Stainless steel suitable for electric arc additive manufacturing

Abstract

The invention discloses stainless steel suitable for electric arc additive manufacturing, and relates to the technical field of stainless steel materials, and the stainless steel comprises the following components: 0.08%-0.18% of C, 0.25%-0.95% of Si, 1.5%-3.5% of Mn, less than or equal to 0.03% of P, less than or equal to 0.03% of S, 16%-17% of Cr, 3.8%-5.2% of Ni, 2.5%-3.5% of Mo, 0.08%-0.15% of N, 0.1%-0.3% of Nb, 0.05%-0.2% of V and the like. The ultrahigh strength and toughness stainless steel prepared through CMT electric arc additive manufacturing has good processing performance and excellent mechanical performance, so that the ultrahigh strength and toughness stainless steel has excellent resistance when bearing tensile stress, and in practical application such as the fields of mechanical structures, aerospace parts and the like, it can be ensured that components are not prone to breakage when subjected to the tensile force effect.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel materials, and in particular to stainless steel suitable for arc additive manufacturing. Background Art

[0002] CMT arc additive manufacturing is an advanced metal additive manufacturing technology. Traditional stainless steel manufacturing methods, such as casting, forging and machining, often require a large number of molds and complex processing techniques when manufacturing parts with complex shapes, which leads to high costs and long production cycles. Arc additive manufacturing can directly stack metal materials layer by layer according to the design model without the need for complex molds, greatly reducing production costs, and can quickly manufacture parts with complex shapes, improving production efficiency.

[0003] At present, the stainless steels suitable for CMT arc additive manufacturing mainly include austenitic stainless steel, duplex stainless steel, high nitrogen steel, etc., and their strength generally does not exceed 1000MPa, which to a certain extent limits its application in some fields with high requirements for material strength. Therefore, it is urgent to develop high-strength and tough stainless steel materials for CMT arc additive manufacturing to meet the ever-changing industrial needs. Summary of the invention

[0004] The purpose of the present invention is to provide a stainless steel suitable for arc additive manufacturing to solve the problem that the stainless steel suitable for CMT arc additive manufacturing mentioned in the above background technology has poor strength and is difficult to be used in fields with high material strength requirements.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: A stainless steel suitable for arc additive manufacturing, comprising the following components, by mass percentage: C: 0.08%-0.18%, Si: 0.25%-0.95%, Mn: 1.5%-3.5%, P: ≤0.03%, S: ≤0.03%, Cr: 16%-17%, Ni: 3.8%-5.2%, Mo: 2.5%-3.5%, N: 0.08%-0.15%, Nb: 0.1%-0.3%, V: 0.05%-0.2%, Ti: 0.2%-0.4%, B: 0.0001%-0.001%, and the balance is Fe.

[0006] A method for preparing stainless steel suitable for arc additive manufacturing comprises the following steps:

[0007] S1. Accurately weigh the raw materials of stainless steel, and obtain stainless steel wire with a diameter of 1.2 mm through a melting-rolling-drawing process;

[0008] S2. Using the stainless steel wire obtained in the previous step, a 30 cm×30 cm×30 cm additive stainless steel block is prepared by using CMT arc additive process technology;

[0009] S3, subjecting the additively formed stainless steel sample to aging heat treatment;

[0010] S4. After aging heat treatment, the finished stainless steel is taken out and stored after passing the inspection.

[0011] Preferably, in step S1, the melting-rolling-drawing process comprises the following steps:

[0012] S11, firstly, a smelting process is performed, wherein various raw materials required are accurately weighed according to a specific ratio, and then put into a high-temperature smelting furnace, melted at high temperature and stirred and mixed evenly, the smelting temperature is 1550-1650°C, and the stirring time is 60-120min;

[0013] S12, then carry out the rolling process, pour the smelted molten steel into a specific mold, and cool it to solidify into a steel billet;

[0014] S13, feeding the steel billet into a rolling mill, and gradually reducing the thickness of the steel billet through continuous rolling, while improving its internal structure and performance;

[0015] The total rolling passes of the continuous rolling process are 5-10 passes, the reduction in the initial rolling pass is 20%-30%, and as the thickness of the rolled piece decreases, the reduction in the subsequent passes gradually decreases to 10%-20%.

