确定GH3128高温拉伸性能设计许用值的方法

Methodology for determining high temperature tensile design allowable strengths of alloy GH3128

国产高温镍基合金GH3128在高温条件下具有良好的强度,有望成为超高温气冷堆(VHTR)供热和发电利用的中间换热器(IHX)的主要结构材料。该文针对美国机械工程师协会(ASME)高温强度许用值设计标准应用于GH3128时无法给出清晰一致有效设计余量的不足,采用正态分布直接计算的方法给出了容限范围母体比例为99%的设计许用值曲线,并同ASME设计标准给出的设计许用值曲线进行了对比。结果表明:容限范围母体比例为99%的设计许用值曲线可以在整个温度区间连续给出可靠的设计许用值以及一致有效的设计余量,可以作为高温气冷堆中间换热器结构设计的参考依据。

The Ni-based superalloy GH3128 has good high-temperature strength and so is a promising main structural material for the intermediate heat exchanger （IHX）, the key component of very high temperature reactors （VHTR） for power generation and process heat supply. This study analyzes the applicability of an existing American Society of Mechanical Engineers （ASME） standard for GH3128. Then, a method is given to determine tensile strength design margins at low and high temperatures. A direct calculation method for the normal distribution gives a 99% lower bound curve for the tensile strength which is better than the ASME standard. The conclusions show that the 99% lower bound curve gives a consistent, quantifiable design margin and reliable allowable design strengths. Thus, the results are a reference for the structural design of the IHX.