Scholarlink

<p>The fracture toughness behavior of X65 welded joints was investigated under a total pressure of 10&#xa0;MPa in hydrogen-mixed natural gas environments with hydrogen volume fractions ranging from 0 to 20&#xa0;vol.%. The study revealed that the introduction of hydrogen significantly deteriorates the fracture toughness of X65 welded joints. Microstructural analysis reveals that the base metal (BM) is mainly composed of polygonal ferrite. A power-law fitting model effectively captures the relationship between hydrogen partial pressure and the relative fracture toughness in mixed gas conditions. Due to the presence of Mn-Si-Al-Ti-O inclusions within the weld metal (WM), its mechanical performance was the lowest among all joint regions at hydrogen mixing ratios of 0-15%. However, at a 20% hydrogen mixing ratio, the<i> J</i><sub><i>IC</i></sub> values of the BM, WM, and HAZ are 244, 145, and 139&#xa0;kJ/m<sup>2</sup>, respectively, with the HAZ exhibiting a hydrogen embrittlement degradation degree of 82%." The addition of hydrogen promoted dislocation motion around the crack tips in both the base metal (BM) and WM, while it suppressed dislocation mobility in the HAZ.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Investigation on the Fracture Toughness Behavior of X65 Pipeline Steel Welded Joints in High-Pressure Natural Gas/Hydrogen-Mixed Environment

  • 期刊论文

  • 发表日期：

    2026年4月11日

查看全文
  • Dong Han,
  • Xue Liu,
  • Fuyang Wang,
  • Youfu Xiao,
  • Yun Cheng,
  • Wenzhou Liang,
  • Lianyong Xu,
  • Yongdian Han

摘要

The fracture toughness behavior of X65 welded joints was investigated under a total pressure of 10 MPa in hydrogen-mixed natural gas environments with hydrogen volume fractions ranging from 0 to 20 vol.%. The study revealed that the introduction of hydrogen significantly deteriorates the fracture toughness of X65 welded joints. Microstructural analysis reveals that the base metal (BM) is mainly composed of polygonal ferrite. A power-law fitting model effectively captures the relationship between hydrogen partial pressure and the relative fracture toughness in mixed gas conditions. Due to the presence of Mn-Si-Al-Ti-O inclusions within the weld metal (WM), its mechanical performance was the lowest among all joint regions at hydrogen mixing ratios of 0-15%. However, at a 20% hydrogen mixing ratio, the JIC values of the BM, WM, and HAZ are 244, 145, and 139 kJ/m2, respectively, with the HAZ exhibiting a hydrogen embrittlement degradation degree of 82%." The addition of hydrogen promoted dislocation motion around the crack tips in both the base metal (BM) and WM, while it suppressed dislocation mobility in the HAZ.