CN118341987A

CN118341987A - Component control and preparation method for high-strength and high-toughness isotropic additive manufacturing 316L stainless steel

Info

Publication number: CN118341987A
Application number: CN202410469970.XA
Authority: CN
Inventors: 黎颖熹; 宋淼
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2024-04-18
Filing date: 2024-04-18
Publication date: 2024-07-16

Abstract

The invention relates to a component control and preparation method for manufacturing 316L stainless steel by high-strength isotropic additive, which comprises the following steps: vacuum smelting the master batches of the raw materials according to the element proportion of the 316L stainless steel to prepare an alloy ingot; the stainless steel raw material components in percentage by weight are required to meet the following requirement ：C≤0.03wt.％,S≤0.01wt.％,O≤0.06wt.％,N≤0.02wt.％,Cr 16.0-18.0wt.％,Ni 10.0-13.0wt.％,Mn 0.9-1.5wt.％,Mo 2.0-3.0wt.％,Si≤1.0wt.％,, and the balance of Fe and unavoidable impurities. The prepared alloy ingot is used for preparing 316L stainless steel powder by using electrode induction smelting gas atomization equipment, and is sieved and graded; and then printing layer by additive manufacturing to obtain the 316L stainless steel. Compared with the prior art, the invention effectively inhibits the anisotropic tissue behavior in the original additive manufacturing austenitic stainless steel, has uniform microstructure, realizes grain refinement, solves the problem of tissue and performance anisotropy in the existing additive manufacturing steel material, and promotes the development of the steel material additive manufacturing technology.

Description

Component control and preparation method for high-strength and high-toughness isotropic additive manufacturing 316L stainless steel

Technical Field

The invention belongs to the technical field of additive manufacturing nuclear materials, and particularly relates to a component design and preparation strategy for refining grains and eliminating anisotropism of stainless steel in additive manufacturing.

Background

Additive manufacturing technology is a preparation method for controlling alloy layer-by-layer printing through a computer program, and can provide extremely high freedom degree in the manufacturing process, so that components with various complex geometric shapes can be manufactured. Additive manufacturing is thus leading a number of industries, such as aerospace, automotive, biomedical and energy, into a new era of manufacturing. Compared with the traditional manufacturing technology, the additive manufacturing technology can greatly shorten the production period and reduce the material cost. In addition, the alloy obtained by the additive manufacturing technology undergoes rapid solidification and repeated heating processes in the preparation process, and the special microstructure provides a new idea for solving the tough synergy problem.

However, during rapid cooling of additive manufacturing, the sample observed a large number of columnar crystals and texture phenomena in a direction parallel to the printing direction. The presence of columnar crystals can lead to anisotropy in properties and increase the cracking sensitivity of the alloy. Therefore, the formation of columnar crystals has become a problem to be solved in the industrial process of manufacturing alloys by additive manufacturing.

Common methods for achieving grain refinement or equiaxed grain structure in additive manufactured alloys are to adjust process parameters and scanning strategies, to add inoculants to create a large number of heterogeneous nuclei, or by adjusting chemical components in the additive manufactured alloy to alter solidification paths.

Although columnar grain growth may be prevented by printing process parameters or scanning strategies, grain refinement is inefficient. In addition, although proper microstructure and excellent mechanical properties can be obtained by adding inoculant, powder mixing is difficult to ensure uniformity of components, and uneven distribution of inoculant can lead to inconsistent microstructure of the matrix.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a component control and preparation method for high-strength and high-toughness isotropic additive manufacturing 316L stainless steel, which is suitable for additive manufacturing technologies (such as laser powder bed melting, direct energy deposition, electron beam selective melting and the like), and improves the microstructure of the 316L stainless steel by optimizing alloy components and printing parameters, improves the mechanical property of the microstructure, and provides a preparation process foundation support for additive manufacturing of related structural members in the field of energy industry.

