CN113025949B

CN113025949B - Boron-sulfur co-permeation reagent, boron-sulfur chemical permeation method, boron-sulfur co-permeation metal workpiece and application

Info

Publication number: CN113025949B
Application number: CN202110216616.2A
Authority: CN
Inventors: 王鹏飞; 房晓勇; 赵志远
Original assignee: Hisense Visual Technology Co Ltd
Current assignee: Hisense Visual Technology Co Ltd
Priority date: 2021-02-26
Filing date: 2021-02-26
Publication date: 2023-04-11
Anticipated expiration: 2041-02-26
Also published as: CN113025949A

Abstract

The application relates to the field of metal surface treatment, and discloses a boron-sulfur co-permeation reagent, a boron-sulfur chemical permeation method, a boron-sulfur co-permeation metal workpiece and application. The boron-sulfur co-permeation reagent comprises the following components in percentage by weight: 25-55% of boron carbide, 7-13% of a sulfurizing main agent, 12-17% of an active agent, 5-12% of a rare earth compound and the balance of a filling agent, wherein the sulfurizing main agent comprises ferrous sulfide and/or thiourea. The borosulfurizing-sulfurizing reagent can realize borosulfurizing-sulfurizing of metal workpiece without need of boronizing and sulfurizing separately, and can realize borosulfurizing-sulfurizing and sulfurizing at relatively low temperature. The boron-sulfur co-permeation method adopts the boron-sulfur co-permeation reagent to carry out boron-sulfur co-permeation on the metal workpiece, the process is simple, the co-permeation temperature is low, the cost is low, and the obtained boron-sulfur co-permeation metal workpiece has excellent wear resistance and self-lubricating property.

Description

Boron-sulfur co-permeation reagent, boron-sulfur chemical permeation method, boron-sulfur co-permeation metal workpiece and application

Technical Field

The application relates to the field of metal surface treatment, in particular to a boron-sulfur co-permeation reagent, a boron-sulfur chemical permeation method, a boron-sulfur co-permeation metal workpiece and application.

Background

The chemical heat treatment of the metal surface can introduce interstitial atoms or alloy phases into the surface structure of the metal, can greatly improve the mechanical properties of the surface of a workpiece, such as hardness, wear resistance, fatigue performance and the like, on the premise of not changing the components and properties of a base material, and has very important significance for reducing the production cost and improving the production efficiency of enterprises.

In recent years, researchers at home and abroad carry out a great deal of research work in the field of surface modification and develop various surface modification technologies, wherein the boronizing process gradually becomes the focus of attention. Boronizing refers to a process technique in which a steel sample is placed in a medium containing boron, heated to a certain temperature, and kept warm for a certain period of time, so that boron atoms penetrate into the surface of the sample to a certain depth through chemical or electrochemical reaction and generate iron boride. The boronizing treatment can obviously improve the surface hardness, wear resistance, hot hardness and oxidation resistance of the workpiece, and meanwhile, the boronizing process is simple, has less investment and is rapidly developed in recent years. The traditional boronizing process mainly comprises solid boronizing, liquid salt bath boronizing and ion boronizing, the temperature of the traditional boronizing process is high (above 800-1000 ℃), the energy consumption is high, and a metal workpiece is easy to deform in the boronizing process; meanwhile, the boronized metal workpiece is difficult to be directly quenched due to the fact that the boronized layer is easy to break due to the fact that the large difference of thermal expansion coefficients exists between the boronized layer and the substrate and the too high cooling rate is caused. Therefore, if the boronizing treatment can be carried out at a lower temperature, the deformation of the metal workpiece can be effectively reduced, and the energy consumption and the production cost of enterprises can be reduced.

In addition to boronizing, sulfurizing is also a common surface solid lubrication process for various metal workpieces (e.g., dies). Sulfurization refers to a chemical heat treatment process for generating sulfide by reacting a steel material with a sulfur-containing medium, and after sulfurization, the surface layer of a steel workpiece can form a layer containing FeS + FeS ₂ The chemical conversion film has a close-packed hexagonal structure, and interfacial slippage easily occurs under the action of shearing force, so that the chemical conversion film has a self-lubricating effect. The self-lubricating property of the solid lubricating film can effectively reduce the friction coefficient of a die workpiece during working and improve the anti-scratching and anti-seizure properties. The process of iron and steel sulfurization mainly includes solid sulfurization, liquid salt bath sulfurization and low-temp. electrolytic sulfurization, in which the solid sulfurization usually uses FeS as sulfur-supplying agent and NH ₄ Cl is used as catalyst, the temperature includes high temperature (800-930 deg.C) and medium temperature sulfurization (520-600 deg.C), its advantages are simple and easy operation, low investment in early stage and low cost. At present, the method adopts low-temperature electrolytic sulfurization, the components of a salt bath of the method are mainly KCNS and NaCNS, a sulfurization layer with the thickness of about 5-15 mu m can be formed, although the operation is simple, the toxicity of the thiocyanato is high, the salt bath is easy to age, the sulfurization effect is lost, and the pollution problem is caused in the later period. It is noted that sulfur has a very low solid solubility in iron, so that if there is no strong support under the sulfide, the sulfide is very easily worn out and loses its lubricating effect, so that elemental sulfur often penetrates simultaneously with other elements in a single process to achieve a good overall performance.

