Superplastic forming nanocrystalline antibacterial martensitic stainless steel and preparation method thereof

Abstract

The invention relates to the technical field of materials, and discloses superplastic forming nanocrystalline antibacterial martensitic stainless steel and a preparation method thereof. The superplastic forming nanocrystalline antibacterial martensitic stainless steel is characterized by being prepared from the following chemical components in percentage, by weight, 0.16 to 0.32 of C; 12.8 to 14.4 of Cr; 1.4 to 3.0 of Cu; 1.2 to 2.8 of W; 0.04 to 0.20 of V; 0.01 to 0.03 of La; Mn is less than 0.15; N is less than 0.03; and the balance Fe. The preparation method of the stainless steel comprises the following steps of (1) preserving heat at 980-1060 DEG C for a period of time, and then quickly cooling to room temperature; (2) carrying out thermal deformation within the temperature of 820-900 DEG C and the strain rate of 0.1-1s <-1 >, and converting the nanolath precursor into an equiaxial nanocrystal structure, wherein the total strain capacity is greater than or equal to 70%; (3) carrying out superplastic forming under the conditions that the temperature is 760-840 DEG C and the strain rate of 0.001-0.02 s <-1 >; and (4) aging the material subjected to superplastic forming at the temperature of 460-500 DEG C for 3-5 hours. The prepared superplastic forming nanocrystalline antibacterial martensitic stainless steel has excellent hot working performance, corrosion resistance, antibacterial performance and comprehensive mechanical performance, and can be widely applied to medical instruments in the cutting fields of knives, scissors and the like.

Description

technical field [0001] The invention relates to the technical field of materials, in particular to a superplastic formed nanocrystalline antibacterial martensitic stainless steel and a preparation method thereof. Background technique [0002] Copper-containing antibacterial martensitic stainless steel is to add Cu element with broad-spectrum antibacterial function to traditional martensitic stainless steel, and use the Cu ions released continuously during the contact with the medium solution environment to participate in the killing process of bacteria. Applying copper-containing antibacterial martensitic stainless steel to the preparation of cutting medical instruments such as scalpels and surgical scissors is expected to significantly reduce the risk of bacterial infection during surgery. However, the copper-containing antibacterial martensitic stainless steel has also exposed the following two deficiencies in the actual use process: first, the addition of Cu leads to a si...

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Problems solved by technology

However, the copper-containing antibacterial martensitic stainless steel has also exposed the following two deficiencies in the actual use process: first, the addition of Cu leads to a significant decrease in the thermal processing performance of the material, which greatly increases the cost of thermal processing of the material; second, in the Although the Cu-rich phase precipitated during the aging process can endow the material with antibacterial properties, the reduction in the corrosion resistance of the material cannot be ignored.

Common large plastic deformation methods include equal channel angular extrusion (ECAP), cumulative composite rolling (ARB), multidirectional forging (MF) and high pressure torsion (HPT), etc., all of which require high-power equipment and expensive molds , the size of the prepared material is also small, which cannot meet the needs of large-scale industrial production

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