A method and system for determining the range of heat effects on the heat resistance of low temperature primers

Abstract

The application provides a method and system for determining the heat resistance influence range of welding heat on low-temperature primer, the method comprising: building a simulated weld according to an actual welding structure; arranging n reference lines on the surface of the plate, the reference lines being parallel to the simulated weld and having the same interval; arranging a temperature measuring point on each reference line; segmentally welding the weld according to a preset unit weld length, and recording the temperature value of the temperature measuring point; and determining the preselection result of the heat resistance influence range boundary line based on the temperature value of the temperature measuring point. The technical scheme of the application can accurately measure the temperature by arranging multiple reference lines and temperature measuring points around the weld, determine the heat resistance influence range of welding heat on the low-temperature primer, reduce unnecessary polishing and repairing, save resources, and improve the construction efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ship welding, in particular to a method and system for determining the influence range of welding heat on the heat resistance of low-temperature primer. BACKGROUND

[0002] In the construction process of a thin-film LNG ship, the integrity of the Mark_III containment system is one of the key technical indicators. In the later stage of the construction of the cargo hold, process holes are opened on the side inner shell plate to improve the efficiency and convenience of the construction, but at the same time, it also brings corresponding difficulties. In the process of sealing and repairing the process holes, the welding heat generated will damage the low-temperature primer on the inner shell plate, so the primer on the edge of the process hole needs to be completely removed and the low-temperature primer needs to be repainted after the process hole is sealed and repaired. There is no special method to determine the area of the influence range of the welding heat on the heat resistance of the low-temperature primer, and only the experience of workers and the detection of the temperature gun outside the 300mm area of the process hole are relied on to ensure that the temperature of the area does not exceed 82℃.

[0003] According to experience and the temperature gun, the protection of the low-temperature primer in the construction process can be met, but there are still some deficiencies. First, the temperature gun cannot continuously measure the temperature, and the workers cannot guarantee that the detection point always falls in one position in the actual application process, and for the steel plate, a deviation of a few millimeters may cause a temperature difference of more than 10℃, so the accuracy of the measurement cannot be guaranteed. Second, the current guarantee construction detection scheme, i.e. detecting the temperature outside the 300mm area of the process hole, basically detects the temperature below 60℃, which meets the requirements in terms of results, but it leads to the fact that the area of the low-temperature primer that needs to be polished and then repaired reaches 17.5㎡, which not only wastes a large amount of low-temperature primer and human cost, but also causes the insulation box and the corrugated plate in this part of the area to be unable to be installed, affecting the integrity of the containment system and reducing the construction efficiency. Finally, in the early construction process, the measurement area and data are based on experience and hand-holding, so there are certain flaws in the accuracy and rationality of the data. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a method and system for determining the influence range of welding heat on the heat resistance of low-temperature primer, which accurately measures the temperature by arranging a plurality of reference lines and temperature measuring points around the weld, determines the influence range of welding heat on the heat resistance of low-temperature primer, reduces unnecessary polishing and repair, saves resources, and improves the construction efficiency.

[0005] In a first aspect, a method for determining the influence range of welding heat on the heat resistance of low-temperature primer is provided, comprising:

[0006] S0, according to the actual welding structure, a simulation weld is built by using the same plate material as the actual one;

[0007] S1, setting n reference lines on the surface of the plate material, the reference lines being parallel to the simulated weld, and the reference lines being sequentially the first reference line, the second reference line,..., and the nth reference line from the direction close to the simulated weld to the direction away from the simulated weld;

[0008] S2, setting a temperature measuring point on each reference line; wherein the temperature measuring point on the ith reference line is Pi;

[0009] S3, segmentally welding the weld according to a preset unit welding segment length L, and recording the temperature values of the temperature measuring points; wherein the temperature value of the temperature measuring point Pi is Ti;

[0010] S4, determining the preselected result of the heat resistance influence range boundary line based on the temperature values of the temperature measuring points; comprising:

[0011] judging whether the temperature value Ti of the outermost temperature measuring point Pn is less than the preset heat resistance temperature value Tm;

[0012] if yes, determining the temperature measuring point Tx closest to the preset heat resistance temperature value Tm and having a temperature value less than the preset heat resistance temperature value Tm, and taking the xth reference line where the temperature measuring point Tx is located as the preselected result of the heat resistance influence range boundary line, wherein x = 1, 2, 3,..., n; x x

[0013] if no, decreasing the value of the preset unit welding segment length L according to a preset interval difference, and repeating steps S3 to S4; if the temperature value Ti of the temperature measuring point Pn is still greater than or equal to the preset heat resistance temperature value Tm when the preset unit welding segment length L is decreased to the lower limit value of the preset unit welding segment length, increasing the number of the reference lines, and repeating steps S2 to S4.

