阅读说明：本技术 一种适用于刀具刃口强化的离子渗氮装置及方法 (Ion nitriding device and method suitable for strengthening cutting edge of cutter ) 是由 罗建东 胡雁鸿 于 2021-07-21 设计创作，主要内容包括：本发明公开了一种适用于刀具刃口强化的离子渗氮装置及方法,其中,适用于刀具刃口强化的离子渗氮装置,包括至少一组刀具安装组件,所述刀具安装组件包括上下置放的交流阴极板和直流阴极板,所述交流阴极板和直流阴极板之间具有供工件置放的安放空间,所述直流阴极板用于安放工件；至少一根交流阴极导电杆,用于连接交流脉冲电源,所述交流阴极导电杆与所述交流阴极板电连接,以产生等离子体；以及至少一根直流阴极导电杆,用于连接直流脉冲电源,所述直流阴极导电杆与所述直流阴极板电连接,以形成指向直流阴极板方向的加速电场。本发明能加快低温下的渗氮速率,在不降低耐蚀性的前提下,提高刀刃处的硬度和耐磨性。(The invention discloses an ion nitriding device and method suitable for strengthening a cutting edge of a cutter, wherein the ion nitriding device suitable for strengthening the cutting edge of the cutter comprises at least one group of cutter mounting assemblies, each cutter mounting assembly comprises an alternating current negative plate and a direct current negative plate which are vertically placed, a placing space for placing a workpiece is formed between the alternating current negative plate and the direct current negative plate, and the direct current negative plate is used for placing the workpiece; the alternating current cathode conducting rod is used for being connected with an alternating current pulse power supply and is electrically connected with the alternating current cathode plate so as to generate plasma; and the direct current cathode conducting rod is used for connecting a direct current pulse power supply and is electrically connected with the direct current cathode plate so as to form an accelerating electric field pointing to the direction of the direct current cathode plate. The invention can accelerate the nitriding rate at low temperature and improve the hardness and the wear resistance of the blade on the premise of not reducing the corrosion resistance.)

1. The utility model provides an ion nitriding device suitable for cutter blade is reinforceed which characterized in that: comprises that

The tool mounting assembly comprises an alternating current negative plate and a direct current negative plate which are vertically placed, a placing space for placing a workpiece is formed between the alternating current negative plate and the direct current negative plate, and the direct current negative plate is used for placing the workpiece;

the alternating current cathode conducting rod is used for being connected with an alternating current pulse power supply and is electrically connected with the alternating current cathode plate so as to generate plasma; and

and the direct current cathode conducting rod is electrically connected with the direct current cathode plate to form an accelerating electric field pointing to the direction of the direct current cathode plate.

2. Ion nitriding device suitable for tool edge strengthening according to claim 1, characterized by: the cutter mounting assemblies are at least two groups and are sequentially arranged up and down, the alternating current cathode conducting rods are electrically connected with the alternating current cathode plates of the cutter mounting assemblies from bottom to top, the direct current cathode plates are provided with first through holes for the alternating current cathode conducting rods to penetrate through, the direct current cathode conducting rods are electrically connected with the direct current cathode plates of the cutter mounting assemblies from bottom to top, and the alternating current cathode plates are provided with second through holes for the direct current cathode conducting rods to penetrate through.

3. Ion nitriding device suitable for tool edge strengthening according to claim 2, characterized in that: a first insulator is arranged at the joint of the alternating current cathode conducting rod and the direct current cathode plate, and a second insulator is arranged at the joint of the direct current cathode conducting rod and the alternating current cathode plate.

4. Ion nitriding device suitable for tool edge strengthening according to claim 3, characterized in that: the number of the direct current cathode conducting rods is one, the number of the alternating current cathode conducting rods is multiple and is distributed in a circumferential mode, and the alternating current cathode conducting rods are matched with the direct current cathode conducting rods to support the cutter mounting assemblies.

5. Ion nitriding device suitable for tool edge strengthening according to claim 4, characterized in that: and the bottom end of the alternating current cathode conducting rod is provided with an alternating current cathode joint, and the bottom end of the direct current cathode conducting rod is provided with a direct current cathode joint.

6. The ion nitriding device for tool edge strengthening according to any one of claims 1 to 5, wherein: a plurality of fixture bodies are placed on the direct current negative plate, and the fixture bodies are provided with a plurality of insertion openings for inserting workpieces.

