A kind of ultra-high strength nanocrystalline 20cr13w3co2 stainless steel and its preparation method

Abstract

The invention relates to the technical field of materials, in particular to an ultra-high-strength nanocrystalline 20Cr13W3Co2 stainless steel and a preparation method thereof. The chemical composition of the stainless steel is as follows (% by weight): C: 0.16-0.24; Cr: 12.6-13.4; Co: 1.6-2.4; W: 2.6-3.4; Ti: 0.02-0.04; Ce: 0.01-0.03; Mn<0.15 ; N<0.01; the balance is Fe. The preparation method of the stainless steel is as follows: (1) after being kept at 1000-1080°C for a period of time, it is rapidly cooled to room temperature to obtain the nano-slab precursor; The rate is 0.5~2s ‑1 Thermal deformation within a certain range, the total strain is greater than or equal to 70%, so that the nano-slab precursor is transformed into a nano-crystalline structure; (3) The nano-crystalline material is aged at 460-500 ° C for 4 hours, and rapidly cooled to room temperature after aging. The nanocrystalline stainless steel prepared by the invention has super high strength, good plastic toughness and excellent corrosion resistance, and can be widely used in the preparation of various cutting tools, moulds, steam turbine blades and wear-resistant medical instruments and other devices.

Description

technical field [0001] The invention relates to the technical field of materials, in particular to a high-strength nanocrystalline 20Cr13W3Co2 stainless steel and a preparation method thereof. Background technique [0002] With the rapid development of economy and society, the performance of traditional stainless steel materials is gradually difficult to meet the needs of all walks of life, and it is urgent to develop new stainless steel materials with higher performance. People try to increase the hardness and wear resistance of stainless steel by increasing the content of carbon and chromium. However, with the improvement of material strength, its plasticity and corrosion resistance are significantly reduced. This bottleneck problem has not been properly resolved, resulting in the long-term stagnation of the development of traditional stainless steel materials. [0003] Compared with coarse-grained steel materials, nanocrystalline steel materials have excellent comprehens...

AI Technical Summary

Problems solved by technology

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

Images