Manufacturing process of high-strength high-temperature-resistant steel material

Abstract

The invention discloses a manufacturing process of a high-strength high-temperature-resistant steel material, the steel material adopts a surface layer-transition layer-matrix composite reinforced structure, and the matrix is prepared from the following elements in percentage by mass: less than or equal to 0.030 wt% of C, 16.0-18.0 wt% of Cr, 10.0-14.0 wt% of Ni, 2.0-3.0 wt% of Mo, less than or equal to 2.00 wt% of Mn, less than or equal to 1.00 wt% of Si, less than or equal to 0.045 wt% of P, less than or equal to 0.030 wt% of S, less than or equal to 0.11 wt% of N and the balance of Fe and inevitable impurity elements; the transition layer comprises pure titanium foil and 0.1-0.3% (wt%) of Y2O3, and a Ti-Fe intermetallic compound interface is formed through vacuum hot pressing; and the surface layer adopts a plasma spraying TiC ceramic layer. According to the gradient composite design, through structural innovation and process cooperation, the steel material has better surface hardness, interface bonding strength, matrix tensile strength and high temperature resistance, directional regulation and control of the material performance are achieved, and wide application prospects are shown in the fields of aerospace, biomedicine, energy storage and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steel materials, and particularly relates to a manufacturing process of a high-strength high-temperature-resistant steel material. BACKGROUND

[0002] With the improvement of the performance requirements of materials in extreme service environments in the fields of aerospace, energy equipment and the like, the traditional high-strength high-temperature-resistant steel faces the following technical bottlenecks:

[0003] 1. Limitations of single material performance and lack of composite structure

[0004] The traditional high-temperature-resistant steel (such as GH2132 high-temperature alloy) is difficult to meet the multi-target requirements of high surface hardness (>= 600HV), matrix tensile strength (>= 1100MPa) and high-temperature resistance (>= 600℃) at the same time through the optimization of a single alloy system. For example, although the conventional hot work die steel (such as H13) has good thermal stability (600℃ hardness >= 600HV), the matrix toughness (impact energy <= 60J) and the interfacial bonding strength (<= 150MPa) limit its application in complex load scenarios.

[0005] 2. Interface bonding defects and insufficient gradient regulation

[0006] The existing composite plates rely on direct welding or hot pressing processes, and the interface is prone to form brittle intermetallic compounds and oxidation inclusions, resulting in an interface shear strength < 180MPa, and the interlayer peeling is prone to occur under high-temperature cyclic load. In addition, the traditional process lacks precise regulation of the gradient design of the transition layer composition, and cannot realize the continuous transition of hardness / toughness / corrosion resistance, which aggravates the risk of stress concentration.

[0007] 3. Low process coordination and design efficiency

[0008] The traditional material development relies on the trial-and-error method, such as the high-temperature-resistant steel, which needs to adjust the composition (such as Cr, Mo content) and heat treatment parameters through multiple pilot tests, and the development cycle is long and the cost is high. At the same time, the process parameters such as hot rolling and nitriding are optimized in isolation, which is difficult to match the synergistic strengthening requirements of the composite structure. For example, although single nitriding treatment can improve the surface hardness, it will aggravate the brittleness of the matrix, resulting in unbalanced overall performance.

[0009] 4. Performance degradation problem under high-temperature environment

[0010] The conventional high-temperature-resistant steel is prone to organization coarsening and carbide aggregation in long-term high-temperature service, for example, the strength retention rate of 42CrMo4 steel is < 70% at 600℃, and the surface oxide film is prone to peel off under thermal shock conditions, accelerating material failure. SUMMARY

[0011] The present application proposes the following technical solutions to solve the problems in the prior art:

[0012] High-strength high-temperature-resistant steel material, the steel material adopts a composite reinforcement structure of surface layer-transition layer-matrix, the preparation of the matrix includes the following mass percentages of elements: C: ≤0.030(wt%), Cr: 16.0-18.0(wt%), Ni: 10.0-14.0(wt%), Mo: 2.0-3.0(wt%), Mn: ≤2.00(wt%), Si: ≤1.00(wt%), P: ≤0.045(wt%), S: ≤0.030(wt%), N: ≤0.11(wt%), the rest is Fe and inevitable impurity elements;

[0013] The transition layer includes pure titanium foil and 0.1-0.3% (wt%) Y2O3, and a Ti-Fe intermetallic compound interface is formed by vacuum hot pressing; by setting the transition layer, the strength of the interface bonding can be strengthened, 0.1-0.3% (wt%) Y2O3 is added to purify the interface through grain boundary segregation and inhibit high-temperature oxidation.

