High-temperature resistant, high-creep-resistant micro-nanoparticle reinforced mold steel and its preparation method

Abstract

This invention provides a high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel and its preparation method, comprising: Step 1, under N2 protection, subjecting Ti-Si-Nb wire to an electro-explosion reaction to obtain mixed nanoparticles containing TiN, Si3N4, and NbN; Step 2, mixing the obtained TiN, Si3N4, and NbN mixed nanoparticles with pure iron powder to obtain three mixed powders, then sequentially adding the three mixed powders to aluminum foil, and encapsulating them with a wire wrapping machine to obtain aluminum foil-coated mixed particle gradient distribution wire; Step 3, melting the mold steel into molten steel under argon atmosphere, adding aluminum foil-coated mixed particle gradient distribution wire, and then performing refining, casting, electroslag remelting, high-temperature diffusion, multi-directional forging, and heat treatment to obtain a high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel.

Description

Technical Field

[0001] This invention belongs to the field of high-performance hot work die steel technology, and specifically relates to high-temperature resistant, high-creep-resistant micro-nano-particle reinforced die steel and its preparation method. Background Technology

[0002] In many high-temperature and high-pressure applications, such as power plants and petrochemical plants, mold steel plays a crucial role, and its excellent high-temperature resistance makes it an indispensable material in many high-temperature processes. Currently, when mold steel is used in die-casting molds, hot forging molds, and extrusion molds, its resistance to thermal fatigue, high-temperature wear, and high-temperature creep is struggling to meet the ever-increasing demands. In recent years, some progress has been made in improving the thermal fatigue and wear resistance of mold steel. However, in practical applications, the harsh conditions of high temperature, high pressure, and high friction that mold steel endures can still cause creep deformation, affecting its shape accuracy, surface quality, and even the integrity of the mold steel. Existing technologies mainly improve the high-temperature creep resistance of mold steel through alloying design, optimized heat treatment processes, and surface treatments, but these methods suffer from complex processes and increased costs. Therefore, improving the high-temperature creep resistance of mold steel is of great significance for extending mold service life and improving forming accuracy. How to significantly improve the high-temperature creep resistance, thermal fatigue resistance, and high-temperature wear resistance of mold steel without increasing costs or process complexity has become an urgent technical challenge. Summary of the Invention

[0003] To address the aforementioned technical challenges, this invention provides a high-temperature resistant, high-creep-resistant micro-nanoparticle reinforced mold steel, the preparation method of which includes the following steps:

[0004] 1. A high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel, characterized in that its preparation method includes the following steps:

[0005] (1) Under N2 protection, Ti-Si-Nb filaments are subjected to an electro-explosion reaction to obtain mixed nanoparticles containing TiN, Si3N4 and NbN, hereinafter referred to as the first mixed nanoparticles. The electro-explosion reaction is as follows: voltage 200-600V, current 400-800A, pressure 1-5MPa. The composition of Ti-Si-Nb filaments by mass percentage is as follows: Ti: 5-35%, Si: 20-50%, Nb: 20-70%.

[0006] (2) The first mixed nanoparticles obtained in step (1) are mixed with pure iron powder at a speed of 10-30 r / min for 10-20 h according to mass ratios of 20-45:55-80, 30-55:45-70 and 40-65:35-60 to obtain the second mixed particles, the third mixed particles and the fourth mixed particles. The second, third and fourth mixed particles are added to pure aluminum foil in sequence according to mass ratios of 10-30:25-40:35-60, and then encapsulated with a wire wrapping machine at a speed of 3-8 m / min to obtain aluminum foil-coated mixed particle gradient distribution wire.

[0007] The pure iron powder has a particle size of 30-180 μm;

[0008] (3) Under argon protection, the mold steel is melted at 1700-1800℃ for 60-120 min, and the aluminum foil-coated mixed particle gradient distribution wire obtained in step (2) is added. After refining for 50-80 min, casting, electroslag remelting, high-temperature diffusion, multi-directional forging and heat treatment, a high-temperature resistant and high-creep-resistant micro-nano particle reinforced mold steel is obtained. The mass ratio of the aluminum foil-coated mixed particle gradient distribution wire to the mold steel is 0.005-0.0045%:1.

