Scholarlink

<p>Understanding how defect morphology strongly influences both microstructural evolution and corrosion behavior is essential for establishing a process–defect–property linkage in laser powder bed fusion (L-PBF) 17-4PH stainless steel. In this study, the influence of process parameters and volumetric energy density (VED) on defect morphology, δ-ferrite formation, hardness, and electrochemical behavior was systematically investigated. Quantitative image analysis revealed that lack-of-fusion defects dominate at low VED, while keyhole defects appear at high VED due to excessive energy input. X-ray diffraction and electron backscatter diffraction indicate a BCC-dominant microstructure, which is consistent with substantial retention of δ-ferrite as the primary solidification phase, attributed to the rapid cooling and high thermal gradient inherent to L-PBF. Electrochemical impedance spectroscopy and potentiodynamic polarization tests showed that defect morphology critically affects charge-transfer resistance (Rct) and corrosion current density (i<sub>corr</sub>), suggesting that interconnected lack-of-fusion pores may provide preferential corrosion initiation sites. The optimized process window (65–75&#xa0;J&#xa0;mm<sup>−3</sup>) achieved a dense δ-ferrite microstructure with superior hardness (294 HV) and enhanced corrosion resistance. These findings elucidate the direct correlation between process parameters, defect morphology, and corrosion behavior, providing practical guidance for optimizing L-PBF 17-4PH stainless steel components for service in corrosive environments.</p> Graphical Abstract <p></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

Defect Morphology-Dependent Microstructure and Corrosion Behavior in Selective Laser Melted 17-4PH Stainless Steel

  • 期刊论文

  • 发表日期：

    2026年6月26日

查看全文
  • Zahra Yasaman,
  • Ali Fardi Ilkhchy,
  • Abdollah Saboori,
  • Kasim Sakran Abass,
  • Shi Woo Lee,
  • Hyoung Seop Kim,
  • Akbar Heidarzadeh

摘要

Understanding how defect morphology strongly influences both microstructural evolution and corrosion behavior is essential for establishing a process–defect–property linkage in laser powder bed fusion (L-PBF) 17-4PH stainless steel. In this study, the influence of process parameters and volumetric energy density (VED) on defect morphology, δ-ferrite formation, hardness, and electrochemical behavior was systematically investigated. Quantitative image analysis revealed that lack-of-fusion defects dominate at low VED, while keyhole defects appear at high VED due to excessive energy input. X-ray diffraction and electron backscatter diffraction indicate a BCC-dominant microstructure, which is consistent with substantial retention of δ-ferrite as the primary solidification phase, attributed to the rapid cooling and high thermal gradient inherent to L-PBF. Electrochemical impedance spectroscopy and potentiodynamic polarization tests showed that defect morphology critically affects charge-transfer resistance (Rct) and corrosion current density (icorr), suggesting that interconnected lack-of-fusion pores may provide preferential corrosion initiation sites. The optimized process window (65–75 J mm−3) achieved a dense δ-ferrite microstructure with superior hardness (294 HV) and enhanced corrosion resistance. These findings elucidate the direct correlation between process parameters, defect morphology, and corrosion behavior, providing practical guidance for optimizing L-PBF 17-4PH stainless steel components for service in corrosive environments.

Graphical Abstract