CN113652904B

CN113652904B - Elastic strip and preparation method thereof

Info

Publication number: CN113652904B
Application number: CN202111009328.6A
Authority: CN
Inventors: 乐林江; 沈伟; 乐政
Original assignee: Yancheng Keao Mechanical Co ltd
Current assignee: Yancheng Keao Mechanical Co ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2023-09-19
Anticipated expiration: 2041-08-31
Also published as: CN113652904A

Abstract

The application provides a spring strip and a preparation method thereof, wherein the spring strip comprises a base material and an alloy layer, and the alloy layer is an alloy layer containing multiple elements formed by penetrating a powder penetrating agent into the surface of the base material; the alloy layer comprises the following components in percentage by weight: 1 to 22 weight percent of aluminum, 0.1 to 7 weight percent of magnesium, 20 to 80 weight percent of zinc, 0.01 to 1.25 weight percent of manganese and the balance of components in the base material. For the elastic strip protected in the application, when the ratio of zinc, aluminum, magnesium and manganese in the alloy layer is the ratio of claim 1, and the alloy layer is larger than 20 mu m, the hardness, the salt spray resistance, the instantaneous bearing capacity and the like of the elastic strip are all optimal, the comprehensive performance is high, and the service life of the elastic strip is greatly prolonged. The preparation method is simple, low in cost and has larger application and popularization.

Description

Elastic strip and preparation method thereof

Technical Field

The application relates to the chemical field, in particular to the technical field of elastic strip surface treatment and the like, and particularly relates to an elastic strip and a preparation method thereof.

Background

The railway rail is fixed on the sleeper through the elastic buckle, so that the train can pass through the rail safely and quickly. The most important of the elastic fasteners is an elastic strip, and a space three-dimensional torsion beam structure is common. The buckling pressure is generated to act on the rail through bending and twisting deformation of the elastic strip, so that reliable connection between the rails is effectively ensured for a long time, the integrity of the rail is kept as much as possible, the rail is prevented from moving longitudinally and transversely relative to the sleeper, the track gauge is ensured to be normal, and the running safety of a railway vehicle is ensured. In addition, the contact between the train wheel and the steel rail is rigid, so that vibration is inevitably generated, and the special elastic structure of the elastic strip can absorb impact energy generated when a vehicle passes through, so that the shock absorption effect is achieved. The elastic strip works under repeated alternating stress, and is subjected to various actions such as bending, torsion, fatigue, corrosion and the like, and extremely high instantaneous impact load is also born when a vehicle passes through, so that the performance requirement on the elastic strip is very strict.

The existing anti-corrosion treatment method of the elastic strip mainly comprises powder zinc impregnation and closed passivation treatment, and the closed passivation layer is easy to fall off under the comprehensive factors of alternating load, sand wind, acid rain, ultraviolet and the like, so that the actual service life of the elastic strip is difficult to reach the design life. Therefore, there is a need to develop a highly corrosion-resistant, highly wear-resistant spring strip product that better meets the use of railway systems.

In the art, related researches are mature, and the related researches want to break through various barriers in the prior art have a great challenge.

Disclosure of Invention

In view of the above, the embodiment of the application provides an elastic strip and a preparation method thereof, so as to solve the technical defects in the prior art.

The application provides an elastic strip, which comprises a base material and an alloy layer, wherein the alloy layer is formed by penetrating a powder penetrating agent into the surface of the base material to form a multi-element alloy layer;

the alloy layer comprises the following components in percentage by weight: 1 to 22wt% of aluminum, 0.1 to 7wt% of magnesium, 20 to 80wt% of zinc, 0.01 to 1.25wt% of manganese, the balance being components in the substrate, the balance being typically 8 to 32wt%, such as 8%, 10%, 12%, 14%, 15%, 18%, 22%, 25%, 28%, 30%, 31%, 32%, etc.

Further, the thickness of the alloy layer is greater than 20 μm, such as 20 μm to 100 μm.

Further, the balance contains iron, and the content of the iron is not less than 8%.

Further, in the alloy layer, the content of manganese is 1% to 15%, preferably 5% to 12%, of the content of magnesium.

Further, the powder penetrating agent is a multi-element powder penetrating agent, and the components and parts by weight of the components comprise: 60-80 parts of zinc powder, 5-20 parts of zinc-aluminum alloy powder, 1-20 parts of aluminum-magnesium alloy powder and 0.1-5 parts of activating agent, wherein the activating agent contains Mn. Preferably 65-75 parts of zinc powder, 10-18 parts of zinc-aluminum alloy powder, 8-18 parts of aluminum-magnesium alloy powder and 2-4 parts of activating agent, wherein the activating agent contains Mn.

Further, the activator is ammonium chloride and potassium permanganate, wherein in the activator, the potassium permanganate accounts for 2-20wt% and the balance is ammonium chloride.

Further, the powder penetrating agent also comprises rare earth oxide and/or dispersing agent, wherein in the powder penetrating agent,

further, the weight part of the rare earth oxide is 0.1 to 1 part, preferably 0.3 to 0.6 part.

Further, the weight part of the dispersant is 10 to 100 parts, preferably 20 to 30 parts.

Further, the dispersant is at least one of alumina, silica, magnesia, aluminum nitride, silicon nitride and silicon carbide.

Further, the rare earth oxide includes cerium oxide and/or lanthanum oxide.

Further, in the zinc-aluminum alloy powder, the aluminum content is 5 to 15 weight percent, and the balance is zinc.

Further, in the aluminum magnesium alloy powder, the aluminum content is 40 to 60 weight percent, and the balance is magnesium.