[0009] The composition of the mold steel, by weight percentage, is as follows: C: 0.35-0.45 wt.%; Si: 0.20-0.25 wt.%; Mn: 0.35-0.40 wt.%; P: ≤0.010 wt.%; S: ≤0.005 wt.%; Cr: 4.5-5.0 wt.%; V: 0.50-0.60 wt.%; Mo: 2.7-3.0 wt.%; N: ≤0.05 wt.%; H: ≤0.0005 wt.%; O: ≤0.0010 wt.%, with the balance being Fe;

[0010] The electroslag remelting is characterized by: current of 5000-10000A, voltage of 20-40V, and molten pool temperature of 1500-1800℃.

[0011] The high-temperature diffusion is described as follows: maintaining a temperature of 1250-1300℃ for 5-15 hours;

[0012] The multi-directional forging process is characterized by a forging temperature of 1050–1200℃ and a forging ratio of 5–10:1.

[0013] The heat treatment is as follows: under vacuum conditions, hold at 550℃ for 30 minutes, then raise the temperature to 1150℃ and hold for 100 minutes; use oil quenching, and then hold at 550℃ for 6 hours.

[0014] The obtained high-temperature resistant and high-creep-resistant micro-nanoparticle reinforced die steel has a creep life ≥10.1h, creep strain ≥24.9%, and minimum strain rate ≤8.38×10⁻⁶. -7 s -1 .

[0015] Further, the electro-explosion reaction in step (1) is: voltage 300-500V, current 500-700A, pressure 2-4MPa; the composition of the Ti-Si-Nb wire by mass percentage is: Ti: 10-30%, Si: 25-45%, Nb: 25-65%.

[0016] Further, in step (2), the first mixed nanoparticles obtained in step (1) are mixed with pure iron powder at a speed of 15-25 r / min for 12-18 h according to mass ratios of 25-40:60-75, 35-50:50-65 and 45-60:40-55 to obtain second mixed particles, third mixed particles and fourth mixed particles. The second, third and fourth mixed particles are added to pure aluminum foil in sequence according to mass ratios of 15-25:30-35:40-55, and then encapsulated with a wire wrapping machine at a speed of 4-6 m / min to obtain aluminum foil-coated mixed particle gradient distribution wire.

[0017] Further, the composition of the mold steel described in step (3) by mass percentage is as follows: C: 0.36-0.42 wt.%; Si: 0.21-0.24 wt.%; Mn: 0.36-0.39 wt.%; P: ≤0.009 wt.%; S: ≤0.004 wt.%; Cr: 4.6-4.9 wt.%; V: 0.51-0.59 wt.%; Mo: 2.8-2.9 wt.%; N: ≤0.04 wt.%; H: ≤0.0004 wt.%; O: ≤0.0009 wt.%, with the balance being Fe.

[0018] Furthermore, the electroslag remelting is characterized by: a current of 6000-9000A, a voltage of 25-35V, and a molten pool temperature of 1600-1700℃;

[0019] The high-temperature diffusion is described as follows: maintaining a temperature of 1260-1290℃ for 8-12 hours;

[0020] The multi-directional forging process is characterized by a forging temperature of 1100-1150℃ and a forging ratio of 6-9:1. Attached Figure Description

[0021] Figure 1 The image shows the creep curves of the high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel 1 obtained in Example 1 of this invention at 600℃ and 630MPa.

[0022] Figure 2 The image shows the creep curves of the high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel 2 obtained in Example 2 of this invention at 600℃ and 630MPa.

[0023] Figure 3 The image shows the creep curves of the high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel 3 obtained in Example 3 of the present invention at 600℃ and 630MPa.

