High-temperature corrosion-resistant alloy bar and preparation method thereof

Abstract

The invention relates to the technical field of alloy materials, in particular to a high-temperature corrosion-resistant alloy bar and a preparation method thereof. The technical scheme adopted by the invention is as follows: the steel consists of the following elements in percentage by weight: less than or equal to 0.015% of C; less than or equal to 0.50% of Si; mn: < = 2.0%; cr: 31.0 to 35.0%; ni: 30.0 to 33.0%; less than or equal to 0.015% of S; p: less than or equal to 0.025%; 0.50% to 2.00% of Mo; 0.30% to 1.20% of Cu; 0.35% to 0.60% of N; o: < = 50 PPM; h: < = 3PPM; and the balance of Fe and inevitable impurities. The corrosion-resistant and salt-fog-resistant coating has the advantages that the corrosion-resistant and salt-fog-resistant coating integrally has reliable corrosion resistance and salt fog resistance, but is relatively poor in temperature resistance, is specifically applied to equipment with relatively high corrosion resistance requirements and relatively low other performance requirements during use, and is lower in cost during use.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and particularly to a high-temperature corrosion-resistant alloy bar and a preparation method thereof. Background Art

[0002] High-temperature alloy materials are important structural materials in products such as ships and aviation. When the existing high-temperature alloy materials are used in the structure of engine room products, their salt spray resistance, deformation resistance, and crack resistance are not ideal. Long-term use will cause damage to the products, and it is difficult to guarantee the service life during use. Especially when used in an ultra-low temperature environment below 40 degrees, the safety is unstable. The existing high-temperature alloy materials require a relatively large variety of materials during production, and the production and processing costs are relatively high. When used in application environments with high strength requirements but relatively low performance requirements such as heat resistance, it is necessary to optimize the existing materials to effectively reduce the production cost on the basis of ensuring the use performance, and avoid excessive use of materials and reduce material waste. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-temperature corrosion-resistant alloy bar and a preparation method thereof. Through the optimization of the existing high-temperature alloy materials, it has reliable corrosion resistance and salt spray resistance as a whole, but the heat resistance is relatively poor. It is specifically applied to equipment with relatively high corrosion resistance requirements and relatively low other performance requirements during use. The cost during use is lower, effectively avoiding material waste, making the utilization rate of the products higher, more targeted. The overall production and processing process can improve the compactness of the overall bar and the structural strength is more reliable through the improvement of the existing technology, and the production and processing efficiency is also relatively high.

[0004] The technical solution of the present invention is as follows:

[0005] A high-temperature corrosion-resistant alloy bar, characterized in that it is composed of the following elements, and the weight percentage content is:

[0006] C: ≤0.015%;

[0007] Si: ≤0.50%;

[0008] Mn: ≤2.0%;

[0009] Cr: 31.0 - 35.0%;

[0010] Ni: 30.0 - 33.0%;

[0011] S: ≤0.015%;

[0012] P: ≤0.025%;

[0013] Mo: 0.50 - 2.00%;

[0014] Cu: 0.30 - 1.20%;

[0015] N: 0.35 - 0.60%;

[0016] O: ≤50 PPM;

[0017] H: ≤3 PPM;

[0018] The balance is Fe and unavoidable impurities.

[0019] Furthermore, C: 0.012%; Si: 0.30%;

[0020] Mn: 1.5%;

[0021] Cr: 32.6%;

[0022] Ni: 31.5%;

[0023] S: 0.015%;

[0024] P: 0.015%;

[0025] Mo: 0.59%;

[0026] Cu: 0.80%;

[0027] N: 0.55%;

[0028] O: 30 PPM;

[0029] H: 3 PPM.

[0030] Furthermore, C: 0.015%; Si: 0.20%;

[0031] Mn: 1.0%;

[0032] Cr: 31.8%;

[0033] Ni: 32.5%;

[0034] S: 0.010%;

[0035] P: 0.025%;

[0036] Mo: 0.77%;

[0037] Cu: 0.65%;

[0038] N: 0.38%;

[0039] O: 40 PPM;

[0040] H: 2 PPM.

[0041] Further,

[0042] C: 0.015%;

[0043] Si: 0.50%;

[0044] Mn: 1.4%;

[0045] Cr: 32.8%;

[0046] Ni: 30.2%;

[0047] S: 0.005%;

[0048] P: 0.015%;

[0049] Mo: 0.750%;

[0050] Cu: 0.80%;

[0051] N: 0.35%;

[0052] O: 50 PPM;

[0053] H: 3 PPM.

