Anti-sulfur corrosion cladding material for boiler tube bank and preparation method thereof

Abstract

The present application relates to the technical field of surface protection, and particularly relates to a boiler tube row anti-sulfur corrosion cladding material and a preparation method thereof, which comprises the following steps: filling alloy powder into a metal outer skin and sealing to obtain a blank; when the preparation of the blank is determined to be substandard according to a structure uniformity characterization value, increasing a preset vibration frequency or issuing an alloy powder supply abnormality alarm; drawing the blank that meets the standard to obtain a powder core wire; when a drawing thermal characterization value is greater than or equal to a first preset drawing thermal characterization value and less than a second preset drawing thermal characterization value, determining whether the preparation of the powder core wire meets the standard according to a diameter fluctuation range; when the drawing thermal characterization value is greater than or equal to the second preset drawing thermal characterization value, determining the cause of the substandard preparation of the powder core wire according to a thermal abnormality aggregation degree; and winding and packaging the powder core wire that meets the standard to obtain the boiler tube row anti-sulfur corrosion cladding material. The present application improves the preparation efficiency of the cladding material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of surface protection, in particular to a boiler tube bank sulfur corrosion resistant cladding material and a preparation method thereof. BACKGROUND

[0002] The "four tubes" (water wall, superheater, reheater, economizer) of coal-fired power plant boilers, biomass furnaces and waste incinerators are exposed to high-temperature, sulfur-containing and vanadium-containing corrosive flue gas for a long time, and face serious high-temperature sulfur corrosion problems. In particular, sulfides in the flue gas react with the tube wall metal to form low-melting-point composite sulfates, which severely erode the tube wall material and greatly shorten the service life of the boiler tube bank, posing a serious threat to the safe and stable operation of the power plant.

[0003] At present, using cladding technology to prepare a sulfur corrosion resistant protective coating on the surface of the boiler tube bank is one of the effective solutions, and among them, the powder core wire is widely concerned as the cladding material because of its flexible composition design and lower preparation cost. In the prior art, a nickel-based alloy system is usually used as the powder core material, and the powder core wire is prepared through filling and drawing processes, and then a protective coating is formed through a thermal spraying or electric arc cladding process.

[0004] Chinese patent application publication No. CN113369639A discloses a preparation method of an ultra-thin ultra-low dilution rate high-temperature alloy cladding layer for a waste incinerator, which is a protection process for preparing a high-temperature alloy cladding layer resistant to chlorine, sulfur and their compounds, etc. on the heating surface of a waste incinerator, and belongs to the technical field of new material surface protection. The cladding layer plays a good anti-corrosion role on the heating surface of the waste furnace, and can effectively prolong the service life. Therefore, it is of great significance to ensure the safe and efficient operation of the waste incineration power plant boiler, environmental protection and promote the harmonious development of society.

[0005] It can be seen that the above technical solution does not consider the influence of powder filling voids and skin cooperative deformation failure on the preparation of the cladding material, thereby causing the problem of poor preparation efficiency of the cladding material. SUMMARY

[0006] Therefore, the present application provides a boiler tube bank sulfur corrosion resistant cladding material and a preparation method thereof, to overcome the problem in the prior art that the influence of powder filling voids and skin cooperative deformation failure on the preparation of the cladding material is not considered, thereby causing the problem of poor preparation efficiency of the cladding material.

[0007] To achieve the above-mentioned purpose, on the one hand, the present application provides a boiler tube bank sulfur corrosion resistant cladding material and a preparation method thereof, comprising:

[0008] filling the alloy powder into the metal skin at a preset vibration frequency, and sealing to obtain a blank; obtaining a plurality of diameters of the blank, and obtaining a structure uniformity representation value of the blank;

[0009] determining that the preparation of the blank does not meet the preset standard according to the structure uniformity characterization value of the blank;

[0010] drawing the blank meeting the preset standard at a preset drawing rate to obtain a powder core wire, collecting a thermal image of the powder core wire, and obtaining a drawing thermal characterization value of the powder core wire;

[0011] when the drawing thermal characterization value is greater than or equal to a first preset drawing thermal characterization value and less than a second preset drawing thermal characterization value, determining whether the preparation of the powder core wire meets the preset standard according to a diameter fluctuation range of the powder core wire;

[0012] when the drawing thermal characterization value is greater than or equal to the second preset drawing thermal characterization value, determining the reason why the preparation of the powder core wire does not meet the preset standard according to a thermal abnormality aggregation degree of the powder core wire, wherein the reason is that the internal friction of the alloy powder is too large or the plasticity of the metal skin is insufficient;

[0013] winding the powder core wire meeting the preset standard to obtain a boiler tube row anti-sulfur corrosion cladding material.