[0014] The surface layer adopts a plasma sprayed TiC ceramic layer.

[0015] As a preferred embodiment of the above technical solution, the thickness of the surface layer is controlled to be 100-120μm, and the porosity is <5%, which can improve the density and thus ensure that the Vickers hardness of the surface layer is ≥3000HV.

[0016] As a preferred embodiment of the above technical solution, the spraying parameters of the plasma sprayed TiC are: power 40-60kW, powder feeding rate 30-50g / min, argon protection (flow rate 30L / min), and molten pool temperature >2000℃.

[0017] As a preferred embodiment of the above technical solution, the thickness of the transition layer is 10-20μm, and the mass percentage of Ti in the pure titanium foil is ≥99.6% (wt%).

[0018] As a preferred embodiment of the above technical solution, the vacuum hot pressing parameters are: temperature 900℃, pressure 20MPa.

[0019] A steel material manufacturing process, the manufacturing process is used for the above-mentioned high-strength high-temperature-resistant steel material, comprising the following steps:

[0020] S1, prepare raw materials based on the proportion of matrix elements, and pretreat the raw materials, put the pretreated raw materials into a melting furnace, melt at high temperature to form an alloy liquid, and then perform solid solution treatment after casting;

[0021] S2, sandblast pretreatment of the casted matrix, and clean and degrease to improve the surface activity;

[0022] S3, sticking pure titanium foil on the surface of the substrate treated in S2 and adding 0.1-0.3% (wt%) Y2O3 to form a Ti-Fe intermetallic compound interface by vacuum hot pressing;

[0023] S4, spraying a TiC ceramic layer by plasma spraying and immediately cooling by helium gas after spraying, so that grain coarsening can be inhibited.

[0024] As a preferred embodiment of the above technical solution, the pretreatment comprises impurity removal, classification and weighing of raw materials.

[0025] As a preferred embodiment of the above technical solution, the cooling rate of the helium gas cooling in S4 is ≥150℃ / s.

[0026] The present application has the following advantages:

[0027] The steel material of the present application adopts a composite strengthening structure of surface layer-transition layer-substrate, and gradient composite design through structural innovation and process synergy makes the steel material have better surface hardness, interface bonding strength, substrate tensile strength and high temperature resistance, realizes directional regulation of material performance, and shows broad application prospects in the fields of aerospace, biomedical, energy storage, etc. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution of the present application will be described clearly and completely below in combination with embodiments.

[0029] Embodiment 1

[0030] The high-strength high-temperature-resistant steel material adopts a composite strengthening structure of surface layer-transition layer-substrate, and the preparation of the substrate comprises the following elements in mass percentage: C: 0.025 (wt%), Cr: 17.0 (wt%), Ni: 12.0 (wt%), Mo: 2.5 (wt%), Mn: 1.05 (wt%), Si: 0.15 (wt%), P:.040 (wt%), S: 0.020 (wt%), N: 0.07 (wt%), and the rest is Fe and inevitable impurity elements.

[0031] The transition layer comprises pure titanium foil and 0.1 (wt%) Y2O3 to form a Ti-Fe intermetallic compound interface by vacuum hot pressing;

[0032] The surface layer adopts a TiC ceramic layer sprayed by plasma spraying;

[0033] The spraying thickness of the surface layer is 100 μm, and the control porosity is less than 5%; the spraying parameters of the plasma sprayed TiC are as follows: power 50 kW, powder feeding rate 40 g / min, argon protection (flow rate 30 L / min), and molten pool temperature 2500 ℃; the thickness of the transition layer is 10 μm, and the mass percentage of Ti in the pure titanium foil is greater than or equal to 99.6% (wt%); the vacuum hot pressing parameters are as follows: temperature 900 ℃, and pressure 20 MPa;

[0034] The steel material manufacturing steps are as follows: S1, preparing raw materials based on the proportion of base elements, pretreating the raw materials, putting the pretreated raw materials into a melting furnace, high-temperature melting to form an alloy liquid, solid solution treatment (1050 ℃ x 1 h) after casting forming;

[0035] S2, sandblasting pretreatment of the cast-formed base, and cleaning and degreasing to improve the surface activity;

[0036] S3, surface pasting of the base treated in S2 with a pure titanium foil and adding 0.2% (wt%) Y2O3, and forming a Ti-Fe intermetallic compound interface through vacuum hot pressing;

[0037] S4, plasma spraying of a TiC ceramic layer, and helium cooling immediately after spraying;

[0038] The pretreatment includes impurity removal, classification and weighing of the raw materials, and the cooling rate of the helium cooling in S4 is greater than or equal to 150 ℃ / s.