The boronizing treatment can effectively improve the surface hardness and the wear resistance of the steel material, but the boride on the surface layer is usually brittle and the self-lubricating effect is not obvious; while the surface hardness of the workpiece is reduced by the sulfurizing treatment, the friction coefficient can be obviously reduced by the self-lubricating property of the workpiece, but the sulfurizing layer needs a high-hardness matrix layer as a support. Therefore, if the advantages of two surface treatment processes can be combined by sulfurizing and boronizing, the wear resistance of the workpiece can be obviously improved, the friction coefficient under the working condition can be effectively reduced, the surface quality of the product can be improved, and the service life of the workpiece can be prolonged.

Patent CN00114511.8 discloses a boronized and sulfurized composite layer on the surface of a steel piece, and specifically discloses a boronized and sulfurized composite co-permeation process, but the boronized process is a conventional process, the temperature is high, and the subsequent boronized process is gas ion sulfurizing, the co-permeation process is complex, and the cost is high.

In view of this, the present application is specifically proposed.

Disclosure of Invention

The application discloses a boron-sulfur co-permeation reagent, a boron-sulfur chemical permeation method, a boron-sulfur co-permeation metal workpiece and application, so that the effects of boron-sulfur co-permeation on the metal workpiece at a lower temperature, simple co-permeation process, low cost and excellent wear resistance and self-lubricating property of the obtained boron-sulfur co-permeation metal workpiece are achieved.

In order to achieve the purpose, the application provides the following technical scheme:

in a first aspect, the present application provides a boro-sulfide co-doping reagent, comprising the following components in percentage by weight:

25-55% of boron carbide, 7-13% of sulfurizing main agent, 12-17% of activating agent, 5-12% of rare earth compound and the balance of filling agent.

As a further preferable technical scheme, the reagent comprises the following components in percentage by weight:

32-48% of boron carbide, 5-11% of sulfurizing main agent, 11-16% of activating agent, 6-11% of rare earth compound and the balance of filling agent;

preferably, the reagent comprises the following components in percentage by weight:

35-45% of boron carbide, 10% of sulfurizing main agent, 15% of active agent, 10% of rare earth compound and the balance of filling agent.

As a further preferred technical solution, the active agent comprises at least one of a fluoroborate or a bicarbonate, preferably a combination of a fluoroborate and a bicarbonate, and the weight ratio of the fluoroborate to the bicarbonate is 2;

preferably, the fluoroborate salt comprises at least one of sodium fluoroborate, potassium fluoroborate, or ammonium fluoroborate;

preferably, the bicarbonate comprises ammonium bicarbonate.

As a further preferred embodiment, the rare earth compound includes a rare earth chloride;

preferably, the rare earth chloride comprises at least one of lanthanum chloride, cerium chloride or scandium chloride;

preferably, the filler comprises at least one of a metal oxide, a non-metallic carbide, or a carbon material;

preferably, the metal oxide comprises aluminum oxide;

preferably, the non-metallic carbide comprises silicon carbide;

preferably, the carbon material comprises activated carbon.

In a second aspect, the present application provides a boron-sulfur co-doping method, wherein the boron-sulfur co-doping reagent is used for performing boron-sulfur co-doping on a metal workpiece.

As a further preferred technical solution, the method comprises the steps of:

and placing the metal workpiece in the boron-sulfur co-permeation reagent, heating, preserving heat, and finally cooling to obtain the boron-sulfur co-permeation metal workpiece.

As a further preferable technical scheme, the heating rate during heating is 8-13 ℃/min, the heat preservation temperature is 560-600 ℃, and the heat preservation time is 10-14h.

As a further preferable technical scheme, after the metal workpiece is placed in the boron-sulfur co-cementation reagent, the method further comprises the steps of sealing the metal workpiece and the boron-sulfur co-cementation reagent, and then heating and preserving heat;

preferably, the sealing comprises: placing the metal workpiece and the boron-sulfur co-permeation reagent in a sealing device, sealing, then coating refractory slurry on the outer side of the sealing device, and finally drying;

preferably, the refractory slurry comprises a refractory material and a solvent;

preferably, the solvent comprises an aqueous silicate solution.

In a third aspect, the present application provides a boro-sulfidizing metallic workpiece produced by the above-described boro-sulfidizing method.

In a fourth aspect, the present application provides a use of a boro-sulfido-infiltrated metal workpiece as described above in a mold.

By adopting the technical scheme of the application, the beneficial effects are as follows:

the borosulfurizing and sulfurizing reagent has borosulfurizing agent of boron carbide as main borosulfurizing agent and sulfurizing agent of RE compound and stuffing in certain weight percentage, and can realize borosulfurizing and sulfurizing of metal workpiece without borosulfurizing and sulfurizing separately.