Another aspect of the present application is to provide a method for manufacturing a spring strip according to any one of the preceding paragraphs, where the method includes:

step1: adopting a co-permeation process, and rotating the powder permeation agent and the matrix together in a co-permeation device so as to uniformly mix the permeation agent;

step2: heating the co-permeation device, and preserving heat for 1-10 hours after heating to a preset temperature to finish zinc permeation;

preferably, vacuumizing the co-permeation device to make the vacuum degree smaller than 100Pa, and then heating; more preferably, the reaction temperature in Step2 is between 400 ℃ and 450 ℃ and the reaction time is more than 1 hour.

Further, in Step2, the process of the present application,

(1) vacuumizing the co-permeation device to make the vacuum degree of the co-permeation device smaller than 100Pa;

(2) then the temperature in the co-permeation device is increased to be within the range of 100-200 ℃ and the residence time is more than 1 hour, such as 1-3 hours. Ensures that the ammonium chloride can be fully decomposed under the temperature condition while the potassium permanganate is not decomposed. The following reaction occurs at this time: 2KMnO ₄ +16HCl＝2KCl+2MnCl ₂ +5Cl ₂ ↑+8H ₂ O；

(3) Then the temperature is increased to 400-450 ℃ for 1-9 hours, and the zincification is completed.

The beneficial effects of the application are as follows:

the application breaks through the obstacle in the prior art, improves the suitability of the elastic strip, the powder penetrating agent, the preparation method and the like, ensures that the obtained elastic strip has excellent performance, can work under repeated alternating stress, can bear various complex environments such as bending, torsion, fatigue, corrosion and the like for a long time, and can bear extremely high instantaneous impact load when a vehicle passes. Has great application and popularization prospect. Specifically:

for the elastic strip protected in the application, when the ratio of zinc, aluminum, magnesium and manganese in the alloy layer is the ratio of claim 1 and the alloy layer is larger than 20 mu m, the hardness, brittleness, plasticity, salt spray resistance, instantaneous bearing capacity and the like of the elastic strip are all optimal, namely the comprehensive performance is high, and the service life of the elastic strip is greatly prolonged.

According to the multi-component penetrant for preparing the elastic strip alloy layer, the elastic strip can be obtained by co-permeation with an elastic strip matrix through the multi-component penetrant components and the contents of the components, the contents of the metal elements in the elastic strip are gradually reduced from the surface layer to the deep layer, no deposition phenomenon exists, the penetration depth is deep, the falling phenomenon does not occur, the hardness can reach about HV430-440, and the elastic strip can resist a neutral salt spray test of 3500 hours after sand blowing. The proportion of the components in the penetrating agent not only can prepare the elastic strip, but also has the advantages of no waste phenomenon, synchronous penetration, good effect and low comprehensive cost.

For the preparation method, the preparation method is designed aiming at the type of the penetrating agent and the action of each component in the penetrating agent, and can assist the penetrating agent to enter the elastic strip matrix efficiently and orderly to obtain the alloy layer. The preparation method is low in temperature and can be completed only at 400-450 ℃, the defect that the mechanical property of the elastic strip is easily deteriorated due to the fact that the temperature is too high is avoided, and the preparation method is simple to operate, low in cost and high in economic benefit.

In conclusion, the elastic strip can be applied to complex or harsh environments, such as rails and the like which need to withstand high pressure of wind, sun and the like for a long time, and has long service life, low cost, easy popularization and application and excellent application prospect.

Drawings

FIG. 1 is a schematic view of the appearance of a bullet strip with and without treatment with a permeation reagent according to an embodiment of the present application;

fig. 2 is a schematic view showing the appearance of the elastic strip after 2 years of use according to the embodiment of the present application.

FIG. 3 is a schematic cross-sectional view of an embodiment of the present application after the spring strip has been impregnated.

FIG. 4 is a schematic diagram of a surface electron microscope after the elastic strip according to an embodiment of the present application is impregnated.

Fig. 5 is a photograph of a cross-section of a spring strip after 3000 hours of salt spray according to an embodiment of the present application.

FIG. 6 is a schematic diagram of a surface electron microscope after the elastic strip of a comparative example in the embodiment of the present application is infiltrated.

Detailed Description

The following describes specific embodiments of the present application with reference to the drawings.

In the present application, unless otherwise indicated, scientific and technical terms used herein have the meanings commonly understood by one of ordinary skill in the art. Also, reagents, materials, and procedures used herein are reagents, materials, and conventional procedures widely used in the corresponding field.

Example 1

The embodiment provides a spring strip, which comprises a base material and an alloy layer, wherein the alloy layer is formed by penetrating a powder penetrating agent into the surface of the base material to form an alloy layer containing multiple elements.

The alloy layer comprises the following components in percentage by weight: 1 to 22 weight percent of aluminum, 0.1 to 7 weight percent of magnesium, 20 to 80 weight percent of zinc, 0.01 to 1.25 weight percent of manganese, and the balance of 5 to 20 weight percent of components in the base material, wherein if the base material consists of iron, nickel and other alloy elements, the base material is expected to be iron, nickel and other alloy elements, if the base material only consists of iron and nickel, the balance is iron and nickel, the base material is expected to be iron, the balance is iron, and the like.

