CN114672720A

CN114672720A - Alloy powder, part surface treatment method and application thereof

Info

Publication number: CN114672720A
Application number: CN202210359761.0A
Authority: CN
Inventors: 马宁; 刘体义; 娄战士; 张永昌
Original assignee: China Eleventh Chemical Construction Co Ltd
Current assignee: China Eleventh Chemical Construction Co Ltd
Priority date: 2022-04-06
Filing date: 2022-04-06
Publication date: 2022-06-28

Abstract

The invention relates to the technical field of surface engineering, in particular to a method for treating the surfaces of alloy powder and parts and application thereof. The alloy powder comprises the following components in percentage by mass: 20 to 28 percent of Ti, 12 to 18 percent of Al, 6.5 to 8.5 percent of B, 2.0 to 2.5 percent of C and the balance of Fe. The alloy powder can be used for preparing a cladding layer, not only can improve the wear resistance of parts, but also can repair damaged parts, and has low raw material cost and wide application prospect.

Description

Alloy powder, part surface treatment method and application thereof

Technical Field

The invention relates to the technical field of surface engineering, in particular to a method for treating the surfaces of alloy powder and parts and application thereof.

Background

Wear is one of the main ways mechanical parts fail. With the development of modern industry, the requirements for the surface properties of mechanical parts are higher and higher. Meanwhile, the replacement of the technology also brings a great deal of scrappage of electromechanical products, and in view of the dual pressure of environment and resources, the development of a green and sustainable recycling remanufacturing technology is urgently needed. The cladding technology can improve the surface performance of products by preparing a reinforced cladding layer on the surface of a part, can also be used for repairing parts which fail due to abrasion, and is a green surface technology which is widely applied and still rapidly developed.

The Metal Matrix Composites (MMCs) have a wide application prospect in the field of wear-resistant parts due to the combination of the tough metal and the hard ceramic. Among various metal matrix composite materials, iron-based metal matrix composite material coatings are widely applied to the fields of wear resistance and corrosion resistance due to low manufacturing cost, high rigidity and elastic modulus and good isotropy. In recent years, in order to improve the performance of the iron-based composite coating, the research direction of the combination of multi-alloying and various reinforcing phases is gradually gaining attention. Wherein, TiC and TiB₂The ceramic particles have high hardness (TiC: 3000HV, TiB) as a reinforcing phase₂: 3370HV), high melting point (TiC: 3065 deg.C, TiB₂: 2980 ℃) and good chemical stability, thereby gaining wide attention. However, in the preparation process, the external reinforcing phase is not well combined with the metal matrix, defects are easily generated, and the in-situ self-generated reinforcing phase also has the technical problems of unreasonable distribution of reinforcing particles and the like.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

One aspect of the invention relates to alloy powder, which comprises the following components in percentage by mass:

20 to 28 percent of Ti, 12 to 18 percent of Al, 6.5 to 8.5 percent of B, 2.0 to 2.5 percent of C and the balance of Fe.

The alloy powder can be used for preparing a cladding layer, not only can improve the wear resistance of parts, but also can repair damaged parts.

In another aspect, the invention also relates to a preparation method of the alloy powder, which comprises the following steps:

mixing the components containing the elements uniformly;

preferably, the stirring speed of the uniform mixing is 30-50 r/min; more preferably, the stirring time of the uniform mixing is 1.5-2 h.

The preparation method of the alloy powder is simple and easy to operate, does not need a complex preparation process, and can ensure that the prepared alloy powder has good uniformity.

In another aspect, the present invention relates to a method for surface treatment of a part, comprising the steps of:

coating the mixture of the alloy powder and the binder on the surface of the part, and heating and melting the mixture to form a cladding layer on the surface of the part;

preferably, the thickness of the alloy powder coated on the surface of the part is 0.5-2 mm.

The method for treating the surface of the part is simple, does not need a special process, has wide application prospect, obviously improves the wear resistance of the part after surface treatment, and prolongs the service life.

In another aspect, the invention also relates to a machining method of the steel structure part, and the machining method comprises a method for surface treatment of the part.

The machining method of the steel structure part adopts the part surface treatment method to machine or repair the part, and the obtained part has good wear resistance and long service life.

In another aspect, the invention also relates to a steel structure part, which is prepared by the processing method of the steel structure part.

The steel structure part has good wear resistance and long service life.

