**5. Conclusions**

Erosion-corrosion behaviors of elbow are simulated and the model containing erosion, electrochemistry corrosion, turbulence, and chemistry is built to describe the complicated failure phenomena. The conclusions are summarized as follows:


**Author Contributions:** Q.Z. conceptualized the study and administered the project; Q.Z. and W.Q. performed the simulations; Q.Z. and W.Q. analyzed the data and wrote the manuscript; Q.Z. revised this article. All authors have read and agreed to the published version of the manuscript.

**Funding:** The present work is financially supported by the key project of Shaanxi province Science and Technology Department (2017ZDXM-GY-115) and National Natural Science Foundation of China (51675409), Natural Science Basic Research Plan in Shaanxi Province of China (2019JM-274) and the Open Project Program of Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil & Gas Development (Grant No. BIPT2018001).

**Acknowledgments:** The author would like to thank the Shaanxi Special Equipment Research Institute and coal gasification companies in northern Shaanxi for the valuable data. At the same time, thanks to all the funds provided.

**Conflicts of Interest:** The authors declare no conflict of interest.