The aim of the invention can be achieved by the following technical scheme:

a preparation method of high-strength isotropic additive manufacturing 316L stainless steel comprises the following steps:

S1: alloy smelting: according to the element proportion of the 316L stainless steel, the composition of the raw material components is controlled to be calculated according to the weight percentage, and the following requirement ：C≤0.03wt.％,S≤0.01wt.％,O≤0.06wt.％,N≤0.02wt.％,Cr 16.0-18.0wt.％,Ni 10.0-13.0wt.％,Mn 0.9-1.5wt.％,Mo 2.0-3.0wt.％,Si≤1.0wt.％, is met, and the balance is Fe and unavoidable impurities. Vacuum smelting is carried out on each raw material master batch, wherein the smelting temperature is 1500-1700 ℃, and as a preferable scheme, the smelting temperature is 1600 ℃, the smelting vacuum degree is less than or equal to 5 multiplied by 10 ^-2 Pa, and as a preferable scheme, the smelting pressure is 5.5Mpa, so as to prepare an alloy ingot;

S2: and (3) atomizing and pulverizing: the alloy ingot prepared in the step S1 is prepared into 316L stainless steel powder by using electrode induction melting gas atomization equipment, and is sieved and graded; the gas atomization method is that alloy ingots are filled into a leakage ladle, alloy melt downwards enters a gas atomization furnace through leakage holes, the alloy is crushed into liquid drops under the action of inert gas flow, and finally the alloy powder is obtained through cooling and solidification.

The inert atmosphere is argon atmosphere, and the atomization air pressure is controlled to be 3-5MPa.

The 316L stainless steel powder after sieving is spherical, the maximum grain diameter is less than 150 mu m, the hollow sphere rate is less than or equal to 2%, and the sphericity is more than or equal to 95%.

S3: according to the shape and the size of the metal part to be processed, a three-dimensional CAD model of the sample is established by adopting three-dimensional modeling software, and model information is transmitted to additive manufacturing equipment;

S4: taking the 316L stainless steel powder screened in the step S2 as a raw material, and controlling the technological parameters of additive manufacturing equipment to be as follows: laser power is 180-220W, scanning speed is 750-1250mm/s, layer thickness is 0.03-0.05mm, hatch distance is 0.08-0.14mm, substrate preheating is 80-120 ℃, argon is introduced as shielding gas to perform oxygen reduction treatment on a cabin, oxygen content of the cabin is less than 0.1%, an interlayer rotation and strip scanning strategy is adopted, rotation is 67 degrees between each layer of printing, strip width is 8-12mm, strip overlapping width is 0.08-0.14mm, and printing is performed layer by layer, so that 316L stainless steel is obtained.

The yield strength of the 316L stainless steel tensile sample perpendicular to the printing direction, which is prepared in the step S4, reaches 400.00-472.92MPa at room temperature, the tensile strength reaches 617.88-691.61MPa, the uniform elongation reaches 37.50-43.33%, the performance difference of the tensile sample perpendicular to the printing direction and parallel to the printing direction is small, and the difference of the ultimate strength, the tensile strength and the uniform elongation in the two directions is less than 25%.

The 316L stainless steel prepared in the step S4 is equiaxed crystal, and the grain size is 15-23 mu m, namely the method realizes the conversion of columnar crystal orientation and equiaxed crystal in the additive manufacturing of the stainless steel material.

The high-strength isotropic additive manufactured 316L stainless steel prepared by the method has isotropy in microstructure and mechanical property, realizes conversion of columnar crystal orientation equiaxial crystals in additive manufacturing stainless steel materials, refines crystal grains of alloys, and has yield strength of 400.00-472.92MPa, tensile strength of 617.88-691.61MPa and uniform elongation of 37.50-43.33% under room temperature condition of a tensile sample perpendicular to a printing direction.

