single-specimen method of evaluating the elastic-plastic fracture toughness of nuclear pressure vessel steels. This paper has studied the influence of side-groove depth on fracture toughness and stable increment of crack for several pressure vessel steels in detail, The research results indicate that using pre-cracked Charpy-size specimen with side-groove depth 30% and adopting the energy before the maximum load of three point bending test curve, the elastic-plastic fracture toughness of materials can be evaluated conservatively when crack begin to propagate, and the reasonable design of Charpy-size specimen for fracture toughness test of nuclear surveillance has been established, At the same time, the constraint effect and thichening action of side-groove on Charpy-size specimen have also been discussed, and the theoretical explains have been given.