GH3128高温拉伸强度设计方法的优化

Optimization of the high temperature tensile strength design method for the GH3128Alloy

国产镍基高温合金GH3128在高温下具有良好的强度,有望成为超高温气冷堆(very high temperature reactor,VHTR)核心部件中间换热器(intermediate heat exchanger,IHX)的主要结构材料。该文针对美国机械工程师协会(American Society of Mechanical Engineers,ASME)标准应用于GH3128时无法在全温度段得到一致可靠设计余量的不足,采用正态分布直接计算的方法,通过整体多项式、分段多项式以及分段指数这3种拟合方式,对拉伸性能设计许用值进行了计算。分析结果表明:针对现有的GH3128拉伸性能数据,应分别采用分段多项式拟合及分段指数拟合来求抗拉强度和屈服强度的设计许用值,并且这种方法给出的设计许用值曲线可以在全温度区间给出一致可靠的设计余量,可作为超高温气冷堆中间换热器结构设计的参考依据。

GH3128,a domestic Ni-based superalloy,has good hightemperature performance and is a promising main structural material for intermediate heat exchangers（IHX）which are the key component in very high temperature reactors（VHTR）.The existing American Society of Mechanical Engineers（ASME）standard is shown to be inappropriate.Then,3fitting methods（single polynomial fit,2-step polynomial fit and 2-step exponential fit）are used to calculate the allowable design strengths for the tensile strength.The results show that the 2-step polynomial fit method should be used for the ultimate tensile strength with the 2-step exponential fit method for the yield strength.These design curves give consistent and reliable design margins for the structural design of IHX.