[0016] S14, finally, a drawing process is performed, in which the rolled steel passes through a drawing die, and its diameter is gradually reduced under the action of a pulling force until the required diameter of 1.2 mm is reached;

[0017] The drawing die comprises an inlet cone die, a working cone die, a sizing belt die and an outlet cone die.

[0018] Preferably, in step S2, the CMT arc additive manufacturing block comprises the following steps:

[0019] S21. Debug and calibrate the equipment before additive manufacturing;

[0020] S22, preset equipment processing parameters, set the wire feeding speed to 1-3m / min, control the additive speed to 15-30cm / min, and set the additive current to 180-210A;

[0021] S23, prepare a stainless steel wire with a diameter of 1.2 mm, and clean the working area of ​​the additive manufacturing to remove impurities and dust that may affect the quality of the additive manufacturing;

[0022] S24, start the CMT arc additive equipment, feed the stainless steel wire into the arc area, and under the action of the arc, the wire melts and deposits on the workbench, gradually forming a block;

[0023] S25. After each layer of additive manufacturing is completed, interlayer processing is performed to remove impurities and oxides between layers.

[0024] Preferably, in step S3, the aging heat treatment comprises the following steps:

[0025] S31, placing the sample in a heat treatment furnace and heating it to a temperature range of 450-550°C;

[0026] S32, when the temperature reaches the set value, maintain the temperature for 3-5 hours of insulation treatment;

[0027] S33, after the heat preservation is completed, slowly cool to room temperature.

[0028] Preferably, in step S33, the slow cooling method adopts furnace cooling or natural cooling in the air.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The ultra-high strength and toughness stainless steel prepared by CMT arc additive manufacturing in the present invention has both good process performance and excellent mechanical properties: after heat treatment, its tensile strength is 1350-1760MPa, the yield strength is 1100-1460MPa, and the elongation after break is 8%-18%, which makes the present invention have excellent resistance when subjected to tensile stress. In practical applications, such as in mechanical structures, aerospace components and other fields, it can ensure that the components are not easy to break when subjected to tension, and maintain the stability and integrity of the structure. High tensile strength is usually accompanied by good impact resistance, and it has excellent strength and toughness, which facilitates the present invention to be better applied in some fields with high requirements on material strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of a method for preparing stainless steel suitable for arc additive manufacturing according to the present invention;

[0032] Figure 2 This is an electron microscope scanning of stainless steel suitable for arc additive manufacturing of the present invention Figure 1 ;

[0033] Figure 3 This is an electron microscope scanning of stainless steel suitable for arc additive manufacturing of the present invention Figure 2 . DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Combine the following Figure 1 The present invention is further described with reference to the accompanying drawings and examples.

[0036] Embodiment 1: This embodiment provides a stainless steel suitable for arc additive manufacturing, which comprises the following components, by mass percentage: C: 0.08%, Si: 0.25%, Mn: 1.5%, P: 0.01%, S: 0.01%, Cr: 16%, Ni: 3.8%, Mo: 2.5%, N: 0.08%, Nb: 0.1%, V: 0.05%, Ti: 0.2%, B: 0.0001%, and the balance is Fe.

[0037] A method for preparing stainless steel suitable for arc additive manufacturing comprises the following steps:

[0038] Step 1: accurately weigh the raw materials of stainless steel, and obtain stainless steel wire with a diameter of 1.2 mm through a smelting-rolling-drawing process;

[0039] The specific process of the smelting-rolling-drawing process is as follows: first, the smelting process is carried out, and the various raw materials required are accurately weighed according to a specific ratio, and then placed in a high-temperature smelting furnace, melted at high temperature and stirred to mix evenly; then the rolling process is carried out, and the smelted molten steel is poured into a specific mold to cool and solidify it into a billet; the billet is sent to the rolling mill, and through continuous multiple rolling, the thickness of the billet is gradually reduced, and its internal structure and performance are improved; finally, the drawing process is carried out, and the rolled steel is passed through a drawing die, and its diameter is gradually reduced under the action of tension until it reaches the required diameter of 1.2 mm;

