CN110819989A - Surface treatment process for enhancing corrosion resistance of aluminum electrolysis cathode steel bar - Google Patents

Surface treatment process for enhancing corrosion resistance of aluminum electrolysis cathode steel bar Download PDF

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Publication number
CN110819989A
CN110819989A CN201911149766.5A CN201911149766A CN110819989A CN 110819989 A CN110819989 A CN 110819989A CN 201911149766 A CN201911149766 A CN 201911149766A CN 110819989 A CN110819989 A CN 110819989A
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steel bar
titanium
boron
treated
plating
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李涛
谭敏
商志强
严建川
侯青青
高福朋
周强
郭晓培
朱玉麟
崔贺楠
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Chongqing University
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Chongqing University
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
    • C23C28/322—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer only coatings of metal elements only
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
    • C23C28/325—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with layers graded in composition or in physical properties
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C25C3/08—Cell construction, e.g. bottoms, walls, cathodes

Abstract

The invention discloses a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar, which comprises the following steps: pretreating, namely pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated; titanium plating, namely performing titanium plating treatment on the steel bar to be used by a preset method to prepare a titanium plated steel bar; preparing a steel bar with a gradient functional material layer, namely plating boron at high temperature or plating boron at low temperature on the titanium-plated steel bar subjected to titanium plating treatment to prepare the steel bar with the gradient functional material layer. Has the advantages that: by forming TiB on the surface of the steel bar2The gradient functional composite material layer of-TiB-Ti can effectively prevent the surface carburization of the steel bar, thereby effectively avoiding the increase of the energy consumption of the aluminum electrolysis industry due to the increase of the ineffective power consumption of the cathode.

Description

Surface treatment process for enhancing corrosion resistance of aluminum electrolysis cathode steel bar
Technical Field
The invention relates to the technical field of surface treatment, in particular to a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar.
Background
Aluminum has characteristics of small specific gravity, high strength, excellent electric and thermal conductivity, high corrosion resistance and the like, and is widely applied to various aspects such as transportation, electric power, machine manufacturing, building materials, packaging and the like. The aluminum yield is the top of the world in China over the years, and the electrolytic aluminum industry is the big household of industrial power consumption in China. Meanwhile, the state further promotes the adjustment of industrial structure, actively guides the aluminum industry to save energy and reduce consumption, and eliminates the backward capacity of electrolytic aluminum.
At present, the electrolytic aluminum industry basically adopts a cryolite-alumina molten salt electrolysis method, and the main equipment is an aluminum electrolysis cell (figure 4). In the electrolysis process, current flows in from the anode, sequentially passes through the electrolyte, the aluminum liquid and the cathode carbon block, and then is led into the bus through the cathode steel bar. The cathode is an important component of the electrolyzer equipment and is also an important part of the ineffective energy consumption loss of the electrolyzer. The sum of the voltage drop of the aluminum liquid layer, the voltage drop of the cathode carbon block and the voltage drop of the cathode conductive steel bar forms the cathode voltage drop. The connection between the cathode carbon block and the steel bar is critical to the cathode fall. And the cathode steel bar is at 900-1000 ℃ for years and is in close contact with the cathode carbon block. The surface of the steel bar is severely carburized, so that the resistance of the steel bar is increased, and the ineffective energy consumption of the cathode is increased. Previous researches show that by changing cathode conductive materials, for example, by adopting industrial pure iron with relatively high conductivity as the cathode conductive material, the energy consumption of the cathode can be reduced to a certain extent at the initial stage of slotting the electrolytic cell. However, pure iron and the like cannot continuously maintain better conductivity, and is also easy to carburize to cause the conductivity to deteriorate and the ineffective energy consumption of the electrolytic cell to increase. Therefore, there is an urgent need for a method for preventing carburization of a cathode conductive steel bar and preventing deterioration of the conductivity of a steel for an aluminum electrolysis cathode.
At present, conventional surface treatment processes such as laser selective melting and vapor deposition of a plated layer (hard chromium plating, chemical nickel phosphorus plating, brush plating special alloy plating and the like) and a carburized layer (nitriding, boron, sulfur and the like) are adopted, and a homogeneous tissue layer formed on the surface of steel by the method can improve the strength, the wear resistance and the like of the steel or can prevent the carburization of the steel to a certain extent, but has adverse effect on the conductivity of the steel.