[0014] In an implementable scheme, after determining the xth reference line where the temperature measuring point Tx is located as the preselected result of the heat resistance influence range boundary line in step S4, the scheme further comprises:

[0015] S5, verifying and confirming the preselected result of the heat resistance influence range boundary line; comprising:

[0016] setting a plurality of verification temperature measuring points with uniform intervals along the xth reference line; the verification temperature measuring points being C1, C2,..., and Cm;

[0017] recording the temperatures of the verification temperature measuring points during the segmental welding; wherein the temperature value of the verification temperature measuring point Ci is Ei;

[0018] judging whether the temperatures of all the verification temperature measuring points are less than the preset heat resistance temperature value Tm;

[0019] ​​If yes, the xth reference line is determined as the final heat resistance influence range boundary line;

[0020] If no, the x+1th reference line is selected as the preselected result of the heat resistance influence range boundary line, and step S5 is repeated.

[0021] In an implementable scheme, the number of temperature measurement points is at least 3.

[0022] In an implementable scheme, the number of reference lines is greater than or equal to 3.

[0023] In an implementable scheme, the spacing between adjacent reference lines ranges from 20 to 70 mm.

[0024] In an implementable scheme, the spacing between adjacent reference lines is 50 mm.

[0025] In an implementable scheme, the distance between the first reference line and the simulated weld is 50 to 150 mm.

[0026] In an implementable scheme, the preset unit weld length L ranges from 300 to 500 mm.

[0027] In an implementable scheme, in step S4, the preset interval difference is 50 to 100 mm.

[0028] The second aspect also provides a system for determining the heat resistance influence range of welding heat on low-temperature primer, comprising:

[0029] A simulated plate is used to build a simulated weld identical to the actual weld;

[0030] A first thermocouple probe is used to set n reference lines parallel to the simulated weld on the surface of the simulated plate, and a first thermocouple probe is installed on each reference line.

[0031] A first temperature display device is connected to the first thermocouple probe and used to display the temperature measured by each first thermocouple probe.

[0032] A second thermocouple probe is used to set at least three second thermocouple probes on the xth reference line in a uniform spacing after the xth reference line is determined as the preselected result of the heat resistance influence range boundary line.

[0033] A second temperature display device is connected to the second thermocouple probe and used to display the temperature measured by each second thermocouple probe.

[0034] Compared with the prior art, the application has at least the following beneficial effects:

[0035] The method and system for determining the heat resistance influence range of low-temperature primer by welding heat according to the application, by setting multiple reference lines near the weld and setting temperature measurement points on each reference line, the temperature of the temperature measurement points on the reference lines is measured, the reference line of the heat resistance influence range of low-temperature primer by welding heat is determined, and the grinding and repairing area is determined as the area within the determined reference line, which effectively improves the accuracy of the determination of the heat resistance influence range of low-temperature primer by welding heat, reduces the grinding and repairing range of low-temperature primer, saves the consumption of low-temperature primer, is conducive to environmental protection, and also reduces the construction amount and improves the construction efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0037] Figure 1 A flowchart of a method for determining the heat resistance influence range of low-temperature primer by welding heat according to an embodiment of the application is shown.

[0038] Figure 2 A composition schematic diagram of a system for determining the heat resistance influence range of low-temperature primer by welding heat according to an embodiment of the application is shown.

[0039] Figure 3 A structural schematic diagram of a transverse butt joint groove is shown.

[0040] Figure 4 A weld layer arrangement schematic diagram of a transverse butt joint groove is shown.

[0041] Figure 5 A structural schematic diagram of a vertical butt joint groove is shown.

[0042] Figure 6 A weld layer arrangement schematic diagram of a vertical butt joint groove is shown. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the application more clear, the technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some of the embodiments of the application, not all of the embodiments. The components of the embodiments of the application described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] like Figure 1 As shown, this application first provides a method for determining the range of influence of welding heat on the heat resistance of low-temperature primer, including:

[0046] S0, such as Figure 2 As shown, a simulated weld 101 was constructed using the same plate material as the actual weld structure.

