Low-oxygen and low-humidity storage treatment method for metal cultural relics

Abstract

The invention relates to a low-oxygen and low-humidity storage treatment method for metal cultural relics, which is characterized by comprising the following steps: pretreating the surfaces of the metal cultural relics, storing the metal cultural relics in an enclosure structure, and forming a stable, low-humidity and low-oxygen protection storage environment in the enclosure structure through controlled atmosphere; the exhibition and storage environment is adjusted to be within the range of the relative humidity and the oxygen content suitable for storing the metal cultural relics in a mode of combining active adjustment and passive adjustment, the range of the relative humidity is smaller than or equal to 30%, and the range of the oxygen content is 0.1%-5%; wherein the enclosure structure is sealed, and the storage environment of the metal cultural relics is maintained within a suitable range; wherein when the value of the relative humidity and the value of the oxygen content are determined, an iron test piece is used for replacing a metal cultural relic to simulate a storage experiment. Through the application, the range of the relative humidity and the oxygen content suitable for the long-term storage environment of the metal cultural relics can be determined, the determined parameter range is accurate and reliable, and the long-term proper preservation of the metal cultural relics is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of metal anti-corrosion, in particular to a metal storage method, and in particular to a low-oxygen and low-humidity storage and treatment method for metal cultural relics. Background Art

[0002] The diseases of metal cultural relics are mainly caused by oxygen and water. Although metal cultural relics can be well protected if they are stored in extremely low oxygen content and extremely dry space, it takes a lot of resources to maintain such an extreme environment. After research, it was found that when the relative humidity and oxygen content are maintained within a certain range, the metal stored inside can also be protected from corrosion. Compared with the aforementioned extreme environment, this situation can save a lot of maintenance resources.

[0003] However, the current focus of research on the protection of metal cultural relics is mainly on the impact of humidity on metal cultural relics, while there is still a certain gap in the research on the effect of oxygen on metal cultural relics. In addition, in domestic research on the use of active and / or passive methods to control the micro-environment in the display cabinet, the control target of relative humidity is generally concentrated on medium relative humidity (relative humidity is 40%-60%), and there is no in-depth research on whether the micro-environment with a relative humidity below 30% is suitable for the protection of metal cultural relics.

[0004] Therefore, it is a technical problem that needs to be solved urgently to study the appropriate range of relative humidity and oxygen content in a low-humidity and low-oxygen microenvironment suitable for storing metal artifacts. Summary of the invention

[0005] In view of the technical problems existing in the prior art, the present invention proposes a low-oxygen and low-humidity storage and treatment method for metal cultural relics. The method comprises: Step 1: pre-treating the surface of the metal cultural relics, removing the surface attachments, and storing the metal cultural relics in a protective structure, wherein the interior of the protective structure is gas-conditioned to form a stable, low-humidity, low-oxygen protective storage environment; Step 2: adjusting the storage environment in the protective structure to a relative humidity and oxygen content range suitable for storing metal cultural relics by combining active and passive regulation, wherein the relative humidity range is less than or equal to 30%, and the oxygen content range is 0.1%-5%; Step 3: sealing the protective structure and maintaining the storage environment of the metal cultural relics within a suitable range; wherein, when determining the relative humidity value and the oxygen content value, an iron test piece is used instead of the metal cultural relics to conduct a simulated storage experiment, comprising the following steps: first, pre-treating the multiple iron test pieces to be tested, and placing Among the multiple enclosures, each enclosure contains multiple iron test pieces; secondly, different controlled atmosphere experimental conditions are set for each enclosure, and the controlled atmosphere experimental conditions include a combination of controlled atmosphere parameters including relative humidity parameter values ​​and oxygen content parameter values; thirdly, according to the set controlled atmosphere experimental conditions, the relative humidity and oxygen content in the multiple enclosures are regulated by combining active and passive regulation to form different storage environments inside different enclosures; wherein, silica gel particles are placed in the enclosures corresponding to RH≤10% and RH≤20% as passive humidity-regulating consumables; finally, all the enclosures are sealed and the controlled atmosphere experimental conditions are maintained, and after a preset period of time, the range of relative humidity and oxygen content suitable for storing metal cultural relics is determined based on the morphological changes and weight changes of the iron test pieces in each enclosure.

[0006] According to an embodiment of the present application, optionally, the relative humidity parameter value RH is a plurality of set values ​​between a first value and a second value, the first value ranges from 5% to 15%, and the second value ranges from 15% to 30%.

[0007] According to an embodiment of the present application, optionally, the relative humidity parameter value RH is one of the following: RH≤10%, RH≤20%, RH≤30%, preferably RH≤20%, and more preferably RH≤10%.