[0014] Further, the process of determining whether the preparation of the blank meets the preset standard according to the structure uniformity characterization value of the blank comprises:

[0015] comparing the structure uniformity characterization value with a first preset structure uniformity threshold value and a second preset structure uniformity threshold value, respectively;

[0016] if the structure uniformity characterization value is less than the first preset structure uniformity threshold value, it is determined that the preparation of the blank meets the preset standard;

[0017] if the structure uniformity characterization value is greater than or equal to the first preset structure uniformity threshold value and less than the second preset structure uniformity threshold value, it is determined that the preparation of the blank does not meet the preset standard, and the preset vibration frequency for the preparation of the next batch of blank is increased according to the difference between the structure uniformity characterization value and the first preset structure uniformity threshold value;

[0018] if the structure uniformity characterization value is greater than or equal to the second preset structure uniformity threshold value, it is determined that the preparation of the blank does not meet the preset standard, and an abnormal alarm of the alloy powder supply is issued;

[0019] the structure uniformity characterization value is a ratio of a standard deviation to an average value of the diameter of the blank.

[0020] Further, the increase of the preset vibration frequency for the preparation of the next batch of blank is provided with several frequency adjustment modes, and the increase amplitude of each frequency adjustment mode is different.

[0021] Further, the process of determining whether the preparation of the powder core wire meets the preset standard according to the drawing heat characteristic value of the powder core wire comprises:

[0022] comparing the drawing heat characteristic value with a first preset drawing heat characteristic value and a second preset drawing heat characteristic value respectively;

[0023] if the drawing heat characteristic value is less than the first preset drawing heat characteristic value, it is determined that the preparation of the powder core wire meets the preset standard;

[0024] if the drawing heat characteristic value is greater than or equal to the first preset drawing heat characteristic value and less than the second preset drawing heat characteristic value, it is determined that the preparation of the powder core wire has a risk of not meeting the preset standard, and whether the preparation of the powder core wire meets the preset standard is further determined according to the diameter fluctuation range of the powder core wire;

[0025] if the drawing heat characteristic value is greater than or equal to the second preset drawing heat characteristic value, it is determined that the preparation of the powder core wire does not meet the preset standard, and the reason why the preparation of the powder core wire does not meet the preset standard is determined according to the thermal abnormality aggregation degree of the powder core wire.

[0026] Further, the process of obtaining the drawing heat characteristic value comprises:

[0027] taking a thermal image of the powder core wire of a preset length;

[0028] based on the thermal image, obtaining a plurality of surface temperatures of the powder core wire;

[0029] calculating the standard deviation of the plurality of surface temperatures, denoted as the drawing heat characteristic value.

[0030] Further, when it is determined that the preparation of the powder core wire does not meet the preset standard according to the comparison result that the diameter fluctuation range of the powder core wire is greater than or equal to the preset diameter fluctuation range, the preset drawing speed of the preparation of the next batch of blank is reduced according to the difference between the diameter fluctuation range and the preset diameter fluctuation range;

[0031] the diameter fluctuation range is the difference between the maximum diameter of the powder core wire and the minimum diameter of the powder core wire.

[0032] Further, the reduction range of the preset drawing speed of the preparation of the next batch of blank is positively correlated with the diameter fluctuation deviation value, wherein the diameter fluctuation deviation value is the difference between the diameter fluctuation range and the preset diameter fluctuation range.

[0033] Further, the process of determining the reason why the preparation of the powder core wire does not meet the preset standard according to the thermal abnormality aggregation degree of the powder core wire comprises:

[0034] If the thermal anomaly aggregation degree is less than the preset thermal anomaly aggregation degree, it is determined that the plasticity of the metal skin is insufficient.

[0035] If the thermal anomaly aggregation degree is greater than or equal to the preset thermal anomaly aggregation degree, it is determined that the internal friction of the alloy powder is too large.