Preferably, the alloy layer comprises the following components in percentage by weight: 5-15 wt% of aluminum, 3-5 wt% of magnesium, 60-75 wt% of zinc, 0.04-0.6 wt% of manganese and the balance of components in a base material, wherein the balance is generally 8-32 wt%, and the components permeated in the alloy layer are aluminum, magnesium, zinc and manganese, for example, the contents of the permeated components in the alloy layer can be any one of the following groups: (1) 5wt% of aluminum, 5wt% of magnesium, 60wt% of zinc and 0.6wt% of manganese; (2) 15wt% of aluminum, 3wt% of magnesium, 75wt% of zinc and 0.04wt% of manganese; (3) 12wt% of aluminum, 4wt% of magnesium, 65wt% of zinc and 0.3wt% of manganese; (4) 9wt% of aluminum, 4.5wt% of magnesium, 70wt% of zinc and 0.5wt% of manganese.

The thickness of the alloy layer is greater than 20 μm, such as 20 μm to 100 μm, specifically, such as 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc. In the system of the application, the thickness of the alloy layer is generally between 50 and 75 μm, such as 53 μm, 58 μm, 62 μm, 67 μm, etc., which is far beyond the level of the prior art. The powder is immersed uniformly and the immersed depth is deeper, so that the overall performance of the elastic strip such as corrosion resistance, wear resistance, plasticity, rigidity, instant bearing capacity and the like is more excellent, and the elastic strip can be used in environments such as rails and the like with higher requirements on the elastic strip.

Preferably, the balance contains iron, and the content of iron is not less than 8%. In practice, the spring strip is generally of steel structure, and iron is the main component, so that the iron content is generally more than 10%. In the system of the application, manganese in the alloy layer can also form a composite system with iron, so that the detrimental effects of iron can be reduced and the wear resistance and corrosion resistance of iron can be increased.

As a further preferred embodiment, the manganese content in the alloy layer is 1% to 15%, preferably 5% to 12%, such as 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12% of the magnesium content. During infiltration of the powder into the strand, the infiltrated layer or strand will have some amount of iron therein, which, as mentioned above, is an important factor in the corrosion resistance of the high magnesium content tissue of the facing layer. The addition of manganese can greatly reduce the deleterious effects of iron in the percolated layer. Manganese is added into the seepage layer, mainly for improving the corrosion resistance and the wear resistance of the seepage layer surface layer. When the magnesium contains 1-15% of manganese, the corrosion resistance of the surface layer can be greatly improved, the defect caused by the high content of local magnesium is avoided, and a compound with better performance can be produced with the magnesium. In particular, because excessive magnesium is easily concentrated in the outermost layer of the infiltration layer in the zinc-magnesium-aluminum infiltration layer, the surface layer of the infiltration layer structure can be corroded rapidly in the corrosion process due to the excessive magnesium. Manganese is added into the infiltration layer structure, mainly to improve the corrosion resistance of the infiltration layer surface layer. However, if the manganese content is too much, the plasticity of the alloy layer may be reduced, so that in the system of the application, the content is suitable, other metal components can be balanced, and the comprehensive effect of the spring strip is increased.

In this example, it is shown by a large amount of experimental data that when the alloy layer contains the above-described specific amount of alloy components, and the alloy layer is more than 20 μm, the hardness, brittleness, plasticity, salt spray resistance, and the like thereof are optimal. Namely, when the metal alloy layer on the surface of the elastic strip contains zinc, aluminum, magnesium and manganese with specific contents, the corrosion resistance and the wear resistance of the elastic strip are greatly improved, and the service life is greatly prolonged.

Example 2

Based on the embodiment 1, we know that when the alloy layer of the elastic strip contains zinc, aluminum, magnesium and manganese with specific content, the alloy layer has good comprehensive properties such as corrosion resistance, wear resistance and the like. How to make these components have these contents in the alloy layer, the following multi-component powder penetrating agent is mainly used, and the spring bar in the embodiment can be obtained.

The multicomponent powder penetrating agent comprises the following components in parts by weight: 60-80 parts of zinc powder, 5-20 parts of zinc-aluminum alloy powder, 1-20 parts of aluminum-magnesium alloy powder and 0.1-5 parts of activating agent, wherein the activating agent contains Mn. Preferably, 65-75 parts of zinc powder, 10-18 parts of zinc-aluminum alloy powder, 8-18 parts of aluminum-magnesium alloy powder and 2-4 parts of activating agent. The components of the multi-component powder penetrating agent can be any one of the following components: (1) 65 parts of zinc powder, 18 parts of zinc-aluminum alloy powder, 8 parts of aluminum-magnesium alloy powder and 4 parts of activating agent; (2) 75 parts of zinc powder, 10 parts of zinc-aluminum alloy powder, 18 parts of aluminum-magnesium alloy powder and 2 parts of activating agent; (3) 70 parts of zinc powder, 13 parts of zinc-aluminum alloy powder, 11 parts of aluminum-magnesium alloy powder and 3 parts of activating agent; (4) 72 parts of zinc powder, 16 parts of zinc-aluminum alloy powder, 16 parts of aluminum-magnesium alloy powder and 4 parts of activating agent.

Wherein the activator is ammonium chloride and potassium permanganate, the potassium permanganate accounts for 2-20wt%, preferably 6-15wt%, such as 6wt%, such as 7wt%, such as 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, and the like, and the balance is ammonium chloride. The potassium permanganate starts to decompose approximately at 220 ℃ to 350 ℃, the decomposition starting temperature of the ammonium chloride is 100 ℃, and the ammonium chloride can react with the potassium permanganate at 100-200 ℃ to generate substances capable of penetrating into manganese and catalyzing penetration or reaction of other components. Other ammonium halides are not preferred structures because the hydrogen fluoride from which ammonium fluoride is decomposed does not react with potassium permanganate, whereas ammonium bromide, ammonium iodide, ammonium fluoride are not used because the decomposition temperature is higher than that of potassium permanganate.

