阅读说明：本技术 一种纳米氧化物弥散强化钢件及其快速增材制造方法 (Nano oxide dispersion strengthened steel part and rapid additive manufacturing method thereof ) 是由 严有为 于 2020-05-08 设计创作，主要内容包括：本发明属于增材制造相关技术领域,其公开了一种纳米氧化物弥散强化钢件及其快速增材制造方法,所述方法包括以下步骤：(1)将合金钢粉及纳米氧化物粉进行球磨混合以得到混合粉体；(2)将钢带包裹混合粉体,并通过成型拉丝得到药芯丝材；(3)以药芯丝材为原料,利用电弧熔丝制造设备按照待制造零件的三维模型对应的机器人代码在基板上进行多道多层电弧熔丝增材制造,以得到纳米氧化物弥散强化钢件。本发明利用电弧熔丝小熔池熔炼及其快速冷却凝固的特性,抑制了纳米氧化物的长大与聚集,且利用增材制造无需模具及成形效率高的特点,实现了大型复杂金属构件的制备,提高了制备效率,为纳米ODS钢提供了一条大规模制备的新途径。(The invention belongs to the technical field related to additive manufacturing, and discloses a nano oxide dispersion strengthened steel piece and a rapid additive manufacturing method thereof, wherein the method comprises the following steps: (1) performing ball milling and mixing on alloy steel powder and nano oxide powder to obtain mixed powder; (2) wrapping the steel belt with the mixed powder, and performing forming and wire drawing to obtain a flux-cored wire; (3) taking a flux-cored wire as a raw material, and carrying out multi-channel multi-layer arc fuse additive manufacturing on a substrate by using arc fuse manufacturing equipment according to a robot code corresponding to a three-dimensional model of a part to be manufactured so as to obtain a nano oxide dispersion strengthened steel part. The invention utilizes the characteristics of small arc fuse molten pool smelting and rapid cooling solidification to inhibit the growth and aggregation of nano oxides, and utilizes the characteristics of no need of a mould in additive manufacturing and high forming efficiency to realize the preparation of large-scale complex metal components, improve the preparation efficiency and provide a new way for large-scale preparation of nano ODS steel.)

1. A rapid additive manufacturing method of a nano oxide dispersion strengthened steel part is characterized by comprising the following steps:

(1) performing ball milling and mixing on alloy steel powder and nano oxide powder to obtain mixed powder;

(2) wrapping the mixed powder by a steel belt, and performing forming and wire drawing to obtain a flux-cored wire;

(3) and taking the flux-cored wire as a raw material, and carrying out multi-channel multi-layer arc fuse additive manufacturing on the substrate by using arc fuse manufacturing equipment according to the robot code corresponding to the three-dimensional model of the part to be manufactured so as to obtain the nano oxide dispersion strengthened steel part.

2. The rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member according to claim 1, wherein: a process control agent is also added in the ball milling and mixing process of the alloy steel powder and the nano oxide powder, wherein the process control agent is ethanol or stearic acid, and the mass percent of the process control agent in the mixed powder is 1-10 wt%.

3. The rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member according to claim 1, wherein: the alloy steel powder is stainless steel powder or alloy steel powder, and the average grain size of the alloy steel powder is less than 30 mu m.

4. The rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member according to claim 1, wherein: the nano oxide powder is rare earth oxide powder, metal oxide powder or metalloid oxide powder, and the average grain diameter of the nano oxide powder is less than 40 nm.

5. The rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member according to claim 4, wherein: the nano oxide powder accounts for 1-10 wt% of the mixed powder in percentage by mass.

6. The rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member as claimed in any one of claims 1 to 5, wherein: the ball milling and mixing time is 1-10 hours.

7. The rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member as claimed in any one of claims 1 to 5, wherein: the steel strip is a cold-rolled steel strip with the width of 12mm and the thickness of 2mm, the diameter of the prepared flux-cored wire is 1 mm-2 mm, and the powder filling rate is 10% -30%.

