CN109295393B - High-toughness, high-polishing and high-corrosion-resistance plastic die steel and preparation method thereof - Google Patents

Abstract

The invention provides novel plastic die steel with high toughness, high polishing performance and high corrosion resistance and a preparation method thereof, wherein the material for preparing the plastic die steel comprises the following components in percentage by weight: 0.18 to 0.3 percent of C, 0.1 to 0.5 percent of Si, 0.3 to 0.48 percent of Mn, 11.5 to 12.8 percent of Cr, 0.15 to 0.4 percent of Mo, 0.4 to 0.7 percent of V, 0.3 to 0.59 percent of Ni, 0.025 percent of P, 0.001 percent of S, 0.003 to 0.009 percent of rare earth and the balance of Fe, the plastic die steel can obtain higher hardness, namely 42.2 to 47.7HRC, the impact work is 368-channel 399J, the tempering stability is obviously improved, and the plastic die steel has more excellent wear resistance, corrosion resistance and high polishing property.

Description

High-toughness, high-polishing and high-corrosion-resistance plastic die steel and preparation method thereof

Technical Field

The invention belongs to the field of die steel and processing, and particularly relates to novel plastic die steel with high toughness, high polishing and high corrosion resistance and a preparation method thereof.

Background

With the increasingly wide application of plastic products in industry and daily life, the demand of the plastic mold industry for mold steel is increasing. In the plastic molding process, the quality of the mold has a self-evident effect on the quality of the product. The plastic mold has been developed toward precision, large-scale and multi-cavity, and the performance of the plastic mold steel is required to be higher and higher, and the performance of the plastic mold steel is determined according to the requirements of the type of plastic, the application of products, production batch, dimensional precision and surface quality.

The failure modes of the plastic die steel are as follows:

(1) surface wear

The reinforced resin filler in the plastic has scouring, abrasion and corrosion effects on the surface of the mold cavity, so that the roughness value of the surface of the mold cavity is increased and the size of the mold cavity is out of tolerance.

(2) Deformation of

The local plastic deformation of the mould is generated, which causes the damage of surface such as dent, wrinkle, pock mark, corner stacking collapse and the like.

(3) Fracture of

A fracture phenomenon caused by local stress concentration of the mold.

In view of the above failure modes of fracture, there is a need to improve a plastic die steel with high toughness, high polishing and high corrosion resistance.

Disclosure of Invention

In view of the above problems, the present invention provides a novel plastic die steel with high toughness, high polishing property and high corrosion resistance, which has high wear resistance, high polishing property and high toughness, and a method for preparing the same.

The specific technical scheme of the invention is as follows:

the invention provides novel plastic die steel with high toughness, high polishing performance and high corrosion resistance, and the material for preparing the plastic die steel comprises the following components in percentage by weight: 0.18 to 0.3 percent of C, 0.1 to 0.5 percent of Si, 0.3 to 0.48 percent of Mn, 11.5 to 12.8 percent of Cr, 0.15 to 0.4 percent of Mo, 0.4 to 0.7 percent of V, 0.3 to 0.59 percent of Ni, 0.025 percent of P, 0.001 percent of S, 0.003 to 0.009 percent of rare earth and the balance of Fe.

In a further improvement, the material for preparing the plastic die steel comprises the following components in percentage by weight: 0.2 to 0.24 percent of C, 0.42 to 0.46 percent of Si, 0.35 to 0.43 percent of Mn, 12 to 12.5 percent of Cr, 0.23 to 0.35 percent of Mo, 0.52 to 0.6 percent of V, 0.42 to 0.48 percent of Ni, 0.025 percent of P, 0.001 percent of S, 0.005 to 0.007 percent of rare earth and the balance of Fe.

In a further improvement, the material for preparing the plastic die steel comprises the following components in percentage by weight: 0.22% of C, 0.45% of Si, 0.4% of Mn, 12.3% of Cr, 0.29% of Mo, 0.55% of V, 0.44% of Ni, less than 0.02% of P, less than 0.001% of S, 0.006% of rare earth and the balance of Fe.

In a further improvement, the weight ratio of the rare earth is 1: 2-4 of a mixture of cerium and ferrosilicon.