The boron-sulfur co-permeation method provided by the application adopts the boron-sulfur co-permeation reagent to carry out boron-sulfur co-permeation on the metal workpiece, the process is simple, the co-permeation temperature is low, the cost is low, and the obtained boron-sulfur co-permeation metal workpiece has excellent wear resistance and self-lubricating property.

Drawings

FIG. 1 is an XRD spectrum of a sample treated by boro-sulfide co-infiltration provided in example 1 of the present application;

FIG. 2 is an XRD spectrum of a raw H13 steel sample provided in comparative example 4 of the present application;

FIG. 3 is a graph showing the change of the friction coefficient with the test time of the sample after the borosulfurization treatment provided in example 1 of the present application and the original sample of comparative example 4;

FIG. 4 is a graph comparing the amount of wear of the sample after borosulfurization treatment provided in example 1 of the present application and the original sample of comparative example 4.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. 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 application.

It should be noted that: in the present application, all embodiments and preferred methods mentioned herein can be combined with each other to form new solutions, if not specifically stated. In the present application, all the technical features mentioned herein as well as preferred features may be combined with each other to form new technical solutions, if not specifically stated. In the present application, the percentage (%) or parts refers to the weight percentage or parts relative to the composition, unless otherwise specified. In the present application, the components referred to or the preferred components thereof may be combined with each other to form new embodiments, if not specifically stated. In this application, unless otherwise stated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, a numerical range of "6 to 22" indicates that all real numbers between "6 to 22" have been listed herein, and "6 to 22" is only a shorthand representation of the combination of these numbers. The "ranges" disclosed herein may be in the form of lower limits and upper limits, and may be one or more lower limits and one or more upper limits, respectively. In the present application, the individual reactions or process steps may be performed sequentially or in sequence, unless otherwise indicated. Preferably, the reaction processes herein are carried out sequentially.

Unless otherwise defined, technical and scientific terms used herein have the same meaning as is familiar to those skilled in the art. In addition, any methods or materials similar or equivalent to those described herein can also be used in the present application.

According to one aspect of the present application, there is provided in at least one embodiment a boro-sulfidizing agent comprising, in weight percent:

The "borosulfurizing reagent" is a reagent capable of simultaneously boronizing and sulfurizing a metal workpiece. The boron-sulfur co-cementation reagent is suitable for boron-sulfur co-cementation of a metal workpiece, and the metal workpiece preferably comprises steel or iron.

Boron carbide (B) ₄ C) The alias black diamond has the characteristics of low density, high strength, high-temperature stability and good chemical stability, has high boron content and moderate price, and is suitable for boronizing treatment. The boron carbide content is typically, but not limited to, 25%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50% or 55% by weight in the present application.

Ferrous sulfide (FeS) has a scaly structure similar to molybdenum disulfide or graphite, belongs to a hexagonal system, and a ferrous sulfide film is provided with a plurality of tiny pores capable of adsorbing lubricating oil, so that the ferrous sulfide film can easily slide along the top surface of a hexagonal body, not only can isolate the contact between steel friction pairs, but also can play a good lubricating role, so that the friction coefficient is obviously reduced, and the antifriction effect is achieved.

Thiourea (CH) ₄ N ₂ S) can form sulfides on the metal surface after the sulfurization treatment, for example, feS is formed on the steel surface, thereby playing the role of self-lubrication.

The content of the main agent for sulfurization in the present application is typically, but not limited to, 7%, 8%, 9%, 10%, 11%, 12% or 13% by weight.

The "sulfurizing main agent" mentioned above means an agent mainly functioning to supply elemental sulfur. The main agent for sulfurizing includes ferrous sulfide and/or thiourea, and when the main agent for sulfurizing is a composition of ferrous sulfide and thiourea, the weight ratio of ferrous sulfide and thiourea is not particularly limited, and any ratio may be used.

The activator is also called activator, and is used for promoting boron carbide and sulfurization main agent to generate active boron atom and active sulfur atom. In the present application, the active agent is typically, but not limited to, 12%, 13%, 14%, 15%, 16% or 17% by weight.

The rare earth compound is a compound formed by rare earth metal elements and other elements, and has the effects of cleaning metal workpieces, promoting the progress of the boron-sulfur co-permeation process and reducing the co-permeation temperature. The content of rare earth compounds in the present application is typically, but not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11% or 12% by weight.

The filler is an agent which does not react with other components physically or chemically, can improve the loosening degree of the components and prevent the components from being adhered. "Filler balance" means the weight percent of filler excluding the weight percent of boron carbide, sulfidizing base, activator, rare earth compound, and optional other components (wherein optional other components include, but are not limited to, cerium oxide, sodium thiosulfate, sodium sulfite, boric acid, etc.) for a total of 100 weight percent of all components.

The borosulfurizing and sulfurizing reagent has borocarbide as main borosulfurizing agent and sulfurizing agent as main sulfurizing agent, and is compounded with specific amount of activator, RE compound and stuffing, so that borosulfurizing and sulfurizing may be performed in greatly simplified process.

