Introduction High nitrogen nickel free stainless steel has begun to be used in clinic, which possesses excellent mechanical properties, corrosion resistance and biocompatibility. Especially its strength is two times more than that of the conventional 316L stainless steel, but this advantage is not fully used in optimization of both the structure and the size of the implant devices. Materials and experiments The Fe-18Cr-15Mn-2Mo-0.85N, developed by Institute of Metal Research, Chinese Academy of Science, was melted in a 50 kg pressurized induction melting furnace under 1 MPa pure nitrogen gas pressure, then was forged, rolled and solution treated to obtain a homogeneous austenitic microstructure. In this paper, the mechanical properties of nickel free stanless steel was studied firstly, Lightweight design model of nickel free stainless steel implants was set up using bone plate, and the effect of dimensional of stainless steel bone plate on the biomechanical behavior was studied by means of finite element analysis, finally the effects of lightweight on bone plate biomechanical behavior and implantation performance were studied and veriefied through animal tests. Conclusion The results showed that high nitrogen nickel free stainless steel has excellent mechanical properties, especially after cold deformation. The high nitrogen steel bone plate with 0.8mm in thickness still has better bending strength, compared with 316L stainless steel bone plate with 1.1mm in thickness. The preliminary animal test result also showed the high nitrogen steel bone plate with 0.9mm in thickness (lightweight ratio is about 18%) has better biomechanical compatibility, the lightweight design of High nitrogen nickel free stainless steel implants will promote the development and potential clinical application of high strength stainless steel implant devices.
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