[0039] Example 2

[0040] A high-strength high-temperature-resistant steel material adopts a composite reinforcement structure of a surface layer-transition layer-base, the preparation of the base includes the following mass percentages of elements: C: 0.025 (wt%), Cr: 17.0 (wt%), Ni: 12.0 (wt%), Mo: 2.5 (wt%), Mn: 1.05 (wt%), Si: 0.15 (wt%), P:.040 (wt%), S: 0.020 (wt%), N: 0.07 (wt%), and the rest is Fe and inevitable impurity elements;

[0041] The transition layer includes a pure titanium foil and 0.2 (wt%) Y2O3, and a Ti-Fe intermetallic compound interface is formed through vacuum hot pressing;

[0042] The surface layer adopts a plasma sprayed TiC ceramic layer;

[0043] The spraying thickness of the surface layer is 110 μm, and the control porosity is less than 5%; the spraying parameters of the plasma sprayed TiC are as follows: power 50 kW, powder feeding rate 40 g / min, argon protection (flow rate 30 L / min), and molten pool temperature 2500 ℃; the thickness of the transition layer is 15 μm, and the mass percentage of Ti in the pure titanium foil is greater than or equal to 99.6% (wt%); the vacuum hot pressing parameters are as follows: temperature 900 ℃, and pressure 20 MPa;

[0044] The steel material manufacturing steps are as follows: S1, preparing raw materials based on the proportion of base elements, pretreating the raw materials, putting the pretreated raw materials into a melting furnace, high-temperature melting to form an alloy liquid, solid solution treatment (1050 ℃ x 1 h) after casting forming;

[0045] S2, sandblasting pretreatment of the cast-formed base, and cleaning and degreasing to improve the surface activity;

[0046] S3, surface pasting of the base treated in S2 with pure titanium foil and adding 0.2% (wt%) Y2O3, and forming a Ti-Fe intermetallic compound interface by vacuum hot pressing;

[0047] S4, plasma spraying of a TiC ceramic layer, and helium cooling immediately after spraying;

[0048] The pretreatment includes impurity removal, classification and weighing of the raw materials, and the cooling rate of the helium cooling in S4 is greater than or equal to 150 ℃ / s.

[0049] Example 3

[0050] A high-strength and high-temperature-resistant steel material, the steel material adopts a composite reinforcement structure of a surface layer-transition layer-base, the preparation of the base includes the following mass percentages of elements: C: 0.025 (wt%), Cr: 17.0 (wt%), Ni: 12.0 (wt%), Mo: 2.5 (wt%), Mn: 1.05 (wt%), Si: 0.15 (wt%), P:.040 (wt%), S: 0.020 (wt%), N: 0.07 (wt%), and the rest is Fe and inevitable impurity elements;

[0051] The transition layer includes a pure titanium foil and 0.3 (wt%) Y2O3, and a Ti-Fe intermetallic compound interface is formed by vacuum hot pressing;

[0052] The surface layer adopts a plasma sprayed TiC ceramic layer;

[0053] The spraying thickness of the surface layer is 120 mu m, and the controlled porosity is less than 5%; the spraying parameters of the plasma sprayed TiC are as follows: power 50 kW, powder feeding rate 40 g / min, argon protection (flow rate 30 L / min), and molten pool temperature 2500 DEG C; the thickness of the transition layer is 20 mu m, and the mass percentage of Ti in the pure titanium foil is greater than or equal to 99.6% (wt%); the vacuum hot pressing parameters are as follows: temperature 900 DEG C, and pressure 20 MPa;

[0054] The steel material manufacturing steps are as follows: S1, preparing raw materials based on the proportion of base elements, pretreating the raw materials, putting the pretreated raw materials into a melting furnace, high-temperature melting to form an alloy liquid, solid solution treatment (1050 DEG C x 1 h) after casting forming; S2, sandblasting pretreatment of the cast-formed base, and cleaning and degreasing to improve the surface activity; S3, surface of the base treated in S2 is attached with a pure titanium foil and 0.2% (wt%) Y2O3 is added, and a Ti-Fe intermetallic compound interface is formed by vacuum hot pressing; S4, plasma spraying a TiC ceramic layer, and immediately helium cooling after spraying.