Compared with the prior art, the invention has the beneficial effects that:

1. The characteristic index of the 316L stainless steel alloy powder for additive manufacturing, which is prepared by the invention, meets the characteristic requirement of additive manufacturing technology on alloy powder, and provides technical support for industrially preparing 316L alloy powder.

2. In the iron-based alloy, the solidification path is changed by adjusting the composition, the transformation from the primary austenite mode to the primary ferrite mode is performed, and then the transformation occurs in the solidification process and the cooling process in the rapid cooling mode, so that the grain size and the grain morphology are controlled. In 316L stainless steel, cr, mo and Si are Cr equivalent elements, ni, mn, C, N is Ni equivalent element, and the content of relevant elements is adjusted to obtain proper Cr _eq/Ni_eq, so that the solidification path of the alloy in the rapid cooling process is changed, and the columnar crystal orientation isometric crystal transformation is realized. Specifically, the content of BCC stabilizing elements Cr, mo and Si is properly increased, and the content of FCC stabilizing elements Ni and Mn is reduced. Therefore, the 316L stainless steel for additive manufacturing prepared by the invention has the functions of regulating and controlling microstructure, refining crystal grains and the like due to reasonable component design, so that a formed stainless steel sample has isotropy, the phenomenon that a large number of columnar crystals exist in the microstructure of the original additive manufacturing stainless steel material in a direction parallel to a printing direction is effectively solved, isotropy in performance is realized, and a solid foundation is laid for preparing uniform microstructure materials by an additive manufacturing technology;

3. The 316L stainless steel for additive manufacturing prepared by the method has good mechanical properties, and lays a technical foundation for additive manufacturing of high-strength and high-toughness 316L stainless steel.

4. The 316L stainless steel for additive manufacturing prepared by the method can be popularized and applied to high-performance structural members related to energy industry.

Drawings

Fig. 1 is a microstructure of a 316L stainless steel alloy material for additive manufacturing according to example 1 and comparative example 2 of the present invention.

Fig. 2 is a graph showing the engineering stress-engineering strain curve versus the printing direction (H) and the printing direction (V) of the 316L stainless steel alloy materials for additive manufacturing of example 1, example 3 and comparative example 2 according to the present invention.

Detailed Description

The following representative examples and comparative examples are provided to further illustrate the present invention and are not to be construed as limiting the invention thereto, but to further enable any person skilled in the art to make various modifications and changes without departing from the scope of the present invention.

The raw materials and equipment adopted by the invention are all commercial products unless specified.

Example 1

A method of preparing an isotropic 316L stainless steel for additive manufacturing, comprising the steps of:

s1: alloy smelting: according to the element proportion of the 316L stainless steel in the table 1, each raw material master batch is subjected to vacuum smelting, the smelting temperature is 1600 ℃, and the smelting pressure is 5.5Mpa, so that an alloy ingot is prepared;

S2: and (3) atomizing and pulverizing: the alloy ingot prepared in the step S1 is prepared into 316L stainless steel powder by using electrode induction melting gas atomization equipment, and is sieved and graded; the method comprises the following specific steps: and filling the alloy ingot into a leakage ladle, allowing the alloy melt to enter a gas atomization furnace downwards through a leakage hole, crushing the alloy into liquid drops under the action of inert gas flow, and finally cooling and solidifying to obtain alloy powder. Wherein, the atomization air pressure is controlled to be 3-5MPa.

The alloy powder is spherical after sieving, the maximum grain diameter is less than 150 mu m, the hollow sphere rate is less than or equal to 2%, and the sphericity is more than or equal to 95%.

S3: according to the shape and size of the metal part to be processed, three-dimensional modeling software (Solidworks software is adopted in the embodiment) is adopted to construct a three-dimensional model of a cuboid of 55 x 46 x 42mm ³, and data information of the STL file is transmitted to additive manufacturing forming equipment (equipment of model EOS M290 of EOS GmbH Electro Optical System company is selected in the embodiment).