7. An ion nitriding method suitable for strengthening the cutting edge of a cutter is characterized by comprising the following steps: installing the ion nitriding device suitable for tool edge strengthening according to any one of claims 1 to 6 in a vacuum ion nitriding furnace;

connecting the positive pole of the direct current pulse power supply with the infiltration furnace, and connecting the negative pole of the direct current pulse power supply with the direct current cathode conducting rod;

connecting the positive pole of an alternating current pulse power supply with a infiltration furnace, and connecting the negative pole of the alternating current pulse power supply with an alternating current cathode conducting rod;

nitriding at 300-380 deg.c according to the following technological process and parameters; the flow ratio of nitrogen to hydrogen is 1: 3; the vacuum degree is 15Pa-25 Pa; the direct current pulse power supply is 240V-300V; 320V-360V of an alternating current pulse power supply; nitriding time: 6h-8 h.

8. Ion nitriding method suitable for tool edge strengthening according to claim 7, characterized by: the material applied to the cutter is austenitic stainless steel, the hardness of the surface layer is required to be more than 800Hv, and the thickness of the infiltrated layer is required to be more than 0.02 mm;

nitriding is carried out according to the following process and parameters: 300 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 25 Pa; a direct-current pulse power supply: 240V; an alternating current pulse power supply: 320V; nitriding time: and 6 h.

9. Ion nitriding method suitable for tool edge strengthening according to claim 7, characterized by: the material applied to the cutter is martensitic stainless steel, the surface hardness is more than 1000Hv, and the thickness of a seeping layer is more than 0.03 mm;

nitriding is carried out according to the following process and parameters: 340 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 20 Pa; a direct-current pulse power supply: 260V; an alternating current pulse power supply: 340V; nitriding time: and 7 h.

10. Ion nitriding method suitable for tool edge strengthening according to claim 7, characterized by: the material applied to the cutter is non-stainless steel, the surface hardness is above 1300Hv, and the thickness of the infiltrated layer is above 0.04 mm;

nitriding is carried out according to the following process and parameters: 380 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 15 Pa; a direct-current pulse power supply: 300V; an alternating current pulse power supply: 360V; nitriding time: and 8 h.

Technical Field

The invention relates to the technical field of cutter manufacturing, in particular to an ion nitriding device suitable for cutter edge strengthening and an ion nitriding method suitable for cutter edge strengthening.

Background

The traditional cutter is mostly made of martensitic stainless steel (such as 3Cr13) and is formed by quenching, sharpening and polishing; however, the hardness of the martensitic stainless steel after quenching is about 42HRC, and the hardness is lower; and the antirust performance is insufficient, and the rust is easy to generate in the using process.

In order to improve the overall performance of the cutting tool, it is necessary to further improve the hardness, wear resistance and corrosion resistance of the cutting edge portion, and the cutting edge portion may be subjected to nitriding treatment.

However, conventional ion nitriding is performed at a temperature higher than 500 ℃, on one hand, solubility of nitrogen in an austenite phase reaches a maximum value, metastable phase decomposition occurs, and a large amount of CrN is precipitated, thereby causing exhaustion of free chromium in a steel matrix and lowering corrosion resistance of stainless steel, and on the other hand, ion nitriding of a blade portion at 500 ℃ or higher causes deformation of a blade.

The conventional low-temperature ionic nitriding can improve the surface hardness and the wear resistance of a sample and does not influence the corrosion resistance of the sample obviously. However, the conventional low-temperature ion nitriding has very low speed, very long nitriding time, low production efficiency and high cost.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the above-mentioned problems in the prior art. Therefore, the embodiment of the invention provides the ion nitriding device suitable for strengthening the cutting edge of the cutter, so that the nitriding rate at low temperature is accelerated, and the hardness and the wear resistance of the cutting edge are improved on the premise of not reducing the corrosion resistance.

The embodiment of the invention also provides an ion nitriding method suitable for strengthening the cutting edge of the cutter.

According to an embodiment of the first aspect of the invention, an ion nitriding device suitable for strengthening a cutting edge of a cutter is provided, and comprises at least one group of cutter mounting assemblies, wherein each cutter mounting assembly comprises an alternating current cathode plate and a direct current cathode plate which are vertically arranged, a placing space for placing a workpiece is formed between the alternating current cathode plate and the direct current cathode plate, and the direct current cathode plate is used for placing the workpiece; the alternating current cathode conducting rod is used for being connected with an alternating current pulse power supply and is electrically connected with the alternating current cathode plate so as to generate plasma; and the direct current cathode conducting rod is used for connecting a direct current pulse power supply and is electrically connected with the direct current cathode plate so as to form an accelerating electric field pointing to the direction of the direct current cathode plate.

