Scholarlink

<p>To identify the root cause damage in the expansion joint sample used in natural gas reformer of a steel plant, detailed inspections were conducted using visual examination, optical metallography, alloy analysis, and comprehensive fractographic techniques. The results revealed that the cracks predominantly occurred along the weld line and originated due to a knife-line corrosion mechanism at the recessed region adjacent to the weld. Excessive welding heat and prolonged exposure to elevated service temperatures led to the formation of a continuous carbide band at the weld boundary which, in turn, caused chromium depletion in surrounding areas. Under humid atmospheric conditions, this resulted in severe intergranular corrosion, characterized by a ditch-like structure. Significant wall thinning in the anodic region adjacent to the carbide band, combined with thermal stresses and deposit accumulation, increased the tensile stress at the pipe outer surface, promoting crack initiation along the weld toe. These factors accelerated the corrosion mechanisms, ultimately leading to crack propagation and material failure.</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

Stress and Corrosion-Induced Damage of the Inlet Expansion Joint in a Natural Gas Reformer in a Steel Plant

  • 期刊论文

  • 发表日期：

    2025年12月15日

查看全文
  • Navid Saeidi,
  • Fakhreddin Ashrafizadeh,
  • Masoud Karimpour,
  • Iman Soleimani

摘要

To identify the root cause damage in the expansion joint sample used in natural gas reformer of a steel plant, detailed inspections were conducted using visual examination, optical metallography, alloy analysis, and comprehensive fractographic techniques. The results revealed that the cracks predominantly occurred along the weld line and originated due to a knife-line corrosion mechanism at the recessed region adjacent to the weld. Excessive welding heat and prolonged exposure to elevated service temperatures led to the formation of a continuous carbide band at the weld boundary which, in turn, caused chromium depletion in surrounding areas. Under humid atmospheric conditions, this resulted in severe intergranular corrosion, characterized by a ditch-like structure. Significant wall thinning in the anodic region adjacent to the carbide band, combined with thermal stresses and deposit accumulation, increased the tensile stress at the pipe outer surface, promoting crack initiation along the weld toe. These factors accelerated the corrosion mechanisms, ultimately leading to crack propagation and material failure.