[0054] Further, C: 0.011%;

[0055] Si: 0.40%;

[0056] Mn: 1.3%;

[0057] Cr: 32.6%;

[0058] Ni: 32.3%;

[0059] S: 0.010%;

[0060] P: 0.015%;

[0061] Mo: 1.50%;

[0062] Cu: 1.20%;

[0063] N: 0.60%;

[0064] O: 40 PPM;

[0065] H: 3 PPM.

[0066] A preparation method of a high-temperature corrosion-resistant alloy bar, comprising the following steps: 1) Raw material preparation: Take metal materials that meet the standards, return the surface of the same steel type to be polished, and mix them with a proportion ≤ 20% of the amount to be added, and then bake the mixed materials; 2) Vacuum smelting: Add small nickel plates to the bottom with a bottom carbon content of about 0.005%, place JMo and JCr in the upper part of the crucible, and cover the upper part with Ni plates. When performing vacuum smelting, the vacuum degree during the melting period is less than 5 Pa, add Ni-Mg 0.05% during refining, add small amounts of Al and Ti for deoxidation when power is cut off and the film is formed after refining, and control the composition. The vacuum degree during the refining period is ≤ 2 Pa. Adopt at least two high-temperature instantaneous refinings and one low-temperature long-time refining, raise the steel temperature to 1580 °C for 1 - 2 min, lower the steel temperature to 1440 °C (in the state of just forming a film and flushing the film), the low temperature, the refining time ≥ 50 min, the refining temperature is 1480 °C, argon gas does not need to be filled throughout the process, the tapping temperature is 1500 °C, pour 4 electrodes of 750 Kg, and perform sufficient feeding during the later stage of pouring. After pouring is completed, break the vacuum and take out the mold for marking after 30 minutes; 3) Electroslag remelting: The surface of the electrode should be cleaned without impurities, cut off the shrinkage cavities at both ends, use the same steel type bottom pad, the same steel type bell-shaped electric lead rod, and the same steel type welding wire; use purified pre-melted slag for batching, and the slag system ratio is: CaF2:AL2O3:CaO:MgO = 70:15:10:5; Power system: 55 - 60 V, current 6500 - 8000 A; During the initial stage of arc ignition, melting should be maintained to fully melt the slag material, and then enter the automatic melting control after the temperature is raised. Perform sufficient feeding during the later stage. For a 1500 kg electroslag ingot, demold the ingot after air cooling for 50 minutes; 4) Upsetting and forging: The forging heating temperature is 1140 - 1160 °C, and the heating rate during the heating process should ≤

[0067] 300 °C. Slowly raise the temperature at low temperature, keep it at 700 °C for 2.5 hours, then raise the temperature to 1150 °C, and the holding time should ≥ 4.5 h. When upsetting and forging, first perform light forging with a certain deformation and then heavy hammer forging. Heat it back to the furnace at 1160 °C and hold it for more than 90 minutes before forging again. The forging specifications are Φ310 - Φ313 mm * 355 times the length * 11 pieces. Conduct 100% flaw detection on the round bar, and grind the surface to remove defects. The forging ratio is greater than 4, and air cool after forging; 5) Heat treatment and machining: Solution annealing temperature: 980 - 1020 °C, holding time greater than 2.5 hours, water cooling. The processed bar is surface processed by a straightening machine, inspected by ultrasonic inspection, then surface cleaned, and finally packaged.

[0068] The beneficial effects of the present invention:

[0069] Through the optimization of existing superalloy materials, the present invention as a whole has reliable corrosion resistance and salt spray resistance, but relatively poor heat resistance. It is specifically applied to equipment with relatively high corrosion resistance requirements and relatively low requirements for other properties during use, with lower costs during use, effectively avoiding material waste, making the utilization rate of products higher, more targeted. Through the improvement of existing technologies in the overall production and processing process, the compactness of the overall bar can be better, the structural strength is more reliable, and the production and processing efficiency is relatively high. Specific Embodiments

[0070] By weight percentage:

[0071] C: ≤0.015%;

[0072] Si: ≤0.50%;

[0073] Mn: ≤2.0%;

[0074] Cr: 31.0 - 35.0%;

[0075] Ni: 30.0 - 33.0%;

[0076] S: ≤0.015%;

[0077] P: ≤0.025%;

[0078] Mo: 0.50 - 2.00%;

