稀疏数据限制了机理腐蚀模型的预测能力
Sparse data limit what a mechanistic corrosion model can predict
- University of Waterloo（滑铁卢大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
针对机理腐蚀模型参数可辨识性不足的问题，利用可微反演和多种统计检验，发现稀疏数据仅能确定部分参数，并指出延长暴露时间可改善预测。
AI中文摘要：
机理腐蚀模型通常用四到六个参数拟合少量测量数据，并外推至整个服役寿命，但这些数据是否足以确定这些参数却很少被检验。我们通过可微反演方法，并对照闭式参考解进行分级，从模拟沸水堆水中Nb稳定化AISI 347双相氧化物的三个暴露时间的公开深度剖面中，识别出一个简化的点缺陷模型。剖面似然法、1000次自助抽样和先验松弛测试一致表明，五个参数中有一个无法确定，第二个仅弱确定，且95%的拟合统计量依赖于三个铬数据点。动力学在标定窗口内遵循经验幂律，但在十年时偏离该幂律达3.5至6.3倍，超出传播的不确定度带。这种偏离（而非其所界定的厚度）才是这些数据所能确定的；接近3000小时的暴露时间将能解决这一问题。
英文摘要：
Mechanistic corrosion models are routinely fitted with four to six parameters to a few measurements and extrapolated across service lifetimes, yet whether the data determine them is rarely tested. We identify a reduced point defect model for the duplex oxide on Nb-stabilized AISI 347 in simulated boiling-water-reactor water from published depth profiles at three exposure times, by differentiable inversion graded against a closed-form reference. Profile likelihood, a 1000-member bootstrap and a prior-relaxation test agree that one of the five parameters is undetermined and a second only weakly so, and that 95% of the fit statistic rests on three chromium points. The kinetics track an empirical power law over the calibration window but diverge from it by a factor of 3.5 to 6.3 at ten years, outside the propagated uncertainty band. That separation, not the thickness it brackets, is what these data determine; an exposure near 3000 hours would resolve it.
