Scholarlink

<p>Underwater welding plays a crucial role in repairing surface defects in submerged structures and improving their surface properties, particularly their resistance to corrosive-wear. Underwater surfacing layers were deposited using welding currents of 120, 135 and 150&#xa0;A. The microstructural characteristics of underwater-deposited surfacing layers were analyzed. Due to the limited heat input at 120&#xa0;A welding current, the underwater-deposited surfacing layer primarily consists of polygonal ferrite (PF) and pearlite. In contrast, the surfacing layer deposited in air exhibited a microstructure composed of acicular ferrite (AF), ferrite with a second-phase arrangement (FSP), PF, and pearlite. Additionally, the high heat transfer rate underwater induces the formation of columnar grains. As the welding current increased, the presence of AF, FSP, PF, and pearlite reappeared in the microstructure, and a fine-grain zone formed on the surface due to rapid water cooling. The columnar grain structure within the surfacing layer became increasingly distinct with rising welding current. Moreover, the increased welding current led to an elevated volume fraction of AF packets, subsequently raising the proportion of low-angle grain boundaries and dislocation density. Smaller grain size, equiaxed grain morphology, and higher dislocation density are identified as key factors influencing the properties, leading to a 36% increase in microhardness and an improvement in the corrosive-wear resistance of the surfacing layer.</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

Microstructure characteristic of surfacing layers for underwater shielded metal arc welding

  • 期刊论文

  • 发表日期：

    2026年1月16日

查看全文
  • Yi-Fan Wu,
  • Ke Yang,
  • Jian-Hua Zhao,
  • Xian-Ming Cheng,
  • Bo Feng,
  • Si-Si Zhu,
  • Xing Hu

摘要

Underwater welding plays a crucial role in repairing surface defects in submerged structures and improving their surface properties, particularly their resistance to corrosive-wear. Underwater surfacing layers were deposited using welding currents of 120, 135 and 150 A. The microstructural characteristics of underwater-deposited surfacing layers were analyzed. Due to the limited heat input at 120 A welding current, the underwater-deposited surfacing layer primarily consists of polygonal ferrite (PF) and pearlite. In contrast, the surfacing layer deposited in air exhibited a microstructure composed of acicular ferrite (AF), ferrite with a second-phase arrangement (FSP), PF, and pearlite. Additionally, the high heat transfer rate underwater induces the formation of columnar grains. As the welding current increased, the presence of AF, FSP, PF, and pearlite reappeared in the microstructure, and a fine-grain zone formed on the surface due to rapid water cooling. The columnar grain structure within the surfacing layer became increasingly distinct with rising welding current. Moreover, the increased welding current led to an elevated volume fraction of AF packets, subsequently raising the proportion of low-angle grain boundaries and dislocation density. Smaller grain size, equiaxed grain morphology, and higher dislocation density are identified as key factors influencing the properties, leading to a 36% increase in microhardness and an improvement in the corrosive-wear resistance of the surfacing layer.