High-toughness and high-thermal-stability hot work die steel and preparation method thereof

Abstract

The invention relates to a preparation method of high-toughness and high-thermal-stability hot work die steel. The preparation method comprises the following steps of optimizing alloy components, andstrictly controlling the production process; and the specific process route is as follows, electric furnace smelting, ladle refining furnace refining, vacuum refining furnace refining, electrode blankcasting, protective atmosphere electroslag furnace remelting, forging, ultrafine treatment and spheroidizing annealing production processes are adopted at the same time. The invention further relatesto the high-toughness and high-thermal-stability hot work die steel prepared through the preparation method. The product has the advantages of uniform annealed microstructure, favorable spheroidizedstructure, fine and uniform grain distribution and uniform quenched and tempered structure, and the fine precipitated phases of the Mo and Cr carbides have the dispersion strengthening action in the use process, thereby enhancing the properties of the material and endowing the material with high toughness and high isotropy. The product can be widely used for manufacturing hot extrusion dies, mandrels, hammer dies of die forging hammers, dies of forging presses and dies for precision forging machines, and particularly can be used as a high-end die-casting die made of aluminum, copper and alloysthereof.

Description

technical field

[0001] The invention relates to a die steel and a preparation method thereof, in particular to a high-toughness, high-thermal-stability hot-working die steel and a preparation method thereof. Background technique

[0002] With the development of my country's industry, the demand for die steel is increasing rapidly. Among the many products in the machinery industry, molds are listed as key industries to support development, which greatly promotes the development of the mold industry. Hot work dies generally work under harsh working conditions such as high temperature and thermal shock, so hot work die steels are required to have excellent comprehensive properties.

[0003] Working below 600°C, H13 steel has good thermal stability and thermal fatigue resistance, and a good combination of strength and toughness, but above 600°C, the strength and thermal stability of the material drop sharply, and the original excellent performance is lost. However, H21 steel w...

Examples

Embodiment 1

[0050] A kind of hot work die steel, according to the mass fraction, it basically consists of the elements in Table 1:

[0051] Table 1

[0052]

[0053] A preparation method of high toughness, high thermal stability hot work die steel, the preparation method is as follows:

[0054] S1, electric furnace smelting:

[0055] According to the component content of the hot work die steel in Table 1, the pig iron and alloy materials are mixed, melted and smelted in an electric furnace, and the temperature of the molten steel is 1670°C to oxidize and remove the slag. After removing the slag, add ferrosilicon alloy, lime, fluorite, and tap the molten steel The temperature is 1640°C, and 1kg / t of aluminum wire is added for deoxidation during the tapping process. What the inventor needs to explain is that when the temperature of the molten steel in the electric furnace shows 1670°C, the slag begins to precipitate, and at this time it is necessary to carry out oxidation and scraping; ...

Embodiment 2

[0075] A kind of hot work die steel, according to the mass fraction, it basically consists of the elements in Table 2:

[0076] Table 2

[0077]

[0078] S1, electric furnace smelting:

[0079] According to the component content of the hot work die steel in Table 1, the pig iron and alloy materials are mixed, melted and smelted in an electric furnace, and the temperature of the molten steel is 1670°C to oxidize and remove the slag. After removing the slag, add ferrosilicon alloy, lime, fluorite, and tap the molten steel The temperature is 1640°C, and 1kg / t of aluminum is added during the tapping process for deoxidation;

[0080] S2. Ladle refining furnace refining:

[0081] Ladle refining furnace seat ladle heating, and slag material CaO, CaF 2 , C-Si powder reduction to adjust the slag system; when the molten steel temperature is 1590°C, the slag turns white, take samples and analyze, and adjust the composition; when the molten steel temperature is 1680°C, the white sla...

