Scholarlink

<p>Nitrogen absorption during press-and-sinter processing of powder metallurgy high-speed steels (HSS) remains insufficiently understood despite its strong influence on sintering behaviour. In this work, the mechanisms of nitrogen uptake were investigated through experimental studies supported by computational thermodynamics. Experimental HSS grades with compositions beyond the conventional alloying range were designed to assess the influence of individual alloying elements and key processing variables, together with the predictive capability of Thermo-Calc<sup>®</sup> software.</p><p>Water-atomized powders were processed via press-and-sinter, enabling higher alloying levels than conventional wrought routes and challenging established compositional limits. Although the analysed compositions exceeded the validated range of Thermo-Calc<sup>®</sup>, calculated phase diagrams showed good agreement with experiments and provided insight into nitrogen absorption. Vanadium content and nitrogen activity were identified as the primary controlling factors, whereas carbon and strong carbide-forming elements such as tungsten hinder nitrogen uptake.</p><p>Increasing nitrogen potential widens the sintering window and lowers the Optimum Sintering Temperature (OST) by 20–40&#xa0;°C. The sintering window expanded from ~ 40&#xa0;°C to ~ 100&#xa0;°C, representing an almost threefold increase, while the amount of liquid formed during Supersolidus Liquid Phase Sintering at the OST remained essentially constant.</p><p>These findings provide new insight into nitrogen interactions in PM HSS and clarify the role of vanadium carbides in nitrogen uptake during sintering, offering guidelines for controlling nitrogen absorption and improving the robustness of sintering processes for highly alloyed high-speed steels. </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

Nitrogen absorption mechanism in powder metallurgy high-speed steels sintered in nitrogen-rich atmospheres

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年5月19日

查看全文
  • Itziar Iraola-Arregui,
  • Lorena Lozada,
  • Ane Miren Mancisidor,
  • Iñigo Iturriza

摘要

Nitrogen absorption during press-and-sinter processing of powder metallurgy high-speed steels (HSS) remains insufficiently understood despite its strong influence on sintering behaviour. In this work, the mechanisms of nitrogen uptake were investigated through experimental studies supported by computational thermodynamics. Experimental HSS grades with compositions beyond the conventional alloying range were designed to assess the influence of individual alloying elements and key processing variables, together with the predictive capability of Thermo-Calc® software.

Water-atomized powders were processed via press-and-sinter, enabling higher alloying levels than conventional wrought routes and challenging established compositional limits. Although the analysed compositions exceeded the validated range of Thermo-Calc®, calculated phase diagrams showed good agreement with experiments and provided insight into nitrogen absorption. Vanadium content and nitrogen activity were identified as the primary controlling factors, whereas carbon and strong carbide-forming elements such as tungsten hinder nitrogen uptake.

Increasing nitrogen potential widens the sintering window and lowers the Optimum Sintering Temperature (OST) by 20–40 °C. The sintering window expanded from ~ 40 °C to ~ 100 °C, representing an almost threefold increase, while the amount of liquid formed during Supersolidus Liquid Phase Sintering at the OST remained essentially constant.

These findings provide new insight into nitrogen interactions in PM HSS and clarify the role of vanadium carbides in nitrogen uptake during sintering, offering guidelines for controlling nitrogen absorption and improving the robustness of sintering processes for highly alloyed high-speed steels.