Scholarlink

<p>The present study investigates the influence of variable weld heat input on the fracture toughness behavior of X80 pipeline steel welded joints under the both impact and quasi-static monotonic loading conditions. X80 pipeline welded joints were fabricated using two distinct heat inputs: (1) low heat input (LHI) 15&#xa0;kJ/cm and (2) high heat input (HHI) 25&#xa0;kJ/cm. The fracture toughness behavior of the weldments was evaluated through Charpy impact testing and three-point bend tests on samples extracted from different weldment regions: fusion line (FL), FL + 1&#xa0;mm, FL + 2&#xa0;mm, and FL + 3&#xa0;mm.</p><p>A finite element–based numerical model was developed to simulate the Charpy impact response, establishing a comparative correlation between experimental and simulated results. The fusion line exhibited the lowest fracture toughness for both heat inputs due to the presence of granular bainite and hard/brittle martensite–austenite (M/A) constituents. Microstructural analysis revealed that a lower heat input promoted the nucleation of refined bainite structures and improved toughness, while higher heat input led to coarser microstructures and M/A segregation. Microstructural features such as granular bainite and hard/brittle M/A particles significantly affected the fracture toughness of weldments. Fractographic observations confirmed ductile, brittle, and mixed fracture modes corresponding to the heat input levels.</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

Experimental and Numerical Characterization of Properties of API X80 Pipeline Steel Weldments for Different Heat Inputs

  • 期刊论文

  • 发表日期：

    2026年4月11日

查看全文
  • Mayur Pratap Singh,
  • Kanwar Arora,
  • Rajnish Kumar,
  • Dinesh Kumar Shukla,
  • Ankit Gupta,
  • Abhishek Kumar

摘要

The present study investigates the influence of variable weld heat input on the fracture toughness behavior of X80 pipeline steel welded joints under the both impact and quasi-static monotonic loading conditions. X80 pipeline welded joints were fabricated using two distinct heat inputs: (1) low heat input (LHI) 15 kJ/cm and (2) high heat input (HHI) 25 kJ/cm. The fracture toughness behavior of the weldments was evaluated through Charpy impact testing and three-point bend tests on samples extracted from different weldment regions: fusion line (FL), FL + 1 mm, FL + 2 mm, and FL + 3 mm.

A finite element–based numerical model was developed to simulate the Charpy impact response, establishing a comparative correlation between experimental and simulated results. The fusion line exhibited the lowest fracture toughness for both heat inputs due to the presence of granular bainite and hard/brittle martensite–austenite (M/A) constituents. Microstructural analysis revealed that a lower heat input promoted the nucleation of refined bainite structures and improved toughness, while higher heat input led to coarser microstructures and M/A segregation. Microstructural features such as granular bainite and hard/brittle M/A particles significantly affected the fracture toughness of weldments. Fractographic observations confirmed ductile, brittle, and mixed fracture modes corresponding to the heat input levels.