8. The rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member as claimed in any one of claims 1 to 5, wherein: the process parameters adopted during the additive manufacturing of the arc fuse are as follows: the current is 150-200A, the voltage is 15-25V, and the moving speed of the welding gun is 1-10 mm/s.

9. Method for manufacturing a nano-oxide dispersion strengthened steel member according to claim 1The rapid additive manufacturing method is characterized in that: the step (3) is carried out in an inert atmosphere, and the inert gas is pure Ar +20 percent CO₂The flow rate of the mixed gas is 10L/min-20L/min, in the multi-channel multi-layer additive manufacturing, the lap joint quantity between channels in each layer is 20% -40%, and the additive height of each layer is 2 mm-5 mm.

10. A nanometer oxide dispersion strengthening steel member is characterized in that: the nano-oxide dispersion strengthened steel part is prepared by adopting the rapid additive manufacturing method of the nano-oxide dispersion strengthened steel part according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field related to additive manufacturing, and particularly relates to a nano oxide dispersion strengthened steel piece and a rapid additive manufacturing method thereof.

Background

The organization structure of Oxide Dispersion Strengthened (ODS) steel is characterized in that a large number of nano Oxide particles are dispersed in a matrix. The second phase nano-oxide particles with high melting point and good thermal stability can effectively block dislocation and grain boundary sliding, thereby endowing the material with excellent high-temperature creep resistance. Moreover, a large number of interfaces formed between the nano oxide particles and the matrix can absorb He bubbles generated in the irradiation process to form He traps, so that the irradiation resistance of the nano oxide particles is obviously improved. Therefore, the ODS steel has great application prospect in the fields of nuclear power energy, petrochemical industry, power machinery and the like.

ODS steel is generally prepared by a traditional powder metallurgy method at present, namely, firstly, high-energy ball-milling alloy and oxide powder to obtain supersaturated solid solution powder, and then, the powder is subjected to thermosetting molding and subsequent heat treatment to disperse and separate out a large number of nano oxide particles in a matrix. In the powder ball milling process, because atoms are diffused in a solid phase mode, the time required for forming the supersaturated solid solution is generally from tens of hours to hundreds of hours, so that the preparation efficiency is reduced, the preparation cost is increased, and impurity pollution is inevitably introduced. Furthermore, subsequent hot isostatic pressing, hot extrusion, and other solidification forming processes are generally difficult to directly fabricate large, complex components. The above-mentioned disadvantages limit the practical production and application of ODS steel to a great extent. Accordingly, there is a need in the art to develop an efficient and low-cost nano-oxide dispersion strengthened steel member and a rapid additive manufacturing method thereof.

Disclosure of Invention

Aiming at the defects or the improvement requirements of the prior art, the invention provides a nano oxide dispersion strengthening steel piece and a rapid additive manufacturing method thereof, which adopt the characteristics of arc fuse small molten pool smelting and rapid cooling solidification to inhibit the aggregation and growth of nano particles and ensure that a large amount of nano oxide particles are dispersed and distributed in a steel matrix, and simultaneously, the method also utilizes the characteristics of no need of a mould and high forming efficiency in additive manufacturing to realize the preparation of large-scale complex metal components, optimizes the existing ODS steel preparation process, improves the preparation efficiency and provides a new way for large-scale preparation of nano ODS steel.

To achieve the above object, according to one aspect of the present invention, there is provided a rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member, the method comprising the steps of:

(1) performing ball milling and mixing on alloy steel powder and nano oxide powder to obtain mixed powder;

(2) wrapping the mixed powder by a steel belt, and performing forming and wire drawing to obtain a flux-cored wire;

(3) and taking the flux-cored wire as a raw material, and carrying out multi-channel multi-layer arc fuse additive manufacturing on the substrate by using arc fuse manufacturing equipment according to the robot code corresponding to the three-dimensional model of the part to be manufactured so as to obtain the nano oxide dispersion strengthened steel part.