[0024] Figure 4 This is a creep curve of the mold steel 4 obtained in Comparative Example 1 of the present invention at 600℃ and 630MPa; Detailed Implementation

[0025] Example 1

[0026] The preparation method of high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel 1 is as follows:

[0027] (1) Under N2 protection, Ti-Si-Nb filaments were subjected to an electro-explosion reaction to obtain mixed nanoparticles containing TiN, Si3N4 and NbN, hereinafter referred to as the first mixed nanoparticles. The electro-explosion reaction was carried out at a voltage of 300V, a current of 500A and a pressure of 2MPa. The composition of the Ti-Si-Nb filaments by mass percentage was: Ti: 10%, Si: 25%, Nb: 65%.

[0028] (2) The first mixed nanoparticles obtained in step (1) were mixed with pure iron powder at a speed of 20 r / min for 15 h according to mass ratios of 25:75, 35:65 and 45:55 respectively to obtain the second mixed particles, the third mixed particles and the fourth mixed particles. The second, third and fourth mixed particles were added to pure aluminum foil in sequence according to a mass ratio of 15:30:55, and then encapsulated with a wire wrapping machine at a speed of 5 m / min to obtain aluminum foil-coated mixed particle gradient distribution wire 1.

[0029] The pure iron powder has a particle size of 30-180 μm;

[0030] (3) Under argon protection, the mold steel is melted at 1700℃ for 100 min, and the aluminum foil-coated mixed particle gradient distribution wire 1 obtained in step (2) is added. After refining, casting, electroslag remelting, high temperature diffusion, multi-directional forging and heat treatment for 60 min, high temperature resistant and high creep resistant micro nanoparticle reinforced mold steel 1 is obtained. The mass ratio of the aluminum foil-coated mixed particle gradient distribution wire 1 to the mold steel is 0.009%:1.

[0031] The composition of the mold steel, by weight percentage, is as follows: C: 0.38 wt.%; Si: 0.23 wt.%; Mn: 0.35 wt.%; P: 0.006 wt.%; S: 0.001 wt.%; Cr: 4.8 wt.%; V: 0.52 wt.%; Mo: 2.8 wt.%; N: 0.01 wt.%; H: 0.0001 wt.%; O: 0.0006 wt.%, with the balance being Fe;

[0032] The electroslag remelting is performed with a current of 6000A, a voltage of 35V, and a molten pool temperature of 1600℃.

[0033] The high-temperature diffusion is described as: holding at 1260℃ for 12 hours;

[0034] The multi-directional forging process is characterized by a forging temperature of 1050-1200℃ and a forging ratio of 8:1.

[0035] The heat treatment is as follows: under vacuum conditions, hold at 550℃ for 30 minutes, then raise the temperature to 1150℃ and hold for 100 minutes; use oil quenching, and then hold at 550℃ for 6 hours.

[0036] The creep curves of the high-temperature resistant, high-creep-resistant micro-nanoparticle reinforced mold steel 1 obtained in this embodiment under conditions of 600℃ and 630MPa are shown below. Figure 1 As shown, its creep life is 10.1 h, creep strain is 24.9%, and minimum strain rate is 8.38 × 10⁻⁶. -7 s -1 Compared with the mold steel in step (3) of the aluminum foil-coated mixed particle gradient distribution wire 1, the high temperature resistant and high creep resistance micro-nano particle reinforced mold steel 1 has a creep life and strain increased by 47.0% and 9.2% respectively, and a minimum strain rate decreased by 25.8%. In addition, the high temperature resistant and high creep resistance micro-nano particle reinforced mold steel 1 improves the creep performance, while also improving the strength, plasticity and thermal stability, that is, it achieves a simultaneous improvement in comprehensive performance and is suitable for industrial production. Its microstructure contains uniformly distributed fine nanoparticles.