The invention also provides a preparation method of the novel plastic die steel with high toughness, high polishing and high corrosion resistance, which comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing materials of the plastic die steel according to the following weight percentages of 0.18-0.3% of C, 0.1-0.5% of Si, 0.3-0.48% of Mn, 11.5-12.8% of Cr, 0.15-0.4% of Mo, 0.4-0.7% of V, 0.3-0.59% of Ni, 0.025% of P, 0.001% of S, 0.003-0.009% of rare earth and the balance of Fe, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and electrolytic nickel or nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting of the steel ingot under the protection of argon to obtain the rare earth content; the purity of the steel is improved, and the solidification condition of the steel is improved, so that the compactness and the tissue uniformity of a steel ingot are reduced and the generation of primary carbide is controlled;

5) high-temperature diffusion: carrying out high-temperature diffusion on the steel ingot subjected to electroslag remelting, and eliminating liquated carbides and interdendritic segregation in the solidification process;

6) forging: forging the steel ingot subjected to high-temperature diffusion to obtain a forged blank; improving the tissue uniformity;

7) and (3) heat treatment: carrying out heat treatment on the forged steel ingot; eliminating the precipitation of secondary carbide along the grain boundary;

8) spheroidizing annealing: and carrying out spheroidizing degradation treatment on the steel ingot after heat treatment.

Through the process, the carbide of the steel can be spheroidized, and the spheroidizing process is suitable in size and convenient for machining.

Further improvement, the specific process of high-temperature diffusion is as follows: and (3) preserving the heat of the steel ingot subjected to electroslag remelting at 1230-1280 ℃ for 8-10 hours.

Further improvement, the specific process of forging is as follows: the heating temperature during forging is 1200-1250 ℃, the heat preservation time is 5 hours, the open forging temperature is 1160-1200 ℃, the finish forging temperature is 840-890 ℃, and preferably, the heating temperature during forging is 1220-1240 ℃, the open forging temperature is 1180-1190 ℃, and the finish forging temperature is 860-880 ℃.

Further improvement, the specific process of the heat treatment is as follows: the forged steel ingot is kept at 1050-1080 ℃ for 10-15 hours, preferably at 1060-1070 ℃ for 10-15 hours, and is cooled to 400-600 ℃ by fog, preferably at 500-540 ℃.

Further improvement, the specific process of spheroidizing annealing comprises the following steps: charging the steel ingot subjected to heat treatment at 400-500 ℃, heating to 890-920 ℃, preserving heat for 6-7h, slowly cooling at 10-15 ℃ to 760-780 ℃, preserving heat for 15-35h, slowly cooling at 5-15 ℃ to 610-650 ℃, discharging and air cooling.

In a further improvement, the preparation method of the novel plastic die steel with high toughness, high polishing and high corrosion resistance provided by the invention comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing materials of the plastic die steel according to the following weight percentages of 0.18-0.3% of C, 0.1-0.5% of Si, 0.3-0.48% of Mn, 11.5-12.8% of Cr, 0.15-0.4% of Mo, 0.4-0.7% of V, 0.3-0.59% of Ni, 0.025% of P, 0.001% of S, 0.003-0.009% of rare earth and the balance of Fe, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and electrolytic nickel or nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the heat of the steel ingot subjected to electroslag remelting at 1265 ℃ for 9.5 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1235 ℃, the heat preservation is carried out for 5 hours, the open forging temperature is 1185 ℃, and the finish forging temperature is 870 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1065 ℃ for 12 hours, and carrying out fog cooling to 520 ℃;

8) spheroidizing annealing: charging the heat-treated steel ingot at 480 ℃, heating to 900 ℃, preserving heat for 6h, slowly cooling to 775 ℃ at the speed of 12 ℃, preserving heat for 27h, slowly cooling to 625 ℃ at the speed of 10 ℃, discharging from the furnace and air cooling.

The novel plastic die steel with high toughness, high polishing and high corrosion resistance and the preparation method thereof provided by the invention have the following advantages: compared with 4Cr13 steel, the novel plastic die steel with high toughness, high polishing performance and high corrosion resistance provided by the invention can obtain higher hardness, namely 42.2-47.7HRC, and at the moment, the impact power is 368-399J, the tempering stability is obviously improved, and the novel plastic die steel has more excellent wear resistance, corrosion resistance and high polishing performance.