In a preferred embodiment, the reagent comprises the following components in percentage by weight:

32-48% of boron carbide, 5-11% of sulfurizing main agent, 11-16% of activating agent, 6-11% of rare earth compound and the balance of filling agent.

By further optimizing the weight percentage of each component, on one hand, the loose property of the reagent can be higher, and on the other hand, the coordination among the boron carbide, the sulfurizing main agent, the activating agent and the rare earth compound can be more scientific, thereby further improving the co-permeation effect.

In a preferred embodiment, the active agent comprises at least one of a fluoroborate or a bicarbonate, preferably a combination of a fluoroborate and a bicarbonate, and tests prove that the active agent has better activation effects on boron and sulfur when the active agent is the combination of the fluoroborate and the bicarbonate. And when the weight ratio of the fluoroborate to the bicarbonate is 2.

Preferably, the fluoroborate salt comprises sodium fluoroborate (NaFB) ₄ ) Potassium fluoroborate (KFB) ₄ ) Or ammonium fluoroborate (NH) ₄ FB ₄ ) At least one of (1). The fluoroborate salt is, for example, sodium fluoroborate, potassium fluoroborate, ammonium fluoroborate, a combination of sodium fluoroborate and potassium fluoroborate, a combination of potassium fluoroborate and ammonium fluoroborate, a combination of sodium fluoroborate and ammonium fluoroborate, or a combination of sodium fluoroborate, potassium fluoroborate and ammonium fluoroborate, or the like.

The sodium fluoroborate, the potassium fluoroborate and the ammonium fluoroborate can react with boron carbide in the heating process to generate active boron atoms, wherein the decomposition temperature of the sodium fluoroborate is lower, and the sodium fluoroborate is more suitable for low-temperature heat treatment, and besides the above effects, the ammonium fluoroborate can also decompose to generate ammonia gas, so that the gas pressure in the reaction container is improved, and the flowability of active gas is improved.

Preferably, the bicarbonate comprises ammonium bicarbonate (NH) ₄ HCO ₃ ). The ammonium bicarbonate can further increase gas pressure and fluidity in the decomposition process, and simultaneously, CO gas is decomposed by heating, so that a certain reducing atmosphere is ensured.

In a preferred embodiment, the rare earth compound comprises a rare earth chloride. The rare earth chloride is a compound formed by rare earth elements and chlorine elements. The rare earth chloride has high activity and can react with the oxide on the surface of the metal workpiece to capture oxygen in the metal workpiece, so that the surface of the workpiece is effectively cleaned.

Preferably, the rare earth chloride comprises at least one of lanthanum chloride, cerium chloride or scandium chloride.

Lanthanum chloride, cerium chloride or scandium chloride is used as rare earth chloride, has extremely high reactivity, and can react with oxygen to clean the surface of a sample.

Preferably, the filler comprises at least one of a metal oxide, a non-metallic carbide, or a carbon material. The filler is, for example, a metal oxide, a non-metal carbide, a carbon material, a combination of a metal oxide and a non-metal carbide, a combination of a non-metal carbide and a carbon material, a combination of a metal oxide, a non-metal carbide and a carbon material, or the like. The non-metal carbide refers to a compound formed by a non-metal element and a carbon element, and the carbon material refers to a material formed by simple substance carbon, such as graphite, activated carbon, graphene and the like.

Preferably, the metal oxide comprises aluminum oxide. The aluminum oxide does not participate in chemical reaction in the co-infiltration process, mainly plays a filling role and ensures the loosening and the bonding resistance of the reagent.

Preferably, the non-metallic carbide comprises silicon carbide. Besides the function of filling and ensuring looseness, the silicon carbide can also promote the decomposition of the fluoborate and accelerate the reaction of the fluoborate and the boron carbide.

Preferably, the carbon material comprises activated carbon. The activated carbon also acts as a loosening agent and in addition reacts with oxygen during heating to provide a certain reducing atmosphere.

The boron-sulfur co-cementation reagent can be obtained by mixing the components.

According to another aspect of the application, a boron-sulfur co-infiltration method is provided, and the boron-sulfur co-infiltration is carried out on a metal workpiece by using the boron-sulfur co-infiltration reagent. The method adopts the boron-sulfur co-permeation reagent to carry out boron-sulfur co-permeation on the metal workpiece, the process is simple, the co-permeation temperature is low, the cost is low, and the obtained boron-sulfur co-permeation metal workpiece has excellent wear resistance and self-lubricating property.

In a preferred embodiment, the method comprises the steps of:

In the preferred embodiment, the metal workpiece is placed in the boron-sulfur co-permeation reagent, heat preservation is carried out after heating, boronizing and sulfurizing to the metal workpiece are achieved, boronizing and sulfurizing do not need to be carried out independently, and can be achieved only by one-step heating and heat preservation.