[0036] Further, the obtaining process of the thermal anomaly aggregation degree comprises:

[0037] Sort the temperature values of all pixel points in the thermal imaging image from high to low, determine the highest temperature value in the thermal imaging image, take the highest temperature value as the upper limit, take a preset temperature value as the lower limit, and record the pixel points in the temperature interval as relative hot spots;

[0038] Count the number of independent connected regions formed by the relative hot spots adjacent in spatial position, and record it as the thermal anomaly aggregation degree;

[0039] The preset temperature value is a temperature value corresponding to a preset percentage in a sequence sorted from high to low of temperature values of all pixel points in the thermal imaging image.

[0040] On the other hand, the present application provides a boiler tube row anti-sulfur corrosion cladding material prepared by the above preparation method, comprising an alloy powder and a metal skin, the material of the metal skin is stainless steel; the alloy powder comprises the following components by mass fraction: C: ≤0.10wt.%; Mn: ≤0.50wt.%; Si: ≤0.50wt.%; P: ≤0.015wt.%; S: ≤0.015wt.%; Cr: 20.0-23.0wt.%; (Nb+Ta): 3.15-4.15wt.%; Co: ≤1.0wt.%; Mo: 8.0-10.0wt.%; Fe: <5.0wt.%; Al: ≤0.40wt.%; Ti: ≤0.40wt.%; Ni: balance.

[0041] Compared with the prior art, the present application has the beneficial effects that by introducing quantitative indexes such as structural uniformity representation value, drawing thermal representation value, and thermal anomaly aggregation degree, a full-chain closed-loop control system of blank uniformity feedback regulation, real-time monitoring during drawing process, grading determination, and precise traceability is constructed, the controllability and intelligence of the preparation process are realized, and the product qualification rate and preparation stability are improved; at the same time, a targeted parameter adjustment strategy is designed, the optimization of vibration frequency and drawing rate is associated with the degree of quality deviation, and the waste of efficiency or process instability caused by blind adjustment is avoided; in terms of material performance, by scientifically proportioning the alloy powder components and selecting a suitable stainless steel skin, the cladding material has excellent sulfur corrosion resistance, high temperature stability, and forming performance, and can perfectly adapt to the complex service conditions of the boiler tube row, thereby improving the preparation efficiency of the cladding material.

[0042] Further, the present application reflects the filling uniformity of the internal alloy powder by setting a structure uniformity value, when the powder is agglomerated or locally voided, the discrete degree of the diameter will intuitively reflect, at the same time, the three-level judgment logic is established layer by layer, for the case of slight deviation from the preset standard, the subsequent filling effect is optimized by increasing the vibration frequency, and small defects are avoided to accumulate into serious quality problems; for the case of serious deviation, an alloy powder supply abnormal alarm is directly sent, and the continuous output of unqualified blank is timely blocked, so that accurate detection is realized.

[0043] Further, the present application realizes the accurate control of the increasing amplitude of the vibration frequency by setting a plurality of frequency adjustment modes and different increasing amplitudes for each mode.

[0044] Further, the present application realizes the accurate identification and classified management of the quality risk of the drawing process by establishing a three-level response mechanism of the drawing thermal value, the system distinguishes the thermal abnormality into two levels of potential risk and determined unqualified, and designs a differentiated processing flow for each level: the potential risk starts secondary judgment to further confirm, and the determined unqualified directly performs cause diagnosis; this hierarchical processing strategy avoids misjudgment and ensures that serious quality problems can be timely processed; by associating the thermal abnormality with different subsequent processing flows, a targeted quality control path is formed, so that intelligent monitoring of the drawing process is realized.

[0045] Further, the present application takes the diameter fluctuation range as the index of secondary judgment, quantifies the diameter fluctuation range of the powder core wire, reflects the uniformity of powder densification in the drawing process, and when the diameter fluctuation abnormality is detected, the system can automatically adjust the drawing speed of the next batch according to the deviation size, so as to avoid the local bulging phenomenon caused by too fast compression. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The flowchart of the preparation method of the anti-sulfur corrosion cladding material of the boiler pipe row of the embodiment of the present application;

[0047] Figure 2 The flowchart of the preparation method of the anti-sulfur corrosion cladding material of the boiler pipe row of the embodiment of the present application;

[0048] Figure 3 The flowchart of the preparation method of the anti-sulfur corrosion cladding material of the boiler pipe row of the embodiment of the present application;

[0049] Figure 4 The flowchart of the preparation method of the anti-sulfur corrosion cladding material of the boiler pipe row of the embodiment of the present application; DETAILED DESCRIPTION

[0050] In order to make the objects and advantages of the present application more clear, the present application will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0051] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and not to limit the protection scope of the present application.