Embodiment 3

[0099] A kind of hot work die steel, according to the mass fraction, it basically consists of the elements in Table 3:

[0100] table 3

[0101]

[0102] S1, electric furnace smelting:

[0103] According to the component content of the hot work die steel in Table 1, the pig iron and alloy materials are mixed, melted and smelted in an electric furnace, and the temperature of the molten steel is 1670°C to oxidize and remove the slag. After removing the slag, add ferrosilicon alloy, lime, fluorite, and tap the molten steel The temperature is 1640°C, and 1kg / t of aluminum is added during the tapping process for deoxidation;

[0104] S2. Ladle refining furnace refining:

[0105] Ladle refining furnace seat ladle heating, and slag material CaO, CaF 2 , C-Si powder reduction to adjust the slag system; when the molten steel temperature is 1590°C, the slag turns white, take samples and analyze, and adjust the composition; when the molten steel temperature is 1680°C, the white sla...

technical field

[0001] The invention relates to a die steel and a preparation method thereof, in particular to a high-toughness, high-thermal-stability hot-working die steel and a preparation method thereof. Background technique

[0002] With the development of my country's industry, the demand for die steel is increasing rapidly. Among the many products in the machinery industry, molds are listed as key industries to support development, which greatly promotes the development of the mold industry. Hot work dies generally work under harsh working conditions such as high temperature and thermal shock, so hot work die steels are required to have excellent comprehensive properties.

[0003] Working below 600°C, H13 steel has good thermal stability and thermal fatigue resistance, and a good combination of strength and toughness, but above 600°C, the strength and thermal stability of the material drop sharply, and the original excellent performance is lost. However, H21 steel w...

Examples

Embodiment 1

[0050] A kind of hot work die steel, according to the mass fraction, it basically consists of the elements in Table 1:

[0051] Table 1

[0052]

[0053] A preparation method of high toughness, high thermal stability hot work die steel, the preparation method is as follows:

[0054] S1, electric furnace smelting:

[0055] According to the component content of the hot work die steel in Table 1, the pig iron and alloy materials are mixed, melted and smelted in an electric furnace, and the temperature of the molten steel is 1670°C to oxidize and remove the slag. After removing the slag, add ferrosilicon alloy, lime, fluorite, and tap the molten steel The temperature is 1640°C, and 1kg / t of aluminum wire is added for deoxidation during the tapping process. What the inventor needs to explain is that when the temperature of the molten steel in the electric furnace shows 1670°C, the slag begins to precipitate, and at this time it is necessary to carry out oxidation and scraping; ...

Embodiment 2

[0075] A kind of hot work die steel, according to the mass fraction, it basically consists of the elements in Table 2:

[0076] Table 2

[0077]

[0078] S1, electric furnace smelting:

[0079] According to the component content of the hot work die steel in Table 1, the pig iron and alloy materials are mixed, melted and smelted in an electric furnace, and the temperature of the molten steel is 1670°C to oxidize and remove the slag. After removing the slag, add ferrosilicon alloy, lime, fluorite, and tap the molten steel The temperature is 1640°C, and 1kg / t of aluminum is added during the tapping process for deoxidation;

[0080] S2. Ladle refining furnace refining:

[0081] Ladle refining furnace seat ladle heating, and slag material CaO, CaF 2 , C-Si powder reduction to adjust the slag system; when the molten steel temperature is 1590°C, the slag turns white, take samples and analyze, and adjust the composition; when the molten steel temperature is 1680°C, the white sla...

Embodiment 3

[0099] A kind of hot work die steel, according to the mass fraction, it basically consists of the elements in Table 3:

[0100] table 3

[0101]

[0102] S1, electric furnace smelting:

[0103] According to the component content of the hot work die steel in Table 1, the pig iron and alloy materials are mixed, melted and smelted in an electric furnace, and the temperature of the molten steel is 1670°C to oxidize and remove the slag. After removing the slag, add ferrosilicon alloy, lime, fluorite, and tap the molten steel The temperature is 1640°C, and 1kg / t of aluminum is added during the tapping process for deoxidation;

[0104] S2. Ladle refining furnace refining:

[0105] Ladle refining furnace seat ladle heating, and slag material CaO, CaF 2 , C-Si powder reduction to adjust the slag system; when the molten steel temperature is 1590°C, the slag turns white, take samples and analyze, and adjust the composition; when the molten steel temperature is 1680°C, the white sla...

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