S4: taking the 316L stainless steel powder screened in the step S2 as a raw material, and controlling the technological parameters of additive manufacturing equipment to be as follows: laser power 189W, scanning speed 928mm/s, layer thickness 0.03mm, hatch distance 0.08mm, laser spot 0.1mm, substrate preheating 80 ℃, introducing argon as shielding gas to perform oxygen reduction treatment on the cabin, wherein the oxygen content of the cabin is less than 0.1%, adopting an interlayer rotation and strip scanning strategy, rotating 67 degrees between each layer of printing, strip width 10mm, strip overlapping width 0.12mm, and printing layer by layer to obtain 316L stainless steel.

It can be seen from fig. 1 that the average grain size of the additive manufactured 316L stainless steel obtained in example 1 is 22.35 μm, and the grain morphology in the V direction is equiaxed.

The obtained 316L stainless steel is made into a plate-shaped pattern, the thickness is 1.5mm, the width of a gauge length section is 2mm, the length of the gauge length section is 8mm, a tensile experiment is carried out, and the experiment is carried out by adopting a Z020 tensile machine of Zwick Roell company, and the strain rate is 1 multiplied by 10 ^-3/s. The mechanical properties of the H-direction tensile sample of the product obtained in example 1 were as follows: tensile strength 617.88MPa, yield strength 400.00MPa and uniform elongation 39.73%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 586.42MPa, yield strength 367.60MPa and uniform elongation 52.56%; the difference in tensile strength between the H direction and the V direction was 5.09%.

Example 2

The raw material formulation of this example is shown in Table 1, and the composition is the same as that of example 1. The parameters of the printing process are set as follows: the laser power 214W, scanning speed 750mm/s, hatch distance 0.12mm, and the rest was the same as in example 1. The average grain size of the obtained additive manufactured 316L stainless steel is 20.10 mu m, and the grain morphology in the V direction is equiaxed. The mechanical properties of the H-direction tensile sample were as follows: tensile strength 624.62MPa, yield strength 398.91MPa and uniform elongation of 42.47%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 591.80MPa, yield strength 371.39MPa and uniform elongation 52.79%; the difference in tensile strength between the H direction and the V direction was 5.25%.

Example 3

The raw material formula of the embodiment is shown in table 1, and the content of Mo element is improved on the basis of the embodiment 1. The parameter settings of the printing process were identical to those of example 1. The average grain size of the obtained additive manufactured 316L stainless steel is 18.27 mu m, and the grain morphology in the V direction is equiaxed. The mechanical properties of the H-direction tensile sample were as follows: tensile strength 654.79MPa, yield strength 430.41MPa and uniform elongation 43.33%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 635.58MPa, yield strength 439.05MPa and uniform elongation of 51.65%; the difference in tensile strength between the H direction and the V direction was 2.93%.

Example 4

The raw material formulation of this example is shown in Table 1, and the Si element content is increased and the Mn element content is reduced based on example 1. The parameter settings of the printing process were identical to those of example 1. The average grain size of the obtained additive manufactured 316L stainless steel is 20.10 mu m, and the grain morphology in the V direction is equiaxed. The mechanical properties of the H-direction tensile sample were as follows: tensile strength 639.51MPa, yield strength 431.12MPa and uniform elongation 37.50%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 613.87MPa, yield strength 448.11MPa and uniform elongation 49.16%; the difference in tensile strength between the H direction and the V direction was 4.01%.

Example 5

The raw material formula of the embodiment is shown in table 1, and the Cr element content is improved on the basis of the embodiment 1. The parameter settings of the printing process were identical to those of example 1. The average grain size of the obtained additive manufactured 316L stainless steel is 17.65 mu m, and the grain morphology in the V direction is equiaxed. The mechanical properties of the H-direction tensile sample were as follows: tensile strength 687.57MPa, yield strength 466.46MPa and uniform elongation of 41.81%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 651.47MPa, yield strength 446.09MPa and uniform elongation of 53.17%; the difference in tensile strength between the H direction and the V direction was 5.25%.

