生物发酵罐叶片电弧增材制造及性能强化工艺研究OA

The stirring device of the bioreactor could rapidly mix the liquid inside the tank evenly.At present,the industrial production of the stirring device is mainly completed through casting and subsequent welding processes.Based on the tradi-tional manufacturing process of blades,a method of using wire arc additive manufacturing(WAAM)to deposit stainless steel blades in an integrated manner was proposed.Laser remelting(RM)was then applied to the surface of the blades to re-duce surface roughness.Subsequently,the microstructure and properties of WAAM and RM were compared to optimize the final process of the bioreactor stirring device blades.The results showed that compared with the blades manufactured by the traditional method,WAAM could deposit the stirring device blades in an integrated manner,reducing production processes and stress concentration caused by welding.The addition of RM not only reduced surface roughness but also decreased the"anisotropy"of microstructure and properties.After RM,the metallographic microstructure in each area was more uniform,and the Vickers hardness value was above 200 HV0.5,effectively reducing stress concentration.The self-corrosion potential was between-0.35 V and-0.2 V,and the difference in self-corrosion current density was reduced,resulting in more uniform corrosion resistance.In terms of tensile properties,the tensile strength was above 450 MPa for all samples.The tensile strength and elongation after fracture of RM were higher.The elongation after fracture along the deposition direction was greater than that perpendicular to the deposition direction.In summary,RM made the properties of different regions of the bioreactor agitator blades more uniform.