[0008] According to an embodiment of the present application, optionally, the oxygen content parameter value OX is a plurality of set values ​​between a third value and a fourth value, the third value has a value range of 0.1% to 0.5%, and the fourth value has a value range of 2% to 21%.

[0009] According to an embodiment of the present application, optionally, the ranges of relative humidity and oxygen content suitable for storing metal cultural relics are determined based on a combination of atmosphere control parameters that can basically maintain the surface of the iron test piece in an initial state; wherein the ranges of relative humidity and oxygen content suitable for storing metal cultural relics are less than or equal to 10% and 0.1%-5%, respectively.

[0010] According to an embodiment of the present application, optionally, pre-treating the multiple iron test pieces to be tested includes: pre-corroding the iron test pieces so that the state of the surfaces of the iron test pieces is close to that of metal artifacts; and removing attachments on the surfaces of the pre-corroded iron test pieces.

[0011] According to an embodiment of the present application, optionally, the morphological changes include the shape of rust generated on the surface of the iron test piece, the size of rust particles, the color of rust, and the degree of fit between the rust and the pre-corroded iron test piece.

[0012] According to an embodiment of the present application, optionally, the morphological changes of the iron test piece in the microenvironments with relative humidity of RH≤10%, RH≤20%, RH≤30%, RH≤40% and RH≤50% respectively include: in the microenvironment with OX=0.1% and RH≤10% or RH≤20%, the surface of the iron test piece basically maintains the initial state; in the microenvironment with OX=2% or OX=5% and RH≤10%, the surface of the iron test piece basically maintains the initial state; in the microenvironment with OX=21% and RH≤ In the micro-environment of OX=10%, the color of the rust on the surface of the iron test piece has local black signs; in the micro-environment of OX=2%, OX=5% or OX=21%, and RH≥20%, the rust on the surface of the iron test piece is powdery rust; in the micro-environment of OX=0.1%, OX=2%, OX=5% or OX=21%, and RH≥30%, the rust on the surface of the iron test piece is powdery rust; among them, with the increase of relative humidity, the color of the powdery rust gradually deepens from brown to reddish brown The color of the rust is changed, and the size of the rust particles of the powdery rust gradually changes from fine particles to coarse particles; and the morphological changes of the iron test pieces in the microenvironments with relative humidity of RH=65% and RH=80%, respectively, include: in the microenvironment with RH=65% or RH=80%, and OX=0.1%, the color of the rust is green rust, and the rust morphology is dotted rust; in the microenvironment with RH=65% or RH=80%, and OX=2%, the color of the rust is black rust, and the rust morphology is There is spot rust, but the density of the spot rust is less than that when OX=0.1%; in the small microenvironment of RH=65% or RH=80%, and OX=5%, the rust color includes black rust and brown rust, and the rust form is spot rust; in the small microenvironment of RH=65% or RH=80%, and OX=21%, the rust color is dark black rust; the rust form is flaky rust, and the degree of adhesion between the rust and the pre-corroded iron specimen is that the rust can fall off the iron specimen naturally.

[0013] According to an embodiment of the present application, optionally, the weight change of the iron test piece in a small microenvironment with relative humidity of RH≤10%, RH≤20%, RH≤30%, RH≤40% and RH≤50%, respectively, includes: when OX=0.1%, OX=2%, OX=5% or OX=21%, as the relative humidity increases, the weight change basically shows a trend of increasing; under the same humidity conditions, when OX=0.1%, the weight change is a weight gain of 0.12%; under the same humidity conditions, when OX=2%, OX=5% or OX=21%, the weight change is a weight gain greater than 0.12%; when OX=0.1%, OX=2% or OX=5%, RH≤10% or RH≤20%, the weight change is a weight gain less than or equal to 0.04%.

[0014] Through this application, the range of relative humidity and oxygen content in a microenvironment suitable for long-term storage of metal cultural relics can be determined. The determined parameter range is accurate and reliable, and is suitable for the long-term and proper preservation of precious metals such as metal cultural relics. Within this atmosphere control parameter range, it is not necessary to control the microenvironment in an extremely low oxygen and extremely low humidity environment, that is, metal cultural relics can be preserved without corrosion reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The preferred embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0016] Figure 1 It is a schematic flow chart of a low-oxygen and low-humidity storage treatment method for metal cultural relics according to one embodiment of the present application;

[0017] Figure 2 It is a schematic diagram of a device for regulating a small microenvironment within an enclosure structure according to an embodiment of the present application;

[0018] Figure 3 is a schematic structural diagram of a nitrogen production device according to an embodiment of the present application;

[0019] Figure 4 This is a physical picture of an oxygen content detector according to an embodiment of the present application;

[0020] Figure 5 This is a physical picture of the enclosure structure of one embodiment of the present application;

[0021] Figure 6 is a schematic structural diagram of a protective structure of another embodiment of the present application;

[0022] Figure 7 is a graph showing a trend of relative humidity content in a housing structure during a group test in one embodiment of the present application; and

[0023] Figure 8A-8D This is a graph showing the weight variation trend of an iron test piece under different oxygen contents according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the following detailed description, reference may be made to the various specification drawings that are part of the present application and are used to illustrate specific embodiments of the present application. In the accompanying drawings, similar reference numerals describe substantially similar components in different figures. The various specific embodiments of the present application are described below in sufficient detail so that a person of ordinary skill in the art with relevant knowledge and skills in the art can implement the technical solutions of the present application. It should be understood that other embodiments may also be used or structural, logical or electrical changes may be made to the embodiments of the present application.

