Heat-resistant steel trapezoidal plate rich in Ni and Cr and casting method thereof

Abstract

The invention provides a heat-resistant steel trapezoidal plate rich in Ni and Cr and a casting method thereof. The steel plate comprises the following chemical components in percentage by mass: 0.30-0.50% of C, 0.5-2.0% of Si, less than or equal to 1.5% of Mn, less than or equal to 0.30% of P, less than or equal to 0.10% of S, 27.0-30.0% of Cr, 47.0-50.0% of Ni, 4.0-6.0% of W, less than or equal to 0.002% of RE and the balance of Fe and impurities. The casting method of the steel plate sequentially comprises the working procedures of burdening, backing material baking, blow-in and nickel adding, carbon powder adding, ferrochrome adding, carbon powder and ferrosilicon adding, rare earth, pure chromium and ferrotungsten adding, mold stripping and the like. The heat-resistant steel trapezoidal plate rich in Ni and Cr, which is cast by the method, is uniform in microstructure and mechanical property, high in heat resistance, high in yield, high in application guidance in the field of casting engineering, and suitable for a high-temperature harsh metallurgical working condition environment.

Description

Technical Field

[0001] The invention discloses a Ni- and Cr-rich heat-resistant steel trapezoidal plate and a casting method thereof, and belongs to the field of ferrous metal metallurgy. Background Art

[0002] High-temperature-resistant materials are widely used in science and industry due to their excellent heat resistance. Common examples include tungsten alloy steel, chromium alloy steel, and nickel alloy steel. These materials maintain their structural and functional integrity in extreme thermal environments. In particular, alloy steel plates rich in nickel and chromium, with their exceptional heat and corrosion resistance, have become essential key materials in engineering valves, oil and gas pipelines, and other fields.

[0003] Trapezoidal plates are usually made of high-temperature resistant materials and have a trapezoidal cross-section. This structure and material design can effectively store liquid metal. Trapezoidal plates are used in various casting processes and their main functions are as follows:

[0004] (1) Directional solidification: The use of trapezoidal plates in conjunction with risers can enhance the directional solidification of castings and improve the efficiency of supplementary shrinkage of risers.

[0005] (2) Adjusting the cooling rate: The trapezoidal plate can speed up the local cooling rate of the casting, so that the castings tend to solidify at the same time, preventing the castings from deformation and cracking.

[0006] (3) Prevent shrinkage cavities or shrinkage: In areas where it is difficult to set up risers, trapezoidal plates can effectively prevent shrinkage cavities or shrinkage.

[0007] The present invention discloses a Ni- and Cr-rich heat-resistant steel trapezoidal plate and a casting method thereof. The outstanding advantages of the plate are uniform microstructure and mechanical properties, strong heat resistance, high yield rate, strong application guidance in the field of casting engineering, and suitability for high-temperature harsh metallurgical working environments. Summary of the Invention

[0008] The invention provides a Ni- and Cr-rich heat-resistant steel trapezoidal plate, whose chemical composition and mass percentage are: C 0.30-0.50%, Si 0.5-2.0%, Mn≤1.5%, P≤0.30%, S≤0.10%, Cr 27.0-30.0%, Ni 47.0-50.0%, W 4.0-6.0%, RE≤0.002%, and the rest are Fe and impurities.

[0009] The present invention also provides a method for casting a Ni- and Cr-rich heat-resistant steel trapezoidal plate, which specifically comprises the steps of:

[0010] (1) Ingredients: 0.5% carbon powder, 1.47% ferrosilicon, 35% V3 chromium, 7% pure chromium, 49% nickel, and 5.8% ferrotungsten;

[0011] (2) Baking of base material: 49% electrolytic nickel is loaded into the furnace and baked at a temperature of 800-1000°C for 1-4 hours;

[0012] (3) Open the furnace and add nickel: open the 100 kg medium frequency melting furnace, put in electrolytic nickel, and heat to 1200 ° C;

[0013] (4) Adding carbon powder: Then add 0.25% carbon powder and continue to heat up to 1500℃;

[0014] (5) Adding ferrochrome: After the molten steel is melted, add 35% V3 ferrochrome alloy;

[0015] (6) Add carbon powder and ferrosilicon: After the molten steel is melted, add 0.25% carbon powder and 1.47% ferrosilicon;

[0016] (7) Adding rare earth, pure chromium and ferrotungsten: After the molten steel is completely melted, add 0.001% pure lanthanum, 7% pure chromium and 5.8% ferrotungsten in sequence;

[0017] (8) After it is completely melted, pour it into the dried mold and remove it from the mold after cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the metallographic structure of Example 1; Figure 2 is the metallographic structure of Example 2; Figure 3 It is a structural diagram of a trapezoidal steel plate, 1 is a front view, and 2 is a side view. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the examples.

[0020] Example 1

[0021] A Ni- and Cr-rich heat-resistant steel trapezoidal plate has the following chemical compositions and mass percentages: C 0.46%, Si 1.24%, Mn 0.96%, P 0.031%, S 0.005%, Cr 28.55%, Ni 48.92%, Mo 0.043%, W 4.17%, La≤0.001%, and the remainder being Fe and impurities.

