CN112139754A

CN112139754A - Method for repairing outdoor thin-wall cast iron cultural relics

Info

Publication number: CN112139754A
Application number: CN202011057644.6A
Authority: CN
Inventors: 青义学; 青光绪
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2020-12-29
Anticipated expiration: 2040-09-30
Also published as: CN112139754B

Abstract

The invention discloses a method for repairing outdoor thin-wall cast iron cultural relics, which comprises the preparation of a novel white cast iron repairing material, welding, sealing, repairing and rust-resisting weather-resisting repairing, and belongs to the field of cast iron cultural relic repairing. The welding method has good spreadability, ensures that no hot crack and cold crack are generated after welding, ensures that the welding seam has better strength and rigidity, and can ensure that the original appearance and the original shape of the cultural relic can be restored after finishing, forming and processing by spraying the antirust oil agent.

Description

Method for repairing outdoor thin-wall cast iron cultural relics

Technical Field

The invention belongs to the field of repairing of iron cultural relics, and particularly relates to a method for repairing an outdoor thin-wall cast iron cultural relic.

Background

The technology of smelting and casting has been invented very early in China, the technology of casting in the period of Tang and Song reaches a prosperous period, a craftsman cleverly and wisely masters the technical method of annealing white cast iron, the cast iron is corroded by wind, frost, rain and snow in nearly two thousand years, is not rusted, and still remains dark and bright, for example, the iron warp which is placed before the ancient mountain ancient heaven in Hede City of Hunan province until 80 years of the last century is a thin-wall iron warp which is cast by white pig iron and is chosen by a Hede craftsman. In the 80 s of the last century, the iron cultural relics were damaged to a certain extent due to natural disasters and personal accidents, and in order to enable the damaged iron cultural relics to be continuously appreciated, researched and stored by people, the damaged iron cultural relics must be repaired and restored. However, as nearly ten chemical substances are discharged by a factory near the cast iron cultural relic 40 years ago to corrode the cultural relic, the self anti-rust function of the iron cultural relic is changed, and additionally, the artificially damaged cultural relic fragments reach more than 30 blocks, so that the oxidation trend and the rust speed of the damaged cultural relic are further accelerated, the rust shell is thickened, the corrosion hidden trouble is left for repairing, welding and repairing the iron cultural relic, and the long-term storage of the outdoor thin-wall iron cultural relic is not facilitated. In addition, if the existing cast iron material and the traditional method are adopted for filling and welding, the local filling and welding edges can be cracked because the filling material is not matched with the parent material, and the strength requirement of the joint can not be met. Therefore, it is necessary to research a rust-proof, corrosion-proof and weather-proof sealing material which is matched with the parent material elements of the cultural relics, and a novel welding method to repair the damaged cultural relics and finally restore the original appearance and shape of the cultural relics.

Disclosure of Invention

Aiming at the problems that the chemical element substance contents of the existing cast iron material and the welding parent material are different, and the welding position is subjected to hot cracking and cold cracking after being welded with the parent material by the existing welding technology, the welding position is annealed and thinned, the oxidation path of cast iron is changed, and the oxidation trend accelerates the corrosion reaction speed. Meanwhile, the rust shell is increased and thickened due to rust, secondary damage to the iron cultural relics can be caused, and long-term storage of the cast iron cultural relics is not facilitated.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for repairing the outdoor thin-wall cast iron cultural relics is characterized by comprising the steps of preparing a novel white cast iron repairing material, welding, sealing, protecting, repairing, rust-resisting and weather-resisting repairing, wherein the specific repairing process comprises the following steps:

preparation of novel white cast iron repairing material

Waste white malleable cast iron is used as a base material, the waste base material contains carbon, silicon, manganese, sulfur and phosphorus elements, 0.04kg of copper, 0.06kg of vanadium, 0.04kg of nickel, 0.06kg of aluminum, 0.02kg of cobalt, 0.02kg of zinc and 9.76kg of waste base material are mixed and mixed, then the mixture is put into a graphite tank, melted at 1600 ℃ and poured into a molding sand model, the molding sand is removed after cooling, and the casting sand is calcined and aged at 300 ℃ in an annealing furnace, thus obtaining the novel white cast iron repairing material. Compared with the common white malleable cast iron base material, the material has the advantages that the iron substances such as copper, vanadium, nickel, aluminum, cobalt, zinc and the like are added, and the material has no thermal cracking and cold cracking through a welding test and is approximately the same as the material of damaged cultural relic fragments.