Comparative example 1

The raw material formulation of this comparative example is shown in Table 1, and the Cr element content is excessively increased on the basis of example 1. The parameter settings of the printing process were identical to those of example 1. The average grain size of the obtained additive manufactured stainless steel is 31.03 mu m, and the grain morphology in the V direction is columnar. The mechanical properties of the H-direction tensile sample were as follows: tensile strength 736.52MPa, yield strength 655.52MPa and uniform elongation 12.44%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 689.20MPa, yield strength 671.64MPa and uniform elongation 7.54%; the uniform elongation difference between the H direction and the V direction was 39.39%.

Comparative example 2

The raw material formulation of this comparative example is shown in Table 1, and the Ni element content is increased on the basis of example 1. The parameter settings of the printing process were identical to those of example 1.

It can be seen from fig. 1 that the average grain size of the additive manufactured 316L stainless steel obtained in comparative example 2 was 77.02 μm, and the morphology of the grains in the V direction was columnar.

The mechanical properties of the H-direction tensile sample were as follows: tensile strength 577.44MPa, yield strength 434.87MPa and uniform elongation 33.77%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 482.88MPa, yield strength 370.17MPa and uniform elongation 69.17%; the uniform elongation difference between the H direction and the V direction is 51.18%.

Comparative example 3

The raw material formulation of this comparative example is shown in Table 1, and the composition is the same as in example 1. The parameters of the printing process are set as follows: the laser power 164W, scanning speed 485mm/s, hatch distance 0.10mm, and the rest was the same as in example 1. Numerous keyhole and cracks appear in the resulting sample.

Comparative example 4

The raw material formulation of this comparative example is shown in Table 1, and the composition is the same as in example 1. The parameters of the printing process are set as follows: the laser power 239W, scanning speed 1250mm/s, hatch distance 0.08mm, and the rest was the same as in example 1. The procedure is as in example 1. A number of insufficiently fused defects appear in the resulting samples.

Comparative example 5

The raw material formulation of this comparative example is shown in Table 1, and the composition is the same as in example 1. The parameter settings of the printing process were identical to those of example 1. The molded sample was subjected to a complete recrystallization treatment in a muffle furnace at 1200℃for 2 hours. The average grain size of the obtained 316L stainless steel is 25.99 mu m, and the grain morphology in the V direction is equiaxed. The mechanical properties of the H-direction tensile sample were as follows: tensile strength 610.97MPa, yield strength 231.02MPa and uniform elongation 54.71%. The mechanical properties of the V-direction tensile samples were as follows: tensile strength 580.11MPa, yield strength 298.66MPa and uniform elongation 64.01%; the difference in tensile strength between the H direction and the V direction was 5.05%.

Table 1 each alloy composition (wt.%) in the present invention

	C	S	O	N	Cr	Ni	Mn	Mo	Si	Fe
											Example 1	0.002	0.004	0.054	0.009	16.500	10.680	1.270	2.210	0.400	Bal.
Example 2	0.002	0.004	0.054	0.009	16.500	10.680	1.270	2.210	0.400	Bal.
											Example 3	0.014	0.004	0.053	0.006	16.140	10.570	1.410	2.980	0.410	Bal.
Example 4	0.021	0.005	0.040	0.011	16.480	10.640	0.990	2.200	0.870	Bal.
											Example 5	0.026	0.002	0.052	0.006	17.780	10.610	1.410	2.190	0.410	Bal.
Comparative example 1	0.021	0.003	0.060	0.005	19.690	10.670	1.420	2.210	0.410	Bal.
											Comparative example 2	0.009	0.003	0.054	0.004	16.320	13.990	1.450	2.240	0.410	Bal.
Comparative example 3	0.002	0.004	0.054	0.009	16.500	10.680	1.270	2.210	0.400	Bal.
											Comparative example 4	0.002	0.004	0.054	0.009	16.500	10.680	1.270	2.210	0.400	Bal.
Comparative example 5	0.002	0.004	0.054	0.009	16.500	10.680	1.270	2.210	0.400	Bal.