Drawings

FIG. 1 is a wear resistance test of the novel high toughness, high polishing, high corrosion resistance plastic mold steel of the present invention;

FIG. 2 is a tempering stability test of the novel high-toughness, high-polishing and high-corrosion resistance plastic mold steel of the present invention;

FIG. 3 is a toughness test of the novel high toughness, high polishing, high corrosion resistance plastic mold steel of the present invention;

FIG. 4 is a polishing performance test of the novel high toughness, high polishing, high corrosion resistance plastic mold steel of the present invention;

FIG. 5 is a corrosion resistance test of the novel high toughness, high polishing and high corrosion resistance plastic mold steel of the present invention.

Detailed Description

Examples 1 to 8

The components and the weight percentages of the components for preparing the novel plastic die steel material with high toughness, high polishing and high corrosion resistance provided by the embodiments of the invention are shown in table 1.

TABLE 1 composition and weight percentage (%)

Examples	1	2	3	4	5	6	7	8
									C	0.18	0.19	0.2	0.22	0.24	0.26	0.28	0.3
Si	0.1	0.2	0.42	0.45	0.46	0.3	0.35	0.5
									Mn	0.3	0.32	0.35	0.4	0.43	0.44	0.46	0.48
Cr	11.5	11.7	12	12.3	12.5	12.6	12.7	12.8
									Mo	0.15	0.2	0.23	0.29	0.35	0.3	0.32	0.35
V	0.4	0.5	0.52	0.55	0.6	0.62	0.65	0.7
									Ni	0.3	0.38	0.42	0.44	0.48	0.5	0.55	0.59
P	0.02	0.015	0.009	0.008	0.01	0.01	0.01	0.011
									S	0.0007	0.0008	0.0002	0.0001	0.0003	0.0004	0.0009	0.0003
Rare earth element	0.003	0.004	0.005	0.006	0.007	0.005	0.008	0.009
									Fe	Balance of	Balance of	Balance of	Balance of	Balance of	Balance of	Balance of	Balance of

The preparation method of the plastic die steel in the above embodiment comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to the following materials by weight percent of 0.18-0.3% of C, 0.1-0.5% of Si, 0.3-0.48% of Mn, 11.5-12.8% of Cr, 0.15-0.4% of Mo, 0.4-0.7% of V, 0.3-0.59% of Ni, 0.025% of P, 0.001% of S, 0.003-0.009% of rare earth and the balance of Fe, preparing materials, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and electrolytic nickel, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the heat of the steel ingot subjected to electroslag remelting at 1265 ℃ for 9.5 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1235 ℃, the heat preservation is carried out for 5 hours, the open forging temperature is 1185 ℃, and the finish forging temperature is 870 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1065 ℃ for 12 hours, and carrying out fog cooling to 520 ℃;

8) spheroidizing annealing: charging the heat-treated steel ingot at 480 ℃, heating to 900 ℃, preserving heat for 6h, slowly cooling to 775 ℃ at the speed of 12 ℃, preserving heat for 27h, slowly cooling to 625 ℃ at the speed of 10 ℃, discharging from the furnace and air cooling.

Example 9

The novel plastic die steel material with high toughness, high polishing performance and high corrosion resistance, which is provided by the embodiment 9 of the invention, comprises the following components in percentage by weight:

0.3% of C, 0.5% of Si, 0.48% of Mn, 12.8% of Cr, 0.15% of Mo, 0.7% of V, 0.5% of Ni, 0.01% of P, 0.0008% of S, 0.006% of rare earth and the balance of Fe.

The preparation method of the plastic die steel comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to the following materials of 0.3% of C, 0.5% of Si, 0.48% of Mn, 12.8% of Cr, 0.15% of Mo, 0.7% of V, 0.5% of Ni, 0.01% of P, 0.0008% of S, 0.006% of rare earth and the balance of Fe by weight, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, a rare earth composite wire and electrolytic nickel, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the temperature of the steel ingot subjected to electroslag remelting at 1230 ℃, wherein the preserving time is 10 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1200 ℃, the heat preservation time is 5 hours, the open forging temperature is 1160 ℃, and the finish forging temperature is 840 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1050 ℃ for 15 hours, and carrying out fog cooling to 400 ℃;

8) spheroidizing annealing: charging the steel ingot subjected to heat treatment at 400 ℃, heating to 890 ℃, preserving heat for 6h, slowly cooling to 760 ℃ at the speed of 15 ℃, preserving heat for 35h, slowly cooling to 610 ℃ at the speed of 5 ℃, discharging from the furnace and air cooling.