(II) welding, sealing and repairing

Welding in the repairing process is a very important step, namely, the cultural relics and the repairing materials are integrated into a whole through welding at the thin-wall pig iron cracks of the cultural relics, iron wires or wrought iron welding rods are needed to be added during welding to carry out cold welding, as the wrought iron or the iron wires contain elements which can improve the welding performance such as copper, vanadium, nickel, aluminum, cobalt, zinc and the like besides iron and carbon, the iron wires or the copper wires are added or the wrought iron welding rods are adopted to change the ferrite of the welding positions.

Before welding the repair material prepared in the step (one) and the cultural relic parent body, firstly polishing the two side edges of the thin-walled section of the cultural relic parent body, polishing the section into a V-shaped knife edge shape, and then preheating the knife edge-shaped section to ensure that the temperature reaches 300-400 ℃; then cutting the prepared repairing material into a shape matched with the section, fixing a plurality of positions on the edge of the repairing material by spot welding, adding iron wires or wrought iron welding rods into the gap between the repairing material and the repairing material, modulating the voltage by 180V, welding by adopting a welding rod with the model of MG289, relieving the stress by utilizing the principle of ferrite, avoiding various cracks at the welding position, and keeping the welding path smooth and straight. Because of the iron substance of the new elements such as copper, vanadium, nickel, aluminum, cobalt, zinc and the like, the welding part can be rusted and sealed, and can not rust before the cultural relics of the parent body, thereby achieving the purposes of rust resistance and weather resistance.

(III) Rust-resistant weather-resistant repair

a. A corrosion-inhibition weather-resistant antirust oil agent is prepared in advance by adopting natural tung oil and tea oil according to the weight ratio of 9: 1, boiling at 270 ℃, decocting with 200 ℃ medium fire for 10 minutes, and then slowly decocting with 120 ℃ slow fire for 30 minutes to prepare the antirust oil agent.

b. During repair, adding the wire enamel insulating paint into the rust preventive oil prepared in the step a, wherein the mixing ratio of the rust preventive oil to the wire enamel insulating paint is 10: and 1, uniformly stirring, and then spraying and brushing the mixture on the whole outer wall of the parent thin-wall cast iron cultural relic uniformly. The wire enamel is a commercially available product, is not in the protection scope of the invention, and is not described in detail herein.

Through field operation, the common material and the traditional welding method are adopted, stress variation is generated after the welding and cooling of the welding and the parent body, the explosion and thinning are generated, the self-anti-corrosion function is lost, and the requirements of the parent body on the strength of filling materials and welding joints, cultural relic anti-corrosion and anti-corrosion cannot be met. Therefore, a new material ferrite with the same chemical element composition and function as the parent material, a welding technology and an antirust oil agent must be researched to ensure that the welded joint has the same strength and weather resistance as the parent material.

Compared with the prior common welding technology and common solder, the invention has the advantages that: the repairing material of the invention is white malleable cast iron, and adds iron wire or uses a wrought iron welding rod at the welding position of the thin-wall cast iron cultural relic, and matches with C-Si-Mn-S-P-Cu-V-Ni-Al-Co-Zn element material in the welding repairing process, so that ferrite has good welding performance, no thermal cracking and cold cracking are generated when the repairing material is welded with a matrix, a joint has high strength, and the repairing material has no corrosivity to the matrix material of the thin-wall cast iron cultural relic, and the sulfur slag after welding is easy to be removed, thus being particularly suitable for damage, corrosion resistance, rust resistance, sealing protection and repairing of outdoor ancient thin-wall cast iron cultural relics into original appearance, and the concrete reasons are as follows:

1. the cast iron cultural relic filling and repairing material has better corrosion resistance, weldability and weather resistance. The reason is that the problem that the weather resistance of the product is reduced and the product is easy to rust due to the fact that the content of harmful substances such as sulfur is too high is avoided as much as possible in the preparation process of the repair material. In view of this, the content of the metal element in the repair material of the present invention is mainly carbon element, and copper, vanadium, nickel, aluminum, cobalt and zinc elements are added, so that the corrosion-resistant crystal has a weather-resistant function. The metal elements of carbon, silicon, manganese, sulfur, phosphorus, copper, vanadium, nickel, aluminum, cobalt and zinc can enhance the strength and hardness of the repair material so as to form the corrosion resistance of the alloy metal surface, and can be used as a ligand to interact with various metal ions. After the annealing process of warm aging in a annealing furnace, the corrosion-resistant crystal ferrite alloy with high strength is generated, so as to achieve the purpose of corrosion inhibition, weather resistance and rust resistance.