On the premise of considering high-temperature use environment and conductivity, titanium and titanium boride are the first choice for steel surface coating materials. Titanium is high temperature resistant, high in strength, good in ductility, and can form a firmer bonding layer with steel. The existing titanium plating method is mature and mainly comprises the following steps: magnetron sputtering, ion implantation, physical vapor deposition, electric spark deposition, selective laser melting and the like. Titanium boride, as a novel ceramic material, has extremely excellent properties, such as extremely high melting point and hardness, excellent chemical stability and excellent heat conductivity, and particularly has good electrical conductivity. Research shows that titanium boride as cathode coating material can reduce power consumption and prolong the service life of the cathode of the aluminum electrolytic cell. And the titanium boride is relatively stable and does not react with carbon. Therefore, the titanium boride can be used as a surface coating of the steel bar for the cathode of the aluminum electrolytic cell, thereby preventing the steel bar from being carburized and not influencing the conductivity of the steel bar.
At present, the methods for depositing titanium boride on the surface of steel mainly comprise electric spark deposition and selective laser melting technology. But the cost is high, and the processing of the steel for the large-size aluminum electrolysis cathode is difficult to process in batches. Further, when only the surface of steel is plated with titanium alone or with titanium boride, the following problems occur: titanium is easy to generate titanium carbide with carbon at high temperature, and the conductivity of the titanium carbide is poor; and the titanium boride has a thermal expansion coefficient of 4.6 to 7.8 x 10-6A/° C) coefficient of thermal expansion of less than that of steel (10.6 to 12.2 × 10)-5/° c), the plating and the substrate are easily damaged by tension due to performance mismatch when the temperature fluctuates. For this reason, these methods are all performed by coating the steel surface with a coating solutionA layer of homogeneous structure is added, but the homogeneous structure and a steel matrix have property function difference, and a macroscopic interface between the homogeneous structure and the steel matrix is also a key factor influencing the conductivity. Therefore, the difference of the thermal expansion coefficients of the coating and the substrate should be reduced as much as possible in the aspects of material selection and process, and the macroscopic interface is eliminated. And simultaneously, the reaction of the plating layer and the cathode carbon block in a high-temperature environment is prevented. On the other hand, the boron plating process on the titanium and steel surfaces mainly comprises the following steps: salt bath boronizing, molten salt electroplating techniques and the like, which have obvious advantages for batch surface treatment of large-size aluminum electrolysis cathode steel. Therefore, the invention provides a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar to solve the problems in the related art.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects of the prior art, the invention provides a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar, which has the advantage of preventing the surface of the steel bar from being carburized, and further solves the problems in the background art.
(II) technical scheme
In order to realize the advantage of preventing the surface of the steel bar from being carburized, the invention adopts the following specific technical scheme:
according to one aspect of the invention, the surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar comprises the following steps:
pretreatment: pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated;
titanium plating: carrying out titanizing treatment on the steel bar to be used by a preset method to prepare a titanizing steel bar;
high-temperature boron plating: and carrying out boron plating treatment on the titanium-plated steel bar by adopting a preset method to prepare the steel bar with the gradient functional material layer.
Preferably, the surface of the steel bar to be treated is pretreated by a preset method, and the preparation of the steel bar to be treated specifically comprises the following steps:
the surface of a preset steel bar to be treated is subjected to primary treatment by methods such as steel brush scrubbing, sand paper polishing and the like;
cleaning and deoiling the preliminarily treated steel bar through deoiling liquid;
carrying out acid cleaning treatment on the steel bar after cleaning and oil removing by using etching solution;
and cleaning and blow-drying the steel bar subjected to acid cleaning treatment, and taking the steel bar subjected to cleaning and blow-drying as a steel bar to be used. Through the treatment, impurities on the surface of the steel bar are removed, so that a matrix is exposed, and organic matters such as oil and the like do not exist on the surface, and titanium plating is carried out subsequently; the steel bar after acid cleaning is cleaned to remove surface acid liquid, prevent corrosion and influence subsequent processes.
Preferably, the titanium plating treatment is carried out on the steel bar to be used by a preset method, and the preparation of the titanium plated steel bar specifically comprises the following steps: and forming a titanium layer with the thickness of about 5-100 mu m on the surface of the steel bar to be used by adopting the technologies of magnetron sputtering, ion implantation, physical vapor deposition, selective laser melting, electric spark deposition and the like to obtain the titanium-plated steel bar. Through the treatment, a titanium layer meeting the requirements is generated on the surface of the steel bar and is used as a raw material for preparing the gradient functional material subsequently; in addition, the titanium layer also serves as a transition layer here, which can effectively prevent TiB in the event of temperature changes2Cracks occur due to the difference in thermal expansion coefficient from steel.