As a further preferable embodiment, the powder infiltrant further comprises rare earth oxide and/or dispersant, wherein in the powder infiltrant, the weight part of the rare earth oxide is 0.1-1 part; preferably 0.3 to 0.6 parts, such as 0.3 part, 0.4 part, 0.5 part, 0.6 part, of rare earth oxide. The rare earth oxide has the function of accelerating permeation.

Preferably, the rare earth oxide is a nano rare earth oxide comprising cerium oxide and/or lanthanum oxide.

In a further preferred embodiment, the dispersant is 10 to 100 parts by weight. Preferably, the dispersant is 20 to 30 parts, such as 20 parts, 22 parts, 26 parts, 28 parts, 30 parts.

Preferably, the dispersant is preferably at least one of alumina, silica, magnesia, aluminum nitride, silicon nitride and silicon carbide. These dispersants are effective in preventing metal powders from binding in the system of the present application.

As a further preferred embodiment, in the zinc-aluminum alloy powder, the aluminum content is 5wt% to 15wt%, and the balance is zinc, for example, the aluminum content may be 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, etc. The zinc-aluminum alloy powder can promote a certain amount of aluminum to synchronously infiltrate in the process of zinc impregnation; if the aluminum content in the zinc-aluminum alloy powder is too high, the synchronous infiltration effect of aluminum is poor, and therefore, the proportion is optimal. Moreover, if a certain amount of aluminum is synchronously infiltrated into the infiltration layer, aluminum and iron in the matrix can form an iron-aluminum intermetallic compound phase, so that the method has obvious effect on improving the overall wear resistance of the infiltration layer.

In the aluminum magnesium alloy powder, the aluminum content is 40-60 wt%, and the balance is magnesium, such as the aluminum content can be 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, and the like. The two are eutectic alloys, and when the mass ratio of the two is in the proportion, the melting point of the alloy is just about 450 ℃, and is far lower than that of the elemental magnesium and aluminum, and the elemental magnesium and aluminum are both higher than that of 650 ℃, so that the powder zinc-impregnation process is more beneficial to promoting the synchronous infiltration of the magnesium and the aluminum, and the infiltration uniformity and the infiltration amount are better compared with other proportions, so that the comprehensive effect is better. In addition, by forming the magnesium and aluminum into alloy powder, the defects that the magnesium powder is easy to explode, is easy to oxidize and is difficult to continuously infiltrate when the content is small, and the metal performance is lowered due to local overmuch are avoided. Moreover, in the system of the application, the magnesium content in the aluminum magnesium alloy powder is generally not more than 70wt%, and as the zinc magnesium permeate layer is easy to concentrate excessive magnesium in the outermost layer of the permeate layer, the corrosion resistance and the wear resistance of the permeate layer surface layer are relatively poor due to excessive magnesium.

In this example, the multi-component powder infiltrant used contained pure zinc powder which was able to penetrate normally in the process of the application; the alloy powder comprises zinc-aluminum alloy powder and aluminum-magnesium alloy powder, wherein the zinc-aluminum alloy powder enables a certain amount of aluminum to be permeated simultaneously when zinc is permeated through the alloy powder. The aluminum magnesium alloy powder is eutectic alloy, and the melting point of the aluminum magnesium alloy powder and the eutectic alloy is low in the proportion given by the application, and in the system and the infiltration method of the application, the synchronous infiltration of magnesium and aluminum is promoted while the zinc infiltration is more favorableAnd (5) entering. The multi-element powder penetrating agent also contains an activating agent, wherein ammonium chloride in the activating agent occupies a large amount, ammonia and hydrogen halide gas can be decomposed and provided, the effect of cleaning the surface of a metal piece can be achieved, and the hydrogen halide can be used for activating other components to promote the zinc impregnation. Meanwhile, hydrogen halide can react with potassium permanganate, the generated manganese chloride can be used as a manganese source to enable manganese to enter the permeation layer, and the manganese chloride also has a certain effect of promoting metal permeation, and more importantly, chloride ions in the active manganese chloride also help to promote manganese to permeate into the permeation layer tissue. The reaction of potassium permanganate and hydrogen chloride can not only provide manganese chloride and manganese permeation agent, but also generate potassium chloride, which is a good catalyst and is favorable for the permeation of various metals. However, pure manganese metal cannot permeate, and manganese chloride is basically hydrated manganese chloride, cannot be used, and is also not preferable to directly add potassium chloride because of being hydrated potassium chloride. In addition, the application realizes synchronous infiltration of aluminum, magnesium and manganese in the zinc impregnation process by matching with the functions of rare earth oxide, dispersing agent and the like. The synchronous infiltration is achieved as much as possible, so that a certain metal element is not easy to enrich in the surface layer to influence the performance, and the system can enable the thickness of the infiltration layer to reach 20-100 mu m while synchronously infiltration, so that the metal can realize excellent corrosion resistance and wear resistance. More importantly, in the percolated layer, the system of the application also allows zinc and magnesium to act, thus increasing its corrosion resistance. Specifically, the atomic radius of zinc is 0.1332 nanometers, the atomic radius of magnesium is 0.1598 nanometers, the difference of the atomic radii of the zinc and the magnesium is less than 15 percent, and meanwhile, the magnesium and the zinc are in close-packed hexagonal structures, so that the magnesium and the zinc can jointly act to form a seepage layer. Although magnesium itself is not corrosion-resistant, it can occupy part of the zinc atom sites in the zinc crystal structure, especially at grain boundaries, and a certain amount of magnesium can be accumulated at weak grain boundaries of zinc and form MgZn by high temperature reaction ₂ 、Mg ₂ Zn ₁₁ Equal zinc magnesium alloy phase, mgZn ₂ 、Mg ₂ Zn ₁₁ The isoalloy phase itself is a highly corrosion-resistant phase, and forms a strong grain boundary structure which can promote the original weak grain boundary structure to be changed into a strong grain boundary structure, in particular, the strong grain boundary structure is specific to chloride ions and the likeThe corrosive substances are opaque and can be blocked from the outside. At the same time, mgZn ₂ 、Mg ₂ Zn ₁₁ In the corrosion process of the zinc-magnesium alloy phase, the corrosion product is changed from a loose structure of common powder zinc impregnation into a compact structure, so that the corrosion resistance of the metal piece is greatly improved, and the service life of the metal piece is greatly prolonged.

