## 4 Conclusions  
In this experiment, the maximum tensile strain at fracture was determined for three specimens submerged in various corrosive solutions, the true stress in tension was calculated using the maximum tensile stress of the specimens, the ratio of the tensile length between the specimen moments recorded at one point in the test to the initial specimen distance, and the maximum tensile stress of the specimens was calculated. The failure periods of the three specimens at various PH values were then determined by the relationship between the failure time and the strain-hardening modulus. The strain-hardening modulus of the specimens was calculated following Equation (1).  
The results reveal that: (1) Tensile fracture strain of the specimen after immersion in PH1 solution is smallest at a specific time (17.4268 N/mm\({}^{2}\), 21.1221 N/mm\({}^{2}\), 17.9097 N/mm\({}^{2}\)), and highest at PH8 solution immersion (21.2630 N/mm\({}^{2}\), 21.3598 N/mm\({}^{2}\), 20.7667 N/mm\({}^{2}\)). (2) The failure time for PE specimens after soaking in PH1 solution was 1.872 days, while the failure time for PE specimens after soaking in PH8 solution was 1128.58 days. (3) A relationship between corrosion solution PH value and three different types of specimen failure time was established. A life prediction curve for the specimen after immersion corrosion accelerated aging was proposed, and the best life prediction equation was obtained by mathematical curve fitting. This equation is \(y=-1.19352+1.29333\times x-0.094\times x^{2}\). (4) Since the aging mechanism and physical properties of many thermoplastic materials are similar and this experiment is based on the aging mechanism and physical properties of polyethylene materials, the prediction method of this experiment is also applicable to other thermoplastic materials. However, it should be emphasized that the procedure might not be appropriate for pipelines running under other unique circumstances; thus, it must be carefully considered before usage. Even if the knowledge acquired from macroscopic tests is crucial for understanding the behavior and properties of materials, it is still restricted when it comes to microscopic description. Future research will therefore continue to use micro-level analyses to confirm the validity of macro-level investigations.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Serial Number** & **Algorithms** & **Formulas** & **Parameters a/b/c** & **R-Squared** \\ \hline
1 & Exp2 PMod2 & y = e\({}^{(a+b\times x)}\) & a = \(-\)2.45627, b = 0.61248 & 0.631 \\
2 & Allometric1 & y = a \(\times\) x & a = 0.8158, b = 1.3052 & 0.672 \\
3 & Asymptotic1 & y = a \(-\) b \(\times\) c\({}^{\rm x}\) & a = \(-\)16.426, b = 11.03702, c = 0.3153 & 0.728 \\
4 & Log2P1 & y = b \(\times\) ln(x - a) & a = 2.93547, b = 3.12234 & 0.898 \\
5 & Secondary regression curve & y = a + b \(\times\) x + c \(\times\) x\({}^{\rm 2}\) & a = \(-\)1.19352, b = 1.29333, c = \(-\)0.0947 & 1 \\ \hline \end{tabular}
\end{table}
Table 6: Mathematical Models.  
**Author Contributions:** Conceptualization, W.-S.R.; writing--original draft, L.N.; funding acquisition, Y.W.; investigation, G.-W.F.; writing--review and editing, L.N. and W.-S.R.; resources, Y.W. and N.L.; supervision, Y.W. and H.-Q.L.; validation, W.-S.R. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by the Sponsored by Natural Science Foundation of Xinjiang Uygur Autonomous Region (no. 2022D01C389), the Xinjiang University Doctoral Start-up Foundation (no. 620321029), and the Science and technology planning project of State Administration for Market Regulation (no. 2022 MK201).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.