[0026] Figure 1 This is a schematic flow chart of a low-oxygen and low-humidity storage treatment method for metal cultural relics according to an embodiment of the present application. Figure 2 FIG. 1 is a schematic diagram of a device for regulating a microenvironment within an enclosure structure according to an embodiment of the present application. Figure 1 Combined with Figure 2 As shown, the low oxygen and low humidity storage treatment method for metal cultural relics in this embodiment includes:

[0027] Step 1: Pre-treat the surface of the metal cultural relic, remove the surface attachments, and store the metal cultural relic in an enclosure structure, wherein the interior of the enclosure structure is formed into a micro-environment through air conditioning.

[0028] Step 2: By combining active and passive regulation, the microenvironment within the enclosure is adjusted to a relative humidity and oxygen content range suitable for storing metal artifacts, wherein the relative humidity range is less than or equal to 30%, and the oxygen content range is 0.1%-5%.

[0029] Step 3: Seal the enclosure and maintain the microenvironment within a suitable range for the metal artifacts;

[0030] There may be floating rust on the surface of metal cultural relics. Removing the floating rust on the surface can prevent the rust from accelerating the corrosion of the metal cultural relics. The relative humidity and oxygen content within the enclosure structure constitute a microenvironment inside the enclosure structure. This process needs to be adjusted through a combination of active and passive atmosphere control methods, and the enclosure structure must be sealed after adjustment.

[0031] For the specific process of gas conditioning, please refer to Figure 2 First, the microenvironment within the enclosure is actively adjusted by a nitrogen generating device, including using the nitrogen generating device to release dry nitrogen to actively adjust the oxygen content in the enclosure and using the humidity control system in the nitrogen generating device to actively adjust the relative humidity in the enclosure.

[0032] Figure 3 is a schematic structural diagram of a nitrogen production device according to an embodiment of the present application. Figure 4 This is a physical picture of an oxygen content detector according to an embodiment of the present application. Figure 3 Combined with Figure 4As shown, in some embodiments, the nitrogen production equipment is an integrated high-purity nitrogen production display and control box including an air compressor, which can perform operations such as air compression, cold drying and humidity control on nitrogen, and output dry and clean nitrogen to the inside of the enclosure structure through a pipe extending into the enclosure structure. During inflation, an oxygen detector is used for real-time detection to ensure that the oxygen content in the bag is accurately controlled.

[0033] After the nitrogen-generating equipment actively adjusts the gas-conditioning parameters, the relative humidity and oxygen content in the microenvironment can be maintained within a relatively low range, for example, the relative humidity is 30% and the oxygen content is 15%. At this time, the relative humidity and oxygen content in the enclosure can be further reduced by placing humidity-conditioning consumables and deoxygenation consumables inside the enclosure in a passive manner. For example, the silica gel particles in the humidity-conditioning consumables can reduce the relative humidity in the enclosure to below 20%, and the deoxygenation consumables can adjust the oxygen content in the enclosure to below 0.5%. The humidity-conditioning consumables and deoxygenation consumables can maintain the microenvironment in the enclosure without large fluctuations, and basically maintain it near the parameter value of the gas-conditioning, without the need for electricity to maintain the gas-conditioning parameters in the microenvironment. Therefore, the gas-conditioning method in this application can effectively save electricity resources and create a constant humidity and low-oxygen storage environment for metal cultural relics.

[0034] In some embodiments, the range of relative humidity and oxygen content suitable for storing metal cultural relics is determined by group experimental testing. The experiment uses a metal iron test piece to simulate a metal cultural relic, places it in a small microenvironment composed of different atmosphere control parameters, and performs qualitative and quantitative analysis on the metal iron test piece after storage for a period of time, thereby recording the atmosphere control parameters of the small microenvironment in which the iron test piece where basically no oxidation reaction occurs is located, thereby obtaining a relative humidity range and oxygen content range suitable for storing metal cultural relics.

[0035] The group experiment detection includes the following steps:

[0036] First, the multiple iron test pieces to be tested are pre-treated and placed in multiple enclosures, each of which contains multiple iron test pieces. The pre-treatment includes pre-corroding the iron test pieces so that the surface state of the iron test pieces is close to that of metal cultural relics; and removing the attachments on the surface of the pre-corroded iron test pieces.