[0040] Step 2: Using the stainless steel wire obtained in the previous step, a 30 cm × 30 cm × 30 cm additive stainless steel block is prepared by using CMT arc additive process technology;

[0041] Among them, CMT arc additive manufacturing of blocks includes the following steps

[0042] S21. Debug and calibrate the equipment before additive manufacturing;

[0043] S22, preset equipment processing parameters, set the wire feeding speed to 1-3m / min, control the additive speed to 15-30cm / min, and set the additive current to 180-210A;

[0044] S23, prepare a stainless steel wire with a diameter of 1.2 mm, and clean the working area of ​​the additive manufacturing to remove impurities and dust that may affect the quality of the additive manufacturing;

[0045] S24, start the CMT arc additive equipment, feed the stainless steel wire into the arc area, and under the action of the arc, the wire melts and deposits on the workbench, gradually forming a block;

[0046] S25, after each layer of material addition is completed, interlayer processing is performed to remove impurities and oxides between layers;

[0047] Step 3, subjecting the additively formed stainless steel sample to aging heat treatment;

[0048] Among them, the aging heat treatment includes the following steps:

[0049] S31, placing the sample in a heat treatment furnace and heating it to a temperature range of 450-550°C;

[0050] S32, when the temperature reaches the set value, maintain the temperature for 3-5 hours of insulation treatment;

[0051] S33, after the heat preservation is completed, the device is slowly cooled to room temperature, and the slow cooling method is furnace cooling or natural cooling in the air;

[0052] Step 4: Take out the finished stainless steel after aging heat treatment and store it after passing the inspection.

[0053] Example 2: This example provides a stainless steel suitable for arc additive manufacturing, which comprises the following components, by mass percentage: C: 0.1%, Si: 0.5%, Mn: 2%, P: 0.02%, S: 0.02%, Cr: 16.5%, Ni: 4.3%, Mo: 3%, N: 0.1%, Nb: 0.1%, V: 0.1%, Ti: 0.2%, B: 0.0003%, and the balance is Fe.

[0054] A method for preparing stainless steel suitable for arc additive manufacturing comprises the following steps:

[0055] Step 1: accurately weigh the raw materials of stainless steel, and obtain stainless steel wire with a diameter of 1.2 mm through a smelting-rolling-drawing process;

[0056] The specific process of the smelting-rolling-drawing process is as follows: first, the smelting process is carried out, and the various raw materials required are accurately weighed according to a specific ratio, and then placed in a high-temperature smelting furnace, melted at high temperature and stirred to mix evenly; then the rolling process is carried out, and the smelted molten steel is poured into a specific mold to cool and solidify it into a billet; the billet is sent to the rolling mill, and through continuous multiple rolling, the thickness of the billet is gradually reduced, and its internal structure and performance are improved; finally, the drawing process is carried out, and the rolled steel is passed through a drawing die, and its diameter is gradually reduced under the action of tension until it reaches the required diameter of 1.2 mm;

[0057] Step 2: Using the stainless steel wire obtained in the previous step, a 30 cm × 30 cm × 30 cm additive stainless steel block is prepared by using CMT arc additive process technology;

[0058] Among them, CMT arc additive manufacturing of blocks includes the following steps

[0059] S21. Debug and calibrate the equipment before additive manufacturing;

[0060] S22, preset equipment processing parameters, set the wire feeding speed to 1-3m / min, control the additive speed to 15-30cm / min, and set the additive current to 180-210A;

[0061] S23, prepare a stainless steel wire with a diameter of 1.2 mm, and clean the working area of ​​the additive manufacturing to remove impurities and dust that may affect the quality of the additive manufacturing;

[0062] S24, start the CMT arc additive equipment, feed the stainless steel wire into the arc area, and under the action of the arc, the wire melts and deposits on the workbench, gradually forming a block;