[0079] Cu: 0.30 - 1.20%;

[0080] N: 0.35 - 0.60%;

[0081] O: ≤50PPM;

[0082] H: ≤3PPM;

[0083] The remainder is Fe and inevitable impurities. The processing is carried out according to the following steps: 1) Raw material preparation: Take metal materials that meet the standards, return the surface of the same steel type should be polished, and the blending amount ≤ 20% is mixed, and then the mixed materials are roasted; 2) Vacuum smelting: Add small nickel plates to the bottom, about 0.005% of the bottom carbon is added, JMo and JCr are placed in the upper part of the crucible, and the upper part is covered with Ni plates. When carrying out vacuum smelting, the vacuum degree during the melting period is less than 5 Pa, 0.05% of Ni-Mg is added during refining, and small materials of Al and Ti are added for deoxidation when power is cut off and the film is formed after refining, and the composition is controlled. The vacuum degree during the refining period ≤ 2 Pa. Adopt no less than two high-temperature instantaneous refinings and one low-temperature long-time refining. Raise the steel temperature to 1580 °C / 1 - 2 min, lower the steel temperature to 1440 °C (just in the state of film formation and film flushing), low temperature, the refining time ≥ 50 min, the refining temperature is 1480 °C, the whole process can be carried out without argon gas injection, the tapping temperature is 1500 °C, pour 4 electrodes of 750 Kg, and the feeding during the later stage of pouring is sufficient. After 30 minutes of pouring completion, break the vacuum and take out the mold for marking; 3) Electroslag remelting: The surface of the electrode should be cleaned without impurities, cut off the shrinkage cavities at both ends, the bottom pad of the same steel type, the electric conduction rod of the same steel bell, and the welding wire of the same steel bell; Use purified pre-melted slag for batching, the slag system ratio: CaF2: AL2O3: CaO: MgO = 70:15:10:5; Power system: 55 - 60 V, current 6500 - 8000 A; At the initial stage of arc ignition, melting should be carried out to keep the slag material fully melted and the temperature is raised before entering the automatic melting control. In the later stage, sufficient feeding is carried out. For a 1500 kg steel ingot by electroslag, it is demoulded after cooling for 50 minutes and the steel ingot is air-cooled; 4) Upsetting forging: The forging heating temperature is 1140 - 1160 °C, the heating rate during the heating process should ≤ 300 °C, slowly raise the temperature at low temperature to 700 °C and keep it warm for 2.5 hours, then raise the temperature to 1150 °C, and the holding time should ≥ 4.5 h. When upsetting forging, it should be forged lightly first with a certain deformation and then with a heavy hammer. Reheat to 1160 °C and keep it warm for more than 90 minutes and then forge again. The forging specifications are Φ310 - Φ313 mm * 355 times the length * 11 pieces. The round bars are inspected by 100% flaw detection, and the surface is ground to remove defects. The forging ratio is greater than 4, and it is air-cooled after forging; 5) Heat treatment and machining: Solution annealing temperature: 980 - 1020 °C, holding time is greater than 2.5 hours, water-cooled. The processed bars are surface processed through a straightening machine, inspected by ultrasonic, then surface cleaned, and finally packaged. This material is optimized from the existing superalloy materials, and overall has reliable corrosion resistance and salt spray resistance, but the heat resistance is relatively poor. It is specifically applied to equipment with relatively high corrosion resistance requirements and relatively low other performance requirements during use. The cost during use is lower, effectively avoiding material waste, making the utilization rate of the product higher, more targeted. The overall production and processing process can make the overall bars have better compactness and more reliable structural strength through the improvement of existing technologies, and the production and processing efficiency is also relatively high.

[0084] Preferably, C: 0.012%;

[0085] Si: 0.30%;

[0086] Mn: 1.5%;

[0087] Cr: 32.6%;

[0088] Ni: 31.5%;

[0089] S: 0.015%;

[0090] P: 0.015%;

[0091] Mo: 0.59%;

[0092] Cu: 0.80%;

[0093] N: 0.55%;

[0094] O: 30 PPM;

