阅读说明：本技术 一种桥梁支座渗铝的方法 (Method for aluminizing bridge support ) 是由 张启祥 王超凡 于玉成 吕娜 姚帆 张英虹 范兴平 于 2019-08-14 设计创作，主要内容包括：本发明提供了一种桥梁支座渗铝的方法,涉及桥梁、建筑支座技术领域。方法包括：对桥梁支座进行除锈和清洗除油,其中,用NaOH水溶液和热水对桥梁支座交替清洗、除油；对所述桥梁支座进行助渗,其中,采用KF水溶液作为助渗液；进行熔铝,其中,熔铝时,首先,把铝锭在200℃～500℃保温预设时间,然后,在铝锭的表面覆盖熔融剂；对所述桥梁支座进行热浸渗铝；对所述桥梁支座进行渗后处理,其中,用水冲洗粘附在所述桥梁支座表面上的所述熔融剂。方该法可以有效控制渗铝层的厚度、缩短整个渗铝工艺周期、取消渗铝铝液中稀有金属、减少环境污染,同时使球冠和滑动面耐磨、且摩擦系数小。(The invention provides a method for aluminizing a bridge support, and relates to the technical field of bridges and building supports. The method comprises the following steps: carrying out rust removal, cleaning and oil removal on the bridge support, wherein the bridge support is alternately cleaned and deoiled by using NaOH aqueous solution and hot water; carrying out seepage assistance on the bridge support, wherein KF aqueous solution is adopted as seepage assistance liquid; melting aluminum, wherein during melting aluminum, firstly, an aluminum ingot is kept at the temperature of 200-500 ℃ for a preset time, and then, a melting agent is covered on the surface of the aluminum ingot; hot dip aluminizing the bridge support; and carrying out infiltration post-treatment on the bridge bearing, wherein the fusing agent adhered to the surface of the bridge bearing is washed by water. The method can effectively control the thickness of the aluminized layer, shorten the whole aluminizing process period, eliminate rare metals in aluminized aluminum liquid, reduce environmental pollution, and simultaneously ensure that the spherical crown and the sliding surface are wear-resistant and have small friction coefficient.)

1. A method for aluminizing a bridge support is characterized by comprising the following steps:

derusting the bridge support, wherein a rust layer of the bridge support is removed in a sand blasting or shot blasting manner;

cleaning and deoiling the bridge support, wherein the bridge support is alternately cleaned and deoiled by using NaOH aqueous solution and hot water;

carrying out seepage assistance on the bridge support, wherein KF aqueous solution is adopted as seepage assistance liquid;

melting aluminum, wherein during melting aluminum, firstly, an aluminum ingot is kept at the temperature of 200-500 ℃ for a preset time, and then, a melting agent is covered on the surface of the aluminum ingot;

hot dip aluminizing the bridge support;

and carrying out infiltration post-treatment on the bridge bearing, wherein the fusing agent adhered to the surface of the bridge bearing is washed by water.

2. The method for aluminizing a bridge support according to claim 1, wherein the mass fraction of KF in the aqueous solution of KF is 6%.

3. The method for aluminizing a bridge bearer according to claim 1, wherein the compounding ratio of the melting agent is 47% NaCl + 47% KCl + 6% KF.

4. The method of aluminizing a bridge support according to claim 3, wherein the step of coating the surface of the aluminum ingot with the melting agent comprises:

preserving the heat for 0.5h at the temperature of 200-500 ℃;

and adjusting the furnace temperature to 850 ℃, and keeping the temperature until the aluminum is completely melted and the melting temperature is stable.

5. The method of claim 1, wherein the hot dip aluminizing is performed at a temperature of 750 ℃ for 5 min.

6. The method of claim 1, wherein the bridge bearer after being subjected to the post-cementation treatment comprises:

and grinding and polishing the spherical cap or the sliding plate, wherein an aluminum layer on the surface of the spherical cap or the sliding plate after aluminizing is removed, and the surface is ground and polished.

7. The method of aluminizing a bridge support according to claim 6, wherein the surface of the spherical cap or the sliding plate is ground and polished to a surface roughness of 0.1 μm.