The ion nitriding device suitable for strengthening the cutting edge of the cutter at least has the following beneficial effects:

firstly, two power supplies are adopted to simultaneously supply power to the nitriding furnace, an alternating current pulse power supply is used for generating high-density plasma, and a direct current pulse bias voltage is applied to a direct current cathode plate to form an accelerating electric field pointing to the direction of the direct current cathode plate, so that electrons obtain energy under the action of the accelerating bias voltage to bombard a workpiece, the number of atoms knocked out from the lattice position of the workpiece is increased, structural defects generated on the surface of the workpiece are beneficial to nitrogen entering the surface of the workpiece, and the nitriding rate is improved. Under the action of DC pulse bias voltage, a sheath layer corresponding to the bias voltage value is formed near the DC cathode plate, and the voltage drop of the sheath layer can be changed by adjusting the bias voltage value, so that the energy of incident ions is controlled. With the increase of the voltage of the sheath layer, the energy of electrons bombarding the direct current cathode plate is increased, so that more secondary electrons are generated, and some of the secondary electrons are accelerated by the sheath layer and then possibly enter the plasma to further ionize and decompose the source gas, and the nitridation rate is further improved.

Secondly, a direct current pulse power supply is adopted to electrify the direct current cathode conducting rod, and because the pulse action period is short, the surface of the workpiece can not be arcing, so that the workpiece is prevented from being burnt. Ions are directionally accelerated to the direct current cathode plate under the action of direct current bias voltage and are accumulated on the direct current cathode plate, the surface potential is changed, and the ion energy distribution is influenced. The DC pulse bias can reduce the adverse effect caused by charge accumulation compared with the conventional DC voltage and has better uniformity.

Thirdly, the invention has simple structure and high comprehensive efficiency.

According to an embodiment of the first aspect of the present invention, the cutter mounting assemblies are arranged in at least two groups and are sequentially arranged up and down, the ac cathode conducting rod is electrically connected to the ac cathode plate of each cutter mounting assembly from bottom to top, the dc cathode plate is provided with a first through hole for the ac cathode conducting rod to pass through, the dc cathode conducting rod is electrically connected to the dc cathode plate of each cutter mounting assembly from bottom to top, and the ac cathode plate is provided with a second through hole for the dc cathode conducting rod to pass through.

According to an embodiment of the first aspect of the present invention, a first insulator is mounted at the junction of the ac cathode conducting rod and the dc cathode plate, and a second insulator is mounted at the junction of the dc cathode conducting rod and the ac cathode plate.

According to an embodiment of the first aspect of the present invention, there is one dc cathode conducting rod, a plurality of ac cathode conducting rods are arranged and distributed circumferentially, and the ac cathode conducting rods cooperate with the dc cathode conducting rods to support each of the cutter mounting assemblies.

According to an embodiment of the first aspect of the present invention, the ac cathode rod is mounted with an ac cathode joint at its bottom end, and the dc cathode rod is mounted with a dc cathode joint at its bottom end.

According to an embodiment of the first aspect of the invention, the direct current cathode plate is placed with a plurality of fixture bodies, and the fixture bodies are provided with a plurality of insertion openings for inserting workpieces.

According to the embodiment of the second aspect of the invention, an ion nitriding method suitable for strengthening the cutting edge of a cutter is provided, and the ion nitriding device suitable for strengthening the cutting edge of the cutter is installed in a vacuum ion nitriding furnace; connecting the positive pole of the direct current pulse power supply with the infiltration furnace, and connecting the negative pole of the direct current pulse power supply with the direct current cathode conducting rod; connecting the positive pole of an alternating current pulse power supply with a infiltration furnace, and connecting the negative pole of the alternating current pulse power supply with an alternating current cathode conducting rod; nitriding at 300-380 deg.c according to the following technological process and parameters; the flow ratio of nitrogen to hydrogen is 1: 3; the vacuum degree is 15Pa-25 Pa; the direct current pulse power supply is 240V-300V; 320V-360V of an alternating current pulse power supply; nitriding time: 6h-8 h.

The ion nitriding method suitable for strengthening the cutting edge of the cutter at least has the following beneficial effects: through the ion nitriding device suitable for strengthening the cutting edge of the cutter, the workpiece is subjected to ion nitriding treatment, the nitriding rate at low temperature can be accelerated, and the hardness and the wear resistance of the cutting edge are improved on the premise of not reducing the corrosion resistance.