[0052] It should be pointed out that the data in the present embodiment are obtained by comprehensive analysis and evaluation of historical detection data and corresponding historical detection results of the present application in the past three months before the present detection. Those skilled in the art can understand that the determination method of the present application for a single parameter can be to select the value with the highest proportion as the preset standard parameter according to the data distribution, to use weighted summation to obtain the value as the preset standard parameter, to substitute each historical data into a specific formula and to obtain the value by using the formula as the preset standard parameter, or other selection methods, as long as the present application can clearly define different specific situations in the single determination process by using the obtained value.

[0053] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , which are respectively a flowchart of the preparation method of the boiler tube row anti-sulfur corrosion cladding material according to the present embodiment, a flowchart of the present embodiment for determining whether the preparation of the blank conforms to the preset standard, a flowchart of the present embodiment for determining whether the preparation of the powder core wire conforms to the preset standard according to the drawing heat characteristic value of the powder core wire, and a flowchart of the present embodiment for determining the reason why the preparation of the powder core wire does not conform to the preset standard.

[0054] In one aspect, the present embodiment provides a preparation method of a boiler tube row anti-sulfur corrosion cladding material, which comprises:

[0055] In step S1, a 304 stainless steel strip is used as a metal outer skin, the thickness of the metal outer skin is 0.3 mm, the width of the metal outer skin is 8 mm, the stainless steel strip is rolled into a U-shaped groove, alloy powder is filled into the U-shaped groove at a preset vibration frequency of 50 Hz, and the alloy powder is sealed by argon arc welding after filling is completed to obtain a blank, wherein the particle size of the alloy powder is 45-75 μm; a laser diameter gauge is used to continuously scan and detect along the length direction of the blank at an interval of 10 mm, 100 diameter data of the blank are collected, and a structure uniformity characteristic value of the blank is obtained;

[0056] In step S2, when it is determined that the preparation of the blank does not conform to the preset standard according to the structure uniformity characteristic value of the blank, the preset vibration frequency of the preparation of the next batch of blank is increased or an abnormal alarm of the alloy powder supply is issued.

[0057] Step S3, the blank meeting the preset standard is put into a drawing machine to draw at a preset drawing speed of 2.5 m / min to obtain a powder core wire, a thermal imaging image of the powder core wire is collected, and a drawing thermal characteristic value of the powder core wire is obtained;

[0058] Step S4, when the drawing thermal characteristic value is greater than or equal to a first preset drawing thermal characteristic value and less than a second preset drawing thermal characteristic value, whether the preparation of the powder core wire meets the preset standard is determined again according to the diameter fluctuation range of the powder core wire;

[0059] Step S5, when the drawing thermal characteristic value is greater than or equal to the second preset drawing thermal characteristic value, the reason why the preparation of the powder core wire does not meet the preset standard is determined according to the thermal abnormality aggregation degree of the powder core wire, wherein the reason is that the internal friction of the alloy powder is too large or the plasticity of the metal skin is insufficient;

[0060] Step S6, the powder core wire meeting the preset standard is collected by an automatic take-up device to obtain a boiler tube row anti-sulfur corrosion cladding material.

[0061] It should be pointed out that the data in the embodiment are results obtained through preliminary experiments before the detection by the method of the present application, and each preset value can be adjusted according to the specific use, as long as the method of the present application can determine different specific conditions in the single determination process by the obtained numerical value. The preset values set in the embodiment are obtained according to the preliminary experiments, and each correction coefficient is also selected by experiment verification.

[0062] Specifically, the process of determining whether the preparation of the blank meets the preset standard according to the structure uniformity characteristic value of the blank includes:

[0063] The structure uniformity characteristic value is compared with a first preset structure uniformity threshold value 0.025 and a second preset structure uniformity threshold value 0.046, respectively;

[0064] If the structure uniformity characteristic value is less than the first preset structure uniformity threshold value, it is determined that the preparation of the blank meets the preset standard;

[0065] If the structure uniformity characteristic value is greater than or equal to the first preset structure uniformity threshold value and less than the second preset structure uniformity threshold value, it is determined that the preparation of the blank does not meet the preset standard, and the preset vibration frequency of the next batch of blank preparation is increased according to the difference between the structure uniformity characteristic value and the first preset structure uniformity threshold value;

[0066] If the structure uniformity characteristic value is greater than or equal to the second preset structure uniformity threshold value, it is determined that the preparation of the blank does not meet the preset standard, and an alloy powder supply abnormality alarm is issued.