Table 2 comparative tensile properties of some examples of the invention and comparative examples

TABLE 3 comparison of grain size for some examples of the invention and comparative examples

The microstructure of the additive manufacturing 316L stainless steel in the embodiment of the invention is parallel to the printing direction, the columnar crystal structure is not observed, the columnar crystal direction isometric crystal transformation is realized, no obvious holes and cracks are observed, the density is more than 99.9%, and the grain size is less than 23 mu m. Fig. 2 is a graph showing the engineering stress-engineering strain curve versus the printing direction (H) and the printing direction (V) of the 316L stainless steel alloy materials for additive manufacturing of example 1, example 3 and comparative example 2 according to the present invention. From the tensile property test, it was revealed that the mechanical property difference in the H direction and the V direction was smaller for the example sample than for the comparative example sample.

Examples 1,2 and comparative examples 3 and 4 were identical in composition, but slightly different in printing parameters, focusing mainly on three parameters of laser power, scanning speed and hatch distance. Examples 1 and 2 are controlled within the scope of the claims of the present invention, the sample density can reach more than 99.9%, and the occurrence of defects is avoided. However, the scanning speed of comparative example 3 was too low, resulting in too high a laser energy density input into the molten pool, and occurrence of keyhole defects. In contrast, in comparative example 4, the energy density inputted into the molten pool was too low due to the too high scanning speed, and the metal powder was not sufficiently melted, and the incomplete fusion defect occurred.

Examples 3,4 and 5 are respectively added with proper amounts of BCC stabilizing elements Mo, si and Cr on the basis of example 1, the content is in the scope of the claims, cr _eq/Ni_eq of a sample is improved, so that a primary ferrite mode is realized in the solidification process of a matrix, the sample can finish columnar crystal orientation equiaxed crystal transformation, the refinement of crystal grains is realized, and the problem of anisotropy in performance in the original additive manufacturing stainless steel is improved.

In comparative example 1, cr element was excessively added beyond the standard range of 316L, so that a large amount of ferrite phase was finally present in the molded sample, which was not in conformity with the austenitic matrix of 316L.

In comparative example 2, ni element was added to reduce Cr _eq/Ni_eq of the sample, so that the matrix realizes a primary austenite mode in the solidification process, the sample can realize epitaxial growth of crystal grains at the boundary of the molten pool, a large number of columnar crystals can be observed on the section parallel to the printing direction, and the tensile property figure 2 reflects the apparent anisotropic behavior in mechanical properties in comparative example 2.

In addition, the comparative example 4 is a 316L stainless steel sample subjected to complete recrystallization treatment, and has a microstructure similar to that of an as-cast 316L stainless steel sample, and the yield strength in the H direction is 231.02MPa which is far lower than 398.91-466.46MPa in the embodiment, so that compared with the traditional casting technology, the additive manufacturing technology realizes the improvement of the mechanical property of the 316L stainless steel.

Therefore, the invention realizes the columnar crystal orientation equiaxial crystal change of the additive manufacturing 316L stainless steel in the direction parallel to the printing direction (as shown in figure 1) by utilizing the additive technology and optimizing the alloy components and the printing parameters, ensures good alloy compactness, inhibits the generation of holes and cracks, realizes isotropy in structure and performance (as shown in figure 2), and effectively improves the original mechanical property of the alloy. The novel strength is given to the application of the additive manufacturing stainless steel in the energy industry.