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

(1) the alloy powder provided by the invention has the advantages of reasonable component and dosage proportion and low cost, can improve the wear resistance of a new product when used for preparing a cladding layer, can repair waste parts, and has wide application prospect.

(2) The method for treating the surface of the part is simple, does not need a special process, and utilizes the argon arc cladding technology to prepare the composite reinforced cladding layer on the surfaces of the low-carbon steel and low-alloy structural steel parts, so that the wear resistance of the parts is improved, and the service life of the parts is prolonged; the method can be used for improving the wear resistance of a new product, can also be used for repairing waste parts, and has wide application prospect.

(3) According to the processing method of the steel structure part, the part is processed or repaired by adopting the part surface treatment method, and the obtained part has good wear resistance and long service life.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a surface view of a cladding layer provided in an embodiment of the present invention;

FIG. 2 is a metallographic observation of a cladding layer provided by an embodiment of the invention;

fig. 3 is a view for observing the microstructure from the cladding layer surface to the base material according to the embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and the detailed description, but those skilled in the art will understand that the following described embodiments are some, not all, of the embodiments of the present invention, and are only used for illustrating the present invention, and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

In some specific embodiments, Ti, for example, may be, but is not limited to, 20%, 22%, 24%, 26%, or 28%; al, for example, may be, but is not limited to, 12%, 13%, 14%, 15%, 16%, or 18%; b may be, for example, but is not limited to, 6.5%, 7.0%, 7.5%, 8.0%, or 8.5%; c may be, for example, but is not limited to, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, or 2.5%.

The alloy powder has reasonable proportion of components and dosage, low cost, can improve the wear resistance of a new product when used for preparing a cladding layer, can repair waste parts, and has wide application prospect.

The alloy powder can be prepared by mixing elemental powders of all elements or alloy powders, and the mass ratio of all the elements is within a limited range.

Preferably, the alloy powder comprises the following components in percentage by mass:

21 to 26 percent of Ti, 14 to 16 percent of Al, 7.0 to 8.0 percent of B, 2.1 to 2.4 percent of C and the balance of Fe.

mixing the components containing the elements uniformly;

In some embodiments, the blending can be performed at a stirring speed of, but not limited to, 30r/min, 33r/min, 35r/min, 37r/min, 40r/min, 43r/min, 45r/min, 47r/min, or 50 r/min.

In some embodiments, the mixing time may be, for example, but not limited to, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, or 2 h.

In some specific embodiments, the thickness of the alloy powder coated on the surface of the part may be, for example, but not limited to, 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.3mm, 1.7mm, 1.9mm, or 2 mm.

The method for treating the surface of the part is simple, a special process is not needed, and a composite reinforced cladding layer is prepared on the surfaces of the low-carbon steel and low-alloy structural steel parts by utilizing an argon arc cladding technology, so that the wear resistance of the parts is improved, and the service life of the parts is prolonged; the method can be used for improving the wear resistance of a new product, can also be used for repairing waste parts, and has wide application prospect.

The invention coats alloy powder containing Fe, Ti, Al, B and C on the surface of a part, and then adopts tungsten inert gas welding technology to prepare a cladding layer. The wear resistance and the service life of the existing low-carbon steel and low-alloy structural steel parts can be greatly improved. In-situ TiC and TiB generation by using bath metallurgical reaction₂The reinforcing phases have high melting points and relatively low densities, so that the quantity of the reinforcing phases from the surface layer to the inner layer of the cladding layer formed on the surface of the part is in a gradient descending trend, and the gradient descending trend can ensure that the surface of the cladding layer has high hardness and high resistanceThe wear resistance can also relieve the difference of the structure performance of the cladding layer and the surface of the part, reduce the residual stress and the defect of the cladding layer, reduce the risk of cracking and stripping of the cladding layer in the service process and greatly improve the wear resistance of the part.

The addition of the Al element can increase the existence time of a molten pool, promote the full and effective reaction of the molten pool and ensure the good forming of a cladding layer.

Preferably, the part is pre-treated prior to applying the alloy powder and the binder.

Preferably, the pretreatment specifically comprises: cleaning with alcohol or acetone to remove oil stains, machining to enable the surface size of the part to be regular, and performing sand blasting or abrasive paper grinding on the surface of the part to achieve the purposes of derusting and surface roughening.

Preferably, the heating to melt includes welding with tig.

