本公告对有关长期（标称10000小时或以上）高温暴露对奥氏体钢和高镍合金缺口冲击性能和断裂韧性影响的文献进行了解释性审查，并对可用数据进行了分析。主要重点是ASME锅炉和压力容器规范施工中使用的材料的合金、等级和产品形式。具体而言，这些材料包括200、300和XM系列锻造奥氏体钢、CF系列奥氏体钢铸件、用于焊接奥氏体钢的焊接填充合金，以及锻造等级的高镍合金。根据这些材料的ASME规范设计载荷和应力，分析和评估了暴露导致的缺口冲击值和断裂韧性变化的影响。 本报告由美国压力容器研究委员会第378号公告赞助。

This bulletin presents an interpretative review of the literature and an analysis of the available data relating to the effect of long-term (nominal 10,000 hours or greater), elevated temperature exposure on the notched impact properties and the fracture toughness of austenitic steels and high nickel alloys. The chief emphasis is on the alloys, grades, and product forms of those materials accepted for use in ASME Boiler and Pressure Vessel Code construction. Specifically, these materials include the 200, the 300, and the XM series wrought austenitic steels, the CF series austenitic steel castings, weld filler alloys used in welding austenitic steels, and the wrought grades of high nickel alloys. The effects of the changes in notch impact values and fracture toughness as a result of the exposure are analyzed and evaluated in relation to the ASME Code design loadings and stresses for these materials.Publication of this report - WRC Bulletin No. 378 was sponsored by the Materials and Fabrication Division of the Pressure Vessel Research Council.