Further, a process control agent is added in the ball milling and mixing process of the alloy steel powder and the nano oxide powder, wherein the process control agent is ethanol or stearic acid, and accounts for 1 wt% -10 wt% of the mixed powder.

Further, the alloy steel powder is stainless steel powder or other alloy steel powder for special purposes, and the average grain diameter of the alloy steel powder is less than 30 mu m.

Furthermore, the nano oxide powder is rare earth oxide powder, metal oxide powder or metalloid oxide powder, and the average particle size of the nano oxide powder is less than 40 nm.

Further, the mass percentage of the nano oxide powder in the mixed powder is 1 wt% -10 wt%.

Further, the ball milling mixing time is 1 to 10 hours.

Furthermore, the steel strip is a cold-rolled steel strip with the width of 12mm and the thickness of 2mm, the diameter of the prepared flux-cored wire is 1 mm-2 mm, and the powder filling rate is 10% -30%.

Further, the process parameters adopted during the additive manufacturing of the arc fuse are as follows: the current is 150-200A, the voltage is 15-25V, and the moving speed of the welding gun is 1-10 mm/s.

Further, step (3) is carried out in an inert atmosphere using pure Ar + 20% CO₂The flow rate of the mixed gas is 10L/min-20L/min, in the multi-channel multi-layer additive manufacturing, the lap joint quantity between channels in each layer is 20% -40%, and the additive height of each layer is 2 mm-5 mm.

According to another aspect of the present invention, there is provided a nano-oxide dispersion-strengthened steel member prepared by the rapid additive manufacturing method of a nano-oxide dispersion-strengthened steel member as described above.

Generally, compared with the prior art, the nano oxide dispersion strengthened steel piece and the rapid additive manufacturing method thereof provided by the invention have the following beneficial effects:

1. in the process of preparing ODS steel by the existing powder metallurgy method, the process of obtaining non-equilibrium supersaturated solid solution powder by high-energy ball milling is an important link, but the link takes dozens of hours or even hundreds of hours.

2. In the ball milling and mixing process, a process control agent is required to be added, the content of the process control agent is 1 wt% -10 wt%, and the process control agent is ethanol or stearic acid, so that the material mixing and ball milling process is more stable, and the obtained mixed powder is more uniformly mixed.

3. The method can design and adjust the composition and the components of the flux-cored wire to meet the requirements of different service properties of the ODS steel, and has wider practical application range.

4. The metal cored wire obtained by the invention has small diameter (less than or equal to 2mm), and in the electric arc fuse wire additive manufacturing process, the continuously conveyed wire is synchronously melted under the action of electric arc heat, the formed molten pool is small and is rapidly cooled and solidified, the metal cored wire has the characteristics of small molten pool melting and casting, the aggregation and growth of nano particles introduced by the cored wire can be inhibited, the size of the nano particles in the prepared material tissue is small and the distribution is uniform, and the problem of component segregation in the casting process of a large-scale metal member is solved.

5. The invention melts the metal wire material by electric arc heat according to the principle of layer-by-layer deposition, gradually forms the required metal component from a wire-surface-body under the control of a software program, does not need a mould, has high efficiency and low cost, has unique advantages particularly on manufacturing large complex metal components, and solves the problem that the traditional powder metallurgy method is difficult to prepare the large complex components.

6. The forming process of the ODS steel member provided by the invention is carried out under the control of a software program, and can realize mechanized and large-scale production.

