Scholarlink

<p>This study investigates the effect of electroless Ni-B coatings and subsequent heat treatments on the corrosion behavior of spring steels used in high-speed railway systems. Ni-B coatings were deposited via a commercial electroless plating bath, followed by heat treatment at 250&#xa0;°C and 400&#xa0;°C for 1&#xa0;h. Surface morphology, elemental composition, and phase structure were characterized using SEM, EDS, and XRD analyses. Vickers microhardness measurements and pin-on-disk wear tests were conducted to evaluate the mechanical performance of the coatings. Corrosion resistance was evaluated by a 720-h salt spray test in accordance with EN ISO 9227. The results revealed that heat-treated Ni-B coatings exhibited improved mechanical properties, including a notable increase in surface hardness from 324 HV (uncoated) to 948 HV (400&#xa0;°C heat-treated), and substantial reduction in wear loss. Ni-B coatings markedly enhanced corrosion resistance versus uncoated steel; however, post-deposition heat treatment reduced this benefit (HT-250 &gt; HT-400 in corrosion). Crystalline Ni-borides and surface NiO formed upon annealing increase hardness and wear resistance, but introduced grain boundary-assisted corrosion pathways, lowering corrosion resistance. Corrosion performance was reported via time-to-full-rust and mass-loss-based corrosion rates. Time-to-full-rust improved from 1&#xa0;h (uncoated) to 720&#xa0;h (Ni-B), 240&#xa0;h (HT-250), and 24&#xa0;h (HT-400); corresponding corrosion rates decreased by ~ 6.6 ×, ~ 3.1 ×, and ~ 1.8 ×.</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

Corrosion and Wear Performance of Electroless Ni-B-Coated Spring Steels for High-Speed Railway Applications: Effect of Post-Deposition Heat Treatment

  • 期刊论文

  • 发表日期：

    2025年10月27日

查看全文
  • Mustafa Dursunlar,
  • Zakir Taş,
  • Mustafa Kocabaş,
  • Müslim Çelebi,
  • Bekir Akgül

摘要

This study investigates the effect of electroless Ni-B coatings and subsequent heat treatments on the corrosion behavior of spring steels used in high-speed railway systems. Ni-B coatings were deposited via a commercial electroless plating bath, followed by heat treatment at 250 °C and 400 °C for 1 h. Surface morphology, elemental composition, and phase structure were characterized using SEM, EDS, and XRD analyses. Vickers microhardness measurements and pin-on-disk wear tests were conducted to evaluate the mechanical performance of the coatings. Corrosion resistance was evaluated by a 720-h salt spray test in accordance with EN ISO 9227. The results revealed that heat-treated Ni-B coatings exhibited improved mechanical properties, including a notable increase in surface hardness from 324 HV (uncoated) to 948 HV (400 °C heat-treated), and substantial reduction in wear loss. Ni-B coatings markedly enhanced corrosion resistance versus uncoated steel; however, post-deposition heat treatment reduced this benefit (HT-250 > HT-400 in corrosion). Crystalline Ni-borides and surface NiO formed upon annealing increase hardness and wear resistance, but introduced grain boundary-assisted corrosion pathways, lowering corrosion resistance. Corrosion performance was reported via time-to-full-rust and mass-loss-based corrosion rates. Time-to-full-rust improved from 1 h (uncoated) to 720 h (Ni-B), 240 h (HT-250), and 24 h (HT-400); corresponding corrosion rates decreased by ~ 6.6 ×, ~ 3.1 ×, and ~ 1.8 ×.