[0037] Secondly, different atmosphere conditioning experimental conditions are set for each enclosure structure, and the atmosphere conditioning experimental conditions include atmosphere conditioning parameter combinations including relative humidity parameter values ​​and oxygen content parameter values. Among them, the relative humidity parameter value RH is one of the following: RH≤10%, RH≤20%, RH≤30%, RH≤40%, RH≤50%, RH=65%, RH=80%; the oxygen content parameter value OX is one of the following: OX=0.1%, OX=2%, OX=5%, OX=21%;

[0038] Thirdly, according to the set atmosphere conditioning experimental conditions, the relative humidity and oxygen content in multiple enclosures are regulated by a combination of active and passive regulation, so that different micro-environments are formed inside different enclosures. Among them, silica gel particles are placed in the enclosures corresponding to RH≤10% and RH≤20% as passive humidity control consumables.

[0039] Finally, all the enclosures are sealed and maintained under controlled atmosphere experimental conditions. After a preset period of time, the range of relative humidity and oxygen content suitable for storing metal cultural relics is determined based on the morphological changes and weight changes of the iron test pieces in each enclosure. Among them, the relative humidity in the controlled atmosphere experimental conditions is RH=65% and RH=80%.

[0040] Studies have shown that when the humidity of iron artifacts exceeds 65%, chemical reactions and electrochemical reactions work together, and the corrosion rate accelerates exponentially. Therefore, microenvironments with a relative humidity of more than 65% are not suitable for storing metal artifacts because of excessive humidity and belong to the experimental reference group.

[0041] Figure 5 This is a physical picture of the enclosure structure of an embodiment of the present application, such as Figure 5 As shown in the figure, in the test experiment, the enclosure structure used to store the metal iron specimens is a flexible airtight bag, one end of which has an opening for accommodating the pipeline for nitrogen delivery from the nitrogen generator. After the gas conditioning parameters are adjusted, the flexible airtight bag is completely sealed using a heat sealer to make the environment inside the bag independently controllable. Thereafter, the relative humidity and oxygen content in the flexible airtight bag are regularly monitored. If the iron specimens in some bags consume oxygen during the reaction, clean nitrogen needs to be regularly added to the bag to ensure that the oxygen content remains basically unchanged.

[0042] By qualitatively analyzing the morphological changes of the iron specimens under different atmosphere test parameters, the degree of oxidation on the surface of the iron specimens can be intuitively seen. The morphological changes include the rust form, rust particle size, rust color, and the degree of fit between the rust and the pre-corroded iron specimen.

[0043] By analyzing the morphological changes of the iron specimens in microenvironments with relative humidity of RH≤10%, RH≤20%, RH≤30%, RH≤40% and RH≤50%, it can be found that:

[0044] a) In a micro-environment with OX=0.1% and RH≤10% or RH≤20%, the surface of the iron specimen basically maintains its initial state;

[0045] b) In a micro-environment with OX=2% or OX=5% and RH≤10%, the surface of the iron specimen basically maintains its initial state;

[0046] c) In a micro-environment with OX=21% and RH≤10%, the rust on the surface of the iron test piece showed local black color;

[0047] d) In the micro-environment of OX=2%, OX=5% or OX=21% and RH≥20%, the rust generated on the surface of the iron test piece is in the form of powdery rust;

[0048] e) In a micro-environment of OX=0.1%, OX=2%, OX=5% or OX=21% and RH≥30%, the rust produced on the surface of the iron test piece is in the form of powdery rust;

[0049] Among them, with the increase of relative humidity, the color of the rust of the generated powdery rust gradually deepens from brown to reddish brown, and the size of the rust particles of the powdery rust gradually evolves from fine particles to coarse particles.

[0050] By analyzing the morphological changes of the iron specimens in microenvironments with relative humidity of RH=65% and RH=80%, it can be found that:

[0051] a) In the micro-environment of RH=65% or RH=80% and OX=0.1%, the rust color appears green rust and the rust morphology appears dot rust;

[0052] b) In the micro-environment with RH=65% or RH=80% and OX=2%, the rust color appears black rust and the rust morphology appears spot rust, but the density of the spot rust is less than that of the spot rust when OX=0.1%;

[0053] c) In a micro-environment with RH=65% or RH=80% and OX=5%, the rust colors include black rust and brown rust, and the rust forms are all dot rust;

[0054] d) In a micro-environment of RH=65% or RH=80% and OX=21%, the color of the rust is dark black rust; the rust is in the form of flaky rust, and the degree of adhesion between the rust and the pre-corroded iron test piece is that the rust can fall off the iron test piece naturally.