In a preferred embodiment, the heating rate is 8 to 13 ℃/min. The temperature increase rate is, for example, 8, 9, 10, 11, 12 or 13 ℃/min. The heating rate is not too fast or too slow, too fast is not beneficial to the full activation of boron and sulfur, too slow can slow down the whole process and the production efficiency is low. When the temperature rise rate is in the range, the boron-sulfur activation and the production efficiency can be considered, and the optimal effect is achieved.

Preferably, the heat preservation temperature is 550-600 ℃, and the heat preservation time is 11-13h. The incubation temperature is, for example, 550 ℃, 560 ℃, 570 ℃, 580 ℃, 590 ℃ or 600 ℃, and the incubation time is, for example, 11 hours, 11.5 hours, 12 hours, 12.5 hours or 13 hours. The heat preservation temperature of the device can realize the co-permeation of boron and sulfur only at 550-600 ℃, the energy consumption is lower compared with the traditional temperature of 800-930 ℃, however, the heat preservation temperature can not be too low, and when the temperature is less than 550 ℃, the boron and the sulfur in the boron-sulfur co-permeation reagent can not be fully permeated into a metal workpiece. At the temperature, the heat preservation time is preferably 11-13h, the co-permeation efficiency cannot be further improved if the heat preservation time is too long, the efficiency is reduced, energy is wasted, and the co-permeation layer is thinner if the heat preservation time is too short, so that the practical application value is lower.

In a preferred embodiment, after the metal workpiece is placed in the boron-sulfur co-permeation reagent, the method further comprises the steps of sealing the metal workpiece and the boron-sulfur co-permeation reagent, and then carrying out heat preservation after heating. The direct heating of the metal workpiece and the boron-sulfur co-permeation reagent can cause the oxidation or other side reactions of the surface of the metal workpiece to occur due to the contact with air, and the effect of the boron-sulfur co-permeation is influenced. The metal workpiece and the boron-sulfur co-permeation reagent are sealed before heating, so that air can be isolated, side reaction is avoided, and the boron-sulfur co-permeation effect and efficiency are improved.

Preferably, the sealing comprises: and (3) placing the metal workpiece and the boron-sulfur co-permeation reagent in a sealing device, sealing, then coating the refractory slurry on the outer side of the sealing device, and finally drying. The optimal selection mode actually comprises two steps of sealing, namely the first step is sealing by adopting a sealing device, the second step is sealing by adopting refractory slurry, and after the two steps of sealing, the metal workpiece and the boron-sulfur co-permeation reagent are completely in a closed environment, so that the stability of the co-permeation process is effectively ensured.

The sealing device can be used for selectively sealing the tank.

The temperature for drying is, for example, 100 to 200 ℃.

Preferably, the refractory slurry comprises a refractory material and a solvent. As for the refractory and the solvent, the present application is not particularly limited as long as the refractory performance can be achieved. For example, the refractory material may be selected from refractory earth.

Preferably, the solvent comprises an aqueous silicate solution. The aqueous silicate solution is, for example, an aqueous sodium silicate solution, an aqueous potassium silicate solution, an aqueous aluminum silicate solution, or the like.

Optionally, the method further comprises the step of performing surface pretreatment on the metal workpiece before the metal workpiece is placed in the boro-sulphur co-cementation agent. Surface pre-treatments include, but are not limited to, mechanical surface pre-treatments and chemical surface pre-treatments, including one or more of chemical degreasing and chemical caustic washing, to remove oil stains and impurities from the surface of the metal workpiece and to reduce the barrier effect of such contaminants on the penetration of boron and sulfur atoms.

According to another aspect of the present application, there is provided a boron-sulfur co-infiltrated metal workpiece made using the above-described boron-sulfur co-infiltration method. The boron-sulfur co-diffusion metal workpiece prepared by the method has the advantages of excellent wear resistance and self-lubricating property.

According to another aspect of the application, the application of the boron-sulfur co-diffusion metal workpiece in the mold is provided, and the service life of the mold can be effectively prolonged by applying the boron-sulfur co-diffusion metal workpiece in the mold.

The present application will be described in further detail with reference to examples and comparative examples.

Example 1

A boron-sulfur co-cementation method adopts a boron-sulfur co-cementation reagent to carry out boron-sulfur co-cementation on steel, wherein the boron-sulfur co-cementation reagent comprises the following components in percentage by weight:

30% of boron carbide, 10% of ferrous sulfide, 15% of an active agent, 10% of cerium chloride and 35% of a filler; wherein the activating agent comprises sodium fluoroborate, ammonium fluoroborate and ammonium bicarbonate with the weight ratio of 1; the filler is silicon carbide and active carbon with the weight ratio of 6; the components are dried and weighed in proportion, and are uniformly ground and mixed in a mortar for standby.

1) Pretreatment of metal surfaces

Selecting H13 hot-working die steel as a boron-sulfur co-penetration test sample with the specification of 10 x 10mm, polishing by using metallographic waterproof abrasive paper of No. 400, no. 1500 and No. 2500, then placing the test sample in acetone for ultrasonic cleaning for 10 minutes, then performing ultrasonic cleaning in absolute ethyl alcohol for 10 minutes, and finally drying for later use.