[0063] S25, after each layer of material addition is completed, interlayer processing is performed to remove impurities and oxides between layers;

[0064] Step 3: subjecting the additively formed stainless steel sample to aging heat treatment;

[0065] Among them, the aging heat treatment includes the following steps:

[0066] S31, placing the sample in a heat treatment furnace and heating it to a temperature range of 450-550°C;

[0067] S32, when the temperature reaches the set value, maintain the temperature for 3-5 hours of insulation treatment;

[0068] S33, after the heat preservation is completed, the device is slowly cooled to room temperature, and the slow cooling method is furnace cooling or natural cooling in the air;

[0069] Step 4: Take out the finished stainless steel after aging heat treatment and store it after passing the inspection.

[0070] Example 3: This example provides a stainless steel suitable for arc additive manufacturing, which comprises the following components, by mass percentage: C: 0.15%, Si: 0.75%, Mn: 2.5%, P: 0.025%, S: 0.025%, Cr: 16.8%, Ni: 4.8%, Mo: 3%, N: 0.12%, Nb: 0.2%, V: 0.15%, Ti: 0.3%, B: 0.0006%, and the balance is Fe.

[0071] A method for preparing stainless steel suitable for arc additive manufacturing comprises the following steps:

[0072] Step 1: accurately weigh the raw materials of stainless steel, and obtain stainless steel wire with a diameter of 1.2 mm through a smelting-rolling-drawing process;

[0073] The specific process of the smelting-rolling-drawing process is as follows: first, the smelting process is carried out, and the various raw materials required are accurately weighed according to a specific ratio, and then placed in a high-temperature smelting furnace, melted at high temperature and stirred to mix evenly; then the rolling process is carried out, and the smelted molten steel is poured into a specific mold to cool and solidify it into a billet; the billet is sent to the rolling mill, and through continuous multiple rolling, the thickness of the billet is gradually reduced, and its internal structure and performance are improved; finally, the drawing process is carried out, and the rolled steel is passed through a drawing die, and its diameter is gradually reduced under the action of tension until it reaches the required diameter of 1.2 mm;

[0074] Step 2: Using the stainless steel wire obtained in the previous step, a 30 cm × 30 cm × 30 cm additive stainless steel block is prepared by using CMT arc additive process technology;

[0075] Among them, CMT arc additive manufacturing of blocks includes the following steps

[0076] S21. Debug and calibrate the equipment before additive manufacturing;

[0077] S22, preset equipment processing parameters, set the wire feeding speed to 1-3m / min, control the additive speed to 15-30cm / min, and set the additive current to 180-210A;

[0078] S23, prepare a stainless steel wire with a diameter of 1.2 mm, and clean the working area of ​​the additive manufacturing to remove impurities and dust that may affect the quality of the additive manufacturing;

[0079] S24, start the CMT arc additive equipment, feed the stainless steel wire into the arc area, and under the action of the arc, the wire melts and deposits on the workbench, gradually forming a block;

[0080] S25, after each layer of material addition is completed, interlayer processing is performed to remove impurities and oxides between layers;

[0081] Step 3, subjecting the additively formed stainless steel sample to aging heat treatment;

[0082] Among them, the aging heat treatment includes the following steps:

[0083] S31, placing the sample in a heat treatment furnace and heating it to a temperature range of 450-550°C;

[0084] S32, when the temperature reaches the set value, maintain the temperature for 3-5 hours of insulation treatment;

[0085] S33, after the heat preservation is completed, the device is slowly cooled to room temperature, and the slow cooling method is furnace cooling or natural cooling in the air;

[0086] Step 4: Take out the finished stainless steel after aging heat treatment and store it after passing the inspection.

[0087] Example 4: This example provides a stainless steel suitable for arc additive manufacturing, which comprises the following components, by mass percentage: C: 0.18%, Si: 0.95%, Mn: 3.5%, P: 0.03%, S: 0.03%, Cr: 17%, Ni: 5.2%, Mo: 3.5%, N: 0.15%, Nb: 0.3%, V: 0.2%, Ti: 0.4%, B: 0.001%, and the balance is Fe.