In summary, as shown in fig. 1, the top of the drawing is a schematic surface view of the elastic strip after the treatment of the penetrating agent according to the present application, and the bottom of the drawing is a schematic surface view of the elastic strip without any treatment. The treated elastic strip has good comprehensive performance, and the multi-element powder penetrating agent can realize that the alloy layer of the elastic strip product contains specific content of aluminum, magnesium, zinc and manganese, so that the penetrating agent complements the elastic strip product, and the excellent corrosion resistance and wear resistance of the elastic strip product are comprehensively realized.

Example 3

On the basis of embodiment 1 and/or embodiment 2, this embodiment discloses a preparation method of the elastic strip, which comprises the following steps:

step1: the powder penetrant and the matrix are rotated together in a multi-element alloy co-permeation furnace by adopting a rotary furnace co-permeation process, so that the uniform mixing of the powder penetrant is ensured, and the uniform reaction can be ensured; for uniform mixing and uniform reaction, the conventional technology in the field can be realized at present, and the method is very basic condition guarantee.

Step2: heating the co-permeation device, and preserving heat for 1-10 hours, usually 4-7 hours after heating to a preset temperature to finish zinc permeation;

preferably, the co-permeation furnace is evacuated to a vacuum degree of less than 100Pa, and then subjected to a temperature-raising treatment, and it is noted that the vacuum degree is maintained throughout the reaction. The reaction temperature in Step2 is 400-450 ℃ and the reaction time is more than 1 hour.

As a further preferred embodiment, in Step2,

(1) vacuumizing the co-permeation furnace to make the vacuum degree smaller than 100Pa, heating, and maintaining the vacuum degree smaller than 100Pa to rapidly pump out generated chlorine and water vapor. Prevent the water vapor from affecting the powder permeation and prevent the potential safety hazard caused by chlorine.

(2) The temperature in the co-cementation furnace is then raised to a temperature in the range of 100 ℃ to 200 ℃ for a residence time of greater than 1 hour, typically 1 to 3 hours, such as 1 hour, 2 hours, 3 hours. Ensure that the ammonium chloride can be fully decomposed under the temperature condition (the decomposition starting temperature of the ammonium chloride is 100 ℃ and the ammonium chloride is decomposed into HCl), while the potassium permanganate is not decomposed, and the following reaction formula occurs at the moment: 2KMnO ₄ +16HCl＝2KCl+2MnCl ₂ +5Cl ₂ ↑+8H2O；

(3) Then the temperature is increased to 400-450 ℃ for 1-9 hours, usually 2-5 hours, such as 2 hours, 3 hours, 4 hours and 5 hours, to finish the zincification.

In the method and the penetrating agent system of the embodiment, the temperature is lower, and the method and the penetrating agent system can be completed only at 400-450 ℃, so that the defect that the mechanical property of the elastic strip is easily deteriorated due to the too high temperature is avoided.

In this example, the above specific reaction can make the reaction effect of the present application better, make more effective use of the penetrating agent, and make it penetrate into the elastic strip effectively, so as to obtain the elastic strip as described in example 1.

Example 4

The preparation method comprises the following steps: the multi-element powder infiltration agent and the elastic strip are both placed into a multi-element alloy co-infiltration furnace by adopting a rotary furnace co-infiltration process, and rotate together, so that the infiltration agent is ensured to be uniformly mixed and react uniformly. After the two are mixed, the vacuum is pumped to the co-permeation furnace so that the vacuum degree is less than 100Pa, and then the temperature in the co-permeation device is increased to about 120 ℃ for 2 hours. Then the temperature was raised to about 420℃for a further 6 hours.

Experimental example 1: multicomponent powder penetrating agent: 70 parts of zinc powder, 15 parts of zinc-aluminum alloy powder, 13 parts of aluminum-magnesium alloy powder, 3 parts of activating agent, 0.4 part of lanthanum oxide and 25 parts of dispersing agent.

Wherein the activator is ammonium chloride and potassium permanganate, and in the activator, the potassium permanganate accounts for 13wt% and the ammonium chloride accounts for 87%.

The dispersing agent is aluminum oxide and magnesium oxide, and the weight ratio of the aluminum oxide to the magnesium oxide is 3:1.

In the zinc-aluminum alloy powder, the aluminum content is 12wt percent, and the balance is zinc;

in the aluminum magnesium alloy powder, the aluminum content is 50wt%, and the balance is magnesium.

The multi-element powder penetrating agent and the elastic strip in the experimental example are prepared into the processed elastic strip with the surface containing the alloy layer of the application by adopting the method.