[0055] A large number of literature studies have shown that humidity has a much greater impact on iron specimens than oxygen, and humidity control has become the main method for preserving iron and bronze cultural relics. In a low-oxygen environment, humidity is still the determining factor in the type and growth cycle of rust. Quantitative analysis results during the experimental test process show that the rust generated in microenvironments with different relative humidity, oxygen content, and size has different colors and structures, and there are also certain differences in the distribution pattern. However, as the relative humidity continues to increase, the degree of oxidation of the metal becomes higher and higher. Even in microenvironments with extremely low oxygen content (oxygen content is 0.1%), green dotted rust will appear, so a high humidity environment is not suitable for storing metal cultural relics.

[0056] In addition to the qualitative analysis, this experiment also measured the weight change of the metal iron specimen. Since it has been clear in the qualitative analysis that an environment with a relative humidity of more than 65% is not suitable for storing metals, there is no need to conduct a quantitative analysis in order to simplify the experimental process.

[0057] The weight changes of the iron test piece in the microenvironments with relative humidity of RH≤10%, RH≤20%, RH≤30%, RH≤40% and RH≤50% respectively include:

[0058] (1) When OX = 0.1%, OX = 2%, OX = 5% or OX = 21%, the weight change basically shows a larger trend with the increase of relative humidity;

[0059] (2) Under the same humidity conditions, for example, 50% relative humidity, when OX = 0.1%, the weight change is a weight gain of 0.12%;

[0060] (3) Under the same humidity conditions, for example, relative humidity of 50%, when OX = 2%, OX = 5% or OX = 21%, the weight change is greater than 0.12%;

[0061] (4) When OX=0.1%, OX=2% or OX=5%, RH≤10% or RH≤20%, the weight change is less than or equal to 0.04%. However, when the oxygen content is 2% or 5% and the relative humidity is 20%RH in the morphology analysis, powdery rust will appear on the iron specimen.

[0062] Therefore, combined with the morphology change analysis and the weight change analysis, the optimal storage range of relative humidity and oxygen content for the iron test piece is when the oxygen content is between 0.1% and 5% and the relative humidity is less than or equal to 10%.

[0063] Figure 6 is a schematic diagram of the structure of the enclosure structure of another embodiment of the present application, such as Figure 6 As shown in the figure, when storing metal cultural relics, the enclosure structure can be a square airtight storage cabinet, a long airtight display cabinet, or an airtight warehouse. Figure 6 The storage cabinet shown is used for storage, and the storage cabinet is sealed after adjusting the atmosphere parameters in the storage cabinet. In some embodiments, the metal cultural relics with small volume and suitable for flat placement can be stored in the display cabinet. In some embodiments, the display cabinet can be made of glass material to facilitate the display of the collection in the cabinet to the public.

[0064] Below, a specific example is used to demonstrate the experimental detection process of simulating the storage of metal artifacts.

[0065] In the first group of experiments, the oxygen content parameters were pre-set to OX=0.1%, OX=2%, OX=5%, OX=21%, and the relative humidity parameter value RH was pre-set to RH≤10%, RH=20%, RH=30%, RH=40%, RH=50%. The experiment adopted a single variable method, with a total of 4×5=20 groups of experiments, each group with 5 iron test pieces, a total of 100 iron test pieces, and an observation period of 1 month.

[0066] In order to further explore the effect of oxygen concentration on iron test pieces in a high humidity environment, a second set of experiments was added. The oxygen content parameters were set to OX=0.1%, OX=2%, OX=5%, and OX=21%, and the relative humidity was controlled at RH=65% and RH=80%, respectively. The experiment adopted the single variable method, with a total of 4×2=8 groups of experiments, 5 iron test pieces in each group, and a total of 40 iron test pieces.

[0067] Step 1: Pre-treat the sample. There is some floating rust on the surface of the pre-corroded iron test piece. These rusts may affect the subsequent weight detection work. In order to eliminate possible errors, the experimenter uses a brush to clean the surface of the iron test piece.

[0068] Step 2: Adjust the parameters of the controlled atmosphere experiment.

[0069] Step 2.1, place the iron test piece. The enclosure used in the experiment is as follows: Figure 6 The high barrier PE film flexible airtight bag shown. Each iron test piece should be relatively independent and placed at a certain distance. When placing, the observation side of the iron test piece should face inward to ensure that it is in full contact with the environment inside the bag. At the same time, put in the humidity regulating material and data logger in advance.

[0070] Step 2.2, adjust relative humidity and oxygen content.

[0071] When filling with nitrogen, use Figure 4 The oxygen detector in the bag performs real-time detection to ensure accurate regulation of the oxygen content in the bag; after the oxygen content is adjusted, the relative humidity parameters of the constant humidity machine are preset, and combined with the humidity regulating consumables, active and passive control of the relative humidity in the flexible airtight bag is achieved; after the regulation is completed, the flexible airtight bag is completely sealed using a heat sealer to make the environment inside the bag independently controllable.