[0088] A method for preparing stainless steel suitable for arc additive manufacturing comprises the following steps:

[0089] Step 1: accurately weigh the raw materials of stainless steel, and obtain stainless steel wire with a diameter of 1.2 mm through a smelting-rolling-drawing process;

[0090] The specific process of the smelting-rolling-drawing process is as follows: first, the smelting process is carried out, and the various raw materials required are accurately weighed according to a specific ratio, and then placed in a high-temperature smelting furnace, melted at high temperature and stirred to mix evenly; then the rolling process is carried out, and the smelted molten steel is poured into a specific mold to cool and solidify it into a billet; the billet is sent to the rolling mill, and through continuous multiple rolling, the thickness of the billet is gradually reduced, and its internal structure and performance are improved; finally, the drawing process is carried out, and the rolled steel is passed through a drawing die, and its diameter is gradually reduced under the action of tension until it reaches the required diameter of 1.2 mm;

[0091] Step 2: Using the stainless steel wire obtained in the previous step, a 30 cm × 30 cm × 30 cm additive stainless steel block is prepared by using CMT arc additive process technology;

[0092] Among them, CMT arc additive manufacturing of blocks includes the following steps

[0093] S21. Debug and calibrate the equipment before additive manufacturing;

[0094] S22, preset equipment processing parameters, set the wire feeding speed to 1-3m / min, control the additive speed to 15-30cm / min, and set the additive current to 180-210A;

[0095] S23, prepare a stainless steel wire with a diameter of 1.2 mm, and clean the working area of ​​the additive manufacturing to remove impurities and dust that may affect the quality of the additive manufacturing;

[0096] S24, start the CMT arc additive equipment, feed the stainless steel wire into the arc area, and under the action of the arc, the wire melts and deposits on the workbench, gradually forming a block;

[0097] S25, after each layer of material addition is completed, interlayer processing is performed to remove impurities and oxides between layers;

[0098] Step 3, subjecting the additively formed stainless steel sample to aging heat treatment;

[0099] Among them, the aging heat treatment includes the following steps:

[0100] S31, placing the sample in a heat treatment furnace and heating it to a temperature range of 450-550°C;

[0101] S32, when the temperature reaches the set value, maintain the temperature for 3-5 hours of insulation treatment;

[0102] S33, after the heat preservation is completed, the device is slowly cooled to room temperature, and the slow cooling method is furnace cooling or natural cooling in the air;

[0103] Step 4: Take out the finished stainless steel after aging heat treatment and store it after passing the test

[0104] Comparative Example 1

[0105] The stainless steel suitable for arc additive manufacturing provided in this embodiment is substantially the same as that in Embodiment 1, with the main difference being that no nitrogen is added to the raw material.

[0106] Comparative Example 2

[0107] The stainless steel suitable for arc additive manufacturing provided in this embodiment is substantially the same as that in Embodiment 1, with the main difference being that Nb is not added to the raw material.

[0108] Comparative Example 3

[0109] The stainless steel suitable for arc additive manufacturing provided in this embodiment is substantially the same as that in Embodiment 1, with the main difference being that V is not added to the raw material.

[0110] Performance testing and result analysis

[0111] The stainless steel suitable for arc additive manufacturing prepared in Examples 1-4 and Comparative Examples 1-3 were subjected to performance tests, including tensile strength, yield strength and elongation after fracture tests, according to the test standard: GB / T228.1-2010, and the relevant data are recorded in Table 1;

[0112] Table 1: Test data record table

[0113]

[0114]

[0115] As shown in Table 1, compared with the comparative example, the tensile strength of the stainless steel suitable for arc additive manufacturing prepared in Examples 1-4 is 1350-1760MPa, the yield strength is 1100-1460MPa, and the elongation after fracture is 8%-18%. The high tensile strength means that the material has excellent resistance when subjected to tensile stress. In practical applications, such as in the fields of mechanical structures, aerospace components, etc., it can ensure that the components are not easy to break when subjected to tensile force, and maintain the stability and integrity of the structure. High tensile strength is usually accompanied by good impact resistance. Higher yield strength means that the material is not easy to plastically deform, and can maintain the shape and dimensional stability of the structure. It also has good fatigue resistance. Higher elongation after fracture means that the material has good toughness and ductility, and can undergo a certain degree of plastic deformation without immediate fracture when subjected to external force. It can better adapt to changes in various environmental conditions and stress concentration during use.