The foregoing detailed description of embodiments of the invention has been presented to enable one of ordinary skill in the art to make and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments without affecting the spirit of the invention, and that various changes and modifications within the scope of the claims. Therefore, the present invention is not limited to the above-described embodiments, and those skilled in the art, based on the present disclosure, should make improvements and modifications without departing from the scope of the present invention.

Claims

1. The component control and preparation method of the high-strength and high-toughness isotropic additive manufactured 316L stainless steel is characterized by comprising the following steps:

s1: alloy smelting: vacuum smelting the master batches of the raw materials according to the element proportion of the 316L stainless steel to prepare an alloy ingot;

S2: and (3) atomizing and pulverizing: the alloy ingot prepared in the step S1 is prepared into 316L stainless steel powder by using electrode induction melting gas atomization equipment, and is sieved and graded;

S4: taking the 316L stainless steel powder screened in the step S2 as a raw material, and controlling the technological parameters of additive manufacturing equipment to be as follows: the laser power is 180-220W, the scanning speed is 750-1250mm/s, the layer thickness is 0.03-0.05mm, the hatch distance is 0.08-0.14mm, the substrate is preheated to 80-120 ℃, an interlayer rotation and strip scanning strategy is adopted, the rotation between each layer of printing is 67 degrees, the strip width is 8-12mm, the strip overlapping width is 0.08-0.14mm, and the 316L stainless steel is obtained by layer-by-layer printing.

2. The method for controlling and preparing the components of the 316L stainless steel manufactured by the high-strength isotropic additive according to claim 1, wherein the raw material components of the 316L stainless steel are calculated according to the following requirements ：C≤0.03wt.％,S≤0.01wt.％,O≤0.06wt.％,N≤0.02wt.％,Cr 16.0-18.0wt.％,Ni 10.0-13.0wt.％,Mn 0.9-1.5wt.％,Mo 2.0-3.0wt.％,Si≤1.0wt.％, and the balance of Fe and unavoidable impurities in percentage by weight.

3. The method for controlling and preparing the components of the high-strength isotropic additive manufactured 316L stainless steel according to claim 1, wherein the smelting temperature of the vacuum smelting in the step S1 is 1500-1700 ℃, and the smelting vacuum degree is less than or equal to 5 multiplied by 10 ^-2 Pa.

4. The method for controlling and preparing the components of the 316L stainless steel manufactured by the isotropic additive with high strength and toughness according to claim 1, wherein the gas atomization method in the step S2 is to fill alloy ingots into a leakage ladle, enable alloy melt to enter a gas atomization furnace downwards through leakage holes, enable the alloy to be crushed into liquid drops under the action of inert gas flow, and finally cool and solidify the alloy into alloy powder.

5. The method for controlling and preparing the components of the 316L stainless steel by using the high-strength isotropic additive according to claim 4, wherein the inert atmosphere is argon atmosphere, and the atomization air pressure is controlled to be 3-5MPa.

6. The method for controlling and preparing the components of the 316L stainless steel by using the high-strength isotropic additive according to claim 1, wherein the 316L stainless steel powder prepared in the step S2 is spherical, the maximum particle size is less than 150 μm, the hollow sphere rate is less than or equal to 2%, and the sphericity is more than or equal to 95%.

7. The method for controlling and preparing the components of the 316L stainless steel manufactured by the high-strength isotropic additive according to claim 1, wherein the yield strength of the 316L stainless steel manufactured by the step S4 under the room temperature condition is 400.00-472.92MPa, the tensile strength is 617.88-691.61MPa, the uniform elongation is 37.50-43.33%, the performance difference of the drawn sample perpendicular to the printing direction and the drawn sample parallel to the printing direction is small, and the difference of the ultimate strength, the tensile strength and the uniform elongation in the two directions is less than 25%.

8. The method for controlling and preparing the components of the high-strength and high-toughness isotropic additive manufactured 316L stainless steel according to claim 1, wherein the 316L stainless steel prepared in the step S4 is an isometric crystal, and the grain size is 15-23 μm.