Scholarlink

<p>For P91 steel weldment, performing post-weld heat treatment immediately after welding can enhance welding efficiency and reduce the risk of hydrogen-induced cracking. However, determining the post-weld cooling temperature (PWCT) is challenging due to potential impact on the mechanical properties of weldment after subsequent heat treatment. A systematic investigation is conducted to explore the effect of PWCT on the impact toughness of P91 steel welded joints. It has been demonstrated that the impact energy of the weld metal gradually increases from 40.2 to 49.5 J as the PWCT decreases from 300 to 100&#xa0;°C. Microstructural analysis reveals that PWCTs above 100&#xa0;°C led to an increased dislocation density in the weld metal. Furthermore, in situ observations using a high-temperature confocal laser scanning microscope confirm that excessively high PWCTs result in the formation of untempered martensite after post-weld heat treatment. Such untempered martensites are identified as the primary cause of the reduced impact toughness in the weld metal. These findings underscore the importance of carefully controlling PWCT in welding procedures for P91 steel and similar grades.</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

Impact toughness dependence upon post-weld cooling temperature in P91 steel weldments

  • 期刊论文

  • 发表日期：

    2025年2月22日

查看全文
  • Ying-chao Feng,
  • Jing-xin Ren,
  • Jin-ping Liu,
  • Zheng-man Gu,
  • Ming Zhong,
  • Cong Wang

摘要

For P91 steel weldment, performing post-weld heat treatment immediately after welding can enhance welding efficiency and reduce the risk of hydrogen-induced cracking. However, determining the post-weld cooling temperature (PWCT) is challenging due to potential impact on the mechanical properties of weldment after subsequent heat treatment. A systematic investigation is conducted to explore the effect of PWCT on the impact toughness of P91 steel welded joints. It has been demonstrated that the impact energy of the weld metal gradually increases from 40.2 to 49.5 J as the PWCT decreases from 300 to 100 °C. Microstructural analysis reveals that PWCTs above 100 °C led to an increased dislocation density in the weld metal. Furthermore, in situ observations using a high-temperature confocal laser scanning microscope confirm that excessively high PWCTs result in the formation of untempered martensite after post-weld heat treatment. Such untempered martensites are identified as the primary cause of the reduced impact toughness in the weld metal. These findings underscore the importance of carefully controlling PWCT in welding procedures for P91 steel and similar grades.