2. The repairing material has the same chemical components and materials as the parent elements of the cultural relics, has good mechanical property, is weather-proof and resists the erosion of the natural environment, ensures that the repairing material is not oxidized, hot cracked or cold cracked in the heating and welding processes so as to improve the formation of the welding line of the welding contact surface of the newly added parent material and ensure that the melting point and the lowest active temperature of the welded objects are slightly lower than the melting temperature of the welding rods. Compared with a plurality of welding tests, the welding position of the parent body and the added and supplemented novel material has no phenomena of obvious thinning, hot cracking and cold cracking, the effect is obvious, and various requirements in the aspect of cultural relic protection are met.

3. The welding method has good spreadability, ensures that no hot crack and cold crack (stress) are generated after welding, ensures that the welding seam has better strength and rigidity, and can ensure that the original appearance and the original shape of the cultural relic can be recovered by spraying the antirust oil agent after finishing and forming. After the strength destructive contrast test and the repair, the technical requirements of the cultural relic protection of the cast iron thin-wall cultural relic are met.

4. The rust-resisting and rust-preventing oil agent has weather resistance, and before construction, a certain proportion of insulating paint for enameled wires is added, and after stirring, the insulating paint is coated to form integral sealing, protecting and corrosion inhibiting, so that the purposes of rust resistance, rust prevention and weather resistance are achieved, and the original appearance of cultural relics is ensured to be restored. Through the acid-etching freeze-thaw repeated destructive contrast test, the cast iron thin-wall cultural relic temple ancient clock and the like coated with the antirust oil agent meet various technical requirements of cultural relic protection of the cast iron thin-wall cultural relic.

5. The novel material, welding, sealing, weather-proof and rust-proof technical means of the invention can be restored into a complete iron book which can be provided for people to view, study and weather-proof protect the cast iron cultural relics. When the tung oil and the tea oil are matched and boiled, according to the weather holding and batching technique, the anti-rust oil prepared by special boiling and construction through the experiences of hearing and watching the duration of heat, oil temperature change, hand stirring and the like of an inventor during oil boiling has the characteristics of high temperature resistance, strong adhesive force, acid resistance, alkali resistance, corrosion resistance, water resistance, anti-rust function and the like compared with the tung oil boiled by the traditional method, and the anti-rust oil is typical quick drying oil and has better hardness and gloss after film forming.

Detailed Description

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

Example (b):

a method for repairing outdoor thin-wall cast iron cultural relics comprises the steps of preparing a novel white cast iron repairing material, welding, sealing, protecting, repairing, rust-resisting and weather-resisting repairing, wherein the specific repairing process comprises the following steps:

preparation of novel white cast iron repairing material

Waste white malleable cast iron is used as a base material, the waste base material contains carbon, silicon, manganese, sulfur and phosphorus elements, 0.04kg of copper, 0.06kg of vanadium, 0.04kg of nickel, 0.06kg of aluminum, 0.02kg of cobalt, 0.02kg of zinc and 9.76kg of waste base material are mixed and mixed, then the mixture is put into a graphite tank, melted at 1600 ℃ and poured into a molding sand model, the molding sand is removed after cooling, and the casting sand is calcined and aged at 300 ℃ in an annealing furnace, thus obtaining the novel white cast iron repairing material.

(II) welding, sealing and repairing

The welding in the repairing process is a very important step, namely, the cultural relics and the repairing materials are integrated into a whole by welding at the thin-wall pig iron crack of the cultural relics, iron wires need to be added to the pig iron welding rods or cooked iron welding rods are adopted to carry out cold welding during the welding, the cooked iron or the iron wires contain elements which can improve the welding performance such as copper, vanadium, nickel, aluminum, cobalt, zinc and the like besides iron and carbon, and the iron wires or the copper wires are added or the cooked iron welding rods are adopted to change the quality of the ferrite at the welding position.

Before welding the repair material prepared in the step (one) and the cultural relic parent body, firstly polishing the two side edges of the thin-walled section of the cultural relic parent body, polishing the section into a V-shaped knife edge shape, and then preheating the knife edge-shaped section to ensure that the temperature reaches 300-400 ℃; then cutting the prepared repairing material into a shape matched with the section, fixing a plurality of positions on the edge of the repairing material by spot welding, adding iron wires or wrought iron welding rods into the gap between the repairing material and the repairing material, modulating the voltage by 180V, welding by adopting a welding rod with the model of MG289, and utilizing the principle that the stress is relieved by using the ferrite, so that various explosive cracks can not appear at the welding position, and the welding path is kept smooth and straight. Because of the iron substance of the new elements such as copper, vanadium, nickel, aluminum, cobalt, zinc and the like, the welding part can be rusted and sealed, and can not rust before the cultural relics of the parent body, thereby achieving the purposes of rust resistance and weather resistance.