Preferably, the titanium-plated steel bar is subjected to boron plating treatment by a preset method, and the preparation of the steel bar with the gradient functional material layer specifically comprises the following steps: carrying out boron plating treatment on the titanium-plated steel bar at 850-1100 ℃ by the technologies of selective laser melting, electric spark deposition, salt bath boronizing, molten salt electroplating and the like to obtain a boron-plated steel bar, and standing for 0.5-4h to enable boron to diffuse inwards to obtain the titanium-titanium alloy steel bar with Ti-TiB2A steel bar of gradient functional material layer. Through the treatment, a boron layer meeting the requirement is generated on the surface of the titanium-plated steel bar and is used as a raw material for preparing the gradient functional material subsequently.
According to another aspect of the invention, the surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar is characterized by comprising the following steps:
pretreatment: pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated;
titanium plating: carrying out titanizing treatment on the steel bar to be used by a preset method to prepare a titanizing steel bar;
low-temperature boron plating: carrying out boron plating treatment on the titanium-plated steel bar by adopting a preset method to prepare a boron-plated steel bar;
preparing a gradient functional material layer: and placing the boron-plated steel bar in a protective atmosphere at a preset temperature to prepare the steel bar with the gradient functional material layer. Specifically, since the thermodynamic and kinetic conditions of the boron layer generated by the low-temperature boron plating process are not sufficient to satisfy the requirement of B penetration Ti layer formation of the required gradient functional material layer, the necessary conditions of B penetration and reaction with Ti are provided by this step.
Preferably, the surface of the steel bar to be treated is pretreated by a preset method, and the preparation of the steel bar to be treated specifically comprises the following steps:
the surface of a preset steel bar to be treated is subjected to primary treatment by methods such as steel brush scrubbing, sand paper polishing and the like;
cleaning and deoiling the preliminarily treated steel bar through deoiling liquid;
carrying out acid cleaning treatment on the steel bar after cleaning and oil removing by using etching solution;
and cleaning and blow-drying the steel bar subjected to acid cleaning treatment, and taking the steel bar subjected to cleaning and blow-drying as a steel bar to be used. Through the treatment, impurities on the surface of the steel bar are removed, so that a matrix is exposed, and the surface does not contain organic matters such as oil and the like, and titanium plating is carried out subsequently; the steel bar after acid cleaning is cleaned to remove surface acid liquid, prevent corrosion and influence subsequent processes.
Preferably, the titanium plating treatment is carried out on the steel bar to be used by a preset method, and the preparation of the titanium plated steel bar specifically comprises the following steps: and forming a titanium layer with the thickness of about 5-100 mu m on the surface of the steel bar to be used by adopting the technologies of magnetron sputtering, ion implantation, physical vapor deposition, selective laser melting, electric spark deposition and the like to obtain the titanium-plated steel bar. Through the above-mentionedGenerating a titanium layer meeting the requirements on the surface of the steel bar, and taking the titanium layer as a raw material for preparing the gradient functional material subsequently; in addition, the titanium layer also serves as a transition layer here, which can effectively prevent TiB in the event of temperature changes2Cracks occur due to the difference in thermal expansion coefficient from steel.
Preferably, the titanium-plated steel bar is subjected to boron plating treatment by a preset method, and the preparation of the boron-plated steel bar specifically comprises the following steps: and forming a boron layer with the thickness of about 5-100 mu m on the surface of the titanium-plated steel bar by using the technologies of selective laser melting, electric spark deposition, salt bath boronizing, molten salt electroplating and the like to obtain the boron-plated steel bar. Through the treatment, a boron layer meeting the requirement is generated on the surface of the titanium-plated steel bar and is used as a raw material for preparing the gradient functional material subsequently.
Preferably, the boron-plated steel bar is placed in a protective atmosphere with a preset temperature, and the preparation of the steel bar with the gradient functional material layer specifically comprises the following steps: placing the boron-plated steel bar in a protective atmosphere at 850-1100 ℃ for 0.5-4h to enable boron to diffuse inwards and form TiB from outside to inside2A gradient functional material layer of TiB-Ti-steel base to obtain the steel bar with the gradient functional material layer. This step provides the necessary conditions for B penetration and reaction with Ti, since certain boron plating processes do not have sufficient thermodynamic and kinetic conditions to allow B penetration into the Ti layer to form a satisfactory graded functional material layer.
Preferably, the protective atmosphere is in an argon protective atmosphere or a vacuum environment, the maximum heating rate is 10 ℃/min when the gradient functional material layer is prepared, and 2 ℃/min, 4 ℃/min, 6 ℃/min, 8 ℃/min and 10 ℃/min can be selected. The temperature rise rate is not more than 10 ℃/min when the gradient functional material layer is prepared, and the TiB is mainly avoided in the temperature rise process2Cracks are caused by the difference in thermal expansion properties of the Ti and steel substrates.