[0037] Example 2

[0038] The preparation method of high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel 2 is as follows:

[0039] (1) Under N2 protection, Ti-Si-Nb filaments were subjected to an electro-explosion reaction to obtain mixed nanoparticles containing TiN, Si3N4 and NbN, hereinafter referred to as the first mixed nanoparticles. The electro-explosion reaction was carried out at a voltage of 400V, a current of 600A and a pressure of 3MPa. The composition of the Ti-Si-Nb filaments by mass percentage was: Ti: 20%, Si: 35%, Nb: 45%.

[0040] (2) The first mixed nanoparticles obtained in step (1) were mixed with pure iron powder at a speed of 25 r / min for 12 h according to mass ratios of 32:68, 43:57 and 54:46 respectively to obtain the second mixed particles, the third mixed particles and the fourth mixed particles. The second, third and fourth mixed particles were added to pure aluminum foil in sequence according to a mass ratio of 20:35:45, and then encapsulated with a wire wrapping machine at a speed of 6 m / min to obtain aluminum foil-coated mixed particle gradient distribution wire 2.

[0041] The pure iron powder has a particle size of 30-180 μm;

[0042] (3) Under argon protection, the mold steel is melted at 1740℃ for 90 min, and the aluminum foil-coated mixed particle gradient distribution wire 2 obtained in step (2) is added. After refining for 65 min, casting, electroslag remelting, high-temperature diffusion, multi-directional forging and heat treatment, high-temperature resistant, high-creep resistant micro-nano particle reinforced mold steel 2 is obtained; the mass ratio of the aluminum foil-coated mixed particle gradient distribution wire 2 to the mold steel is 0.018%:1.

[0043] The composition of the mold steel, by weight percentage, is as follows: C: 0.39 wt.%; Si: 0.24 wt.%; Mn: 0.38 wt.%; P: 0.008 wt.%; S: 0.001 wt.%; Cr: 5.0 wt.%; V: 0.58 wt.%; Mo: 2.9 wt.%; N: 0.01 wt.%; H: 0.0001 wt.%; O: 0.0009 wt.%, with the balance being Fe;

[0044] The electroslag remelting is performed with a current of 10000A, a voltage of 20V, and a molten pool temperature of 1650℃.

[0045] The high-temperature diffusion is described as: holding at 1270℃ for 8 hours;

[0046] The multi-directional forging process is characterized by a forging temperature of 1050-1200℃ and a forging ratio of 9:1.

[0047] The heat treatment is as follows: under vacuum conditions, hold at 550℃ for 30 minutes, then raise the temperature to 1150℃ and hold for 100 minutes; use oil quenching, and then hold at 550℃ for 6 hours.

[0048] The creep curve of the mold steel 2 obtained in this embodiment under conditions of 600℃ and 630MPa is as follows: Figure 2 As shown, its creep life is 12.0 h, creep strain is 26.9%, and minimum strain rate is 6.67 × 10⁻⁶. -7 s -1 Compared with the mold steel in step (3) of the aluminum foil-coated mixed particle gradient distribution wire 2, the high temperature resistant and high creep resistance micro-nano particle reinforced mold steel 2 has a creep life and strain increased by 74.7% and 18.0% respectively, and a minimum strain rate decreased by 41.0%. In addition, the high temperature resistant and high creep resistance micro-nano particle reinforced mold steel 2 improves the creep performance, while also improving the strength, plasticity and thermal stability, that is, it achieves a simultaneous improvement in comprehensive performance and is suitable for industrial production. Its microstructure contains uniformly distributed fine nanoparticles.

[0049] Example 3

[0050] The preparation method of high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel 3 is as follows:

[0051] (1) Under N2 protection, Ti-Si-Nb filaments were subjected to an electro-explosion reaction to obtain mixed nanoparticles containing TiN, Si3N4 and NbN, hereinafter referred to as the first mixed nanoparticles. The electro-explosion reaction was carried out at a voltage of 500V, a current of 700A and a pressure of 4MPa. The composition of the Ti-Si-Nb filaments by mass percentage was: Ti: 30%, Si: 45%, Nb: 25%.