[0067] The structure uniformity value is a ratio of a standard deviation to an average value of the diameter of the blank.

[0068] Specifically, the first preset structure uniformity threshold value is in a range of [0.015, 0.030], and the second preset structure uniformity threshold value is in a range of [0.045, 0.060]. In this embodiment, the first preset structure uniformity threshold value is 0.025, and the second preset structure uniformity threshold value is 0.046.

[0069] Specifically, by using the ratio of the standard deviation to the average value of the diameter of the blank as the structure uniformity value, when the structure uniformity value is less than the first preset structure uniformity threshold value, it indicates that the diameters of the cross sections of the blank have relatively small fluctuations, the metal skin and the powder are balanced in stress and cooperatively deformed during drawing, and stress concentration leading to bulging or cracking does not occur, and the thickness of the cladding layer can be ensured to be uniform during subsequent cladding, and a continuous and dense sulfur corrosion resistant protective film is formed, so it is determined that the blank meets the preset standard. When the feature value is greater than or equal to the first preset structure uniformity threshold value and less than the second preset structure uniformity threshold value, the internal powder is slightly agglomerated but not irreversibly caked, and by increasing the preset vibration frequency of the next batch of blank, the slightly agglomerated powder can be dispersed by mechanical vibration impact force, so that the filling density deviation is adjusted to the qualified range, and therefore it is determined that the blank does not meet the preset standard and is repaired by adjusting the vibration frequency. When the feature value is greater than or equal to the second preset structure uniformity threshold value, it means that the internal powder is seriously agglomerated, caked or locally voided, and simply increasing the vibration frequency cannot eliminate the serious unevenness caused by powder moisture absorption, caking or supply pipeline blockage, and the skin will inevitably crack due to local stress concentration during drawing, so it is determined that the blank does not meet the preset standard and an alloy powder supply abnormality alarm is issued, thereby establishing a one-to-one correspondence between the feature value and the defect severity and the processing method, screening qualified blanks from the source, repairing slight defects, and blocking serious abnormalities, thereby avoiding misjudgment and improving production efficiency.

[0070] Specifically, the increase of the preset vibration frequency for the next batch of blank is provided with several frequency adjustment modes, wherein,

[0071] If the structure uniformity difference value is less than the first preset structure uniformity difference value 0.005, the preset vibration frequency for the next batch of blank is increased to the corresponding value by using the first adjustment coefficient 1.04;

[0072] If the structure uniformity difference value is greater than or equal to the first preset structure uniformity difference value and less than the second preset structure uniformity difference value 0.019, the preset vibration frequency for the next batch of blank is increased to the corresponding value by using the second adjustment coefficient 1.06;

[0073] If the structural uniformity representation difference is greater than or equal to the second preset structural uniformity representation difference, a third adjustment coefficient 1.08 is used to increase the preset vibration frequency of the next batch of blank to a corresponding value.

[0074] The structural uniformity representation difference is a difference between the structural uniformity representation value and a first preset structural uniformity threshold.

[0075] Specifically, the process of determining whether the preparation of the powder core wire meets the preset standard according to the drawing heat representation value of the powder core wire includes:

[0076] The drawing heat representation value is compared with a first preset drawing heat representation value 1.6°C and a second preset drawing heat representation value 3.4°C, respectively.

[0077] If the drawing heat representation value is less than the first preset drawing heat representation value, it is determined that the preparation of the powder core wire meets the preset standard.

[0078] If the drawing heat representation value is greater than or equal to the first preset drawing heat representation value and less than the second preset drawing heat representation value, it is determined that the preparation of the powder core wire has a risk of not meeting the preset standard, and whether the preparation of the powder core wire meets the preset standard is determined according to the diameter fluctuation range of the powder core wire.

[0079] If the drawing heat representation value is greater than or equal to the second preset drawing heat representation value, it is determined that the preparation of the powder core wire does not meet the preset standard, and the reason why the preparation of the powder core wire does not meet the preset standard is determined according to the thermal abnormal aggregation degree of the powder core wire.

[0080] Specifically, the first preset drawing heat representation value has a value range of [1.2°C, 2.1°C], and the second preset drawing heat representation value has a value range of [2.9°C, 3.8°C]. In this embodiment, the first preset drawing heat representation value is 1.6°C, and the second preset drawing heat representation value is 3.4°C.