(III) advantageous effects
Compared with the prior art, the invention provides the surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar, and the surface treatment process has the following beneficial effects:
(1) by applying on the surface of the steel barFormation of TiB2The gradient functional composite material layer of-TiB-Ti can effectively prevent the resistance from increasing due to the carburization of titanium carbide generated by carbon infiltration and steel base, thereby effectively avoiding the energy consumption increase of the aluminum electrolysis industry due to the increase of the ineffective power consumption of the cathode.
(2) By forming TiB on the surface of the steel bar2-TiB-Ti gradient functional composite material layer, outer layer TiB with good high temperature stability2And under the action of the TiB layer, the carbon can be effectively prevented from permeating the steel bar for the cathode of the aluminum electrolytic cell, and the carbon is prevented from reacting with steel or titanium. Further improving the corrosion resistance and mechanical properties (such as surface hardness and wear resistance) of the surface of the steel bar.
(3) By forming TiB on the surface of the steel bar2The gradient functional composite material layer of TiB-Ti ensures that no macroscopic interface exists inside the gradient functional composite material layer and between the gradient functional composite material layer and the steel base, thereby eliminating the problem of macroscopic interface caused by the traditional plating process, ensuring tight and firm combination and effectively preventing the occurrence of crack condition caused by temperature change.
(4) By forming TiB on the surface of the steel bar2The gradient functional composite material layer of-TiB-Ti can realize the protection effect on the steel bar and is convenient for subsequent repeated recycling.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a process flow diagram of a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar according to an embodiment of the invention;
FIG. 2 is a flow chart of a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar according to a first embodiment of the invention;
FIG. 3 is a flow chart of a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar according to a second embodiment of the invention;
figure 4 is a schematic view of an aluminium cell according to the prior art.
Detailed Description
For further explanation of the various embodiments, the drawings which form a part of the disclosure and which are incorporated in and constitute a part of this specification, illustrate embodiments and, together with the description, serve to explain the principles of operation of the embodiments, and to enable others of ordinary skill in the art to understand the various embodiments and advantages of the invention, and, by reference to these figures, reference is made to the accompanying drawings, which are not to scale and wherein like reference numerals generally refer to like elements.
According to the embodiment of the invention, the surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar is provided.
The present invention will be further described with reference to the accompanying drawings and specific embodiments, and according to an embodiment of the present invention, there is provided a surface treatment process for enhancing corrosion resistance of an aluminum electrolysis cathode steel bar, as shown in fig. 1, the surface treatment process includes the following steps:
pretreatment: pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated; in specific application, the steel bar pretreatment mainly aims at removing impurities on the surface of the steel bar, so that a matrix is exposed, and the surface of the steel bar is free of organic matters such as oil and the like, so that titanium plating can be carried out subsequently;
titanium plating: carrying out titanizing treatment on the steel bar to be used by a preset method to prepare a titanizing steel bar;
preparing a steel bar with a gradient functional material layer: preparing a steel bar with a gradient functional material layer by high-temperature boron plating or low-temperature boron plating on the titanium-plated steel bar after the titanium plating treatment;
when the steel bar with the gradient functional material layer is prepared by adopting high-temperature boron plating, the titanium-plated steel bar is subjected to boron plating treatment by a preset method to prepare the steel bar with the gradient functional material layer. In particular, the boron plating operation in this step is a high temperature process, such as molten salt electroplating, which itself is a processThe temperature of the molten salt is above 900 ℃, the time for electrolysis is 1-3 hours, the boron plating process and the gradient functional material layer are synchronously carried out, and when boron is plated, B reacts with Ti to generate TiB due to proper conditions2Or TiB;
when the steel bar with the gradient functional material layer is prepared by adopting low-temperature boron plating, firstly, carrying out boron plating treatment on the titanium-plated steel bar by adopting a preset method to prepare a boron-plated steel bar; and then, preparing the gradient functional material layer on the obtained boron-plated steel bar, namely placing the boron-plated steel bar in a protective atmosphere at a preset temperature to prepare the steel bar with the gradient functional material layer. Specifically, if the boron plating process in this step is performed at a local high temperature (or the high temperature duration is short) which is not sufficient to react B with Ti and form a gradient functional material layer with a certain thickness on the surface, another process is required to perform heat treatment on the boron-plated material to form a gradient functional material layer on the steel surface. Local high temperature (or short duration of high temperature) is divided into two cases: 1) the process is low in temperature and insufficient for the penetration of B and the reaction with Ti to generate TiB2(ii) a 2) The local high-temperature (or high-temperature short-duration) boron plating process can perform B penetration and react with Ti to generate TiB to a very limited extent2But not sufficient to produce a satisfactory layer of gradient functional material.
In order to facilitate a further understanding of the above-described technical solutions of the present invention, the present invention will now be further described with reference to the accompanying drawings and detailed description.
