CN-121976128-A - Light-weight high-strength and high-toughness medium manganese steel and preparation method and application thereof

Abstract

The invention relates to the technical field of metal materials, and particularly discloses a lightweight high-strength and high-toughness medium manganese steel, and a preparation method and application thereof. The method comprises the steps of firstly pre-oxidizing a hot rolled plate in a specific low oxygen partial pressure atmosphere, and forming a compact Al 2 O 3 -MnO composite oxide layer which is well combined with a matrix on the surface in situ. Then, in multi-pass warm rolling, the oxide layer can realize synchronous plastic deformation with the matrix, and interfacial peeling is avoided. Finally, in the cyclic annealing process, the surface oxide layer is used as a diffusion barrier to inhibit the leakage of Mn element and enrich the core, so that a heterogeneous structure with continuous gradient characteristics is successfully constructed, wherein the surface layer is superfine martensite, the transition region is an austenite-ferrite dual-phase structure, and the core is Mn-rich coarse-grain austenite. The gradient tissue enables the material to have high strength, high wear resistance and high plasticity, and is suitable for medical instruments with comprehensive requirements on mechanical properties, light weight and biocompatibility, such as a knee joint tractor fixing support.

Inventors

• WANG CONG
• ZHANG YU
• ZHANG DI
• WANG BO
• XU LONGYANG
• Wei Pengdie

Assignees

• 河北省体育科学研究所(河北省体育局反兴奋剂服务中心)
• 河北科技大学

Dates

Publication Date

20260505

Application Date

20251219

Claims (10)

1. 1. A lightweight high-strength medium manganese steel is characterized by comprising, by weight, 0.15% -0.25% of C, 7.0% -9.0% of Mn, 2.5% -3.5% of Al, 3.0% -4.0% of Ni, 1% -2% of Cu, less than or equal to 0.005% of S, less than or equal to 0.01% of P, less than or equal to 0.006% of N, less than or equal to 0.1% of Si, and the balance of Fe and unavoidable impurities.
2. 2. The method for preparing the lightweight high-strength and high-toughness medium manganese steel as claimed in claim 1, which is characterized by comprising the following steps: s1, smelting and casting a steelmaking raw material to obtain a steel ingot; s2, carrying out rough rolling after homogenizing the steel ingot at 1150-1250 ℃, carrying out hot rolling after heating to 1150-1250 ℃ and preserving heat, and carrying out water cooling to obtain a hot rolled plate; S3, pre-oxidizing the hot rolled plate in a mixed atmosphere of 450-500 ℃ and N 2 +H 2 with oxygen partial pressure of 10 -4 Pa~10 -3 Pa to form an Al 2 O 3 -MnO oxide layer on the surface of the hot rolled plate, and performing multi-pass warm rolling to obtain a warm rolled plate; And S4, preserving the heat of the warm rolled plate at the austenitizing temperature, entering a cryogenic medium after the heat preservation is finished, carrying out cryogenic heat preservation, and then carrying out cyclic annealing treatment to obtain the lightweight high-strength and high-toughness medium manganese steel.
3. 3. The method for preparing lightweight high-strength medium manganese steel according to claim 2, wherein in S2, the homogenization treatment is carried out for 110-120 min, and/or S2, the heat preservation time is 110-130 min, and/or In S2, the hot rolling is performed in 6-7 passes, the reduction rate of each pass is 25% -35%, and the hot rolling temperature is 900-1100 ℃.
4. 4. A method for producing a lightweight high strength and toughness medium manganese steel according to claim 2 or 3, wherein in S2, the diameter D of the hot rolling medium roll and the thickness h of the rolled product satisfy 10≤D/h≤110, and/or In S2, the cooling rate of the water cooling is 20-50 ℃ per second, and/or And S2, the thickness of the hot rolled plate is 1 mm-5 mm.
5. 5. The method for preparing the lightweight high-strength medium manganese steel according to claim 2, wherein in S3, the volume ratio of H 2 in the mixed atmosphere is 4% -6%, and/or And S3, the pre-oxidation time is 20-30 min.
6. 6. The method for preparing the lightweight high-strength medium manganese steel according to claim 2, wherein in S3, the temperature of warm rolling is 550-600 ℃, the pass deformation is 20-35%, the total deformation is 50-70%, and heat preservation treatment is carried out between two adjacent warm rolling, the heat preservation temperature is 550-600 ℃, the heat preservation time is 4.5-5.5 min, and/or In S3, the strain rate of warm rolling is 0.1S -1 ~1s -1 .
7. 7. The method for preparing light-weight high-strength medium manganese steel according to claim 2, wherein in S4, the austenitizing temperature is 790-810 ℃, the heat preservation time is 50-70 min, and/or In S4, the cryogenic medium is liquid nitrogen, and the time of cryogenic heat preservation is not less than 30S.
8. 8. The method for preparing the lightweight high-strength medium manganese steel according to claim 2, wherein in the step S4, the temperature of the cyclic annealing treatment is 640-660 ℃, and the heat preservation time is 15-25 min.
9. 9. The method for preparing the lightweight high-strength medium manganese steel according to claim 2, wherein in the step S4, the number of times of the cyclic annealing treatment is 2-3.
10. 10. The use of the lightweight high strength and toughness medium manganese steel of claim 1 in a knee joint retractor fixation brace.