Experimental example 2: multicomponent powder penetrating agent: 65 parts of zinc powder, 18 parts of zinc-aluminum alloy powder, 8 parts of aluminum-magnesium alloy powder, 4 parts of an activating agent, 0.3 part of lanthanum oxide and 30 parts of a dispersing agent.

Wherein the activator is ammonium chloride and potassium permanganate, and in the activator, the potassium permanganate accounts for 8wt% and the ammonium chloride accounts for 92%.

The dispersing agent is aluminum nitride and magnesium oxide, and the weight ratio of the aluminum nitride to the magnesium oxide is 1:2.

In the zinc-aluminum alloy powder, the aluminum content is 15wt percent, and the balance is zinc;

in the aluminum magnesium alloy powder, the aluminum content is 40wt%, and the balance is magnesium.

Experimental example 3: multicomponent powder penetrating agent: 75 parts of zinc powder, 10 parts of zinc-aluminum alloy powder, 18 parts of aluminum-magnesium alloy powder, 2 parts of an activating agent, 0.6 part of cerium oxide and 20 parts of a dispersing agent.

Wherein the activator is ammonium chloride and potassium permanganate, and in the activator, the potassium permanganate accounts for 15wt% and the ammonium chloride accounts for 85%.

The dispersing agent is alumina and silica, and the weight ratio of the alumina to the silica is 1:1.

In the zinc-aluminum alloy powder, the aluminum content is 5wt%, and the balance is zinc;

in the aluminum magnesium alloy powder, the aluminum content is 60 weight percent, and the balance is magnesium.

Blank control: the spring strip is not subjected to any treatment.

Manganese is not added: the potassium permanganate in the experimental example 1 is removed, and the simple removal has a large influence on the product performance, so that the magnesium content is doubled, and the active reagent magnesium chloride is added, so that the product has high comprehensive performance.

The untreated spring bar was used in the above experimental examples, blank, and method without manganese addition. The main component of the spring strip is iron.

The results of the neutral salt spray test after blowing sand were shown in the following table, with respect to the spring bars obtained in the methods of experimental example 1, experimental example 2, experimental example 3, blank control and no manganese addition, respectively.

Performance in use	Experimental example 1	Experimental example 2	Experimental example 3	Blank control	No addition of manganese
						Hardness (HV)	440	432	433	350	395
Salt spray resistance test	＞3500h	＞3500h	＞3500h	＜100h	＜2000h
						Sulfur dioxide resistance	Strong strength	Strong strength	Strong strength	Weak and weak	Preferably, it is

From the above table, the comprehensive effects of the experimental examples were excellent. As shown in the table above, the original surface of the matrix has microhardness HV350, and does not contain HV395 of manganese after infiltration, but the hardness of the matrix can be greatly improved between HV430 and HV440, so that the wear resistance of the matrix is improved, and the effect is excellent. And the salt fog resistance performance in the experimental example is excellent, the salt fog resistance test shows that the salt fog resistance is more than 3500h, compared with the effect in the blank control and the non-manganese addition, the salt fog resistance test has very surprise, and the comprehensive practical application can reasonably speculate that the service life of the elastic strip can reach 100 years or more. Fig. 2 is a photograph of a railway test section using the spring strip described in this patent, after two years of use, showing no signs of rust and corrosion on the surface. Fig. 5 shows a microscopic photograph of a cross section of a salt spray of 3000 hours, and shows that the thickness of the alloy layer can be about 21 μm after a salt spray test of 3000 hours, and the effect is obvious. In the test without manganese, the salt spray test was only 2000 hours.

Fig. 3 is a schematic cross-sectional electron microscope of the elastic strip of experimental example 1 after the infiltration of the infiltration agent, and fig. 4 is a schematic surface electron microscope of the elastic strip after the infiltration agent. As can be seen from the graph, the thickness of the alloy layer is relatively uniform, and the thickness is relatively thick, and the average thickness is about 60-70 mu m. The alloy layer of experimental example 1 was impregnated with 70wt% of zinc, 8.7wt% of aluminum, 4.0wt% of magnesium, 0.46wt% of manganese, 12wt% of iron, and the balance nickel contained in the matrix. In the surface layer as shown in the figure, the contents of each metal were 78% of zinc, 10.5% of aluminum, 5.1% of magnesium, 0.7% of manganese, 5% of iron and the balance of nickel. The metal content in the alloy layer is basically uniform from top to bottom and is less, and the phenomenon of deposition at a certain place is avoided. In the direction from the table to the inside, the contents of the elements are 74% of zinc, 9.8% of aluminum, 4.7% of magnesium and 0.44% of manganese at the depth of about 20 μm; the contents of the elements were zinc 63%, aluminum 8.1%, magnesium 3.4% and manganese 0.29% at a depth of about 40. Mu.m, and zinc 27%, aluminum 2.5%, magnesium 1.4% and manganese 0.1% at a depth of about 55. Mu.m. And the surface of the experimental example of the application is smooth and even.

As is clear from the above experiments, the multi-element metal penetrating agent of the application can obtain the metal penetrating amount as described in the example 1, has obviously improved salt spray resistance and wear resistance, has good sulfur dioxide resistance effect, and can be suitable for use in severe environments such as rails and the like.

Example 5

To further investigate the spring strip according to the present application, the inventors have also performed several tests on the treated spring strip, such as the thickness of the alloy layer, and the distribution of the metallic elements in different thicknesses.

Comparative example 1: the content of each metal powder of the multi-component powder infiltrant was the same as that of experimental example 1 in example 4, and the preparation was the same, except that: with metal Mn, the same mole number of Mn as potassium permanganate was added, and the activator was only ammonium chloride in the same amount as in experimental example 1.