First embodiment, according to an embodiment of the present invention, there is provided a surface treatment process for enhancing corrosion resistance of an aluminum electrolysis cathode steel bar, as shown in fig. 2, the surface treatment process includes the following steps:
step S1: pretreating, namely pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated;
wherein, the step S1 specifically includes the following steps:
the surface of a preset steel bar to be treated is subjected to primary treatment by methods such as steel brush scrubbing, sand paper polishing and the like;
cleaning and deoiling the preliminarily treated steel bar through deoiling liquid;
carrying out acid cleaning treatment on the steel bar after cleaning and oil removing by using etching solution;
and cleaning and blow-drying the steel bar subjected to acid cleaning treatment, and taking the steel bar subjected to cleaning and blow-drying as a steel bar to be used.
In addition, the steel brush scrubbing, sanding and the like, the degreasing and cleaning treatment, the acid cleaning treatment and the blow drying treatment in step S1 are prior art and will not be described in detail herein for step S1.
Step S2: titanium plating, namely performing titanium plating treatment on the steel bar to be used by a preset method to prepare a titanium plated steel bar;
wherein, the step S1 specifically includes the following steps: and forming a titanium layer with the thickness of about 5-100 mu m on the surface of the steel bar to be used by adopting the technologies of magnetron sputtering, ion implantation, physical vapor deposition, selective laser melting, electric spark deposition and the like to obtain the titanium-plated steel bar.
In addition, for the above step S2, the techniques of magnetron sputtering, ion implantation, physical vapor deposition, laser selective melting, and electrical discharge deposition in step S2 are prior art and will not be described in detail here.
Step S3: and (3) high-temperature boron plating, wherein the titanium-plated steel bar is subjected to boron plating treatment by adopting a preset method to prepare the steel bar with the gradient functional material layer.
Wherein, the step S3 specifically includes the following steps: carrying out boron plating treatment on the titanium-plated steel bar at 850-1100 ℃ by the technologies of selective laser melting, electric spark deposition, salt bath boronizing, molten salt electroplating and the like to obtain a boron-plated steel bar, and standing for 0.5-4h to enable boron to diffuse inwards to obtain the titanium-titanium alloy steel bar with Ti-TiB2A steel bar of gradient functional material layer. Specifically, the selective laser melting and spark deposition technology belongs to a local high-temperature process, namely the local temperature is higher than the melting point temperature of the material, but the duration is extremely short. In the step, a high-temperature environment can be additionally added for the large-size aluminum electrolysis cathode conductive steel bar, and the two processes are adopted for boron plating operation, namely, the high-temperature process (the temperature is 85℃)0-1100 ℃) and the high temperature environment is also required to be maintained for 0.5-4 hours.
In addition, for the above step S3, the techniques of selective laser melting, electric spark deposition, salt bath boronizing, molten salt plating, etc. in step S3 are prior art and will not be described in detail here.
In a second embodiment, there is provided a surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar according to another embodiment of the present invention, as shown in fig. 3, the surface treatment process includes the following steps:
step S1: pretreating, namely pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated;
wherein, the step S1 specifically includes the following steps:
the surface of a preset steel bar to be treated is subjected to primary treatment by methods such as steel brush scrubbing, sand paper polishing and the like;
cleaning and deoiling the preliminarily treated steel bar through deoiling liquid;
carrying out acid cleaning treatment on the steel bar after cleaning and oil removing by using etching solution;
and cleaning and blow-drying the steel bar subjected to acid cleaning treatment, and taking the steel bar subjected to cleaning and blow-drying as a steel bar to be used.
Step S2: titanium plating, namely performing titanium plating treatment on the steel bar to be used by a preset method to prepare a titanium plated steel bar;
wherein, the step S2 specifically includes the following steps: and forming a titanium layer with the thickness of about 5-100 mu m on the surface of the steel bar to be used by adopting the technologies of magnetron sputtering, ion implantation, physical vapor deposition, selective laser melting, electric spark deposition and the like to obtain the titanium-plated steel bar.
Step S3，: plating boron at low temperature, and performing boron plating treatment on the titanium-plated steel bar by adopting a preset method to prepare a boron-plated steel bar;
wherein the step S3，The method specifically comprises the following steps: forming a layer with a thickness of about one layer on the surface of the titanium-plated steel bar by the technologies of selective laser melting, electric spark deposition, salt bath boronizing, molten salt electroplating and the likeAnd (5) obtaining a boron-plated steel bar by using a boron layer of 5-100 mu m.
Step S4，: and preparing a gradient functional material layer, namely placing the boron-plated steel bar in a protective atmosphere at a preset temperature to prepare the steel bar with the gradient functional material layer.