[0052] (2) The first mixed nanoparticles obtained in step (1) were mixed with pure iron powder at a speed of 15 r / min for 18 h according to mass ratios of 40:60, 50:50 and 60:40 to obtain the second mixed particles, the third mixed particles and the fourth mixed particles. The second, third and fourth mixed particles were added to pure aluminum foil in sequence according to a mass ratio of 25:35:40, and then encapsulated with a wire wrapping machine at a speed of 7 m / min to obtain aluminum foil-coated mixed particle gradient distribution wire 3.

[0053] The pure iron powder has a particle size of 30-180 μm;

[0054] (3) Under argon protection, the mold steel is melted at 1780℃ for 80 minutes, and the aluminum foil-coated mixed particle gradient distribution wire 3 obtained in step (2) is added. After refining for 70 minutes, casting, electroslag remelting, high-temperature diffusion, multi-directional forging and heat treatment, high-temperature resistant, high-creep resistant micro-nano particle reinforced mold steel 3 is obtained; the mass ratio of the aluminum foil-coated mixed particle gradient distribution wire 3 to the mold steel is 0.036%:1.

[0055] The composition of the mold steel, by weight percentage, is as follows: C: 0.40 wt.%; Si: 0.25 wt.%; Mn: 0.39 wt.%; P: 0.004 wt.%; S: 0.001 wt.%; Cr: 4.9 wt.%; V: 0.55 wt.%; Mo: 3.0 wt.%; N: 0.01 wt.%; H: 0.0001 wt.%; O: 0.0007 wt.%, with the balance being Fe;

[0056] The electroslag remelting is performed with a current of 8000A, a voltage of 25V, and a molten pool temperature of 1700℃.

[0057] The high-temperature diffusion is described as: holding at 1265℃ for 10 hours;

[0058] The multi-directional forging process is characterized by a forging temperature of 1050-1200℃ and a forging ratio of 10:1.

[0059] The heat treatment is as follows: under vacuum conditions, hold at 550℃ for 30 minutes, then raise the temperature to 1150℃ and hold for 100 minutes; use oil quenching, and then hold at 550℃ for 6 hours.

[0060] The creep curves of the high-temperature resistant, high-creep-resistant micro-nanoparticle reinforced mold steel 3 obtained in this embodiment under conditions of 600℃ and 630MPa are shown below. Figure 3 As shown, its creep life is 11.2 h, creep strain is 26.0%, and minimum strain rate is 7.39 × 10⁻⁶. -7 s -1 Compared with the die steel in step (3) without aluminum foil-coated mixed particle gradient distribution wire 3, the creep life and strain of die steel 3 are increased by 63.0% and 14.0% respectively, and the minimum strain rate is reduced by 34.6%. In addition, the high temperature resistant and high creep resistant micro-nano particle reinforced die steel 3 improves the creep performance, while also improving the strength, plasticity and thermal stability, making it suitable for industrial production, that is, achieving a simultaneous improvement in comprehensive performance; its microstructure contains uniformly distributed fine nanoparticles.

[0061] Comparative Example 1

[0062] The preparation method for mold steel 4 is as follows:

[0063] (1) Under argon protection, the mold steel is melted at 1700℃ for 100 min, and then refined, cast, electroslag remelted, high temperature diffusion, multi-directional forging and heat treatment for 60 min to obtain mold steel 4.

[0064] The composition of the mold steel, by weight percentage, is as follows: C: 0.38 wt.%; Si: 0.23 wt.%; Mn: 0.35 wt.%; P: 0.006 wt.%; S: 0.001 wt.%; Cr: 4.8 wt.%; V: 0.52 wt.%; Mo: 2.8 wt.%; N: 0.01 wt.%; H: 0.0001 wt.%; O: 0.0006 wt.%, with the balance being Fe;

[0065] The electroslag remelting is performed with a current of 6000A, a voltage of 35V, and a molten pool temperature of 1600℃.