2) Co-cementation treatment

Spreading a proper amount of uniformly mixed reagent at the bottom of a stainless steel sealing tank, then placing the cleaned metal sample on the reagent, then burying the reagent, ensuring that a metal workpiece is positioned at the center of the reagent, screwing a tank cover after canning is finished, performing secondary sealing on the outer side of the tank body by using refractory soil prepared by liquid sodium silicate solution, and finally drying at 100-200 ℃. And (3) placing the dried sealed tank in a heating furnace, heating to 580 ℃ according to the heating rate of 10 ℃/minute, carrying out co-cementation treatment for 12 hours, cooling along with the furnace after the co-cementation is finished, and opening the tank to take out the metal sample after the co-cementation is finished.

Example 2

40% boron carbide, 10% thiourea, 15% active agent, 10% lanthanum chloride, and 25% filler; wherein the activating agent comprises potassium fluoborate, ammonium fluoborate and ammonium bicarbonate with the weight ratio of 1; the filler is activated carbon and silicon carbide with the weight ratio of 1; the components are dried and weighed in proportion, and are uniformly ground and mixed in a mortar for standby.

1) Pretreatment of metal surfaces

Selecting H13 hot-working die steel as a boron-sulfur co-penetration sample with the specification of 10 x 10mm, grinding the sample by using 400#, 1500# and 2500# metallographic waterproof abrasive paper, then placing the sample in acetone for ultrasonic cleaning for 10 minutes, then performing ultrasonic cleaning in absolute ethyl alcohol for 10 minutes, and finally drying for later use.

2) Co-cementation treatment

Spreading a proper amount of uniformly mixed reagent at the bottom of a stainless steel sealing tank, then placing the cleaned metal sample on the reagent, then burying the reagent, ensuring that a metal workpiece is positioned at the center of the reagent, screwing a tank cover after canning is finished, performing secondary sealing on the outer side of the tank body by using refractory soil prepared by liquid sodium silicate solution, and finally drying at 100-200 ℃. And (3) placing the dried sealed tank in a heating furnace, heating to 580 ℃ according to the heating rate of 13 ℃/minute, carrying out co-cementation treatment for 12 hours, cooling along with the furnace after the co-cementation is finished, and opening the tank to take out the metal sample after the co-cementation is finished.

Example 3

50% of boron carbide, 10% of ferrous sulfide, 15% of an active agent, 10% of scandium chloride and 15% of a filler; wherein the activating agent comprises sodium fluoroborate, ammonium fluoroborate and ammonium bicarbonate with the weight ratio of 1; the filler is activated carbon and silicon carbide with the weight ratio of 1; the components are dried and weighed in proportion, and are uniformly ground and mixed in a mortar for standby.

1) Pretreatment of metal surfaces

2) Co-cementation treatment

Spreading a proper amount of uniformly mixed reagent at the bottom of a stainless steel sealing tank, then placing the cleaned metal sample on the reagent, then burying the reagent, ensuring that a metal workpiece is positioned at the center of the reagent, screwing a tank cover after canning is finished, performing secondary sealing on the outer side of the tank body by using refractory soil prepared by liquid sodium silicate solution, and finally drying at 100-200 ℃. And (3) placing the dried sealed tank in a heating furnace, heating to 560 ℃ according to the heating rate of 10 ℃/minute, carrying out co-cementation treatment for 12 hours, cooling along with the furnace after the co-cementation is finished, and opening the tank to take out the metal sample after the co-cementation is finished.

Example 4

A boron-sulfur co-doping method, which is different from embodiment 1 in that the boron-sulfur co-doping reagent of the embodiment comprises the following components in percentage by weight:

30% of boron carbide, 10% of ferrous sulfide, 15% of an active agent, 10% of cerium chloride and the balance of a filler;

the activator of the embodiment is adjusted to be sodium fluoroborate, ammonium fluoroborate and ammonium bicarbonate with the weight ratio of 2.

Example 5

A boron-sulfur co-doping method, which is different from embodiment 2 in that a boron-sulfur co-doping reagent in the embodiment comprises the following components in percentage by weight:

40% of boron carbide, 10% of thiourea, 15% of an active agent, 10% of lanthanum chloride and the balance of a filling agent;

the fillers of the embodiment are activated carbon and alumina with the weight ratio of 1.

Example 6

A boron-sulfur co-doping method, which is different from embodiment 3 in that a boron-sulfur co-doping reagent in the embodiment comprises the following components in percentage by weight:

50% of boron carbide, 10% of ferrous sulfide, 15% of an active agent, 5% of scandium chloride and the balance of a filler;

the fillers in this example are activated carbon and silicon carbide in a weight ratio of 1.

Example 7

Different from embodiment 1, the boron-sulfur co-doping method in this embodiment includes the following components by weight percent:

30% of boron carbide, 5% of ferrous sulfide, 5% of thiourea, 15% of an active agent, 10% of cerium chloride and the balance of a filling agent.