According to the embodiment of the second aspect of the invention, the material applied to the cutter is austenitic stainless steel, the hardness of the surface layer is required to be more than 800Hv, and the thickness of the infiltrated layer is required to be more than 0.02 mm; nitriding is carried out according to the following process and parameters: 300 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 25 Pa; a direct-current pulse power supply: 240V; an alternating current pulse power supply: 320V; nitriding time: and 6 h.

According to the embodiment of the second aspect of the invention, the material applied to the cutter is martensitic stainless steel, the surface hardness is above 1000Hv, and the thickness of the infiltrated layer is above 0.03 mm; nitriding is carried out according to the following process and parameters: 340 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 20 Pa; a direct-current pulse power supply: 260V; an alternating current pulse power supply: 340V; nitriding time: and 7 h.

According to the embodiment of the second aspect of the invention, the material applied to the cutter is non-stainless steel, the hardness of the surface layer is above 1300Hv, and the thickness of the infiltrated layer is above 0.04 mm; nitriding is carried out according to the following process and parameters: 380 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 15 Pa; a direct-current pulse power supply: 300V; an alternating current pulse power supply: 360V; nitriding time: and 8 h.

Drawings

The invention is further described below with reference to the accompanying drawings and examples;

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

fig. 3 is a schematic structural view of the cutter mounted on the clamp body in the embodiment of the invention.

Detailed Description

Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

Referring to fig. 1 and 3, an embodiment of the present invention shows an ion nitriding apparatus suitable for tool edge strengthening, comprising at least one set of tool mounting assembly 10, at least one ac cathode conducting rod 21, and at least one dc cathode conducting rod 31.

The cutter mounting assembly 10 comprises an alternating current cathode plate 11 and a direct current cathode plate 12 which are arranged up and down, a placing space 13 for placing workpieces is arranged between the alternating current cathode plate 11 and the direct current cathode plate 12, and the direct current cathode plate is used for placing the workpieces. In the embodiment of the invention, corresponding to the low-temperature ion nitriding treatment of the cutting edge of the cutter, as shown in fig. 3, a plurality of clamp bodies 41 are placed on a direct current cathode plate 12, and the clamp bodies 41 are provided with a plurality of sockets for inserting workpieces, namely the cutter 42 in the embodiment. That is, a plurality of cutters 42 are fixed by the fixture body 41, the cutting edges of the cutters 42 are arranged upward, and a plurality of fixture bodies 41 can be placed on one direct current cathode plate 12, and the cutting edges of the cutters 42 can be processed at the same time.

The alternating current cathode conducting rod 21 is used for connecting an alternating current pulse power supply, and the alternating current cathode conducting rod 21 is electrically connected with the alternating current cathode plate 11 to generate plasma. The dc cathode conductive rod 31 is used for connecting a dc pulse power supply, and the dc cathode conductive rod 31 is electrically connected to the dc cathode plate 12 to form an accelerating electric field pointing to the direction of the dc cathode plate 12.

The ion nitriding device suitable for strengthening the cutting edge of the cutter is installed in a vacuum ion nitriding furnace when being applied. It can be understood that in the embodiment, two power supplies are adopted to simultaneously supply power to the nitriding furnace, the alternating current pulse power supply is used for generating high-density plasma, and the direct current pulse bias voltage is applied to the direct current cathode plate 12 to form an accelerating electric field pointing to the direction of the direct current cathode plate 12, so that electrons obtain energy under the action of the accelerating bias voltage to bombard a workpiece, the number of atoms knocked out from the lattice position of the workpiece is increased, structural defects generated on the surface of the workpiece are beneficial to nitrogen entering the surface of the workpiece, and the nitriding rate is improved. A sheath layer corresponding to the bias voltage value is formed near the direct current cathode plate 12 under the action of the direct current pulse bias voltage, and the voltage drop of the sheath layer can be changed by adjusting the bias voltage value, so that the energy of the incident ions is controlled. As the voltage of the sheath increases, the energy of electrons bombarding the dc cathode plate 12 increases, thereby generating more secondary electrons, some of which may enter the plasma after being accelerated by the sheath to further ionize and decompose the source gas, further increasing the nitridation rate.

The direct current cathode conducting rod 31 is electrified by adopting a direct current pulse power supply, and the surface of the workpiece cannot be arcing due to the short pulse action period, so that the workpiece is prevented from being burnt. The ions are directionally accelerated to the DC cathode plate 12 under the action of the DC bias voltage and are accumulated on the DC cathode plate 12, the surface potential is changed, and the ion energy distribution is influenced. The DC pulse bias can reduce the adverse effect caused by charge accumulation compared with the conventional DC voltage and has better uniformity.