[0081] The drawing heat representation value is a standard deviation of the surface temperature in the drawing process of the powder core wire, which represents the uniformity of the surface temperature distribution in the drawing process, and further reflects the deformation coordination state of the internal alloy powder and the metal skin and the friction degree of the powder. The smaller the drawing heat representation value, the more uniform the heat production of each part of the wire, the more stable the rearrangement and compaction process of the powder particles, and the better the deformation coordination of the metal skin and the powder without local stress concentration or abnormal friction. The larger the drawing heat representation value, the more the local heat production increases in the drawing process, which leads to the deformation imbalance caused by excessive internal friction of the powder or insufficient plasticity of the skin, and the risk of defects such as bulging and cracking of the wire increases.

[0082] Specifically, the process of obtaining the drawing heat representation value includes:

[0083] An infrared thermal imager is used to take a thermal imaging image of the powder core wire of a preset length of 1 m at the exit side of the drawing die of the wire drawing machine;

[0084] Based on the thermal imaging image, 30 sampling points are uniformly selected along the length direction of the wire using FLIR Research Studio analysis software, and the surface temperature of each sampling point is extracted.

[0085] The standard deviation of the surface temperature of the 30 sampling points is calculated using MATLAB, and is denoted as the drawing thermal characterization value.

[0086] In this embodiment, the preset length is 1 m, but the above value is not limited thereto, and those skilled in the art can adjust the above value according to actual needs.

[0087] Specifically, whether the preparation of the powder core wire meets the preset standard is determined according to the diameter fluctuation range, and wherein,

[0088] If the diameter fluctuation range is less than the preset diameter fluctuation range 0.03 mm, it is determined that the preparation of the powder core wire meets the preset standard;

[0089] If the diameter fluctuation range is greater than or equal to the preset diameter fluctuation range, it is determined that the preparation of the powder core wire does not meet the preset standard, and the preset drawing speed of the next batch of blank preparation is reduced according to the difference between the diameter fluctuation range and the preset diameter fluctuation range.

[0090] The diameter fluctuation range is the difference between the maximum diameter of the powder core wire and the minimum diameter of the powder core wire, wherein the diameter of the powder core wire is obtained by a laser scanning diameter gauge.

[0091] Specifically, the diameter fluctuation range represents the radial dimensional stability and internal powder densification uniformity of the powder core wire, and the diameter fluctuation range directly reflects the uniformity of the wire shape during drawing. The smaller the range, the better the dimensional consistency. A stable drawing process should produce a wire with a very small diameter fluctuation range, and an increased range indicates that the process system is disturbed.

[0092] In this embodiment, statistical analysis of the diameter data of 100 batches of powder core wires under normal production conditions determines that the diameter fluctuation range conforms to a normal distribution with a mean of 0.018 mm and a standard deviation of 0.005 mm. Accordingly, the preset diameter fluctuation range is set to 0.03 mm, but the above value is not limited thereto, and those skilled in the art can adjust the above value according to actual needs.

[0093] Specifically, the reduction range of the preset drawing speed for preparing the next batch of blank material is positively correlated with the diameter fluctuation deviation value, for example, linear positive correlation or nonlinear positive correlation, and the linear slope of the linear positive correlation is not particularly limited. It can be understood that the greater the diameter fluctuation deviation value, the greater the reduction range of the preset drawing speed for preparing the next batch of blank material. The diameter fluctuation deviation value is the difference between the diameter fluctuation range and the preset diameter fluctuation range.

[0094] Specifically, the process of determining the reason for the preparation of the powder core wire not meeting the preset standard according to the thermal abnormal aggregation degree of the powder core wire includes:

[0095] If the thermal abnormal aggregation degree is less than 8 preset thermal abnormal aggregation degrees, it is determined that the plasticity of the metal sheath is insufficient.

[0096] If the thermal abnormal aggregation degree is greater than or equal to the preset thermal abnormal aggregation degree, it is determined that the internal friction of the alloy powder is too large.