8. The method of claim 1, wherein the cleaning and de-oiling the bridge bearer comprises:

vibrating and washing the bridge support in NaOH aqueous solution;

brushing the bridge support with hot water at 70-80 ℃;

in the presence of NaOH and Na₂CO₃、Na₃PO₄、Na₂SiO₃The bridge support is finely washed in the alkali liquor, wherein the temperature of the alkali liquor is 45-60 ℃, and the time is 10-20 min;

and (3) putting the bridge support into hot water at the temperature of 70-80 ℃ for cleaning, taking out and drying.

9. The method for aluminizing a bridge support according to claim 8, wherein the concentration of NaOH in the NaOH aqueous solution is 4 mol/L.

10. The method for aluminizing bridge supports according to claim 8, wherein the concentration of NaOH in the alkaline solution is 80g/L, Na₂CO₃Has a concentration of 30g/L, Na₃PO₄Has a concentration of 30g/L, Na₂SiO₃The concentration of (2) is 8 g/L.

Technical Field

The invention relates to the technical field of bridge and building supports, in particular to a method for aluminizing a bridge support.

Background

The spherical steel support serves as an important component in the field of bridges and buildings, on one hand, plays a role in supporting the load of an upper structure, and on the other hand, sensitively transmits the load and deformation of the upper structure to a lower structure. The spherical steel support usually comprises an upper support plate, a lower support plate and a spherical crown positioned between the upper support plate and the lower support plate, wherein the convex surface of the spherical crown is in spherical surface fit with the bottom surface of the upper support plate to form a rotary friction pair to bear the rotary function of the bridge support; the bottom surface of the spherical crown is in plane fit with the top surface of the lower support plate to form a sliding friction pair, and the sliding function of the bridge support is borne. The two groups of friction pairs need higher wear resistance, smaller roughness and friction coefficient in the working process.

In order to enable the two groups of friction pairs to sensitively transmit the rotation and displacement of the bridge structure, the domestic related railway and highway standards are regulated, and two modes of stainless steel plates or chrome plating are welded on the convex spherical surface of the spherical crown and the top surface of the lower support plate. In actual operation, the stainless steel plate coated with the spherical crown needs to be pressed into a corresponding spherical shape (the size of the tool is slightly smaller than the spherical size of the spherical crown) through a spherical tool, then the spherical stainless steel plate is placed on the spherical crown, and the spherical stainless steel plate and the spherical crown are combined in a pressurizing and welding mode. The process pressurizes the stainless steel plate for many times, so that the wear resistance and the surface smoothness of the mirror surface stainless steel plate are greatly reduced, and meanwhile, the stainless steel plate has parts which cannot be tightly attached and are internally hollow in the process of combining with the spherical crown, so that the wear resistance of the spherical crown is also reduced. The wear resistance of the spherical crown can be improved by the chromium plating mode on the surface of the spherical crown, and a smaller friction coefficient can be ensured after polishing, but the process has a longer processing period, and the plating layer is uneven, easy to fall off and has great environmental pollution.

The invention patent application of publication No. CN105970198A discloses a process for increasing the wear resistance of a spherical crown by adopting a multi-element alloy plating layer, and the process also has the problems of complex process, long processing period and great environmental pollution.

The hot dipping and aluminizing process for steel products is a physical and chemical process, solid steel products are placed in liquid aluminum liquid, and physical diffusion and chemical action among different elements occur simultaneously between the surface of the steel products and the liquid aluminum through physical processes such as mutual adsorption, infiltration, dissolution and the like. During diffusion, Fe-Al intermetallic compound with high aluminum content is formed at the interface of the surface layer and the alloy layer, such as FeAl phase and FeAl phase₂Phase, finally form Fe₂Al₅Thereby improving the self corrosion resistance, high temperature oxidation resistance and wear resistance of the steel.

The current, more mature technology combined with product application is the hot dip aluminizing process, which has several problems that are common: 1. the aluminizing pretreatment process uses an acid pickling process; 2. the aluminizing pretreatment process is various; 3. the permeation-assistant agent consists of a plurality of permeation-assistant agents and has complex components; 4. the aluminizing time is long (1-2 hours), or zinc, lead, rare earth and other components are added into the aluminum liquid as an auxiliary to shorten the aluminizing time. Some of the factors cause serious pollution to the environment, some prolong the production period of products, and some increase the aluminizing cost, thereby restricting the development of the aluminizing technology and the large-scale popularization and application of the aluminizing technology in various industries.