Drawings

FIG. 1 is a schematic flow chart of a rapid additive manufacturing method of a nano-oxide dispersion strengthened steel part provided by the invention;

FIG. 2 (a) and (b) are SEM images and EDS results of energy spectrum analysis of the nano-oxide in the nano-oxide dispersion-strengthened steel member prepared in example 2 of the present invention, respectively;

FIG. 3 is a SEM image of the morphology of the nano-oxide in the nano-oxide dispersion strengthened steel part prepared in example 3 of the present invention;

FIG. 4 is a SEM image of the morphology of the nano-oxide in the nano-oxide dispersion strengthened steel member prepared in example 4 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Among the various oxides, yttrium oxide (Y)₂O₃) High melting point, good thermal stability,is an oxide reinforced particle widely adopted in the current ODS steel; meanwhile, 316 stainless steel has good comprehensive performance. Therefore, the embodiment herein uses the commercially available 316 stainless steel powder and nano-Y₂O₃The powder is a representative but not limiting material. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 1, the rapid additive manufacturing method of a nano-oxide dispersion strengthened steel member provided by the present invention mainly includes the following steps:

step one, performing ball milling and mixing on alloy steel powder, nano oxide powder and a process control agent to obtain mixed powder.

Specifically, alloy steel powder and nano oxide powder are subjected to ball milling mixing under the action of a process control agent to obtain mixed powder. Wherein the process control agent accounts for 1-10 wt% of the mixed powder by mass and is ethanol or stearic acid; the ball milling and mixing time is 1-10 h; the alloy steel powder is stainless steel powder or alloy steel powder with other special purposes, and the average grain diameter of the alloy steel powder is less than 30 mu m; the nanometer oxide powder is high-melting point and high-stability rare earth oxide (such as Y)₂O₃) Metal oxide (e.g., Al)₂O₃) Or metalloid oxides (e.g. SiO)₂) A powder having an average particle size of less than 40 nm; the mass content of the oxide powder in the mixed powder is 1-10 wt%.

And step two, wrapping the mixed powder by using a steel belt, and forming and drawing to obtain the flux-cored wire.

Specifically, the steel strip is a cold-rolled steel strip with the width of 12mm and the thickness of 2mm, and the diameter of the flux-cored wire is 1 mm-2 mm; the filling rate of the mixed powder in the flux-cored wire is 10-30%.

And thirdly, taking the flux-cored wire as a raw material, and performing multi-channel multi-layer arc fuse material additive manufacturing on the substrate by using arc fuse manufacturing equipment according to the robot code corresponding to the three-dimensional model of the part to be manufactured so as to obtain the nano oxide dispersion strengthened steel part.

Specifically, the obtained flux-cored wire is subjected to multi-channel multi-layer arc fuse additive manufacturing on a substrate by utilizing arc fuse manufacturing equipment and generating a robot code according to a three-dimensional model of a part to be manufactured under the protection of proper process parameters and inert gas. After printing and forming, the nano oxide dispersion strengthened steel piece can be obtained by grinding and polishing. Wherein, the parameters of the arc fuse additive manufacturing process are set as follows: the current is 150-200A, the voltage is 15-25V, and the moving speed of the welding gun is 1-10 mm/s; the inert gas is pure Ar + 20% CO₂The flow rate of the mixed gas is 10L/min-20L/min; in the multi-channel and multi-layer additive manufacturing, the lap joint quantity between channels in each layer is 20% -40%, and the additive height of each layer is 2 mm-5 mm.

The electric arc fuse wire additive manufacturing technology has the advantages of no need of a mould, high forming efficiency, low cost and the like, so that large-scale preparation of large-scale complex metal components can be realized; the prepared nanometer ODS steel part has the microstructure characteristic of high-density dispersion distribution of oxides, and the particle size of the nanometer oxides is about 40nm, so that the nanometer ODS steel part has excellent high-temperature creep resistance and irradiation resistance, and can be applied to the fields of nuclear power energy, petrochemical industry, power machinery and the like.

The invention also provides a nano oxide dispersion strengthened steel part which is prepared by adopting the rapid additive manufacturing method of the nano oxide dispersion strengthened steel part.

The present invention is further illustrated in detail below with reference to several examples.