[0072] During this process, humidity and oxygen content were monitored regularly. Some iron test pieces in the bags consumed oxygen, so clean nitrogen was added to the bags regularly to ensure that the oxygen content remained basically unchanged.

[0073] Step 3: Analyze the experimental results.

[0074] This experiment explored the pre-corrosion of iron specimens when the oxygen content parameters were set to OX=0.1%, OX=2%, OX=5%, OX=21%, and the relative humidity was controlled at RH≤10%, RH=20%, RH=30%, RH=40%, RH=50%, RH=65% and RH=80%, respectively. Among them, RH≤10%, RH=20%, RH=30%, RH=40% and RH=50% were the first group, and the observation period was 1 month; RH=65% and RH=80% were the second group, and the observation period was 3 months.

[0075] In the first group, the natural environment temperature was between 24 and 30°C, and the humidity fluctuated between 50% and 61%. Figure 7 This is a trend chart of the relative humidity content in the enclosure structure during the group experiment test in one embodiment of the present application. Figure 7 As shown in the figure, the horizontal axis is the number of days of observation, and the vertical axis is the relative humidity value. The top curve is the laboratory temperature curve.

[0076] For the preset RH≤10%, RH=20%, RH=30%, RH=40%, RH=50%, through recording and observation, the humidity curve in the RH range of 20%~50% is stable and maintained within the preset humidity range. For the small microenvironment with the preset RH≤10%, the humidity curve has an upward trend, and the final humidity stabilizes between 6% and 7%.

[0077] During the experiment, when RH≤10% and RH=20%, silica gel particles were used for regulation. Iron artifacts will have different reaction phenomena and characteristics under different humidity and oxygen content conditions. Therefore, in order to further establish the quantitative relationship between the corrosion degradation rate and humidity and oxygen concentration, as well as the humidity and oxygen concentration thresholds that prevent or slow down corrosion degradation, the second group set the humidity to RH=65% and RH=80% under different oxygen concentration conditions, and conducted observations for 3 months.

[0078] In the second group, the natural environment temperature was between 18 and 35.9°C, and the humidity fluctuated between 27.2% and 60.1%. For the preset RH=65% and RH=80%, it was basically consistent with the natural environment temperature changes. However, due to the active and passive humidity control, the humidity curve was in a stable trend, and the daily difference in humidity fluctuation was ≤5%RH.

[0079] Step 3.1, analysis of morphological changes of pre-corroded iron specimens.

[0080] After a predetermined period of time, the pre-corroded iron specimens in different micro-environments were observed and it was found that the pre-corroded iron specimens showed obvious distinctive changes under different oxygen content and humidity conditions.

[0081] Analysis of morphological changes in the first group of experiments:

[0082] (1) When the oxygen content is 0.1%, the relative humidity is less than or equal to 10%, and the relative humidity is 20%, there is basically no powdery rust on the surface of the iron test piece, and the surface of the iron test piece basically maintains the initial state;

[0083] (2) When the oxygen content is 2% and 5% and the relative humidity is less than or equal to 10%, there is basically no powdery rust on the surface of the iron test piece, and the surface of the iron test piece basically maintains the initial state;

[0084] (3) When the oxygen content is 21% and the relative humidity is less than or equal to 10%, the surface of the iron test piece shows local black signs, which may be due to the oxidation reaction caused by sufficient oxygen content in the low humidity state;

[0085] (4) When the oxygen content was 2%, 5%, and 21% (excluding the oxygen content of 0.1%) and the relative humidity was ≥ 20%, powdery rust also appeared on the surface of the iron specimen;

[0086] (5) When the oxygen content was 0.1%, 2%, 5%, and 21%, and the relative humidity was ≥30%, powdery rust appeared on the surface of the iron specimen;

[0087] (6) As the humidity increases, the color of the powdery rust deepens from brown to reddish brown, and the powdery rust gradually evolves from fine particles to coarse particles.

[0088] Therefore, from the perspective of morphology, when the oxygen content is 0.1%, 2%, and 5%, and the relative humidity is ≤10%, basically no powdery rust is generated on the surface of the iron test piece, and the surface of the iron test piece basically maintains the initial state.

[0089] Analysis of morphological changes in the second group of experiments:

[0090] (1) When the oxygen content is 0.1% and the relative humidity is 65% and 80%, green spot rust appears;

[0091] (2) When the oxygen content is 2% and the relative humidity is 65% and 80%, black dots appear, but the density is less than that under the condition of oxygen content of 0.1%;

[0092] (3) When the oxygen content is 5% and the relative humidity is 65% and 80%, black and brown spots of rust appear;

[0093] (4) When the oxygen content is 21%, the surface of the iron test piece is darker and blacker. This indicates that oxygen can pass through the rust layer and react with iron for a long time, causing the surface of the iron test piece to turn black;

[0094] (5) In the natural environment, the rust has appeared in flakes and can fall off naturally.