Description

Light-weight high-strength and high-toughness medium manganese steel and preparation method and application thereof Technical Field The invention relates to the technical field of metal materials, in particular to a lightweight high-strength and high-toughness medium manganese steel, and a preparation method and application thereof. Background The knee joint is used as the joint with the greatest load and the most complex movement of the human body, and the rehabilitation process after injury of the knee joint brings stringent requirements on the mechanical property and the use comfort of the external fixing support. The knee joint tractor fixing support is used as a clinical common rehabilitation auxiliary instrument, and has the core functions of providing stable support for a damaged knee joint, realizing accurate mechanical compensation, ensuring the joint fixing effect and simultaneously considering the moderate activity requirement of the joint so as to promote local blood circulation and functional recovery. However, the conventional knee joint tractor fixing brace products on the market generally have technical bottlenecks that the supporting performance and the use experience are difficult to be compatible, and the improvement of the rehabilitation effect is seriously restricted. The existing fixed brace products are mainly divided into two types, namely a flexible knee pad taking elastic fabric as a core, the flexible knee pad is applied to a certain extent by virtue of the advantages of light weight and wearing and attaching, but is limited by the mechanical characteristics of materials, so that accurate and stable joint mechanical compensation cannot be provided for knee joints, the supporting force is seriously insufficient, the rigid fixing requirements of postoperative or acute stage of injury are difficult to meet, and the rigid knee pad adopting a rigid support made of metal materials such as aluminum alloy, stainless steel and the like is used for ensuring the supporting strength, the weight of the rigid support is usually more than 500 g, the lower limb muscle fatigue and the activity convenience are easy to be reduced when a patient wears the flexible knee pad for a long time, and adverse reactions such as skin allergy, contact dermatitis and the like can be caused when the metal material contacts human skin for a long time, so that the wearing compliance of the patient is reduced. In recent years, due to the unique component design of the medium manganese steel, excellent matching of high strength and high plasticity can be realized through heterostructure regulation, and compared with the traditional materials such as stainless steel, aluminum alloy and the like, the medium manganese steel has remarkable weight reduction potential under the same supporting strength, and a material solution with great prospect is provided for solving the contradiction. However, the application of the medium manganese steel in the field of rehabilitation instruments still faces the key technical obstacle, namely the dynamic adaptability is lost, the mechanical property of the medium manganese steel is difficult to be precisely matched with the motion rule of the knee joint, the self-adaptive adjustment of the supporting rigidity cannot be realized according to different motion states such as joint flexion and extension, and the complex requirement of the fixed support on the dynamic mechanical property is difficult to be met. Therefore, a light-weight high-strength medium manganese steel material is developed and applied to the knee joint tractor fixing support, and has important practical significance and application value for improving the performance level of a rehabilitation instrument and meeting clinical rehabilitation requirements. Disclosure of Invention Aiming at the problems of lack of dynamic adaptability, insufficient light weight and high strength and toughness cooperative performance and the like of the medium manganese steel in the application of the knee joint tractor fixing support, the invention provides the light weight high strength and toughness medium manganese steel, and the preparation method and application thereof. In order to solve the technical problems, the technical scheme provided by the embodiment of the invention is as follows: According to the first aspect, the lightweight high-strength medium manganese steel comprises, by weight, 0.15% -0.25% of C, 7.0% -9.0% of Mn, 2.5% -3.5% of Al, 3.0% -4.0% of Ni, 1% -2% of Cu, less than or equal to 0.005% of S, less than or equal to 0.01% of P, less than or equal to 0.006% of N, less than or equal to 0.1% of Si, and the balance of Fe and unavoidable impurities. Compared with the prior art, the design concept of the chemical components of the lightweight high-strength medium manganese steel provided by the invention is as follows: (1) Carbon can be used as an austenite stabilizing element, can be used for cooperatively prolonging an