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直至最近,ASME锅炉与压力容器规范第Ⅷ篇第1册对设计用在-20℉(-29℃)或高于—20℉(-29℃)的碳钢及低台金钢容器尚未提出缺口韧性的要求。以线弹性断裂力学理论基础的更为广泛的新的韧性规则最近己得到发展。它们发表在1987年12月31日的规范附录中。这些新规则的主要特点是一组免除冲击试验曲线。根据碳钢或低合金钢的种类、厚度及最低设计金属温度(MDMT)由这些曲线决定何时需要进行冲击试验。这些新规则的一个显著特点是厚度达1英寸(25mm)的P11组及2组材料在MDMT为-50℉(-46℃)或高于-50℉(-46℃)时免除冲击试验,而在设计与试验方面有某些限制。
Until recently, the ASME Boiler and Pressure Vessel Code, Section VIII, Book 1 has not yet provided a gap for carbon steel and low-gauge steel containers designed for use at -20 ° F (-29 ° C) or above -20 ° F (-29 ° C) Toughness requirements. The more extensive new toughness rules based on the theory of linear elastic fracture mechanics have recently been developed. They are published in the normative appendix of December 31, 1987. The main feature of these new rules is a set of exemption impact test curves. Depending on the type of carbon steel or low alloy steel, the thickness and the minimum design metal temperature (MDMT), these curves determine when an impact test is required. A notable feature of these new rules is that the P11 group and the two groups of materials up to 1 in. (25 mm) in thickness are exempt from impact testing when MDMT is -50 ° F (-46 ° C) or greater than -50 ° F (-46 ° C) There are some limitations in design and testing.