[0047] S1. Set n equally spaced baselines 102 parallel to the simulated weld on the surface of the plate. The baselines are named as the first baseline, the second baseline, ... the nth baseline, in the direction from the closest to the simulated weld to the furthest from the simulated weld.

[0048] S2. Set a temperature measurement point on each baseline 102; where the temperature measurement point on the i-th baseline is P. i ;

[0049] S3. Perform segmented welding of the weld seam according to the preset unit weld segment length L, and record the temperature values ​​at the temperature measuring points; where the temperature measuring point P... i The temperature value is denoted as T i ;

[0050] S4. Based on the temperature values ​​at the measurement points, determine the preliminary selection results of the boundary line of the heat resistance influence range; including:

[0051] Determine the outermost temperature measuring point P n Temperature value T i Is it less than the preset heat resistance temperature value T? m Size;

[0052] If so, then it is determined that the temperature value is less than the preset heat resistance temperature value T. m And it is closest to the preset heat resistance temperature value T m Temperature measurement point T x Temperature measurement point T x The x-th baseline is the pre-selected boundary line of the heat resistance influence range, where x = 1, 2, 3...n;

[0053] If not, then decrease the preset unit weld length L by the preset interval difference, and repeat steps S3 to S4; if the preset unit weld length L decreases to the lower limit of the preset unit weld length, the temperature measuring point P... n Temperature value T iStill greater than or equal to the preset heat resistance temperature value T m If so, increase the number of baselines and repeat steps S2 to S4.

[0054] In this embodiment, as Figure 1 As shown, in step S4, the temperature measurement point T is determined. x Following the preliminary selection of the x-th baseline as the boundary line of the heat resistance influence range, the following also includes:

[0055] S5. Verify and confirm the pre-selected boundary line of the determined heat resistance influence range; including:

[0056] Multiple uniformly spaced calibration temperature measurement points are set along the x-th baseline; the calibration temperature measurement points are C1, C2...C... m ;

[0057] During the segmented welding process, the temperature of the verification temperature measurement points is recorded; among them, the verification temperature measurement point C... i The temperature value is denoted as E i ;

[0058] Determine whether the temperature at all calibration temperature measurement points is lower than the preset heat resistance temperature value T. m Size;

[0059] If so, then the xth baseline is determined as the final boundary line of the heat resistance influence range;

[0060] If not, select the (x+1)th baseline as the pre-selected result of the boundary line of the heat resistance influence range, and repeat step S5.

[0061] In this embodiment, the number of temperature measurement points for verification can be at least three.

[0062] In this embodiment, the number of baselines can be greater than or equal to 3, for example, 3 or 4 can be set initially.

[0063] In this embodiment, the spacing between adjacent baselines ranges from 20 to 70 mm. In a preferred embodiment, the spacing between adjacent baselines is set to be less than or equal to 50 mm.

[0064] In this embodiment, the distance between the first baseline and the simulated weld can be 50 to 150 mm, for example, 50 mm, 80 mm, 100 mm, 120 mm, 150 mm, etc.

[0065] In this embodiment, the preset unit weld segment length L can be in the range of 300 to 500 mm. In step S3, when performing the first segmented welding, the preset unit weld segment length L can be set to 500 mm.

[0066] In the embodiment, in the step S4, the preset interval difference value can be 50-100 mm, for example, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, etc.

[0067] As shown in Figure 2 , the embodiment of the application provides a system for determining the heat resistance influence range of welding heat on low-temperature primer, comprising:

[0068] The simulation plate 1 is used to build the same simulation weld 101 as the actual weld;

[0069] The first thermocouple probe 2 is arranged on the surface of the simulation plate 1 to form n reference lines 102 parallel to the simulation weld 101, and one first thermocouple probe 2 is arranged on each reference line 102;

[0070] The first temperature display device 3 is connected with the first thermocouple probe 2 and used to display the temperature measured by each first thermocouple probe 2;

[0071] After the xth reference line is determined as the preselected result of the heat resistance influence range boundary line, at least three second thermocouple probes 4 are arranged on the xth reference line in a uniform interval;

[0072] The second temperature display device 5 is connected with the second thermocouple probe 4 and used to display the temperature measured by each second thermocouple probe 4.