[0055] S2, sandblasting pretreatment of the cast-formed base, and cleaning and degreasing to improve the surface activity; S3, surface of the base treated in S2 is attached with a pure titanium foil and 0.2% (wt%) Y2O3 is added, and a Ti-Fe intermetallic compound interface is formed by vacuum hot pressing; S4, plasma spraying a TiC ceramic layer, and immediately helium cooling after spraying.

[0056] S2, sandblasting pretreatment of the cast-formed base, and cleaning and degreasing to improve the surface activity; S3, surface of the base treated in S2 is attached with a pure titanium foil and 0.2% (wt%) Y2O3 is added, and a Ti-Fe intermetallic compound interface is formed by vacuum hot pressing; S4, plasma spraying a TiC ceramic layer, and immediately helium cooling after spraying.

[0057] S2, sandblasting pretreatment of the cast-formed base, and cleaning and degreasing to improve the surface activity; S3, surface of the base treated in S2 is attached with a pure titanium foil and 0.2% (wt%) Y2O3 is added, and a Ti-Fe intermetallic compound interface is formed by vacuum hot pressing; S4, plasma spraying a TiC ceramic layer, and immediately helium cooling after spraying.

[0058] The pretreatment includes impurity removal, classification and weighing of the raw materials, and the cooling rate of the helium cooling in S4 is greater than or equal to 150 DEG C / s.

[0059] The following table is the corresponding data of the steel materials prepared in the above three examples:

[0060]

[0061] In summary, the steel material of the application adopts a composite strengthening structure of surface layer-transition layer-base, gradient composite design realizes directional regulation of material performance through structural innovation and process synergy, and has better surface hardness, interface bonding strength, base tensile strength and high temperature resistance, and has broad application prospects in the fields of aerospace, biomedical, energy storage and the like.

[0062] The above examples are only used to illustrate the technical solutions of the application, rather than limit them.

Claims

1. High-strength and high-temperature resistant steel material, characterized by: The steel material adopts a composite strengthening structure of a surface layer-transition layer-matrix, and the matrix is ​​prepared to include the following elements in percentage by weight: C: ≤0.030 (wt%), Cr: 16.0-18.0 (wt%), Ni: 10.0-14.0 (wt%), Mo: 2.0-3.0 (wt%), Mn: ≤2.00 (wt%), Si: ≤1.00 (wt%), P: ≤0.045 (wt%), S: ≤0.030 (wt%), N: ≤0.11 (wt%), and the rest are Fe and unavoidable impurity elements; The transition layer comprises pure titanium foil and 0.1-0.3% (wt%) Y2O3, and a Ti-Fe intermetallic compound interface is formed by vacuum hot pressing; The surface layer is a plasma sprayed TiC ceramic layer.

2. The high-strength, high-temperature resistant steel material according to claim 1, characterized in that: The thickness of the surface layer is controlled at 100-120 μm, and the porosity is less than 5%.

3. The high-strength, high-temperature resistant steel material according to claim 1, characterized in that: The spraying parameters of the plasma spraying TiC are: power 40-60kW, powder feeding rate 30-50g / min, argon protection (flow rate 30L / min), and molten pool temperature >2000°C.

4. The high-strength, high-temperature resistant steel material according to claim 1, characterized in that: The thickness of the transition layer is 10-20 μm, and the mass percentage of Ti in the pure titanium foil is ≥99.6% (wt%).

5. The high-strength, high-temperature resistant steel material according to claim 1, characterized in that: The vacuum hot pressing parameters are: temperature 900° C., pressure 20 MPa.

6. A steel material manufacturing process, characterized in that: The manufacturing process is used to prepare the high-strength, high-temperature resistant steel material according to any one of claims 1 to 5, comprising the following steps: S1. Prepare raw materials based on the ratio of matrix elements, pre-treat the raw materials, put the pre-treated raw materials into a melting furnace, melt them at high temperature to form alloy liquid, cast them into shape, and then perform solid solution treatment; S2. Pre-treating the cast substrate by sandblasting, cleaning and degreasing to improve surface activity; S3, attaching pure titanium foil to the surface of the substrate treated in S2 and adding 0.1-0.3% (wt%) Y2O3, and forming a Ti-Fe intermetallic compound interface by vacuum hot pressing; S4. Plasma spraying of TiC ceramic layer, followed by helium cooling immediately after spraying.

7. A steel material manufacturing process according to claim 6, characterized in that: The pretreatment includes removing impurities, sorting and weighing the raw materials.

8. A steel material manufacturing process according to claim 6, characterized in that: The cooling rate of the helium cooling in S4 is ≥150°C / s.

Images