Example 10

The novel plastic die steel material with high toughness, high polishing performance and high corrosion resistance, which is provided by the embodiment 10 of the invention, comprises the following components in percentage by weight:

0.22% of C, 0.45% of Si, 0.35% of Mn, 12% of Cr, 0.23% of Mo, 0.52% of V, 0.42% of Ni, 0.008% of P, 0.0001% of S, 0.006% of rare earth and the balance of Fe.

The preparation method of the plastic die steel comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to the following materials of 0.22 wt% of C, 0.45 wt% of Si, 0.35 wt% of Mn, 12 wt% of Cr, 0.23 wt% of Mo, 0.52 wt% of V, 0.42 wt% of Ni, 0.008 wt% of P, 0.0001 wt% of S, 0.006 wt% of rare earth and the balance of Fe, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the temperature of the steel ingot subjected to electroslag remelting at 1280 ℃ for 8 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1250 ℃, the heat preservation time is 5 hours, the open forging temperature is 1200 ℃, and the finish forging temperature is 890 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1080 ℃ for 10 hours, and carrying out fog cooling to 600 ℃;

8) spheroidizing annealing: charging the steel ingot subjected to heat treatment at 500 ℃, heating to 920 ℃, preserving heat for 7h, slowly cooling to 780 ℃ at the speed of 10 ℃, preserving heat for 15h, slowly cooling to 650 ℃ at the speed of 15 ℃, discharging and air cooling.

Example 11

The novel plastic die steel material with high toughness, high polishing performance and high corrosion resistance, which is provided by the embodiment 11 of the invention, comprises the following components in percentage by weight:

0.22% of C, 0.45% of Si, 0.35% of Mn, 12% of Cr, 0.23% of Mo, 0.52% of V, 0.42% of Ni0.008% of P, 0.0001% of S, 0.006% of rare earth and the balance of Fe.

The preparation method of the plastic die steel comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to the following materials of 0.22 wt% of C, 0.45 wt% of Si, 0.35 wt% of Mn, 12 wt% of Cr, 0.23 wt% of Mo, 0.52 wt% of V, 0.42 wt% of Ni, 0.008 wt% of P, 0.0001 wt% of S, 0.006 wt% of rare earth and the balance of Fe, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the heat of the steel ingot subjected to electroslag remelting at 1250 ℃ for 9 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1235 ℃, the heat preservation time is 5 hours, the open forging temperature is 1220 ℃, and the finish forging temperature is 860 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1060 ℃ for 11 hours, and carrying out fog cooling to 500 ℃;

8) spheroidizing annealing: charging the steel ingot subjected to heat treatment at 450 ℃, heating to 895 ℃, preserving heat for 6h, slowly cooling to 765 ℃ at the speed of 12 ℃, preserving heat for 20h, slowly cooling to 620 ℃ at the speed of 10 ℃, discharging from the furnace, and air cooling.

Example 12

The novel plastic die steel material with high toughness, high polishing performance and high corrosion resistance, which is provided by the embodiment 12 of the invention, comprises the following components in percentage by weight:

0.22% of C, 0.45% of Si, 0.35% of Mn, 12% of Cr, 0.23% of Mo, 0.52% of V, 0.42% of Ni0.008% of P, 0.0001% of S, 0.006% of rare earth and the balance of Fe.