(III) Rust-resistant weather-resistant repair

b. During repair, adding the wire enamel insulating paint into the rust preventive oil prepared in the step a, wherein the mixing ratio of the rust preventive oil to the wire enamel insulating paint is 10: and 1, uniformly stirring, and then spraying and brushing the mixture on the whole outer wall of the parent thin-wall cast iron cultural relic uniformly.

The novel white cast iron repairing material is subjected to destructive detection with the existing white cast iron material, and the detection process is as follows:

a first detection product: white cast iron

According to the national KTB400-05 trade mark carbon, silicon, manganese, sulphur, phosphorus, wherein according to the content of each component of mass percent: 3.4 percent of carbon, 1.8 percent of silicon, 0.6 percent of manganese, less than or equal to 0.1 percent of phosphorus, less than or equal to 0.2 percent of sulfur and the balance of iron wire impurities. Firstly, weighing and stacking carbon, silicon, manganese, phosphorus and sulfur together according to mass percent by using a balance, putting the mixture into a graphite tank, and naturally and fully mixing the mixture after the mixture is dissolved to obtain the white cast iron.

And (5) detection product II: the invention relates to a novel white cast iron material.

1. Material comparison experiments were as follows:

the white cast iron and the novel white cast iron are respectively subjected to conventional annealing treatment, and the white cast iron is subjected to explosion cracking and cold cracking during welding, so that the requirements of outdoor thin-wall iron cultural relics in millennium ancient times cannot be met. The novel white malleable cast iron has good strength, hardness and weldability through destructive tests.

2. The corrosion resistance test is as follows:

respectively soaking white cast iron and the novel white cast iron in a 10% low-content hydrochloric acid solution for 168 hours, and naturally drying, wherein the surface color of the white cast iron is obviously changed, and the surface of the white cast iron has obvious rust; the surface of the novel white cast iron has no color change, and the surface of the cast iron has no rust.

Experimental results show that the novel white cast iron obviously has an anti-corrosion effect, and the key point is that the antique thin-wall iron cultural relics are repaired to be successful or not.

3. The weld strength test was as follows:

taking white cast iron and the novel white cast iron, and respectively carrying out hot welding and cold welding, wherein hot welding electrodes adopt MG289 and MG210 pig iron electrodes or pig iron electrodes and iron wires; the cold welding electrode adopts a Wei-European WE-777 cold welding cast iron electrode or a wrought iron electrode, after welding is finished, destructive experiments are carried out on the welding joint, and after checking, the welding joint of the novel white thin-wall cast iron is safe and innoxious, and the welding joint of the white cast iron has destructive traces.

Experimental results show that the novel white cast iron has relatively high welding strength.

4. The iron cultural relic scrap experiment is as follows:

a. comparison of two pig iron welding

MG289 pig iron welding rod for pig iron welding is used for welding standard white thin-wall cast iron scraps and novel white thin-wall cast iron scraps by adding iron wires or wrought iron welding rods, one group is respectively selected, and the welding performance comparison is carried out on the edge seams of the thin-wall cast iron scraps by using a repairing method.

From two groups of welding results, the novel white thin-wall cast iron is added with iron wires or a wrought iron welding rod, the molten iron fluidity of a welding seam is good in comparison with that of the standard white thin-wall cast iron in the welding process, the operation hand feeling and the molten iron solidification time of the welding seam have no obvious difference, but the sulfur slag at the welding joint of the novel white thin-wall cast iron is removed and is kept dark, bright and straight. When the welding joint of the white cast iron is welded, the welding joint has explosive sound and cracks, two sides of the welding joint obviously shrink and become thin, and cold cracks appear.

b. Post-weld alternating humidification test

The welded thin-wall malleable cast iron scraps cannot be subjected to energy spectrum chemical structure analysis, and the relative standards of malleable cast iron are not established in China, so reference cannot be made.

c. Thin-wall iron cultural relic residue immersion corrosion contrast test

Cutting a malleable cast iron scrap into two sections, grinding the surface oxide of the novel white thin-wall cast iron section, respectively soaking the malleable cast iron scrap section and the novel white thin-wall cast iron section in 10 percent low-content hydrochloric acid solution for 24 hours, taking out, and then placing at normal temperature to observe the surface change of the two sections of hanging pieces.