[0095] H: 3PPM. Take the material for vacuum smelting. Add small nickel plates to the bottom, and add about 0.005% of low carbon. Place JMo and JCr in the upper-middle part of the crucible, and cover the upper part with Ni plates. When carrying out vacuum smelting, the vacuum degree in the melting period is less than 5 Pa. Add Ni-Mg 0.05% during refining. The small materials of Al and Ti should be added for deoxidation when power is cut off and the film is formed after refining, and the composition should be controlled. The vacuum degree in the refining period is ≤2 Pa. Adopt at least two times of high-temperature instantaneous refining and one time of low-temperature long-time refining. Raise the steel temperature to 1580°C / 1 - 2 min, then lower the steel temperature to 1440°C (in the state of just forming the film and flushing the film, low temperature). The refining time is ≥50 min, and the refining temperature is 1480°C. Argon gas does not need to be filled throughout the process. The tapping temperature is 1500°C. Pour 4 electrodes of 750 Kg. During the later stage of pouring, sufficient feeding for shrinkage compensation should be carried out. After 30 minutes of casting completion, break the vacuum and take out the mold for marking; For electroslag remelting, the surface of the electrode should be cleaned without impurities, cut off the shrinkage cavities at both ends, use the same steel type bottom pad, the same steel bell electrode lead rod, and the same steel bell welding wire; Use purified pre-melted slag for batching. The slag system ratio is: CaF2: AL2O3: CaO: MgO = 70:15:10:5; Power system: 55 - 60 V, current 6500 - 8000 A; At the initial stage of arc ignition, melting should be maintained to fully melt the slag material, and then enter the automatic melting control after raising the temperature. In the later stage, sufficient feeding for shrinkage compensation should be carried out. For a 1500 kg steel ingot by electroslag remelting, after cooling for 50 minutes, demold the steel ingot and air-cool it; For upset forging, the forging heating temperature is 1140 - 1160°C. The heating rate during the heating process should be ≤300°C. Slowly raise the temperature at low temperature, keep it at 700°C for 2.5 hours, then raise the temperature to 1150°C, and the holding time should be ≥4.5 h. When upset forging, first forge lightly with a certain deformation and then forge with a heavy hammer. Reheat in the furnace at 1160°C and hold for more than 90 minutes before forging again. The forging specification is Φ310 - Φ313 mm * 355 times the length * 11 pieces. The round bar is subject to 100% flaw detection inspection, and the surface is ground to remove defects. The forging ratio is greater than 4, and after forging, air-cool; For heat treatment and machining, the solution annealing temperature is: 980 - 1020°C, the holding time is greater than 2.5 hours, water-cooling. The processed bar is surface processed through a straightening machine, inspected by ultrasonic inspection, then surface cleaned, and finally packaged.

[0096] Preferably, C: 0.015%;

[0097] Si: 0.20%;

[0098] Mn: 1.0%;

[0099] Cr: 31.8%;

[0100] Ni: 32.5%;

[0101] S: 0.010%;

[0102] P: 0.025%;

[0103] Mo: 0.77%;

[0104] Cu: 0.65%;

[0105] N: 0.38%;

[0106] O: 40 PPM;

[0107] H: 2 PPM. During production, the overall efficiency in the material mixing process is higher, and the fusion efficiency between materials can also reach the optimum.

[0108] Preferably, C: 0.015%;

[0109] Si: 0.50%;

[0110] Mn: 1.4%;

[0111] Cr: 32.8%;

[0112] Ni: 30.2%;

[0113] S: 0.005%;

[0114] P: 0.015%;

[0115] Mo: 0.750%;

[0116] Cu: 0.80%;

[0117] N: 0.35%;

[0118] O: 50 PPM;

[0119] H: 3 PPM. On the basis of ensuring the overall performance, the material usage cost is relatively lower.

[0120] Preferably, C: 0.011%;

[0121] Si: 0.40%;

[0122] Mn: 1.3%;

[0123] Cr: 32.6%;

[0124] Ni: 32.3%;

[0125] S: 0.010%;

[0126] P: 0.015%;

[0127] Mo: 1.50%;

[0128] Cu: 1.20%;

[0129] N: 0.60%;

[0130] O: 40 PPM;

[0131] H: 3 PPM. During the refining process, it can make the film-forming rate of the material higher, thus ensuring better quality of the overall processed bar products.

[0132] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements or substitutions can be made, and these improvements or substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A high-temperature corrosion-resistant alloy bar, characterized in that: Composed of the following elements, with the weight percentage contents being: C：≤0.015％； Si: ≤0.50%; Mn: ≤2.0%; Cr：31.0～35.0％； Ni: 30.0 - 33.0%; S：≤0.015％； P：≤0.025％； Mo: 0.50 - 2.00%; Cu: 0.30 - 1.20%; N：0.35-0.60％； O: ≤50 PPM; H: ≤3 PPM; The balance is Fe and unavoidable impurities.