The main vulcanization accelerator in this example was prepared from 1:1 and thiourea, the rest being the same as in example 1.

Example 8

40% of boron carbide, 10% of thiourea, 15% of an active agent, 10% of lanthanum chloride and the balance of a filling agent.

In the present example, the filler is silicon carbide alone, and compared with example 2, the activated carbon is removed, and the rest is the same as example 2.

Example 9

A boron-sulfur co-doping method, which is different from embodiment 8 in that a boron-sulfur co-doping reagent in the embodiment comprises the following components in percentage by weight:

50% of boron carbide, 10% of ferrous sulfide, 15% of an active agent, 10% of cerium chloride and the balance of a filler.

The fillers in this example are graphene and alumina in a weight ratio of 1.

Example 10

A boron-sulfur co-cementation method, which is different from the embodiment 1 in that the sealing mode in the embodiment 10 is not to coat the sealing refractory slurry of the outer layer;

example 11

A boron-sulfur co-infiltration method is different from the embodiment 2 in that the heat preservation temperature in the embodiment is 560 ℃, the heating rate is 8 ℃/min, and the heat preservation time is 10h.

The preparation method of the boron-sulfur co-permeation reagent related in the above embodiments is to uniformly mix the components. The workpieces processed in the above examples were H13 hot work die steel.

Comparative example 1

Different from the embodiment 1, the boron-sulfur co-doping method of the comparative example comprises the following components in percentage by weight:

30% of boron carbide, 10% of sodium thiosulfate, 15% of an active agent, 10% of cerium chloride and the balance of a filling agent.

This comparative example replaces ferrous sulfide for sodium thiosulfate.

Comparative example 2

30% of boron carbide, 10% of ferrous sulfide, 15% of an active agent, 10% of cerium oxide and the balance of a filler.

This comparative example replaces the rare earth reagent cerium chloride with cerium oxide.

Comparative example 3

H13 hot work die steel without boron-sulfur co-cementation treatment.

The results of tests, including wear resistance tests and coefficient of friction tests (using the test method of example 1), on the boro-sulfido-infiltrated metal workpieces prepared in the above examples and comparative examples are shown in table 1. And testing the co-infiltrated sample by using a UMT friction testing machine, and testing the friction coefficient and the relative wear resistance. The friction coefficient is directly output by the testing equipment, the abrasion loss is obtained by measuring the abrasion volume by a laser confocal microscope, and meanwhile, the relative abrasion resistance data of different samples can be obtained by measuring the reciprocal of the abrasion loss. The test conditions were as follows: the sample size is 10 × 10mm, the test load is 30N, the speed is 1mm/s, the frequency is 1Hz, the time is 30min, and the counter grinding pair is Al with the diameter of 10mm ₂ O ₃ Ball, ambient temperature 25 ℃, humidity 50 ± 10% rh.

XRD detection is carried out on the samples of the example 1 and each comparative example 4 after the co-cementation, and the detection pattern results are shown in figures 1 and 2. As shown in FIG. 1, the surface layer of the sample was made of Fe after the co-diffusion treatment of example 1 ₂ B. FeS phase composition, whereas XRD results of the original steel piece in comparative example 4 showed a single alpha-Fe phase on the surface, as shown in fig. 2.

The results of the friction coefficient and the abrasion loss of the samples of example 1 and comparative example 4 are shown in fig. 3 and fig. 4, and the results show that the friction coefficient of the samples is greatly reduced from 1.17 of the original samples to 0.19 of the co-infiltrated samples through the co-infiltration treatment, and the abrasion loss is reduced from 5.15 to 10 of the original samples ⁶ μm ³ Down to 1.98 x 10 ⁶ μm ³ The effect of the co-cementation treatment process of the embodiment on improving the tribological performance of the metal sample is shown.

TABLE 1

Group of	Coefficient of friction	Relative wear resistance
			Example 1	0.19	0.504
Example 2	0.18	0.55
			Example 3	0.21	0.47
Example 4	0.35	0.29
			Example 5	0.26	0.38
Example 6	0.37	0.27
			Example 7	0.18	0.54
Example 8	0.28	0.36
			Example 9	0.15	0.61
Example 10	0.50	0.23
			Example 11	0.42	0.24
Comparative example 1	0.66	0.22
			Comparative example 2	0.76	0.20
Comparative example 3	1.17	0.193

It can be seen from table 1 that the wear resistance and the friction coefficient (an expression of self-lubricating property) of the boron-sulfur co-carburized metal workpiece prepared in each embodiment of the present application are superior to each pair of proportions, which indicates that the boron-sulfur co-carburized reagent provided by the present application is scientifically matched to simultaneously boronize and sulfurize the metal workpiece, so as to effectively improve the wear resistance and self-lubricating property of the metal workpiece, and the effect is deteriorated by replacing the components in the formula or changing the content of each component or omitting any one of the components. From the data in table 1, it can be seen that the workpieces obtained by the borosulfide co-cementation reagent and the co-cementation method of the present application all have surface friction coefficients of 0.5 or less, most of the relative wear resistance is 0.3 or more, some of the relative wear resistance is 0.5 or more, even 0.6 or more, and the workpieces corresponding to the comparative examples have friction coefficients of 0.6 or more, and all of the relative friction properties are about 0.2.