[0095] Step 3.2, weight change analysis of pre-corroded iron coupons.

[0096] The pre-corroded iron specimens showed distinct changes under different oxygen content and humidity conditions.

[0097] In the second group of oxygen content parameters of 0.1%, 2%, 5%, 21%, and relative humidity of 65% and 80%, the surface of the iron test piece has undergone obvious changes due to the dual reaction of oxidation and electrochemical reaction. This also confirms that when the relative humidity is ≥ 65%, the iron test piece will accelerate the chemical reaction and is not suitable for storage conditions.

[0098] In view of this, the range of oxygen content and relative humidity content suitable for storing metal cultural relics was analyzed in combination with the first group of weight changes. Figure 8A-8D : is a graph showing the weight variation trend of an iron test piece under different oxygen contents in one embodiment of the present application. Figure 8A-8D shown. Fig. 8A The oxygen content is 0.1%. Figure 8B The oxygen content is 2%. Figure 8C The oxygen content is 5%. Fig.8D The oxygen content is 21%. The horizontal axis in the figure is 5 pre-corroded iron test pieces in the same micro-environment, and the vertical axis is the weight gain percentage. The double-headed arrow in the figure indicates the case of a weight gain of 0.12%.

[0099] When the oxygen content is 0.1%, 2%, 5%, and 21%, with the increase of humidity, the weight gain basically shows a trend of increasing; under the same humidity conditions, for example, relative humidity of 50% RH, the weight gain is 0.12% under the condition of oxygen content of 0.1%, and the weight gain of iron test pieces is greater than 0.12% when the oxygen content is 2%, 5%, and 21%; when the oxygen content is 0.1%, 2%, and 5%, the relative humidity is 10% RH and 20% RH, the weight gain is ≤0.04%, but combined with the morphology analysis, when the oxygen content is 2%, 5%, and the relative humidity is 20% RH, the iron test piece will have powdery rust.

[0100] In summary, combined with the morphology change analysis and weight change analysis, the threshold and quantitative relationship between humidity and oxygen content for the optimal storage of iron test pieces is recommended to be when the oxygen content is 0.1%-5% and the relative humidity is ≤10%.

[0101] Through the experimental process in the embodiment of the present application, the atmosphere parameters in the micro-environment suitable for preserving metal cultural relics can be obtained, proving that it is not necessary to control the micro-environment in an extremely low oxygen and extremely low humidity environment. Metal cultural relics can be preserved without corrosion reaction within this atmosphere parameter range. Moreover, through the combination of active and passive control in this embodiment, after adjusting the atmosphere parameters, the relative humidity in the micro-environment can be kept constant without the need for power maintenance.

[0102] It can be seen that the method of the embodiment of the present application can save a lot of power resources and reduce the equipment loss of maintaining the parameters of the micro-environment. Furthermore, since it does not rely on electricity to maintain, the micro-environment is safer. Even if there is a power outage, the metal cultural relics are in a safe and stable storage environment.

[0103] The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention.

Claims

1. A method for storing and treating metal cultural relics at low oxygen and low humidity, characterized in that: include: Step 1: Pre-treat the surface of the metal cultural relics, remove the surface attachments, and store the metal cultural relics in a protective structure. The interior of the protective structure is air-conditioned to form a stable, low-humidity, low-oxygen protection storage environment; Step 2: By combining active and passive regulation, the storage environment in the enclosure is adjusted to a relative humidity and oxygen content range suitable for storing metal cultural relics, wherein the relative humidity range is less than or equal to 30%, and the oxygen content range is 0.1%-5%; Step 3: Seal the enclosure structure and maintain the metal artifact storage environment within a suitable range; Wherein, when determining the relative humidity and the oxygen content, an iron test piece is used instead of a metal cultural relic to conduct a simulated storage test, including the following steps: Firstly, a plurality of iron test pieces to be tested are pre-treated and placed in a plurality of enclosure structures, each of which contains a plurality of iron test pieces; Secondly, different atmosphere conditioning experimental conditions are set for each enclosure structure, wherein the atmosphere conditioning experimental conditions include an atmosphere conditioning parameter combination including a relative humidity parameter value and an oxygen content parameter value; Thirdly, according to the set atmosphere conditioning experimental conditions, the relative humidity and oxygen content in multiple enclosures are regulated by combining active and passive regulation to form different storage environments in different enclosures; silica gel particles are placed in the enclosures corresponding to RH≤10% and RH≤20% as passive humidity-regulating consumables; Finally, all the enclosures are sealed and maintained under controlled atmosphere experimental conditions, and after a preset period of time, the range of relative humidity and oxygen content suitable for storing metal cultural relics is determined based on the morphological changes and weight changes of the iron test pieces in each enclosure.