[0097] Specifically, the thermal abnormal aggregation degree represents the spatial distribution of the high-temperature area during the drawing process of the powder core wire. When the plasticity of the metal sheath is insufficient, the sheath cannot uniformly bear the tension during the drawing process, and the heat generated by the local stretching resistance will be dispersed along the length direction of the wire. Such high-temperature areas are mostly scattered and independent, and have no obvious aggregation characteristics, so the corresponding thermal abnormal aggregation degree value is small. When the internal friction of the alloy powder is too large, the agglomerated powder will form local friction, and the intense friction between the agglomerates and the metal sheath and the internal particles of the agglomerates will generate concentrated heat. The high-temperature area is mostly in the form of a block, and there may be multiple independent aggregation high-temperature areas, so the corresponding thermal abnormal aggregation degree value is large.

[0098] Specifically, the preset thermal abnormal aggregation degree is 8, but the above value is not limited thereto, and those skilled in the art can adjust the above value according to actual needs.

[0099] Specifically, the process of obtaining the thermal abnormal aggregation degree includes:

[0100] The thermal imaging image of the powder core wire taken by the infrared thermal imager is imported into the FLIRResearchStudio software, the temperature values of all pixel points in the thermal imaging image are extracted, and a data set containing pixel coordinates-temperature values is generated. Using the FLIRResearchStudio software, all pixel temperature values are sorted from high to low, and the highest temperature value, for example, 93℃, is recorded.

[0101] Based on the sorted temperature sequence, the temperature value corresponding to the first 10% percentile is selected as the preset temperature value, for example, the lowest temperature value of the first 10% (30720) pixels of 307200 pixels is 78℃, and the temperature interval is [78℃, 93℃], and all pixel points in the interval are recorded as relative hot spots.

[0102] All relative hot spots are marked in the thermal imaging image using Image software, the spatial adjacent determination criterion is set as that the upper, lower, left, right and four corner adjacent pixels are all regarded as spatial adjacent, the number of independent connected regions formed by the relative hot spots is automatically counted, and the number is the thermal anomaly aggregation degree, wherein the independent connected regions are formed by the relative hot spots adjacent in spatial position.

[0103] On the other hand, the embodiment of the present application provides a boiler tube bank sulfur corrosion resistant cladding material prepared by the above preparation method, which comprises an alloy powder and a metal skin, the material of the metal skin is stainless steel; the alloy powder comprises the following components in mass fraction: C: ≤0.10wt.%; Mn: ≤0.50wt.%; Si: ≤0.50wt.%; P: ≤0.015wt.%; S: ≤0.015wt.%; Cr: 20.0-23.0wt.%; (Nb+Ta): 3.15-4.15wt.%; Co: ≤1.0wt.%; Mo: 8.0-10.0wt.%; Fe: <5.0wt.%; Al: ≤0.40wt.%; Ti: ≤0.40wt.%; Ni: balance.

[0104] In the embodiment, C: 0.05wt.%; Mn: 0.30wt.%; Si: 0.25wt.%; P: 0.010wt.%; S: 0.008wt.%; Cr: 21.5wt.%; (Nb+Ta): 3.65wt.%; Co: 0.5wt.%; Mo: 9.0wt.%; Fe: 3.2wt.%; Al: 0.20wt.%; Ti: 0.25wt.%; Ni: balance.

[0105] So far, the technical scheme of the present application has been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical scheme after the changes or replacements will fall within the protection scope of the present application.