Wherein the step S4，The method specifically comprises the following steps: placing the boron-plated steel bar in a protective atmosphere at 850-1100 ℃ for 0.5-4h (the specific time depends on the thickness of the required coating), so that boron is diffused inwards to form TiB from outside to inside2A gradient functional material layer of TiB-Ti-steel base to obtain the steel bar with the gradient functional material layer. Specifically, the protective atmosphere is under the protection of argon (or other inert gases) or vacuum environment, the maximum heating rate is 10 ℃/min when the gradient functional material layer is prepared, and the heating rate can be 2 ℃/min, 4 ℃/min, 6 ℃/min, 8 ℃/min and 10 ℃/min. The relationship between the specific standing time and the thickness of the coating is shown in the following table:
thickness of coating Time of standing
＜10μm 0.5 h
10-20μm 1.5 h
20-35μm 2 h
35-50μm 2.5 h
50-60μm 3 h
60-70μm 4 h
In the present invention, the following considerations are mainly taken into account in the order of titanium plating followed by boron plating: 1) in order of thermal expansion coefficient: steel>Ti>TiB2Thus, the surface of the steel is plated with titanium and then with boron to form TiB2. Ti is used as an intermediate layer, and TiB can be effectively prevented under the condition of temperature change2Cracks appear in steel due to the difference of thermal expansion coefficients; 2) both steel and Ti can react with carbon at high temperature to cause deterioration of conductivity, so that Ti cannot be plated on the outermost layer, and the process sequence of plating boron and then plating titanium cannot be adopted. And TiB2Has excellent stability at high temperature and can effectively avoid the penetration of carbon. Thus TiB is mixed2As the outermost layer.
In the invention, the gradient functional material layer has the following advantages:
1) the characteristics and advantages are as follows: a) Ti-TiB2The gradient functional material layer is in continuous gradient change from one side to the other side along the thickness direction, so that a macroscopic interface caused by the traditional plating process is eliminated, and the combination is firmer; b) in addition, the composition and the structure of the functionally graded material are continuously changed in a controlled manner everywhere, so that the problem that the performance of the substrate and the performance of the coating are not matched under severe use conditions does not occur. Particularly, the alloy shows excellent ductility, high strength, excellent electric and heat conducting performance on the side close to Ti and can be firmly combined with a steel matrix. In the near TiB2The composite material has high electric and thermal conductivity, ultrahigh melting point and hardness, oxidation stability, mechanical corrosion resistance and excellent high-temperature stability;
2) advantages after application to aluminum electrolysis cathode conductive steel bars: a) carbon penetration is effectively prevented, and the problems that the conductivity of the conductive steel bar is deteriorated, the ineffective power consumption of the cathode is increased, and the energy consumption of the aluminum electrolysis industry is increased are avoided; b) effectively prevent carbon from permeating steel for the cathode of the aluminum electrolytic cell, and improve the surface corrosion resistance and mechanical properties (such as hardness, wear resistance and the like) of the conductive steel bar; c) the steel bar is protected by the material, so that the steel bar is convenient to recycle repeatedly.
For the convenience of understanding the above technical solution of the present invention, the following detailed description is made on the principle of the present invention regarding the definition and generation of gradient functional material:
the Functionally Graded Materials (FGM) is a new material in which the elements (composition and structure) of the material are continuously Graded from one side to the other side along the thickness direction, so that the properties and functions of the material are Graded. Compared with the problem that the performance of a macroscopic interface and the performance of a substrate and a coating are not matched under severe use conditions caused by the traditional coating process. The composition and structure of the functionally graded material are controllably varied continuously at each location. It features that the composition and microstructure of the material (ceramic, metal, micro-porous, etc.) are continuously distributed, adaptive to environment and controllable. The gradient functional composite material has its inner macroscopic interface eliminated by continuously changing the composition and structure of the two materials, so as to obtain a heterogeneous material with tightly combined and gradually changed functions along with the composition and structure. The purpose that two sides of the same material have different properties and functions is achieved. The design concept of the gradient functional composite material is widely applied to the fields of nuclear energy, electronics, chemistry, biomedical engineering and the like.
The principle of generation of the gradient functional material is explained as follows: a) according to the phase diagram of a Ti-B binary system, TiB and Ti are mainly arranged between titanium and boron3B4、TiB2Three intermetallic compounds, in which TiB and TiB are used2Mainly comprises the following steps. When the boron content in the titanium is close to 50 percent, a TiB phase exists; when the B content in the matrix titanium reaches nearly 66%, the phase in the system will be transformed into TiB2. When the boronizing operation is performed, TiB is easily generated on the titanium surface because a large amount of B exists on the surface of the titanium substrate2. The reaction is as follows: ti +2B = TiB2；
b) B atoms can permeate into the matrix, and react with matrix Ti to generate TiB due to low concentration of B elements, wherein the reaction is as follows: ti + B = TiB;
c) in addition, Ti may be combined with TiB2TiB is generated by the reaction as follows: ti + TiB2=2TiB；
d) Combining the three reactions, the B atoms continuously diffuse into the Ti matrix along with the extension of the heat preservation time, and can be embodied as TiB2With increasing content of TiB2The layer thickness increases and moves into the Ti base, while the intermediate layer TiB also moves into the Ti base;
e) the increase of the temperature can improve the diffusion rate of B atoms, and is beneficial to the diffusion of B to a Ti matrix to form TiB2And TiB.