[0066] The high-temperature diffusion is described as: holding at 1260℃ for 12 hours;

[0067] The multi-directional forging process is characterized by a forging temperature of 1050-1200℃ and a forging ratio of 8:1.

[0068] The heat treatment is as follows: under vacuum conditions, hold at 550℃ for 30 minutes, then raise the temperature to 1150℃ and hold for 100 minutes; use oil quenching, and then hold at 550℃ for 6 hours.

[0069] The creep curves of the mold steel obtained in this comparative example under conditions of 600℃ and 630MPa are as follows: Figure 4 As shown, its creep life is 6.87 h, creep strain is 22.8%, and minimum strain rate is 1.13 × 10⁻⁶. -6 s -1 .

[0070] Table 1 compares the creep performance values ​​of the mold steel in the comparative examples and various embodiments.

[0071]

[0072] The mold steel obtained by this invention exhibits a creep life ≥10.1h, creep strain ≥24.9%, and minimum strain rate ≤8.38×10⁻⁶ under conditions of 600℃ and 630MPa. -7 s -1 The creep life, creep strain, and minimum strain rate of the die steel obtained in Comparative Example 1 are far superior to those of the die steel obtained in Comparative Example 1, which are 6.87 h, 22.8%, and 1.13 × 10⁻⁶, respectively. - 6 s -1 .

[0073] In summary, compared with existing mold steel technologies, this invention, by controlling the mass of trace nanoparticles to within 0.036%, significantly improves the creep resistance of mold steel while maintaining its strength, plasticity, and thermal stability, all while reducing raw material costs and simplifying the process. Furthermore, the mold steel matrix of this invention contains uniformly distributed nanoparticles with a particle size of 80-200 nm. This invention achieves significantly improved technical effects compared to existing technologies. Although the component ratios and process parameters used in each embodiment of this invention differ, the resulting technical effects are significantly different, demonstrating that the superior effects of this invention are not determined by any single component, ratio, process, or parameter. Instead of relying on direct chemical reactions, the significant improvement in performance is achieved through the synergistic control of alloy element interactions, proportions, processes, and process parameters. This improvement is only possible within the scope of the claims of this invention. It overcomes the technical bottleneck of simultaneously improving creep resistance and plasticity in existing technologies. Ultimately, the mold steel obtained by this invention is less prone to creep deformation in actual service environments, better maintaining its shape accuracy, surface quality, and integrity. This significantly improves the service life and forming accuracy of the mold steel, while simultaneously enhancing its plasticity. Specifically, the mold steel obtained by this invention exhibits a creep life ≥ 10.1 h, creep strain ≥ 24.9%, and a minimum strain rate ≤ 8.38 × 10⁻⁶. -7 s -1 .

Claims

1. A high-temperature resistant, high-creep-resistant micro-nano-particle reinforced mold steel, characterized in that, Its preparation method includes the following steps: (1) Under N2 protection, Ti-Si-Nb filaments are subjected to an electro-explosion reaction to obtain mixed nanoparticles containing TiN, Si3N4 and NbN, hereinafter referred to as the first mixed nanoparticles. The electro-explosion reaction is as follows: voltage 200-600V, current 400-800A, pressure 1-5MPa. The composition of Ti-Si-Nb filaments by mass percentage is as follows: Ti: 5-35%, Si: 20-50%, Nb: 20-70%. (2) The first mixed nanoparticles obtained in step (1) are mixed with pure iron powder at a speed of 10-30 r / min for 10-20 h according to mass ratios of 20-45:55-80, 30-55:45-70 and 40-65:35-60 to obtain the second mixed particles, the third mixed particles and the fourth mixed particles. The second, third and fourth mixed particles are added to pure aluminum foil in sequence according to mass ratios of 10-30:25-40:35-60, and then encapsulated with a wire wrapping machine at a speed of 3-8 m / min to obtain aluminum foil-coated mixed particle gradient distribution wire. The pure iron powder has a particle size of 30-180 μm; (3) Under argon protection, the mold steel is melted at 1700-1800℃ for 60-120 min, and the aluminum foil-coated mixed particle gradient distribution wire obtained in step (2) is added. After refining for 50-80 min, casting, electroslag remelting, high-temperature diffusion, multi-directional forging and heat treatment, a high-temperature resistant and high-creep-resistant micro-nano particle reinforced mold steel is obtained. The mass ratio of the aluminum foil-coated mixed particle gradient distribution wire to the mold steel is 0.005-0.0045%:

1. The composition of the mold steel, by weight percentage, is: C: 0.35-0.45 wt.%; Si: 0.20-0.25wt.%; Mn: 0.35-0.40wt.%; P: ≤0.010wt.%; S: ≤0.005wt.%; Cr: 4.5-5.0wt.%; V: 0.50-0.60wt.%; Mo: 2.7-3.0wt.%; N: ≤0.05wt.%; H: ≤0.0005 wt.%; O: ≤0.0010 wt.%, balance Fe; The electroslag remelting is characterized by: current of 5000-10000A, voltage of 20-40V, and molten pool temperature of 1500-1800℃. The high-temperature diffusion is described as follows: maintaining a temperature of 1250-1300℃ for 5-15 hours; The multi-directional forging process is characterized by a forging temperature of 1050-1200℃ and a forging ratio of 5-10:

1. The heat treatment is as follows: under vacuum conditions, hold at 550℃ for 30 minutes, then raise the temperature to 1150℃ and hold for 100 minutes; use oil quenching, and then hold at 550℃ for 6 hours. The obtained high-temperature resistant and high-creep-resistant micro-nanoparticle reinforced die steel has a creep life ≥10.1h, creep strain ≥24.9%, and minimum strain rate ≤8.38×10⁻⁶. -7 s -1 .

2. The high-temperature resistant, high-creep-resistant micro-nano-particle reinforced die steel according to claim 1, characterized in that, The electro-explosion reaction described in step (1) is: voltage 300-500V, current 500-700A, pressure 2-4MPa; the composition of the Ti-Si-Nb wire by mass percentage is: Ti: 10-30%, Si: 25-45%, Nb: 25-65%.

3. The high-temperature resistant, high-creep-resistant micro-nano-particle reinforced die steel according to claim 1, characterized in that, In step (2), the first mixed nanoparticles obtained in step (1) are mixed with pure iron powder at a speed of 15-25 r / min for 12-18 h according to mass ratios of 25-40:60-75, 35-50:50-65 and 45-60:40-55 to obtain the second, third and fourth mixed particles. The second, third and fourth mixed particles are added to pure aluminum foil in sequence according to a mass ratio of 15-25:30-35:40-55, and then encapsulated with a wire wrapping machine at a speed of 4-6 m / min to obtain aluminum foil-coated mixed particle gradient distribution wire.

4. The high-temperature resistant, high-creep-resistant micro-nano-particle reinforced die steel according to claim 1, characterized in that, The composition of the mold steel mentioned in step (3) by mass percentage is: C: 0.36-0.42 wt.%. Si: 0.21-0.24wt.%; Mn: 0.36-0.39wt.%; P: ≤0.009wt.%; S: ≤0.004wt.%; Cr: 4.6-4.9wt.%; V: 0.51-0.59wt.%; Mo: 2.8-2.9wt.%; N: ≤0.04wt.%; H: ≤0.0004 wt.%; O: ≤0.0009 wt.%, balance Fe.

5. The high-temperature resistant, high-creep-resistant micro-nano-particle reinforced die steel according to claim 1, characterized in that, The electroslag remelting is characterized by a current of 6000-9000A, a voltage of 25-35V, and a molten pool temperature of 1600-1700℃. The high-temperature diffusion is described as follows: maintaining a temperature of 1260-1290℃ for 8-12 hours; The multi-directional forging process is characterized by a forging temperature of 1100-1150℃ and a forging ratio of 6-9:1.

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