Claims

1. A method of producing a cladding material for boiler tube banks resistant to sulphur corrosion, characterized in that The application relates to a method for preparing a boiler tube row anti-sulfur corrosion cladding material. The alloy powder is filled into the metal outer skin at a preset vibration frequency, and the blank is obtained after sealing; Obtain the diameter of the blank, and obtain the structural uniformity representation value of the blank; If the structural uniformity representation value is less than the first preset structural uniformity threshold value, it is determined that the preparation of the blank meets the preset standard; If the structural uniformity representation value is greater than or equal to the first preset structural uniformity threshold value and less than the second preset structural uniformity threshold value, it is determined that the preparation of the blank does not meet the preset standard, and the preset vibration frequency of the preparation of the next batch of blank is increased according to the difference between the structural uniformity representation value and the first preset structural uniformity threshold value; If the structural uniformity representation value is greater than or equal to the second preset structural uniformity threshold value, it is determined that the preparation of the blank does not meet the preset standard, and an alloy powder supply abnormality alarm is sent, wherein the value range of the first preset structural uniformity threshold value is [0.015, 0.030], and the value range of the second preset structural uniformity threshold value is [0.045, 0.060]; The structural uniformity representation value is the ratio of the standard deviation to the average value of the diameter of the blank; The blank meeting the preset standard is drawn at a preset drawing rate to obtain a powder core wire, and a thermal imaging diagram of the powder core wire is collected to obtain a drawing thermal representation value of the powder core wire; If the drawing thermal representation value is less than the first preset drawing thermal representation value, it is determined that the preparation of the powder core wire meets the preset standard; If the drawing thermal representation value is greater than or equal to the first preset drawing thermal representation value and less than the second preset drawing thermal representation value, it is determined that the preparation of the powder core wire has a risk of not meeting the standard, and whether the preparation of the powder core wire meets the preset standard is determined according to the diameter fluctuation range of the powder core wire; If the drawing thermal representation value is greater than or equal to the second preset drawing thermal representation value, it is determined that the preparation of the powder core wire does not meet the preset standard, and the reason why the preparation of the powder core wire does not meet the preset standard is determined according to the thermal abnormal aggregation degree of the powder core wire, wherein the reason is that the internal friction of the alloy powder is too large or the plasticity of the metal outer skin is insufficient; the value range of the first preset drawing thermal representation value is [1.2 DEG C, 2.1 DEG C], and the value range of the second preset drawing thermal representation value is [2.9 DEG C, 3.8 DEG C]; The powder core wire meeting the preset standard is taken up to obtain a boiler tube row anti-sulfur corrosion cladding material, wherein the boiler tube row anti-sulfur corrosion cladding material comprises alloy powder and a metal outer skin, and the material of the metal outer skin is stainless steel; the alloy powder comprises the following components in mass fraction: C: <=0.10wt.%; Mn: <=0.50wt.%; Si: <=0.50wt.%; P: <=0.015wt.%; S: <=0.015wt.%; Cr: 20.0-23.0wt.%; (Nb+Ta): 3.15-4.15wt.%; Co: <=1.0wt.%; Mo: 8.0-10.0wt.%; Fe: <5.0wt.%; Al: <=0.40wt.%; Ti: <=0.40wt.%; Ni: balance.

2. The method of claim 1, wherein the method further comprises: The preset vibration frequency for the next batch of blank preparation is increased by several frequency adjustment modes, and the increase amplitude of each frequency adjustment mode is different.

3. The method of claim 2, wherein the method further comprises: The acquisition process of the drawing thermal characteristic value includes: Taking a thermal image of the powder core wire with a preset length; Based on the thermal image, obtaining several surface temperatures of the powder core wire; Calculating the standard deviation of the several surface temperatures, denoted as the drawing thermal characteristic value.

4. The method of claim 3, wherein the method further comprises the step of: When the comparison result of the diameter fluctuation range of the powder core wire is greater than or equal to a preset diameter fluctuation range, it is determined that the preparation of the powder core wire does not meet the preset standard, and the preset drawing speed for the next batch of blank preparation is reduced according to the difference between the diameter fluctuation range and the preset diameter fluctuation range. The diameter fluctuation range is the difference between the maximum diameter of the powder core wire and the minimum diameter of the powder core wire.

5. The method of claim 4, wherein the method further comprises the step of: The reduction amplitude of the preset drawing speed for the next batch of blank preparation is positively correlated with the diameter fluctuation deviation value, wherein the diameter fluctuation deviation value is the difference between the diameter fluctuation range and the preset diameter fluctuation range.

6. The method of claim 5, wherein the method further comprises the step of: The process of determining the cause of the preparation of the powder core wire not meeting the preset standard according to the thermal anomaly aggregation degree of the powder core wire includes: If the thermal anomaly aggregation degree is less than a preset thermal anomaly aggregation degree, it is determined that the plasticity of the metal sheath is insufficient; If the thermal anomaly aggregation degree is greater than or equal to the preset thermal anomaly aggregation degree, it is determined that the internal friction of the alloy powder is too large.

7. The method of claim 6, wherein the method further comprises the step of: The acquisition process of the thermal anomaly aggregation degree includes: Sort the temperature values of all pixel points in the thermal image from high to low, determine the highest temperature value in the thermal image, take the highest temperature value as the upper limit, take a preset temperature value as the lower limit, and record the pixel points in the temperature interval as relative hot spots; Statistical space position of the number of independent connected regions formed by adjacent relative hot spots, denoted as the thermal anomaly aggregation degree; Wherein, the preset temperature value is the temperature value corresponding to the first preset percentage in the sequence of all pixel temperature values in the thermal image sorted from high to low.

Images