In summary, according to the technical scheme of the invention, the titanium layer is preferentially plated on the surface of the steel bar, then the boron layer is generated on the surface of the sample by adopting molten salt electroplating (not limited to the method) on the basis of the titanium layer, the temperature is kept at the high temperature of 850-1100 ℃ for 0.5-4h, the boron is diffused from the titanium surface to the steel base, and meanwhile, the boron reacts with the titanium to generate titanium boride to form TiB2-a gradient functional composite layer of TiB-Ti. The Ti layer has good electrical conductivity, high temperature resistance and good ductility, and the thermal expansibility is between the steel and the titanium boride to serve as a transition layer. Outer layer of TiB2And the TiB layer has good high-temperature stability, and can effectively prevent the infiltration of carbon and prevent the reaction of carbon with steel and titanium. The gradient functional composite material layer has no macroscopic interface inside and between the gradient functional composite material layer and the steel base, and the combination is tight, so that cracks caused by temperature change can be effectively prevented. Meanwhile, the carbon can be effectively prevented from permeating, and the titanium carbide and steel base carburization are prevented from being generated, so that the resistance is increased and the energy consumption is increased.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. A surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar is characterized by comprising the following steps:
pretreatment: pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated;
titanium plating: carrying out titanizing treatment on the steel bar to be used by a preset method to prepare a titanizing steel bar;
high-temperature boron plating: and carrying out boron plating treatment on the titanium-plated steel bar by adopting a preset method to prepare the steel bar with the gradient functional material layer.
2. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar as recited in claim 1, wherein the surface of the steel bar to be treated is pretreated by a preset method, and the preparation of the steel bar to be treated specifically comprises the following steps:
the surface of a preset steel bar to be treated is subjected to primary treatment by methods such as steel brush scrubbing, sand paper polishing and the like;
cleaning and deoiling the preliminarily treated steel bar through deoiling liquid;
carrying out acid cleaning treatment on the steel bar after cleaning and oil removing by using etching solution;
and cleaning and blow-drying the steel bar subjected to acid cleaning treatment, and taking the steel bar subjected to cleaning and blow-drying as a steel bar to be used.
3. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar as recited in claim 1, wherein the titanium plating treatment is performed on the steel bar to be used by a preset method, and the preparation of the titanium plated steel bar specifically comprises the following steps: and forming a titanium layer with the thickness of about 5-100 mu m on the surface of the steel bar to be used by adopting the technologies of magnetron sputtering, ion implantation, physical vapor deposition, selective laser melting, electric spark deposition and the like to obtain the titanium-plated steel bar.
4. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar according to claim 1, wherein the titanium-plated steel bar is subjected to boron plating by a preset method, and the preparation of the steel bar with the gradient functional material layer specifically comprises the following steps: melting the mixture at 850-1100 ℃ by selective laser meltingCarrying out boron plating treatment on the titanium-plated steel bar by using the technologies of electric spark deposition, salt bath boronizing, molten salt electroplating and the like to obtain a boron-plated steel bar, and standing for 0.5-4h to enable boron to diffuse inwards to obtain the titanium-coated steel bar with Ti-TiB2A steel bar of gradient functional material layer.
5. A surface treatment process for enhancing the corrosion resistance of an aluminum electrolysis cathode steel bar is characterized by comprising the following steps:
pretreatment: pretreating the surface of the steel bar to be treated by adopting a preset method to prepare the steel bar to be treated;
titanium plating: carrying out titanizing treatment on the steel bar to be used by a preset method to prepare a titanizing steel bar;
low-temperature boron plating: carrying out boron plating treatment on the titanium-plated steel bar by adopting a preset method to prepare a boron-plated steel bar;
preparing a gradient functional material layer: and placing the boron-plated steel bar in a protective atmosphere at a preset temperature to prepare the steel bar with the gradient functional material layer.
6. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar as recited in claim 5, wherein the surface of the steel bar to be treated is pretreated by a preset method, and the preparation of the steel bar to be treated specifically comprises the following steps:
the surface of a preset steel bar to be treated is subjected to primary treatment by methods such as steel brush scrubbing, sand paper polishing and the like;
cleaning and deoiling the preliminarily treated steel bar through deoiling liquid;
carrying out acid cleaning treatment on the steel bar after cleaning and oil removing by using etching solution;
and cleaning and blow-drying the steel bar subjected to acid cleaning treatment, and taking the steel bar subjected to cleaning and blow-drying as a steel bar to be used.
7. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar as recited in claim 5, wherein the titanium plating treatment is performed on the steel bar to be used by a preset method, and the preparation of the titanium plated steel bar specifically comprises the following steps: and forming a titanium layer with the thickness of about 5-100 mu m on the surface of the steel bar to be used by adopting the technologies of magnetron sputtering, ion implantation, physical vapor deposition, selective laser melting, electric spark deposition and the like to obtain the titanium-plated steel bar.
8. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar according to claim 5, wherein the titanium-plated steel bar is subjected to boron plating treatment by a preset method, and the preparation of the boron-plated steel bar specifically comprises the following steps: and forming a boron layer with the thickness of about 5-100 mu m on the surface of the titanium-plated steel bar by using the technologies of selective laser melting, electric spark deposition, salt bath boronizing, molten salt electroplating and the like to obtain the boron-plated steel bar.
9. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar according to claim 5, wherein the boron-plated steel bar is placed in a protective atmosphere with a preset temperature, and the preparation of the steel bar with the gradient functional material layer specifically comprises the following steps: placing the boron-plated steel bar in a protective atmosphere at 850-1100 ℃ for 0.5-4h to enable boron to diffuse inwards and form TiB from outside to inside2A gradient functional material layer of TiB-Ti-steel base to obtain the steel bar with the gradient functional material layer.
10. The surface treatment process for enhancing the corrosion resistance of the aluminum electrolysis cathode steel bar according to claim 5, wherein the protective atmosphere is under the protection of argon or a vacuum environment, and the temperature rise rate is at most 10 ℃/min when the gradient functional material layer is prepared.
CN201911149766.5A 2019-11-21 2019-11-21 Surface treatment process for enhancing corrosion resistance of aluminum electrolysis cathode steel bar Pending CN110819989A (en)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101768760A (en) * 2009-11-13 2010-07-07 李庆余 TiB2-TiB/Ti gradient composite porous cathode material for aluminum electrolysis and preparation method thereof
CN102373488A (en) * 2011-10-26 2012-03-14 中国铝业股份有限公司 Method for reducing cathode drop of aluminium cell
CN103469252A (en) * 2013-08-22 2013-12-25 毕和清 Anti-carburizing aluminum electrolytic cathode steel bar
CN204491005U (en) * 2015-01-20 2015-07-22 郑州经纬科技实业有限公司 Electrolytic aluminum cathode collector bar
CN105088277A (en) * 2015-08-27 2015-11-25 江苏联合金陶特种材料科技有限公司 Preparation of TiB2-TiB/Ti gradient composite porous material used for aluminum electrolysis
JP2019019353A (en) * 2017-07-13 2019-02-07 株式会社村田製作所 Method for manufacturing ceramic substrate and method for manufacturing power module
CN109695044A (en) * 2018-12-18 2019-04-30 广西师范大学 One kind having even compact TiB2The titanium-based cathode material and preparation method thereof of layer
CN109913815A (en) * 2018-12-21 2019-06-21 北京矿冶科技集团有限公司 A kind of preparation method of adjustable thickness and the boron titanium composite layer of the direction of growth

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101768760A (en) * 2009-11-13 2010-07-07 李庆余 TiB2-TiB/Ti gradient composite porous cathode material for aluminum electrolysis and preparation method thereof
CN102373488A (en) * 2011-10-26 2012-03-14 中国铝业股份有限公司 Method for reducing cathode drop of aluminium cell
CN103469252A (en) * 2013-08-22 2013-12-25 毕和清 Anti-carburizing aluminum electrolytic cathode steel bar
CN204491005U (en) * 2015-01-20 2015-07-22 郑州经纬科技实业有限公司 Electrolytic aluminum cathode collector bar
CN105088277A (en) * 2015-08-27 2015-11-25 江苏联合金陶特种材料科技有限公司 Preparation of TiB2-TiB/Ti gradient composite porous material used for aluminum electrolysis
JP2019019353A (en) * 2017-07-13 2019-02-07 株式会社村田製作所 Method for manufacturing ceramic substrate and method for manufacturing power module
CN109695044A (en) * 2018-12-18 2019-04-30 广西师范大学 One kind having even compact TiB2The titanium-based cathode material and preparation method thereof of layer
CN109913815A (en) * 2018-12-21 2019-06-21 北京矿冶科技集团有限公司 A kind of preparation method of adjustable thickness and the boron titanium composite layer of the direction of growth

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