[0073] In order to describe the steps of the foregoing technical solution and the effects in detail, the following actual experiment process and experiment data are provided.

[0074] Firstly, in the welding of a certain grade of steel plate, the technical index of the heat resistance of the low-temperature primer is determined, and according to the technical requirements of the product using primer (model VP-186), the continuous heating is ≯(not greater than) 82℃, and the intermittent heating is ≯(not greater than) 93℃. That is, the preset heat resistance temperature value T m in the foregoing step S4 is not greater than 93℃.

[0075] As shown in Figure 3 , a simulation weld is built as a horizontal butt joint groove, CO2 gas protection single horizontal butt joint welding is adopted, the groove angle is 25° for the upper groove and 15° for the lower groove, and the plate assembly gap is 6 mm. As shown in Figure 5As shown, a welding seam is built to simulate a vertical butt joint groove, and a CO2 gas shielded single-side vertical butt joint welding is adopted, the groove angle of the left and right sides is 20°, and the plate assembly gap is 6mm. The welding material is a flux-cored wire with a diameter of 1.2mm. The welding process parameters are in accordance with the actual shipbuilding parameters, and the specific data is shown in Table 1.

[0076] Table 1 Welding process parameter table

[0077]

[0078] According to the steps S1 and S2 of the present embodiment, reference is made to Figure 2 Three reference lines are first set at the welding seam. According to the construction experience, the temperature rise caused by the welding heat at 300mm from the welding seam edge is generally 50-60℃ (the cabin environment temperature of the shipbuilding is 23℃), so the distance of the three reference lines from the simulated welding seam is 100mm, 150mm and 200mm from near to far. One temperature measuring point is set on each of the three reference lines. After setting, steps S3 and S4 are performed.

[0079] The welding process strictly refers to the actual situation for welding. The welding seam layer arrangement of the horizontal welding is as shown in Figure 4 The welding seam layer arrangement of the vertical welding is as shown in Figure 6 The first welding is segmented according to the length of 500mm per segment (preset unit welding segment length L). Since the plate material used in the experiment is a common strength low-carbon steel material, preheating and post-heating treatment are not required, and the interpass temperature of welding is controlled below 90℃.

[0080] During the welding process, if the temperature of the probe at the 200mm reference line is greater than 82℃, the welding is stopped. The length of the preset unit welding segment length L is reduced, and the next welding segment is welded as a single welding segment of 400mm. If the temperature still exceeds the standard, the welding segment length can be further reduced to 300mm (the lower limit value of the preset unit welding segment length). When the welding process of the 300mm welding segment also exceeds the temperature standard, the temperature measuring reference line is expanded, and each time 50mm is added outward until the temperature meets the requirements.

[0081] In addition, during the welding process, it is determined that the temperature of the temperature measuring point at the 150mm reference line in the horizontal welding and the vertical welding does not exceed the upper limit of the heat resistance, which is the reference line closest to the upper limit of the heat resistance of the low-temperature primer. Therefore, three calibration temperature measuring points are arranged at the 150mm reference line. When recording the temperature of the calibration temperature measuring point, the maximum value of the three calibration temperature measuring points at the 150mm reference line or the average value of the three calibration temperature measuring points can be recorded.

[0082] During horizontal and vertical welding, the maximum temperature values ​​of each measurement baseline were recorded for each weld pass. These values ​​are shown in Tables 2 and 3 below. In the tables below, column T1 of each baseline represents the temperature measurement point P. i The temperature values ​​are shown in column T2, which represents the temperature values ​​obtained from the temperature measurement points during verification.

[0083] Table 2 Temperature Measurement Record of Butt Welding in Horizontal Position

[0084]

[0085] Table 3. Temperature Measurement Record of Vertical Butt Welding

[0086]

[0087] The data above confirms that the 150mm baseline is the pre-selected boundary line of the heat resistance influence range. After verification by checking the temperature measurement points, the 150mm baseline is confirmed as the final result of the heat resistance influence range boundary line.