In some of the embodiments, the cutter mounting assemblies 10 are arranged in at least two groups and sequentially on top of each other, as shown in fig. 1, the present embodiment is provided with four groups, and the ac cathode plates 11 and the dc cathode plates 12 are alternately arranged on top of each other.

The alternating current cathode conducting rod 21 is electrically connected with the alternating current cathode plate 11 of each cutter mounting assembly 10 from bottom to top, the direct current cathode plate 12 is provided with a first through hole for the alternating current cathode conducting rod 21 to pass through, and a first insulator 22 is arranged at the joint of the alternating current cathode conducting rod 21 and the direct current cathode plate 12.

The direct current cathode conducting rod 31 is electrically connected with the direct current cathode plate 12 of each cutter mounting assembly 10 from bottom to top, the alternating current cathode plate 11 is provided with a second through hole for the direct current cathode conducting rod 31 to pass through, and a second insulator 32 is arranged at the joint of the direct current cathode conducting rod 31 and the alternating current cathode plate 11.

In this embodiment, one dc cathode conducting rod 31 is provided, four ac cathode conducting rods 21 are provided and are circumferentially distributed, and the ac cathode conducting rods 21 are matched with the dc cathode conducting rods 31 to support the cutter mounting assemblies 10, it can be understood that the ac cathode plates 11 and the dc cathode plates 12 are alternately arranged up and down in sequence, and are respectively connected with and supported by the corresponding ac cathode conducting rods 21 or the dc cathode conducting rods 31, without additionally providing a supporting member.

Specifically, an ac cathode terminal 23 is mounted at the bottom end of the ac cathode conducting rod 21, and a dc cathode terminal 33 is mounted at the bottom end of the dc cathode conducting rod 31.

The invention also discloses an ion nitriding method suitable for strengthening the cutting edge of the cutter, which comprises the following specific operation steps:

installing the ion nitriding device suitable for strengthening the cutting edge of the cutter in a vacuum ion nitriding furnace;

connecting the positive pole of the direct current pulse power supply with the infiltration furnace, and connecting the negative pole of the direct current pulse power supply with the direct current cathode conducting rod;

connecting the positive pole of an alternating current pulse power supply with a infiltration furnace, and connecting the negative pole of the alternating current pulse power supply with an alternating current cathode conducting rod;

nitriding at 300-380 deg.c according to the following technological process and parameters; the flow ratio of nitrogen to hydrogen is 1: 3; the vacuum degree is 15Pa-25 Pa; the direct current pulse power supply is 240V-300V; 320V-360V of an alternating current pulse power supply; nitriding time: 6h-8 h.

The invention is suitable for the ion nitriding method for strengthening the cutting edge of the cutter, and aims at cutters made of different materials, and the nitriding is carried out by adopting different processes and parameters, which specifically comprises the following steps:

in the first embodiment, the material applied to the cutter is austenitic stainless steel, the hardness of the surface layer is required to be more than 800Hv, and the thickness of the infiltrated layer is required to be more than 0.02 mm; nitriding is carried out according to the following process and parameters: 300 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 25 Pa; a direct-current pulse power supply: 240V; an alternating current pulse power supply: 320V; nitriding time: and 6 h.

In the second embodiment, the material applied to the cutter is martensitic stainless steel, the surface hardness is more than 1000Hv, and the thickness of a seeping layer is more than 0.03 mm; nitriding is carried out according to the following process and parameters: 340 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 20 Pa; a direct-current pulse power supply: 260V; an alternating current pulse power supply: 340V; nitriding time: and 7 h.

In the third embodiment, the material applied to the cutter is non-stainless steel, the surface hardness is above 1300Hv, and the thickness of the infiltrated layer is above 0.04 mm; nitriding is carried out according to the following process and parameters: 380 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; vacuum degree: 15 Pa; a direct-current pulse power supply: 300V; an alternating current pulse power supply: 360V; nitriding time: and 8 h.

The method lists three embodiments, and aims at cutters made of different materials, adopts different processes and parameters to carry out nitridation, but carries out nitridation in the following processes and parameters, has the characteristic of high nitridation rate at low temperature, and improves the hardness and the wear resistance of the cutter edge on the premise of not reducing the corrosion resistance. The nitriding temperature is 300-380 ℃; the flow ratio of nitrogen to hydrogen is 1: 3; the vacuum degree is 15Pa-25 Pa; the direct current pulse power supply is 240V-300V; 320V-360V of an alternating current pulse power supply; nitriding time: 6h-8 h.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.