A rapid hot aluminizing process for steel parts, a rapid composite aluminizing process, an aluminized steel and a preparation method thereof, and an aluminized highway guardrail and a preparation method thereof are all processes for achieving low-temperature rapid aluminizing by acid pickling, multi-component plating assistant, current heating, and addition of rare metals such as cerium, lanthanum, antimony and the like or lead into molten aluminum. The Q235 aluminized steel and the preparation method thereof are beneficial to environmental protection through multicomponent alkali washing, but have long infiltration assisting time and aluminizing time.

Disclosure of Invention

The invention aims to provide a method for aluminizing a bridge support, which can effectively control the thickness of an aluminized layer, shorten the whole aluminizing process period, cancel rare metals in aluminized aluminum liquid, reduce environmental pollution, and simultaneously ensure that a spherical crown and a sliding surface are wear-resistant and have small friction coefficient.

The invention provides a technical scheme that:

the method for aluminizing the bridge bearing comprises the following steps:

derusting the bridge support, wherein a rust layer of the bridge support is removed in a sand blasting or shot blasting manner;

cleaning and deoiling the bridge support, wherein the bridge support is alternately cleaned and deoiled by using NaOH aqueous solution and hot water;

carrying out seepage assistance on the bridge support, wherein KF aqueous solution is adopted as seepage assistance liquid;

melting aluminum, wherein during melting aluminum, firstly, an aluminum ingot is kept at the temperature of 200-500 ℃ for a preset time, and then, a melting agent is covered on the surface of the aluminum ingot;

hot dip aluminizing the bridge support;

and carrying out infiltration post-treatment on the bridge bearing, wherein the fusing agent adhered to the surface of the bridge bearing is washed by water.

Further, in the KF aqueous solution, the mass fraction of KF is 6%.

Further, the proportion of the melting agent is 47% of NaCl, 47% of KCl and 6% of KF.

Further, after the surface of the aluminum ingot is covered with the melting agent, the method comprises the following steps:

preserving the heat for 0.5h at the temperature of 200-500 ℃;

and adjusting the furnace temperature to 850 ℃, and keeping the temperature until the aluminum is completely melted and the melting temperature is stable.

Further, the temperature of the hot dip aluminizing is 750 ℃ for 5 min.

Further, after the post-infiltration treatment is performed on the bridge bearing, the method includes:

and grinding and polishing the spherical cap or the sliding plate, wherein an aluminum layer on the surface of the spherical cap or the sliding plate after aluminizing is removed, and the surface is ground and polished.

Further, the surface of the spherical cap or the sliding plate is ground and polished to a surface roughness of 0.1 μm.

Further, the cleaning and oil removing of the bridge support comprises:

vibrating and washing the bridge support in NaOH aqueous solution;

brushing the bridge support with hot water at 70-80 ℃;

in the presence of NaOH and Na₂CO₃、Na₃PO₄、Na₂SiO₃The bridge support is finely washed in the alkali liquor, wherein the temperature of the alkali liquor is 45-60 ℃, and the time is 10-20 min;

and (3) putting the bridge support into hot water at the temperature of 70-80 ℃ for cleaning, taking out and drying.

Further, the concentration of NaOH in the NaOH aqueous solution is 4 mol/L.

Further, the concentration of NaOH in the alkali liquor is 80g/L, Na₂CO₃Has a concentration of 30g/L, Na₃PO₄Has a concentration of 30g/L, Na₂SiO₃The concentration of (2) is 8 g/L.

The method for aluminizing the bridge support provided by the invention has the beneficial effects that:

1. the invention adopts a mechanical and chemical combination method to remove rust, clean and remove oil, is suitable for rust of various degrees, and is more energy-saving and more environment-friendly by firstly carrying out sand blasting and mechanical rust removal on a workpiece with a thicker rust layer and then alternately washing by alkali liquor and hot water.