Comparative example 2: the content of each metal powder of the multi-component powder infiltrant was the same as that of experimental example 1 in example 4, and the preparation was the same, except that: ammonium chloride is not added.

Comparative example 3: the content of each metal powder of the multi-component powder infiltrant was the same as that of experimental example 1 in example 4, and the preparation was the same, except that: potassium permanganate is not required.

Comparative example 4: the content of each metal powder of the multi-component powder infiltrant was the same as that of experimental example 1 in example 4, and the preparation was the same, except that: the ammonium chloride is exchanged for ammonium fluoride.

Comparative example 5: the content of each metal powder of the multi-component powder infiltrant was the same as that of experimental example 1 in example 4, and the preparation was the same, except that: the ammonium chloride is exchanged for ammonium bromide.

Comparative example 6: the respective metal powder contents of the multi-component powder infiltrant were the same as those of experimental example 1 in example 4, except that: the preparation method comprises directly heating to about 420 deg.C.

The abrasion resistance and corrosion resistance of the above examples were tested, and the content of the infiltrated metal in the alloy layer thereof was tested.

As is clear from the above table, the overall effect of experimental example 1 was very excellent, and it was described in example 4. Although the comparative example 1 also has a certain manganese content, the content is extremely low, the content of other aluminum, magnesium and the like in the alloy layer is greatly reduced, and magnesium is mainly concentrated in a shallow layer and is hardly detected after 20 mu m; and the overall thickness of the alloy layer was significantly different from that of experimental example 1. For comparative examples 2 to 5, the resistance model is also obviously smaller than that of the experimental example, the thickness of the seepage layer is also obviously smaller than that of the experimental example, in addition, the seepage layer hardly contains manganese element, and the salt spray resistance is poor and the corrosion resistance is obviously inferior to that of the experimental example. For comparative example 6, the overall properties were smaller than those of the experimental example, although the contents of various elements in the alloy layer were substantially within the scope of the present application, due to the change of conditions in the production method.

Further, the uniformity of appearance in the experimental example was good, as can be seen from fig. 4, while the uniformity of appearance in the comparative example was generally poor, and fig. 6 is an exterior electron micrograph of comparative example 1, which shows that the flatness of appearance was poor.

The salt spray test is shown in the following table:

from the above table, the red rust still does not appear after 3500h in experimental example 1, and the salt fog resistance is more than 3500h; comparative example 6 shows red rust at 3500 hours, its salt spray resistance is > 3000 hours, and less than 3500 hours; comparative examples 1, 3 and 5, which all showed a large amount of white rust at about 2000 hours, showed significant red rust at 3000 hours, and had a salt spray resistance of < 3000 hours; the comparative examples 2 and 4 showed red rust at 2000 hours, and their salt spray resistance was < 2000 hours.

The content of each component in the penetrating agent is set according to the characteristics of interaction or mutual restriction among various components, and the effects of the penetrating agent are achieved through the combined action of the components, so that manganese element is an important component in the penetrating agent, and if the manganese element cannot be penetrated normally or is penetrated in a small amount, the impact on the performance of the elastic strip is large. In fact, if the alloy layer does not contain manganese, better performance can be achieved by adjusting the proportion of other components, the type and addition amount of auxiliary agents, and the like. However, according to the action of the spring strips and the like, the applicant finds that the comprehensive performance of the manganese addition is better through experiments and research and development. Therefore, on the premise of adding manganese, the research test adopts the proportion of manganese and other components, and the performance difference is very large if the proportion or other components are unsuitable. Therefore, under the condition of the application, if the amount of one component is greatly adjusted or the component is added little or one or more components are replaced, the elastic strip performance is extremely likely to be greatly influenced.

Example 6

Experimental example: as in experimental example 1 in example 4.

Comparative group 1: multicomponent powder penetrating agent: 50 parts of zinc powder, 45 parts of zinc-aluminum alloy powder, 23 parts of aluminum-magnesium alloy powder, 3 parts of an activating agent, 0.4 part of lanthanum oxide and 25 parts of a dispersing agent. The other steps are the same as in experimental example 1.

Comparative group 2: multicomponent powder penetrating agent: 50 parts of zinc powder, 5 parts of zinc-aluminum alloy powder, 5 parts of aluminum-magnesium alloy powder, 3 parts of activating agent, 0.4 part of cerium oxide and 25 parts of dispersing agent.

Comparative group 3: multicomponent powder penetrating agent: 35 parts of zinc powder, 5 parts of zinc-aluminum alloy powder, 5 parts of aluminum-magnesium alloy powder, 3 parts of an activating agent, 0.4 part of lanthanum oxide and 25 parts of a dispersing agent.

Comparative group 4: multicomponent powder penetrating agent: 50 parts of zinc powder, 45 parts of zinc-aluminum alloy powder, 13 parts of aluminum-magnesium alloy powder, 3 parts of an activating agent, 0.4 part of lanthanum oxide and 25 parts of a dispersing agent. The activator is ammonium chloride and potassium permanganate, wherein the potassium permanganate accounts for 58wt% and the ammonium chloride accounts for 42%

The other parts of the above comparative group (including the preparation method) were identical to those of the experimental group 1, and the hardness and neutral salt spray resistance were measured as follows.