[0116] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A stainless steel suitable for arc additive manufacturing, characterized in that: Calculated by mass percentage, it includes the following components: C: 0.08% ~ 0.18%, Si: 0.25% ~ 0.95%, Mn: 1.5% ~ 3.5%, P: ≤0.03%, S: ≤0.03%, Cr: 16% ~ 17%, Ni: 3.8% ~ 5.2%, Mo: 2.5% ~ 3.5%, N: 0.08% ~ 0.15%, Nb: 0.1% ~ 0.3%, V: 0.05% ~ 0.2%, Ti: 0.2% ~ 0.4%, B: 0.0001% ~ 0.001%, and the balance is Fe.

2. A method for preparing stainless steel suitable for arc additive manufacturing according to claim 1, characterized in that: The following steps are involved: S1. Accurately weigh the raw materials of stainless steel, and obtain stainless steel wire with a diameter of 1.2 mm through a melting-rolling-drawing process; S2. Using the stainless steel wire obtained in the previous step, a 30 cm×30 cm×30 cm additive stainless steel block is prepared by using CMT arc additive process technology; S3, subjecting the additively formed stainless steel sample to aging heat treatment; S4. After aging heat treatment, the finished stainless steel is taken out and stored after passing the inspection.

3. A method for preparing stainless steel suitable for arc additive manufacturing according to claim 2, characterized in that: In step S1, the melting-rolling-drawing process includes the following steps: S11, firstly, a smelting process is performed, wherein various raw materials required are accurately weighed according to a specific ratio, and then placed in a high-temperature smelting furnace, melted at high temperature, and stirred and mixed evenly; S12, then carry out the rolling process, pour the smelted molten steel into a specific mold, and cool it to solidify into a steel billet; S13, feeding the steel billet into a rolling mill, and gradually reducing the thickness of the steel billet through continuous rolling, while improving its internal structure and performance; S14. Finally, a drawing process is performed to pass the rolled steel through a drawing die, and its diameter is gradually reduced under the action of a tensile force until the required diameter of 1.2 mm is reached.

4. The method for preparing stainless steel suitable for arc additive manufacturing according to claim 2, characterized in that: In step S2, the CMT arc additive manufacturing block includes the following steps: S21. Debug and calibrate the equipment before additive manufacturing; S22, preset equipment processing parameters, set the wire feeding speed to 1-3m / min, control the additive speed to 15-30cm / min, and set the additive current to 180-210A; S23, prepare a stainless steel wire with a diameter of 1.2 mm, and clean the working area of ​​the additive manufacturing to remove impurities and dust that may affect the quality of the additive manufacturing; S24, start the CMT arc additive equipment, feed the stainless steel wire into the arc area, and under the action of the arc, the wire melts and deposits on the workbench, gradually forming a block; S25. After each layer of additive manufacturing is completed, interlayer processing is performed to remove impurities and oxides between layers.

5. The method for preparing stainless steel suitable for arc additive manufacturing according to claim 2, characterized in that: In step S3, the aging heat treatment includes the following steps: S31, placing the sample in a heat treatment furnace and heating it to a temperature range of 450-550°C; S32, when the temperature reaches the set value, maintain the temperature for 3-5 hours of insulation treatment; S33, after the heat preservation is completed, slowly cool to room temperature.

6. A method for preparing stainless steel suitable for arc additive manufacturing according to claim 5, characterized in that: In step S33, the slow cooling method adopts furnace cooling or natural cooling in the air.

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