Preferably, the power supply for the tungsten inert gas shielded welding adopts direct current positive connection; the diameter of a tungsten electrode welded by tungsten electrode inert gas protection is 2.0-4.0 mm (such as 2.0mm, 2.5mm, 3.0mm, 3.5mm or 4.0 mm); the current of the tungsten inert gas shielded welding is 150-200A (such as 150A, 160A, 170A, 180A, 190A or 200A); argon with the purity of more than or equal to 99.9 percent is used as protective gas for tungsten electrode inert gas protection welding; the gas flow rate of the tungsten inert gas shielded welding is 10-15L/min (such as 10L/min, 11L/min, 12L/min, 13L/min, 14L/min or 15L/min); the welding gun walking speed of the tungsten electrode inert gas protection welding is 150-500 mm/min (such as 150mm/min, 200mm/min, 250mm/min, 300mm/min, 350mm/min, 400mm/min, 450mm/min or 500 mm/min).

Preferably, the material of the part comprises low carbon steel and/or low alloy structural steel.

Preferably, in the mixture, the volume ratio of the alloy powder to the binder is (70-90): (10-30) (e.g., 70:30, 75: 25, 80: 20, 85: 15, or 90: 10).

The amount of the binder needs to be controlled within a certain range. The dosage is too small, and the mixture of the binder and the alloy powder is not easy to be smeared on the surface of a part; the use amount is too much, and air holes are easily generated, thereby influencing the structure of a cladding layer.

Preferably, the binder comprises at least one of water glass, a water glass binder, a polyvinyl alcohol glue, a resin solution glue, a carbohydrate adhesive or a natural adhesive.

Preferably, after the application of the mixture, the surface of the part is dried before the heating to melt.

Preferably, the drying temperature is 75 to 85 ℃ (e.g., 75 ℃, 77 ℃, 79 ℃, 80 ℃, 81 ℃, 83 ℃ or 85 ℃).

More preferably, the drying time is 2-3 h (e.g. 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3 h).

Drying to remove water from the mixture.

Preferably, the heating and melting step further comprises a cooling step.

Preferably, the cooling is air cooling.

Embodiments of the present invention will be described in detail below with reference to examples and comparative examples.

Example 1

The alloy powder provided by this example includes the following components by mass percent:

Ti 8％，Al 12％，B 6.5％，C 2.5％，Fe 71％。

example 2

Ti 20％，Al 18％，B 8.5％，C 2.0％，Fe 51.5％。

example 3

Ti 21％，Al 16％，B 8.0％，C 2.4％，Fe 52.6％。

example 4

Ti 26％，Al 14％，B 7.0％，C 2.1％，Fe 50.9％。

example 5

The alloy powder provided by this embodiment includes the following components by mass percent:

Ti 21％，Al 15％，B 7.6％，C 2.3％，Fe 64％；

wherein B and C are B₄C, mixing in the form of powder.

Example 6

The method for processing the surface of the part provided by the embodiment comprises the following steps:

1. the Q235 steel plate is used as a part base material, and the chemical components and the mechanical properties of the Q235 steel plate are shown in tables 1 and 2;

table 1 chemical composition (wt.%) of Q235 carbon steel

TABLE 2 mechanical Properties of Q235 steels

2. The alloy powder of example 5 was used, and the required powder raw materials were weighed with an electronic analytical balance and mixed uniformly by mechanical stirring;

3. and (2) dripping glue (7-10 wt% of polyvinyl alcohol aqueous solution) into the mixed alloy powder to serve as a binder, wherein the volume ratio of the alloy powder to the binder is 85: 15, stirring the mixture evenly into paste by using a glass rod;

4. manually pressing a pre-coating layer with the thickness of 0.5-1.2 mm on the surface of a cleaned Q235 steel plate sample, then putting the coated sample into a drying box, drying for 2.5 hours at the temperature of 80 ℃, and removing crystal water and adsorbed water in the coating;

5. a YC-300WX 4N TIG welding machine is adopted as a heat source for cladding, and direct current is directly connected; the diameter of a tungsten electrode is 2.0mm, an arc striking mode is a pulse-free arc striking mode, welding current is 150A, initial current is 50A, arc extinguishing current is 60A, an air cooling mode is adopted, argon with the purity of 99.9% is used as protective gas, gas flow is 10L/min, a welding gun is fixed on a traveling trolley, stepless speed regulation can be achieved, and the regulation range is 50-750 mm/min.