The preparation method of the plastic die steel comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to the following materials of 0.22 wt% of C, 0.45 wt% of Si, 0.35 wt% of Mn, 12 wt% of Cr, 0.23 wt% of Mo, 0.52 wt% of V, 0.42 wt% of Ni, 0.008 wt% of P, 0.0001 wt% of S, 0.006 wt% of rare earth and the balance of Fe, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the heat of the steel ingot subjected to electroslag remelting at 1270 ℃ for 9.7 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1240 ℃, the heat preservation time is 5 hours, the open forging temperature is 1190 ℃, and the finish forging temperature is 880 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1070 ℃ for 13 hours, and carrying out fog cooling to 540 ℃;

8) spheroidizing annealing: charging the steel ingot subjected to heat treatment at 490 ℃, heating to 910 ℃, preserving heat for 6.7h, slowly cooling to 778 ℃ at 13 ℃, preserving heat for 30h, slowly cooling to 640 ℃ at 12 ℃, discharging and air cooling.

Example 13

The novel plastic die steel material with high toughness, high polishing and high corrosion resistance, which is provided by the embodiment 13 of the invention, comprises the following components in percentage by weight:

0.22% of C, 0.45% of Si, 0.35% of Mn, 12% of Cr, 0.23% of Mo, 0.52% of V, 0.42% of Ni0.008% of P, 0.0001% of S, 0.006% of rare earth and the balance of Fe.

The preparation method of the plastic die steel comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to the following materials of 0.22 wt% of C, 0.45 wt% of Si, 0.35 wt% of Mn, 12 wt% of Cr, 0.23 wt% of Mo, 0.52 wt% of V, 0.42 wt% of Ni, 0.008 wt% of P, 0.0001 wt% of S, 0.006 wt% of rare earth and the balance of Fe, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the heat of the steel ingot subjected to electroslag remelting at 1265 ℃ for 9.5 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1235 ℃, the heat preservation is carried out for 5 hours, the open forging temperature is 1185 ℃, and the finish forging temperature is 870 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1065 ℃ for 12 hours, and carrying out fog cooling to 520 ℃;

8) spheroidizing annealing: charging the heat-treated steel ingot at 480 ℃, heating to 900 ℃, preserving heat for 6h, slowly cooling to 775 ℃ at the speed of 12 ℃, preserving heat for 27h, slowly cooling to 625 ℃ at the speed of 10 ℃, discharging from the furnace and air cooling.

Comparative examples 1 to 10

The ingredients and the weight percentages of the ingredients for preparing the novel plastic die steel material with high toughness, high polishing and high corrosion resistance provided by each comparative example of the invention are shown in Table 2.

TABLE 2 composition and weight percentage (%)

The preparation method of the plastic die steel in the comparative example is as follows:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to each comparative example, wherein the plastic die steel comprises the following materials by weight percent of 0.18-0.3% of C, 0.1-0.5% of Si, 0.3-0.48% of Mn, 11.5-12.8% of Cr, 0.15-0.4% of Mo, 0.4-0.7% of V, 0.3-0.59% of Ni, less than 0.025% of P, less than 0.001% of S, 0.006% of rare earth and the balance of Fe, preparing materials, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the heat of the steel ingot subjected to electroslag remelting at 1265 ℃ for 9.5 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1235 ℃, the heat preservation is carried out for 5 hours, the open forging temperature is 1185 ℃, and the finish forging temperature is 870 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1065 ℃ for 12 hours, and carrying out fog cooling to 520 ℃;

8) spheroidizing annealing: charging the heat-treated steel ingot at 480 ℃, heating to 900 ℃, preserving heat for 6h, slowly cooling to 775 ℃ at the speed of 12 ℃, preserving heat for 27h, slowly cooling to 625 ℃ at the speed of 10 ℃, discharging from the furnace and air cooling.

Comparative example 11

The components and the weight percentages of the components for preparing the novel plastic die steel material with high toughness, high polishing and high corrosion resistance provided by the invention in the comparative example 11 are as follows:

0.22% of C, 0.45% of Si, 0.35% of Mn, 12% of Cr, 0.23% of Mo, 0.52% of V, 0.42% of Ni0.008% of P, 0.0001% of S, 0.006% of rare earth and the balance of Fe.