2. The low oxygen and low humidity storage treatment method for metal cultural relics according to claim 1, characterized in that: The relative humidity parameter value RH is a plurality of set values ​​between a first value and a second value. The first value is in the range of 5% to 15%, and the second value is in the range of 15% to 30%.

3. The low oxygen and low humidity storage treatment method for metal cultural relics according to claim 2, characterized in that: The relative humidity parameter value RH is one of the following: RH≤10%, RH≤20%, RH≤30%, preferably RH≤20%, and more preferably RH≤10%.

4. The low oxygen and low humidity storage treatment method for metal cultural relics according to claim 1, characterized in that: The oxygen content parameter value OX is a plurality of set values ​​between a third value and a fourth value. The third value has a value range of 0.1% to 0.5%, and the fourth value has a value range of 2% to 21%.

5. The low oxygen and low humidity storage treatment method for metal cultural relics according to claim 1, characterized in that: According to a combination of atmosphere control parameters that can basically maintain the surface of the iron test piece in its initial state, the ranges of relative humidity and oxygen content suitable for storing metal cultural relics are determined; wherein the ranges of relative humidity and oxygen content suitable for storing metal cultural relics are less than or equal to 10% and 0.1%-5%, respectively.

6. The low oxygen and low humidity storage method for metal cultural relics according to claim 1, characterized in that: The pretreatment of the multiple iron test pieces to be tested includes: pre-corroding the iron test pieces so that the state of the surfaces of the iron test pieces is close to that of metal cultural relics; and removing attachments on the surfaces of the pre-corroded iron test pieces.

7. The low oxygen and low humidity storage treatment method for metal cultural relics according to claim 1, characterized in that: The morphological changes include the shape of rust produced on the surface of the iron test piece, the size of rust particles, the color of rust, and the degree of adhesion between the rust and the pre-corroded iron test piece.

8. The low oxygen and low humidity storage treatment method for metal cultural relics according to claim 1, characterized in that: The morphological changes of the iron specimens in the microenvironments with relative humidity of RH≤10%, RH≤20%, RH≤30%, RH≤40% and RH≤50% respectively include: In a micro-environment with OX = 0.1% and RH ≤ 10% or RH ≤ 20%, the surface of the iron specimen basically maintains its initial state; In a micro-environment with OX=2% or OX=5% and RH≤10%, the surface of the iron specimen basically maintains its initial state; In a micro-environment with OX=21% and RH≤10%, the rust color on the surface of the iron test piece showed local signs of black; In the micro-environment of OX=2%, OX=5% or OX=21% and RH≥20%, the rust produced on the surface of the iron test piece is in the form of powdery rust; In the micro-environment of OX=0.1%, OX=2%, OX=5% or OX=21% and RH≥30%, the rust produced on the surface of the iron test piece is in the form of powdery rust; Wherein, as the relative humidity increases, the color of the rust of the generated powdery rust gradually deepens from brown to reddish brown, and the size of the rust particles of the powdery rust gradually evolves from fine particles to coarse particles; and, The morphological changes of the iron specimens in the microenvironments with relative humidity of RH=65% and RH=80% include: In the micro-environment of RH=65% or RH=80% and OX=0.1%, the rust color appears green rust and the rust morphology appears dot rust; In the micro-environment with RH=65% or RH=80% and OX=2%, the rust color appears black rust and the rust morphology appears spot rust, but the density of the spot rust is less than that when OX=0.1%. In a micro-environment with RH=65% or RH=80% and OX=5%, the rust colors include black rust and brown rust, and the rust forms are all spot rust; In a microenvironment of RH=65% or RH=80% and OX=21%, the color of the rust is dark black rust; the rust morphology is flaky rust, and the degree of adhesion between the rust and the pre-corroded iron test piece is that the rust can fall off the iron test piece naturally.

9. The low oxygen and low humidity storage treatment method for metal cultural relics according to claim 1, characterized in that: The weight changes of the iron test piece in the microenvironments with relative humidity of RH≤10%, RH≤20%, RH≤30%, RH≤40% and RH≤50% respectively include: When OX = 0.1%, OX = 2%, OX = 5%, or OX = 21%, the weight change basically shows a larger trend as the relative humidity increases; Under the same humidity conditions, when OX = 0.1%, the weight change is a weight gain of 0.12%; Under the same humidity conditions, when OX=2%, OX=5% or OX=21%, the weight change is greater than 0.12%; When OX=0.1%, OX=2% or OX=5%, RH≤10% or RH≤20%, the weight change is less than or equal to 0.04%.

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