And (4) conclusion: the section of the malleable cast iron scraps soaked in the 10 percent low-content hydrochloric acid solution is taken out after 24 hours, obvious corrosion change phenomena appear, and corrosion aggravates changes along with the time extension.

5. The comparative experiment of the rust-preventive oil agent of the invention is as follows:

raw tung oil, boiled tung oil decocted by a traditional method and the antirust oil agent are respectively coated on the cast iron scraps, and then repeated freeze thawing corrosion resistance weather resistance tests are respectively carried out for twenty times, the raw tung oil coated cast iron scraps begin to rust for ten times, and the boiled tung oil coated cast iron scraps begin to rust for eighteen times, so that all the requirements of outdoor thin-wall iron cultural relics protection in the past millennium cannot be met. After the antirust oil agent is coated, the freeze-thaw resistance and corrosion resistance test and the weather resistance performance of the antirust oil agent are good, the weather resistance of outdoor thin-wall iron cultural relics in thousands years in ancient times can be met, and various requirements of iron cultural relic protection are met.

Claims

1. The method for repairing the outdoor thin-wall cast iron cultural relics is characterized by comprising the steps of preparing a novel white cast iron repairing material, welding, sealing, protecting, repairing, rust-resisting and weather-resisting repairing, wherein the specific repairing process comprises the following steps:

preparation of novel white cast iron repairing material

Waste white malleable cast iron is used as a base material, the waste base material contains carbon, silicon, manganese, sulfur and phosphorus elements, 0.04kg of copper, 0.06kg of vanadium, 0.04kg of nickel, 0.06kg of aluminum, 0.02kg of cobalt, 0.02kg of zinc and 9.76kg of waste base material are mixed and mixed, then the mixture is put into a graphite tank, the mixture is melted at a high temperature of 1600 ℃, melted molten iron is poured into a molding sand model, the molding sand is removed after cooling, and the casting sand is calcined and aged by a smoldering furnace, so that the novel white malleable cast iron repairing material is obtained;

(II) welding, sealing and repairing

Before welding the repair material prepared in the step (one) and the cultural relic parent body, firstly polishing the two side edges of the thin-walled section of the cultural relic parent body, polishing the section into a V-shaped knife edge shape, and then preheating the knife edge-shaped section to ensure that the temperature reaches 300-400 ℃; then cutting the prepared repairing material into a shape matched with the section, fixing a plurality of positions on the edge of the repairing material by spot welding, adding iron wires into a gap between the repairing material and the gap by using a pig iron welding rod or a wrought iron welding rod for welding, and using the principle that the stress is relieved by using the ferrite, so that cracks do not occur at the welding position, and the welding path is kept smooth and straight;

(III) Rust-resistant weather-resistant repair

a. Preparing a corrosion-inhibition weather-resistant antirust oil agent in advance, wherein the antirust oil agent is prepared by mixing natural tung oil and tea oil, boiling at a high temperature of 270 ℃, decocting with medium fire at 200 ℃, and decocting with slow fire at 120 ℃;

b. and d, during repair, adding the wire enamel insulating paint into the anti-rust oil prepared in the step a, uniformly stirring, spraying and brushing the wire enamel insulating paint on the whole outer wall of the parent thin-wall cast iron cultural relic, and uniformly spraying and brushing the wire enamel insulating paint.

2. The method for repairing an outdoor thin-walled cast iron cultural relic, which is characterized in that the temperature of the annealing furnace in the step (I) is 300 ℃.

3. The method for repairing outdoor thin-walled cast iron cultural relics, which is characterized in that the welding voltage in the step (two) is 180V.

4. The method for repairing outdoor thin-wall cast iron cultural relics as claimed in claim 1, wherein the tung oil and the tea oil in the step (three) are mixed according to the weight ratio of 9: 1, mixing the components according to the proportion of 1.

5. The method for repairing outdoor thin-walled cast iron cultural relics, according to claim 1 or 4, wherein in the step (three), the medium fire boiling time of the mixture of the tung oil and the tea oil is 10 minutes, and the line fire boiling time is 30 minutes.

6. The method for repairing outdoor thin-walled cast iron cultural relics, according to claim 5, wherein the mixing ratio of the rust preventive oiling agent to the wire enamel in the step (three) is 10: 1.