The preparation method of the plastic die steel comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing the plastic die steel according to the following materials of 0.22 wt% of C, 0.45 wt% of Si, 0.35 wt% of Mn, 12 wt% of Cr, 0.23 wt% of Mo, 0.52 wt% of V, 0.42 wt% of Ni, 0.008 wt% of P, 0.0001 wt% of S, 0.006 wt% of rare earth and the balance of Fe, mixing, adding ferrosilicon, ferromanganese, ferrochrome, ferromolybdenum, ferrovanadium, rare earth composite wires and nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1260 ℃, the heat preservation time is 6 hours, the open forging temperature is 1150 ℃, and the finish forging temperature is 830 ℃;

6) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1100 ℃ for 18 hours, and carrying out fog cooling to 350 ℃;

7) spheroidizing annealing: charging the steel ingot subjected to heat treatment at 190 ℃, heating to 880 ℃, preserving heat for 8h, slowly cooling to 710 ℃ at the speed of 20 ℃, preserving heat for 10h, slowly cooling to 600 ℃ at the speed of 20 ℃, discharging and air cooling.

Novel mechanical property investigation of plastic die steel with high toughness, high polishing and high corrosion resistance

Test example 1 examination of abrasion resistance

Abrasion tests were conducted using a rubber wheel abrasion tester to compare the abrasion resistance of the plastic mold steels of examples 1 to 13 and comparative examples 1 to 11. The test results are shown in FIG. 1.

As can be seen from fig. 1, the plastic die steel provided by the present invention has very good wear resistance.

Test example 2 examination of tempering stability

The plastic mold steels of examples 1 to 13 and comparative examples 1 to 11 and 4Cr13 steel were placed at 620 ℃ to measure hardness values (HRC) of the respective samples, and the results of the measurements are shown in FIG. 2.

As can be seen from FIG. 2, the hardness of the plastic die steel provided by the invention is remarkably improved, and the hardness value (HRC) reaches 42.2-47.7.

Test example 3 examination of toughness

The impact energy of the die steels of examples 1 to 13 and comparative examples 1 to 11 and 4Cr13 was measured at a hardness of 45HRC, and the results are shown in FIG. 3.

As can be seen from FIG. 3, the toughness of the plastic die steel provided by the invention is significantly improved, and the impact power reaches 368-.

Test example 4 examination of polishing Properties

The die steels of examples 1 to 13 and comparative examples 1 to 11 were polished by the same procedure, and then the surface roughness Ra (. mu.m) of each steel was measured, and the results are shown in FIG. 4.

As can be seen from fig. 4, the plastic die steel provided by the present invention has very good polishability.

Test example 5 examination of Corrosion Performance

The corrosion rates of the die steels of examples 1-13 and comparative examples 1-11 were measured (GB/T10125-1997, salt spray test for Artificial atmosphere corrosion test), and the corrosion rates were measured by spraying 5% NaCl aqueous solution for 72 hours, and the results are shown in FIG. 5.

As can be seen from fig. 5, the plastic die steel provided by the present invention has very good corrosion resistance.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.

Claims (11)

1. The plastic die steel with high toughness, high polishing performance and high corrosion resistance is characterized in that the material for preparing the plastic die steel comprises the following components in percentage by weight:

0.2 to 0.24 percent of C, 0.42 to 0.46 percent of Si, 0.35 to 0.43 percent of Mn, 12 to 12.3 percent of Cr, 0.23 to 0.29 percent of Mo, 0.52 to 0.6 percent of V, 0.42 to 0.48 percent of Ni, 0.025 percent of P, 0.001 percent of S, 0.005 to 0.007 percent of rare earth and the balance of Fe.

2. The high toughness, high polishing and high corrosion resistance plastic die steel according to claim 1, wherein the material for preparing the plastic die steel comprises the following components in percentage by weight: 0.22% of C, 0.45% of Si, 0.4% of Mn, 12.3% of Cr, 0.29% of Mo, 0.55% of V, 0.44% of Ni, less than 0.02% of P, less than 0.001% of S, 0.006% of rare earth and the balance of Fe.

3. The high toughness, high polishing and high corrosion resistance plastic die steel according to claim 1, wherein the rare earth is in a weight ratio of 1: 2-4 of a mixture of cerium and ferrosilicon.