Performance in use	Experimental example	Comparative group 1	Comparative group 2	Comparative group 3	Comparative group 4
						Hardness (HV)	440	377	368	360	356

The metal content of the alloy layers in the above comparative groups is not consistent with the scope of the present application, i.e., is not within the scope of example 1 or claim 1 of the present application. The corrosion resistance of the comparative group as a whole was weak. The magnesium and aluminum contents in comparative example 1 were greatly increased and concentrated mainly in the surface layer and the depth range of 10 μm, and the local magnesium content was excessive, affecting the performance, and the waste was serious and the cost was high.

The magnesium and aluminum contents in comparative example 2 were greatly reduced, and the overall properties were lowered.

The zinc powder in comparative example 3 is greatly reduced, the metal component permeated in the alloy layer is mainly concentrated within 20 mu m, the whole alloy thickness is small and is basically between 10 and 30, the hardness is greatly reduced, and the corrosion resistance is weak.

The hardness of comparative example 4 was lowered, the plasticity was remarkably lowered, and the instantaneous impact resistance was lowered and the vehicle was easily damaged when passing through. And the instantaneous impact resistance of comparative examples 3 and 2 was also significantly reduced.

Thus, in the present application, the various components and the amounts of the various components complement each other and if one component is reduced, increased or replaced, the performance of the strand is greatly affected.

In the present application, it should be noted that there are a plurality of factors that can affect the performance of the spring strip after the metal element is infiltrated, which are not only related to the proportion of the metal element in the alloy layer, but also have a great relationship with diffusion or infiltration, for example, the metal content is the same as in the present embodiment, but if the infiltration is uneven, there are cases that some portions are deposited more and other portions are too few, etc., the improvement performance of the metal may be extremely weak, and sometimes not only the performance of the metal surface layer is not improved, but also the performance is reduced. Moreover, the same metal content, if infiltrated to too shallow a depth, can also greatly affect the metal properties. The elastic strip type of the application can realize synchronous infiltration and deep infiltration by matching with the penetrant of the application, and each metal is uniformly reduced from the surface layer to the inner layer of the alloy layer, so that the situation of local overmuch certain metal can not occur, and manganese can be greatly compounded with iron and magnesium by adding ammonium chloride and potassium permanganate under specific conditions, thereby forming the alloy layer with increased metal performance, and greatly reducing or avoiding side effects possibly brought by magnesium and the harm of iron in the elastic strip. The method of the application has better effect.

In the application, all raw material powders are market products, and can be purchased normally, and alloy powders such as zinc-aluminum alloy powder, aluminum-magnesium alloy powder and the like can be purchased.

Unless otherwise indicated, numerical ranges herein include not only the entire range within both of its endpoints, but also the several sub-ranges contained therein.

While the preferred embodiments and examples of the present application have been described in detail with reference to the accompanying drawings, the present application is not limited to the above-described embodiments and examples, and various changes may be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. The elastic strip comprises a base material and an alloy layer, wherein the alloy layer is formed by penetrating a powder penetrating agent into the surface of the base material to form an alloy layer containing a plurality of metal elements; the method is characterized in that:

the alloy layer comprises the following components in percentage by weight: 1 to 22 weight percent of aluminum, 0.1 to 7 weight percent of magnesium, 20 to 80 weight percent of zinc, 0.01 to 1.25 weight percent of manganese and the balance of components in the base material; the powder penetrating agent is a multi-element powder penetrating agent, and comprises the following components in parts by weight: 60-80 parts of zinc powder, 5-20 parts of zinc-aluminum alloy powder, 1-20 parts of aluminum-magnesium alloy powder and 0.1-5 parts of activating agent; the activator is ammonium chloride and potassium permanganate, wherein the potassium permanganate accounts for 2-20wt% and the balance is ammonium chloride.

2. The spring strip of claim 1, wherein the alloy layer has a thickness of 20 μm to 100 μm.

3. The spring strip of claim 1 wherein the balance comprises iron and the iron content is not less than 8%.

4. The spring strip of claim 1, wherein the manganese content in the alloy layer is 1-15% of the magnesium content.

5. The spring of claim 1, wherein the powder infiltrant further comprises a rare earth oxide and/or a dispersant, wherein in the powder infiltrant,

the weight part of the rare earth oxide is 0.1-1 part;

the weight portion of the dispersing agent is 10-100 portions.

6. The spring of claim 5, wherein the dispersant is at least one of aluminum oxide, silicon oxide, magnesium oxide, aluminum nitride, silicon nitride, and silicon carbide;

the rare earth oxide comprises cerium oxide and/or lanthanum oxide.

7. The spring strip of claim 1, wherein in the zinc-aluminum alloy powder, the aluminum content is 5wt% to 15wt% and the balance is zinc;

in the aluminum magnesium alloy powder, the aluminum content is 40 to 60 weight percent, and the balance is magnesium.

8. A method of producing a spring strip according to any one of claims 1 to 7, characterized in that the method comprises:

step2: and (3) heating the co-permeation device, and preserving heat for 1-10 hours after heating to a preset temperature to finish the zinc permeation.

9. The method of producing elastic strands according to claim 8, wherein the co-permeation apparatus is evacuated to a vacuum degree of less than 100Pa and then subjected to a temperature-increasing treatment.

10. The method of claim 8, wherein Step2 is performed at a reaction temperature between 400 ℃ and 450 ℃ for a reaction time greater than 1 hour.

11. The method of manufacturing a spring strip of claim 8, wherein Step2 comprises the steps of:

(1) vacuumizing the co-permeation device to make the vacuum degree smaller than 100Pa, and maintaining the vacuum degree in the reaction process;

(2) then the temperature in the co-permeation device is increased to be within the range of 100 ℃ to 200 ℃ and stays for 1 to 3 hours;