Scholarlink

<p>In order to solve the urgent energy crisis, high-performance steels with ultra-high strength and excellent cryogenic toughness are needed for the manufacture of marine and energy storage equipment. In this study, a novel V–N micro-alloyed Ni-saving ultra-high strength cryogenic steel was designed, and the effects of C–N on the prior austenite grains, retained austenite (RA), precipitates, and strength-toughness properties were investigated. With the increase of C–N, the grain size of prior austenite was remarkably refined. The fraction of RA increased with the morphology changing from blocky to filmy, and the stability of RA improved. In addition, the increased content of C–N facilitated the (V, Mo)(C, N) nano-precipitates. The fine grain strengthening, precipitation strengthening, and the durable TRIP effect of stabilized austenite made 11C–100N steel have ultra-high yield strength of 890&#xa0;MPa and tensile strength of 952&#xa0;MPa. The TRIP effect of stable RA and a high fraction of high-angle grain boundaries led to excellent cryogenic toughness of 117.1&#xa0;J at&#xa0;−&#xa0;196&#xa0;°C. Therefore, the combination of V and C–N atoms enabled RA stabilization, precipitation stimulation, and strength-toughness enhancement in 7Ni cryogenic steel, which provided theoretical support for the research and development of ultra-high strength cryogenic alloys.</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

Achieving outstanding yield strength-cryogenic toughness matching in V–N micro-alloyed 7Ni steel via stable austenite and nano-precipitates

  • 期刊论文

  • 发表日期：

    2026年3月25日

查看全文
  • Jun Hu,
  • Yidan Lv,
  • Qiqing Jing,
  • Jialin Chen,
  • Ruiqi Qiao,
  • Wei Xu

摘要

In order to solve the urgent energy crisis, high-performance steels with ultra-high strength and excellent cryogenic toughness are needed for the manufacture of marine and energy storage equipment. In this study, a novel V–N micro-alloyed Ni-saving ultra-high strength cryogenic steel was designed, and the effects of C–N on the prior austenite grains, retained austenite (RA), precipitates, and strength-toughness properties were investigated. With the increase of C–N, the grain size of prior austenite was remarkably refined. The fraction of RA increased with the morphology changing from blocky to filmy, and the stability of RA improved. In addition, the increased content of C–N facilitated the (V, Mo)(C, N) nano-precipitates. The fine grain strengthening, precipitation strengthening, and the durable TRIP effect of stabilized austenite made 11C–100N steel have ultra-high yield strength of 890 MPa and tensile strength of 952 MPa. The TRIP effect of stable RA and a high fraction of high-angle grain boundaries led to excellent cryogenic toughness of 117.1 J at − 196 °C. Therefore, the combination of V and C–N atoms enabled RA stabilization, precipitation stimulation, and strength-toughness enhancement in 7Ni cryogenic steel, which provided theoretical support for the research and development of ultra-high strength cryogenic alloys.

Graphical abstract