4. A method for preparing the high-toughness high-polishing high-corrosion-resistance plastic die steel as claimed in claim 1, wherein the method comprises the following steps:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing materials of the plastic die steel according to the following weight percentages of 0.2-0.24% of C, 0.42-0.46% of Si, 0.35-0.43% of Mn, 12-12.3% of Cr, 0.23-0.29% of Mo, 0.52-0.6% of V, 0.42-0.48% of Ni, 0.025% of P, 0.001% of S, 0.005-0.007% of rare earth and the balance of Fe, preparing materials, adding ferrosilicon, ferromanganese, ferrochromium, ferromolybdenum, ferrovanadium, rare earth composite wires and electrolytic nickel or nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: carrying out high-temperature diffusion on the steel ingot subjected to electroslag remelting;

6) forging: forging the steel ingot subjected to high-temperature diffusion to obtain a forged blank;

7) and (3) heat treatment: carrying out heat treatment on the forged steel ingot;

8) spheroidizing annealing: and carrying out spheroidizing degradation treatment on the steel ingot after heat treatment.

5. The preparation method according to claim 4, wherein the specific process of high-temperature diffusion is as follows: and (3) preserving the heat of the steel ingot subjected to electroslag remelting at 1230-1280 ℃ for 8-10 hours.

6. The preparation method according to claim 5, wherein the forging process comprises the following specific steps: the heating temperature is 1200-1250 ℃ during forging, the temperature is kept for 5 hours, the open forging temperature is 1160-1200 ℃, and the finish forging temperature is 840-890 ℃.

7. The method as claimed in claim 6, wherein the heating temperature during forging is 1220-1240 ℃, the open forging temperature is 1180-1190 ℃, and the finish forging temperature is 860-880 ℃.

8. The preparation method according to claim 7, wherein the specific process of the heat treatment is as follows: the forged steel ingot is subjected to heat preservation at 1050-1080 ℃ for 10-15 hours, and is subjected to mist cooling to 400-600 ℃.

9. The method as claimed in claim 8, wherein the temperature is maintained at 1060-1070 ℃ for 10-15 hours, and the temperature is cooled to 500-540 ℃.

10. The preparation method according to claim 8, wherein the spheroidizing annealing comprises the following specific processes: charging the steel ingot subjected to heat treatment at 400-500 ℃, heating to 890-920 ℃, preserving heat for 6-7h, slowly cooling at 10-15 ℃ to 760-780 ℃, preserving heat for 15-35h, slowly cooling at 5-15 ℃ to 610-650 ℃, discharging and air cooling.

11. The method for preparing according to claim 9, characterized in that it comprises the steps of:

1) smelting: putting scrap iron or iron blocks into an intermediate frequency furnace, smelting to obtain high-temperature molten steel, pouring the high-temperature molten steel into an LF furnace, preparing materials of the plastic die steel according to the following weight percentages of 0.2-0.24% of C, 0.42-0.46% of Si, 0.35-0.43% of Mn, 12-12.3% of Cr, 0.23-0.29% of Mo, 0.52-0.6% of V, 0.42-0.48% of Ni, 0.025% of P, 0.001% of S, 0.005-0.007% of rare earth and the balance of Fe, preparing materials, adding ferrosilicon, ferromanganese, ferrochromium, ferromolybdenum, ferrovanadium, rare earth composite wires and electrolytic nickel or nickel plates, and smelting;

2) degassing: degassing through a VD furnace;

3) pouring: pouring under the protection of argon to form a steel ingot;

4) electroslag remelting: electroslag remelting is carried out on the steel ingot under the protection of argon;

5) high-temperature diffusion: preserving the heat of the steel ingot subjected to electroslag remelting at 1265 ℃ for 9.5 hours;

6) forging: forging the steel ingot subjected to electroslag remelting, wherein the heating temperature during forging is 1235 ℃, the heat preservation is carried out for 5 hours, the open forging temperature is 1185 ℃, and the finish forging temperature is 870 ℃;

7) and (3) heat treatment: preserving the temperature of the forged steel ingot at 1065 ℃ for 12 hours, and carrying out fog cooling to 520 ℃;

8) spheroidizing annealing: charging the heat-treated steel ingot at 480 ℃, heating to 900 ℃, preserving heat for 6h, slowly cooling to 775 ℃ at the speed of 12 ℃, preserving heat for 27h, slowly cooling to 625 ℃ at the speed of 10 ℃, discharging from the furnace and air cooling.

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