After the sample is cladded, the sample is cooled to room temperature in air, the surface image of the cladding layer is shown in figure 1, and the cladding weld joint is well formed, the surface is smooth and has no visible defects such as cracks. Metallographic observation of the cladding cross section was performed as shown in fig. 2. It can be seen in fig. 2 that the strengthening generated by cladding is relatively uniformly embedded in the metal matrix, forming a metal-ceramic composite structure. When the microstructure (SEM) was observed by a scanning electron microscope and photographs were taken sequentially from the clad layer surface toward the Q235 steel plate base material, as shown in fig. 3, a significant gradient transition structure characteristic was observed, in which the number of reinforcement phases near the surface was large and the number of reinforcement phases was small toward the base material side. The gradient structure characteristic can ensure high hardness and high wear resistance of the surface, relieve the structural property difference between the cladding layer and the base metal, reduce the residual stress and defects of the cladding layer and reduce the risk of cracking and stripping of the cladding layer in the service process.

The hardness is measured by an HVS-1000A type digital display microhardness instrument, the average hardness is 1289HV after multiple measurement records of 100-200 micron layers below the surface of the cladding layer, the hardness is gradually reduced when the cladding layer approaches one side of the parent metal, and the hardness of the parent metal is about 150 HV. The hardness of the cladding layer is improved by 8 times compared with that of the base material Q235 steel plate. The wear resistance test of the coating sample and the parent metal sample is respectively carried out on an MM-200 type sliding wear sample machine, a ring-block sliding friction mode is adopted, the test applied force is 150N, the wear time is 5h, the grinding wheel material is GCr15 steel, the surface hardness is 400HV, and the rotating speed is 200 r/min. And (3) comparing the wear loss of the cladding sample with that of the Q235 steel, wherein the 5h wear of the cladding sample is only 5.8mg, and the wear loss of the Q235 steel under the same condition reaches 263 mg. Compared with Q235 steel, the wear resistance of the clad sample is improved by about 50 times, and the performance improvement effect is obvious.

Example 7

1-2, same as example 6;

3. and (2) dripping glue (10 wt% polyvinyl alcohol aqueous solution) into the mixed alloy powder to serve as a binder, wherein the volume ratio of the alloy powder to the binder is 70:30, stirring the mixture evenly into paste by using a glass rod;

4. manually pressing a pre-coating layer with the thickness of 0.5-2 mm on the surface of a cleaned Q235 steel plate sample, then putting the coated sample in a drying box, drying for 2 hours at 82 ℃, and removing crystal water and adsorbed water in the coating;

5. a YC-300WX 4N TIG welding machine is adopted as a heat source for cladding, and direct current is directly connected; the diameter of a tungsten electrode is 3.0mm, an arc striking mode is a pulse-free arc striking mode, welding current is 200A, initial current is 50A, arc extinguishing current is 60A, an air cooling mode is adopted, argon with the purity of 99.9% is used as protective gas, gas flow is 13L/min, a welding gun is fixed on a traveling trolley, stepless speed regulation can be achieved, and the regulation range is 50-750 mm/min.

Example 8

1 to 2, same as example 6;

3. and (3) dripping glue (water glass) into the mixed alloy powder to serve as a binder, wherein the volume ratio of the alloy powder to the binder is 90: 10, stirring the mixture evenly into paste by using a glass rod;

4. manually pressing a pre-coating layer with the thickness of 0.5-2 mm on the surface of a cleaned Q235 steel plate sample, then putting the coated sample in a drying box, drying for 3h at 78 ℃, and removing crystal water and adsorbed water in the coating;

5. a YC-300WX 4N TIG welding machine is adopted as a heat source for cladding, and direct current is directly connected; the diameter of a tungsten electrode is 4.0mm, an arc striking mode is a pulse-free arc striking mode, welding current is 180A, initial current is 50A, arc extinguishing current is 60A, an air cooling mode is adopted, argon with the purity of 99.9% is used as protective gas, gas flow is 15L/min, a welding gun is fixed on a traveling trolley, stepless speed regulation can be achieved, and the regulation range is 50-750 mm/min.

Comparative example 1

Compared with example 6, the method for treating the surface of the part provided by the comparative example is only different in that in step 3, the volume ratio of the alloy powder to the binder is 50: 50.

too much binder easily causes void defects and poor molding. The hardness is measured by adopting an HVS-1000A type digital display microhardness instrument, and the average hardness is 579HV after multiple measurement records of a 100-200 micron layer below the surface of the cladding layer. The coating sample is subjected to a wear resistance test on an MM-200 type sliding wear sample machine, a ring-block sliding friction mode is adopted, the test applied force is 150N, the wear time is 5h, the grinding wheel material is GCr15 steel, the surface hardness is 400HV, the rotating speed is 200r/min, and the 5h wear of the cladding sample is 116 mg.