2. The formula of the invention adopts KF aqueous solution as the infiltration-assisting solution to protect the workpiece from secondary oxidation after rust and oil removal treatment, and simultaneously improve the wettability between steel or a spherical crown matrix and molten aluminum, provide a good matrix for the growth of an aluminized layer and shorten the aluminizing time.

3. The invention adopts pure aluminum as the aluminized liquid, and the surface of the aluminum ingot is added with the fusing agent during aluminizing, thereby saving energy and reducing the aluminizing cost because other metal components are not added and the impurities generated by the aluminum liquid are reduced.

4. The method for aluminizing production has the advantages of short whole process period, high efficiency, low energy consumption, low cost, environmental protection and easy realization of large-scale and profitable industrial production.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a flowchart of a method for aluminizing a bridge support according to a first embodiment of the present invention.

FIG. 2 is a surface topography analysis of an aluminized spherical cap or slip sheet by SEM scanning electron microscopy.

FIG. 3 is an SEM scan electron microscope analysis of the composition of the transition layer image of an aluminized spherical cap or slip sheet.

Fig. 4 is a flowchart of a bridge bearer aluminizing method according to a second embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like, indicate orientations or positional relationships that are based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships that the products of the present invention conventionally put into use, or the orientations or positional relationships that the persons skilled in the art conventionally understand, are only used for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the equipment or elements referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

First embodiment

Referring to fig. 1, the present embodiment provides a method for aluminizing a bridge support, which is mainly used for aluminizing a spherical cap or a sliding plate. The method comprises the following steps:

s1: derusting spherical crown or sliding plate

Specifically, the rust layer of the spherical cap or the sliding plate is removed by sand blasting or shot blasting.

S2: cleaning and degreasing the spherical crown or the sliding plate

Firstly, the spherical cap or the sliding plate is washed or scrubbed by vibration in 4mol/L NaOH aqueous solution, then scrubbed by hot water at 70-80 ℃, and finally scrubbed in80g/L NaOH, 30g/L Na₂CO₃30g/L of Na₃PO₄8g/L of Na₂SiO₃The alkali liquor is finely washed, the temperature of the alkali liquor is 45-60 ℃, the time is 10-20 min, finally, the spherical crown or the sliding plate is put into hot water of 70-80 ℃ for washing, and the spherical crown or the sliding plate is taken out and dried.

S3: to assist the penetration of the spherical crown or sliding plate

Specifically, the spherical crown or the sliding plate is put into a permeation-assisting liquid with mass fraction of 6% of KF, the permeation is assisted for about 5min, and the spherical crown or the sliding plate is taken out and dried by hot air.

S4: carrying out aluminum melting

Firstly, putting an aluminum ingot into a melting furnace, covering a layer of 1% aluminum ingot quality melting agent on the surface, wherein the ratio of the melting agent is 47% NaCl, 47% KCl and 6% KF, then, preserving heat for 0.5h at 200-500 ℃, finally, adjusting the furnace temperature to 850 ℃, preserving heat for 3h, and preserving heat for later use when the aluminum is completely melted and the melting temperature reaches stability.

It is readily understood that S4 need not necessarily be sequentially linked to S1-S3, so long as S4 is guaranteed to precede S5.

S5: hot dip aluminizing of spherical caps or sliding plates

Specifically, scum on the surface of the smelting furnace is removed, aluminum liquid is transferred into an aluminizing pool, the temperature of the aluminum liquid is kept at 750 ℃, a spherical crown or a sliding plate is placed into the aluminum pool, and the aluminum liquid is rapidly taken out after being kept for 5 min.

S6: the spherical crown or the sliding plate is subjected to infiltration post-treatment

Specifically, the melting agent adhering to the surface of the spherical cap or the sliding plate is washed with water.

S7: grinding and polishing the spherical crown or the sliding plate

Specifically, the aluminum layer of the convex spherical surface of the calorized spherical cap or the sliding surface of the sliding plate is removed, and the surface is polished to a surface roughness of 0.1 μm.

Referring to fig. 2 and fig. 3, after the spherical cap or the sliding plate is aluminized by the method of the present embodiment, it can be seen by SEM scanning electron microscope that the structure of the transition layer between the surface of the spherical cap or the sliding plate and the aluminized layer is fine and has no voids, and the transition layer is in the shape of an obvious irregular single-tooth column and grows into the steel matrix perpendicular to the interface.

