Near-net forging of high strength AISI316 stainless steel wires using massively nitrogen supersaturated CoCrMo superalloy dies
Tatsuhiko Aizawa, Tatsuya Fukuda, Takafumi Komatsu
Abstract. A fine grained AISI316 wire with the yield stress of 600 MPa and the ultimate strength of 1.2 GPa, has been highlighted as a new surgical instrument steel in the medical applications. Due to its high strength and hardness, its near-net forging and forming was difficult to be fulfilled in manufacturing without innovative die technology. Massive nitrogen supersaturation (MNS) process was proposed to build up the multi-layered structure into CoCrMo supper alloy dies via the plasma immersion nitriding at 723 K for 21. 6 ks. The top layer with the thickness of 30 m had nano-granular structure with the hardness of 1300 HV1N. These MNSed CoCrMo dies were respectively utilized as an upper and lower die for upsetting the fine grained AISI316 wire with the diameter of 1.0 mm to the reduction of thickness by 70%. Preserving the low friction and adhesive wear conditions, the round wire was homogeneously upset to a thin plate with thickness of 0.3 mm. The effect of plasma nitriding conditions on the hardening behavior was studied to yield a robust MNSed CoCrMo die. A near-net forging experiment was performed to demonstrate that a medical instrument steel with the shaped cross-section was fabricated using the MNSed CoCrMo dies.
Keywords
Near-Net Forging, Massive Nitrogen Supersaturation, Superalloy Die, High Strength AISI316 Wire, Galling-Free, Die Endurance
Published online 5/7/2025, 10 pages
Copyright © 2025 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Tatsuhiko Aizawa, Tatsuya Fukuda, Takafumi Komatsu, Near-net forging of high strength AISI316 stainless steel wires using massively nitrogen supersaturated CoCrMo superalloy dies, Materials Research Proceedings, Vol. 54, pp 1077-1086, 2025
DOI: https://doi.org/10.21741/9781644903599-117
The article was published as article 117 of the book Material Forming
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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