Comparative example 2

The method for treating the surface of the part provided by the comparative example is different from that of example 6 only in that Al is not added to the alloy powder.

Al is not added, the metallurgical reaction of the cladding layer is insufficient, and crack defects are easy to generate. The hardness is measured by an HVS-1000A type digital display microhardness instrument, and the average hardness is 732HV after multiple measurement records of 100-200 micron layers below the surface of the cladding layer. The coating sample is subjected to a wear resistance test on an MM-200 type sliding wear sample machine, a ring-block sliding friction mode is adopted, the test applied force is 150N, the wear time is 5h, the grinding wheel material is GCr15 steel, the surface hardness is 400HV, and the rotating speed is 200 r/min. Cladding sample 5h wearing 69 mg.

Comparative example 3

Compared with example 6, the method for treating the surface of the part provided by the comparative example is only different in component content in the alloy powder, and specifically comprises the following steps in percentage by mass: 32% of Ti, 25% of Al, 4% of B, 1% of C and the balance of Fe.

The hardness is measured by an HVS-1000A type digital display microhardness instrument, and the average hardness is 605HV after multiple measurement records of a 200 micron layer below the surface of the cladding layer. The coating sample is subjected to a wear resistance test on an MM-200 type sliding wear sample machine, a ring-block sliding friction mode is adopted, the test applied force is 150N, the wear time is 5h, the grinding wheel material is GCr15 steel, the surface hardness is 400HV, and the rotating speed is 200 r/min. The cladding sample is abraded by 57mg after 5 hours.

While particular embodiments of the present invention have been illustrated and described, it will be appreciated that the above embodiments are merely illustrative of the technical solution of the present invention and are not restrictive; those of ordinary skill in the art will understand that: modifications may be made to the above-described embodiments, or equivalents may be substituted for some or all of the features thereof without departing from the spirit and scope of the present invention; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; it is therefore intended to cover in the appended claims all such alternatives and modifications that are within the scope of the invention.

Claims

1. An alloy powder, characterized by comprising the following components in mass percent:

2. The alloy powder according to claim 1, comprising the following components in mass percent:

3. The method for preparing an alloy powder according to claim 1 or 2, comprising the steps of:

mixing the components containing the elements uniformly;

preferably, the stirring speed of the uniform mixing is 30-50 r/min; more preferably, the stirring time for uniformly mixing is 1.5-2 h.

4. A method of surface treating a part, comprising the steps of:

applying a mixture of the alloy powder and the binder according to claim 1 or 2 to the surface of the part, and heating and melting the mixture to form a cladding layer on the surface of the part;

5. The method of claim 4, wherein the heating to melt comprises welding with tungsten inert gas;

preferably, the power supply for the tungsten inert gas shielded welding adopts direct current positive connection; the diameter of a tungsten electrode welded by tungsten electrode inert gas protection is 2.0-4.0 mm; the current for tungsten inert gas shielded welding is 150-200A; argon with the purity of more than or equal to 99.9 percent is used as protective gas for tungsten electrode inert gas protection welding; the gas flow of the tungsten inert gas shielded welding is 10-15L/min; the welding gun walking speed of tungsten electrode inert gas protection welding is 150-500 mm/min.

6. A method of surface treatment of a part according to claim 4, characterized in that the material of the part comprises low carbon steel and/or low alloy structural steel.

7. The part surface treatment method according to claim 4, wherein the volume ratio of the alloy powder to the binder in the mixture is (70-90): (10-30);

preferably, the binder comprises at least one of a water glass binder, a polyvinyl alcohol glue, a resin solution glue, a carbohydrate adhesive or a natural adhesive.

8. The method of surface treatment of parts according to claim 4, characterized in that after applying the mixture, the part surface is dried before the heating to melt;

preferably, the drying temperature is 75-85 ℃; more preferably, the drying time is 2-3 h;

preferably, the heating and melting step further comprises a cooling step.

9. A method of machining a steel structural part comprising the method of surface treating a part as claimed in any one of claims 4 to 8.

10. A steel structural part produced by the method of machining a steel structural part of claim 9.