Yingping Guan

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All articles published by MDPI are made immediately available worldwide under an open access license. No special permission is required to reuse all or part of the article published by MDPI, including figures and tables. For articles published under an open access Creative Common CC BY license, any part of the article may be reused without permission provided that the original article is clearly cited. For more information, please refer to https://www.mdpi.com/openaccess.

1. Introduction High strength, toughness, and excellent weldability [1,2,3] have made X80-grade pipeline steel to be considered as the preferred steel for gas and oil transmission pipelines, even in the 21st century. However, higher constraints have been imposed on the wall thickness and low-temperature toughness (≤−45 °C) of X80-grade pipeline steel [1,2,3,4] in order to meet the increasing demands of long-distance transmission in extremely cold regions and high flow rates of natural gas.