Second embodiment

Referring to fig. 4, the present embodiment provides a method for aluminizing a bridge support, which is mainly used for aluminizing an upper support plate or a lower support plate. The method comprises the following steps:

s10: derusting an upper or lower support plate

Specifically, the rust layer of the upper support plate or the lower support plate is removed in a sand blasting or shot blasting mode.

S20: cleaning and degreasing the upper support plate or the lower support plate

Firstly, the upper support plate or the lower support plate is washed or scrubbed in 4mol/L NaOH aqueous solution by vibration, then scrubbed by hot water at 70-80 ℃, and then scrubbed by 80g/L NaOH and 30g/L Na₂CO₃30g/L of Na₃PO₄8g/L of Na₂SiO₃The alkali liquor is finely washed, the temperature of the alkali liquor is 45-60 ℃, the time is 10-20 min, and finally the upper support plate or the lower support plate is put into hot water of 70-80 ℃ for washing and is taken out for drying.

S30: to the upper support plate or the lower support plate

Specifically, the upper support plate or the lower support plate is placed into a permeation assisting liquid with mass fraction of 6% of KF, permeation assisting is carried out for about 5min, and then the upper support plate or the lower support plate is taken out and dried by hot air.

S40: carrying out aluminum melting

Firstly, putting an aluminum ingot into a melting furnace, covering a layer of 1% aluminum ingot quality melting agent on the surface, wherein the ratio of the melting agent is 47% NaCl, 47% KCl and 6% KF, then, preserving heat for 0.5h at 200-500 ℃, finally, adjusting the furnace temperature to 850 ℃, preserving heat for 3h, and preserving heat for later use when the aluminum is completely melted and the melting temperature reaches stability.

S50: hot dip aluminizing an upper support plate or a lower support plate

Specifically, scum on the surface of the smelting furnace is removed, aluminum liquid is transferred into an aluminizing pool, the temperature of the aluminum liquid is kept at 750 ℃, an upper support plate or a lower support plate is placed into the aluminum pool, and the aluminum liquid is rapidly taken out after being kept for 5 min.

S60: performing infiltration post-treatment on the upper support plate or the lower support plate

Specifically, the melting agent adhered to the surface of the upper or lower seat plate is washed with water.

It can be seen from the first and second embodiments that the aluminizing methods for the spherical cap, the sliding plate, the upper support plate and the lower support plate are basically the same, and the aluminizing for the bridge support can be completed by adopting the method for aluminizing the bridge support provided by the invention.

The method for aluminizing the bridge support has the beneficial effects that:

1. the invention adopts a mechanical and chemical combination method to remove rust, clean and remove oil, is suitable for rust of various degrees, and is more energy-saving and more environment-friendly by firstly carrying out sand blasting and mechanical rust removal on a workpiece with a thicker rust layer and then alternately washing by alkali liquor and hot water.

2. The formula of the invention is that KF aqueous solution with the mass fraction of 6% is used as infiltration-assisting liquid, the infiltration-assisting time is 5min, so as to protect the workpiece from secondary oxidation after rust removal and oil removal treatment, improve the infiltration between the sliding plate or spherical crown and the aluminum liquid, provide a good matrix for the growth of an aluminized layer and shorten the aluminizing time.

3. The invention adopts pure aluminum as the aluminizing liquid, and the surface of the aluminum ingot is added with the fusing agent with the proportion of 47 percent NaCl, 47 percent KCl and 6 percent KF during aluminizing, thereby saving energy and reducing the aluminizing cost because other metal components are not added and the impurities generated by the aluminum liquid are reduced.

4. The rapid aluminizing process at 750 ℃ for 5min adopted by the invention can rapidly generate Fe on the surface of steel or spherical cap₂Al₅The compound, the compound and the steel substrate are tightly combined, the surface hardness can reach 694HV, the thickness reaches more than 151 mu m, and the wear resistance and the corrosion resistance of the surface of the sliding plate or the spherical cap are greatly improved.

5. The method for aluminizing production has the advantages of short whole process period, high efficiency, low energy consumption, low cost, environmental protection and easy realization of large-scale and profitable industrial production.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.