[0022] The casting method of the Ni and Cr-rich heat-resistant steel trapezoidal plate conforming to the above chemical composition comprises the following steps:

[0023] (1) Ingredients: 0.5% carbon powder, 1.47% ferrosilicon, 35% V3 chromium, 7% pure chromium, 49% nickel, and 5.8% ferrotungsten;

[0024] (2) Baking of base material: 49% electrolytic nickel is loaded into the furnace and baked at a temperature of 800-1000°C for 1-4 hours;

[0025] (3) Open the furnace and add nickel: open the 100 kg medium frequency melting furnace, put in electrolytic nickel, and heat to 1200 ° C;

[0026] (4) Adding carbon powder: Then add 0.25% carbon powder and continue to heat up to 1500℃;

[0027] (5) Adding ferrochrome: After the molten steel is melted, add 35% V3 ferrochrome alloy;

[0028] (6) Add carbon powder and ferrosilicon: After the molten steel is melted, add 0.25% carbon powder and 1.47% ferrosilicon;

[0029] (7) Adding rare earth, pure chromium and ferrotungsten: After the molten steel is completely melted, add 0.001% pure lanthanum, 7% pure chromium and 5.8% ferrotungsten in sequence;

[0030] (8) After it is completely melted, pour it into the dried mold and remove it from the mold after cooling.

[0031] The mechanical properties test results are shown in Table 1.

[0032]

[0033] Example 2

[0034] A Ni- and Cr-rich heat-resistant steel trapezoidal plate has the following chemical compositions and mass percentages: C 0.42%, Si 1.32%, Mn 1.052%, P 0.029%, S 0.003%, Cr 28.27%, Ni 48.64%, Mo 0.045%, W 4.12%, Ce 0.001%, and the remainder being Fe and impurities.

[0035] The casting method of the Ni and Cr-rich heat-resistant steel trapezoidal plate conforming to the above chemical composition comprises the following steps:

[0036] (1) Ingredients: 0.5% carbon powder, 1.47% ferrosilicon, 35% V3 chromium, 7% pure chromium, 49% nickel, and 5.8% ferrotungsten;

[0037] (2) Baking of base material: 49% electrolytic nickel is loaded into the furnace and baked at a temperature of 800-1000°C for 1-4 hours;

[0038] (3) Open the furnace and add nickel: open the 100 kg medium frequency melting furnace, put in electrolytic nickel, and heat to 1200 ° C;

[0039] (4) Adding carbon powder: Then add 0.25% carbon powder and continue to heat up to 1500℃;

[0040] (5) Adding ferrochrome: After the molten steel is melted, add 35% V3 ferrochrome alloy;

[0041] (6) Add carbon powder and ferrosilicon: After the molten steel is melted, add 0.25% carbon powder and 1.47% ferrosilicon;

[0042] (7) Adding rare earth, pure chromium and ferrotungsten: After the molten steel is completely melted, add 0.001% pure lanthanum, 7% pure chromium and 5.8% ferrotungsten in sequence;

[0043] (8) After it is completely melted, pour it into the dried mold and remove it from the mold after cooling.

[0044] The mechanical properties test results are shown in Table 2.

[0045]

Claims

1. A Ni and Cr rich heat resistant steel trapezoidal plate, characterized in that The chemical composition (weight percentage) is: C 0.30-0.50%, Si 0.5-2.0%, Mn≤1.5%, P≤0.30%, S≤0.10%, Cr 27.0-30.0%, Ni 47.0-50.0%, W4.0-6.0%, RE≤0.002%, and the rest are Fe and impurities.

2. The method for casting a Ni and Cr-rich heat-resistant steel trapezoidal plate according to claim 1, characterized in that The smelting process uses a 100 kg medium frequency melting furnace pure alloy, including 0.5% carbon powder, 1.47% ferrosilicon, 35% V3 chromium, 7% pure chromium, 49% nickel, and 5.8% ferrotungsten.

3. The method for casting a Ni and Cr-rich heat-resistant steel trapezoidal plate according to claim 1, characterized in that First, the electrolytic nickel is baked at a baking temperature of 800-1000°C, then an electric furnace is opened and heated to 1200°C, and then 0.25% carbon powder is added.

4. The method for casting a Ni and Cr-rich heat-resistant steel trapezoidal plate according to claim 1, characterized in that Continue to heat up to 1500℃ and then add V3 ferrochrome alloy.

5. The method for casting a Ni and Cr-rich heat-resistant steel trapezoidal plate according to claim 1, characterized in that After melting, add the remaining 0.25% carbon powder and ferrosilicon.

6. The method for casting a Ni and Cr-rich heat-resistant steel trapezoidal plate according to claim 1, characterized in that After the molten steel is completely melted, pure chromium and ferrotungsten are added in sequence. After it is completely melted, it is poured into the dried mold and removed from the mold after cooling.

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