2. A high-temperature corrosion-resistant alloy bar according to claim 1, characterized in that: C：0.012％； Si: 0.30%; Mn: 1.5%; Cr：32.6％； Ni: 31.5%; S：0.015％； P：0.015％； Mo: 0.59%; Cu: 0.80%; N：0.55％； O: 30 PPM; H: 3 PPM.

3. A high-temperature corrosion-resistant alloy bar according to claim 1, characterized in that: C：0.015％； Si: 0.20%; Mn: 1.0%; Cr：31.8％； Ni: 32.5%; S：0.010％； P：0.025％； Mo: 0.77%; Cu: 0.65%; N：0.38％； O: 40 PPM; H: 2 PPM.

4. A high-temperature corrosion-resistant alloy bar according to claim 1, characterized in that: C：0.015％； Si: 0.50%; Mn: 1.4%; Cr：32.8％； Ni: 30.2%; S：0.005％； P：0.015％； Mo: 0.750%; Cu: 0.80%; N：0.35％； O: 50 PPM; H: 3 PPM.

5. A high-temperature corrosion-resistant alloy bar according to claim 1, characterized in that: C：0.011％； Si: 0.40%; Mn: 1.3%; Cr：32.6％； Ni: 32.3%; S：0.010％； P：0.015％； Mo: 1.50%; Cu: 1.20%; N：0.60％； O: 40 PPM; H: 3 PPM.

6. The preparation method of a high-temperature corrosion-resistant alloy bar according to claim 1 comprises the following steps: 1) Raw material preparation: Select metal materials that meet the standards. Return the surface of the same steel type that should be polished and mixed with a proportion ≤ 20%. Then roast the mixed materials. 2) Vacuum smelting: Add small nickel plates to the bottom with a bottom carbon content of about 0.005%. Place JMo and JCr in the upper part of the crucible and cover the upper part with Ni plates. During vacuum smelting, the vacuum degree in the melting period is less than 5 Pa. Add Ni-Mg 0.05% during refining. Add small amounts of Al and Ti for deoxidation when power is cut off and the film is formed after refining, and control the composition. The vacuum degree in the refining period is ≤ 2 Pa. Adopt no less than two high-temperature instantaneous refinings and one low-temperature long-term refining. Raise the steel temperature to 1580 °C for 1 - 2 min, then lower the steel temperature to 1440 °C (in the state of just forming a film and flushing the film, low temperature). The refining time is ≥ 50 min, and the refining temperature is 1480 °C. Argon gas does not need to be filled throughout the process. The tapping temperature is 1500 °C. Pour 4 electrodes of 750 Kg. Adequately compensate for shrinkage in the later stage of pouring. After 30 minutes of pouring completion, break the vacuum and take out the mold for marking. 3) Electroslag remelting: The surface of the electrode should be cleaned without impurities. Cut off the shrinkage cavities at both ends. Use the same steel type bottom pad, the same steel type bell-shaped electrode lead rod, and the same steel type welding wire. Use purified pre-melted slag for batching. The slag system ratio is: CaF2:AL2O3:CaO:MgO = 70:15:10:

5. Power system: 55 - 60 V, current 6500 - 8000 A. During the initial arc ignition and melting, keep the slag material fully melted and raise the temperature before entering the automatic melting control. Adequately compensate for shrinkage in the later stage. For a 1500 kg electroslag ingot, demold after cooling for 50 minutes and air-cool the ingot. 4) Upsetting and forging: The forging heating temperature is 1140 - 1160 °C. The heating rate during the heating process should be ≤ 300 °C. Slowly raise the temperature at low temperature to 700 °C and keep it warm for 2.5 hours, then raise the temperature to 1150 °C and keep it warm for ≥ 4.5 h. During upsetting and forging, first forge lightly with a certain deformation and then forge with a heavy hammer. Reheat in the furnace at 1160 °C and keep it warm for more than 90 minutes before forging again. The forging specifications are Φ310 - Φ313 mm * 355 times the length * 11 pieces. Conduct 100% flaw detection on the round bars and grind the surface to remove defects. The forging ratio is greater than 4. Air-cool after forging. 5) Heat treatment and machining: Solution annealing temperature: 980 - 1020 °C, holding time is greater than 2.5 hours, water-cool. The processed bars are surface processed through a straightening machine, inspected by ultrasonic, then surface cleaned, and finally packaged.