Further, it can also be seen from the data in table 1 that the overall performance of example 1 is better than that of example 4, indicating that the effectiveness of the boro-sulphur co-cementation agent can be further improved by optimizing the ratio of the active agents; the overall performance of example 2 is better than that of example 5, demonstrating that the effectiveness of the boro-sulphur co-cementation agent can be further enhanced by the preference for fillers; the comprehensive performance of example 3 is better than that of example 6, which shows that the effect of the boron-sulfur co-doping agent can be improved by further optimizing the content of the rare earth agent; the overall performance of example 7 is slightly better than that of example 1, which shows that the preferred proportion of the sulfurizing agent can further improve the effect of the boron-sulfur process agent; the comprehensive performance of the embodiment 9 is superior to that of the embodiment 3, which shows that the effect of the boron-sulfur co-permeation reagent can be obviously optimized by adding the graphene; the combination of the properties of example 1 is better than that of example 10, which shows that the effect of the boron-sulfur co-doping method can be further improved by adding a sealing step; the overall performance of example 1 is better than that of example 11, indicating that the preferred incubation temperature and time will further enhance the effectiveness of the boro-sulfidation process.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. The boron-sulfur co-doping reagent is characterized by being capable of carrying out boron-sulfur co-doping in the temperature range of 550-600 ℃, and comprising the following components in percentage by weight:

25% -55% of boron carbide, 7% -13% of a sulfurizing main agent, 12% -17% of an active agent, 5% -12% of a rare earth compound and the balance of a filling agent, wherein the sulfurizing main agent comprises ferrous sulfide and/or thiourea;

the active agent is a combination of fluoborate and bicarbonate, and is used for promoting the boron carbide and the sulfurizing main agent to generate active boron atoms and active sulfur atoms;

the weight ratio of the fluoborate to the bicarbonate is 2;

the fluoroborate comprises at least one of sodium fluoroborate, potassium fluoroborate or ammonium fluoroborate;

the bicarbonate comprises ammonium bicarbonate;

the rare earth compound comprises a rare earth chloride;

the filler includes at least one of a metal oxide, a non-metallic carbide, or a carbon material.

2. The boro-sulphur co-cementation reagent according to claim 1, wherein the reagent comprises the following components in percentage by weight:

32-48% of boron carbide, 7-11% of sulfurizing main agent, 12-16% of activating agent, 6-11% of rare earth compound and the balance of filling agent.

3. The boro-sulphur co-cementation reagent according to claim 1, wherein the reagent comprises the following components in percentage by weight:

35-45% of boron carbide, 10% of sulfurizing main agent, 15% of active agent, 10% of rare earth compound and the balance of filler.

4. A boro-sulphur co-cementation reagent according to any one of claims 1 to 3, wherein the rare earth chloride comprises at least one of lanthanum chloride, cerium chloride or scandium chloride.

5. The boro-sulfide co-cementation reagent according to any one of claims 1 to 3, wherein the metal oxide comprises aluminum oxide.

6. A boro-sulphur co-cementation agent according to any one of claims 1 to 3, wherein the non-metallic carbide comprises silicon carbide.

7. The borosulfurizing agent according to any one of claims 1 to 3, wherein the carbon material comprises activated carbon.

8. A borosulfurizing method, characterized in that a metal workpiece is borosulfurized using the borosulfurizing reagent according to any one of claims 1 to 7.

9. The boro-sulfide co-doping method according to claim 8, wherein said method comprises the steps of:

10. The borosulfurizing method according to claim 9, wherein the heating rate is 8-13 ℃/min, the holding temperature is 550-600 ℃, and the holding time is 11-13h.

11. The borosulfurizing method according to claim 9 or 10, further comprising a step of sealing the metal workpiece and the borosulfurizing agent after placing the metal workpiece in the borosulfurizing agent, and then holding the temperature after heating.

12. The boro-sulfidisation process of claim 11, wherein said sealing metal workpiece and boro-sulfidisation reagent comprises: and (3) placing the metal workpiece and the boron-sulfur co-permeation reagent in a sealing device, sealing, then coating the refractory slurry on the outer side of the sealing device, and finally drying.

13. The boro-sulfidisation process of claim 12, wherein the refractory slurry comprises a refractory material and a solvent.

14. The boro-sulfide co-doping method of claim 13, wherein the solvent comprises an aqueous silicate solution.

15. A borosulfido-coinfused metal workpiece, characterized in that it has been obtained by the borosulfido-coinfusion process according to any of claims 8 to 14.

16. Use of a boro-sulphur co-infiltrated metal workpiece according to claim 15 in a mould.