[0088] Therefore, during the actual ship construction process, the area requiring grinding and repair after the sealing and welding of the cargo hold inner hull process doors is within 150mm of the weld edge. The area requiring low-temperature primer grinding has been expanded from the original 300mm weld edge, resulting in a total construction area of ​​17.5m². 2 Reduced to 8.4m 2 This not only saves on the consumption of low-temperature primer, which is beneficial to environmental protection, but also reduces the amount of construction work and improves construction efficiency. Meanwhile, this 9.1m... 2 Enclosure system construction can be carried out to further improve the integrity of the insulation layer and corrugated sheet installation.

[0089] In summary, the method and system for determining the range of influence of welding heat on the heat resistance of low-temperature primers in this embodiment, by setting multiple baselines near the weld and setting temperature measurement points on each baseline, analyzes and determines the baseline of the range of influence of welding heat on the heat resistance of low-temperature primers by measuring the temperature of the measurement points on the baselines, and then determines that the grinding and repair area is within the determined baseline area. This effectively improves the accuracy of determining the range of influence of welding heat on the heat resistance of low-temperature primers, reduces the grinding and repair area of ​​low-temperature primers, saves the consumption of low-temperature primers, is beneficial to environmental protection, reduces the amount of construction work, and improves construction efficiency.

[0090] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for determining the range of influence of welding heat on the heat resistance of low-temperature primers, characterized in that, include: S0. Construct a simulated weld using the same plate material as the actual weld structure; S1. Set n equally spaced baselines parallel to the simulated weld on the surface of the plate. The baselines are named as the first baseline, the second baseline, ... the nth baseline, in the direction from the closest to the simulated weld to the furthest from the simulated weld. S2. Set a temperature measurement point on each baseline; where the temperature measurement point on the i-th baseline is P. i ; S3. Perform segmented welding of the weld seam according to the preset unit weld segment length L, and record the temperature values ​​at the temperature measuring points; where the temperature measuring point P... i The temperature value is denoted as T i ; S4. Based on the temperature values ​​at the measurement points, determine the preliminary selection results of the boundary line of the heat resistance influence range; including: Determine the outermost temperature measuring point P n Temperature value T i Is it less than the preset heat resistance temperature value T? m Size; If so, then it is determined that the temperature value is less than the preset heat resistance temperature value T. m And it is closest to the preset heat resistance temperature value T m Temperature measurement point T x Temperature measurement point T x The x-th baseline is the pre-selected boundary line of the heat resistance influence range, where x = 1, 2, 3...n; If not, then decrease the preset unit weld length L by the preset interval difference, and repeat steps S3 to S4; if the preset unit weld length L decreases to the lower limit of the preset unit weld length, the temperature measuring point P... n Temperature value T i Still greater than or equal to the preset heat resistance temperature value T m If so, increase the number of baselines and repeat steps S2 to S4.

2. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 1, characterized in that, In step S4, the temperature measurement point T is determined. x Following the preliminary selection of the x-th baseline as the boundary line of the heat resistance influence range, the following also includes: S5. Verify and confirm the pre-selected boundary line of the determined heat resistance influence range; including: Multiple uniformly spaced calibration temperature measurement points are set along the x-th baseline; the calibration temperature measurement points are C1, C2...C... m ; During the segmented welding process, the temperature of the verification temperature measurement points is recorded; among them, the verification temperature measurement point C... i The temperature value is denoted as E i ; Determine whether the temperature at all calibration temperature measurement points is lower than the preset heat resistance temperature value T. m Size; If so, then the xth baseline is determined as the final boundary line of the heat resistance influence range; If not, select the (x+1)th baseline as the pre-selected result of the boundary line of the heat resistance influence range, and repeat step S5.

3. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 2, characterized in that, The number of temperature measurement points for verification is at least three.

4. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 1 or 2, characterized in that, The number of baselines is greater than or equal to 3.

5. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 4, characterized in that, The spacing between adjacent baselines ranges from 20 to 70 mm.

6. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 4, characterized in that, The spacing between adjacent baselines is 50mm.

7. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 4, characterized in that, The distance between the first baseline and the simulated weld is 50-150 mm.

8. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 1 or 2, characterized in that, The preset unit weld length L ranges from 300 to 500 mm.

9. The method for determining the range of influence of welding heat on the heat resistance of low-temperature primer according to claim 8, characterized in that, In step S4, "reduce the preset unit weld length L according to the preset interval difference", the preset interval difference is 50-100mm.

10. A system for determining the range of influence of welding heat on the heat resistance of low-temperature primers, characterized in that, include: Simulated plate (1) is used to build a simulated weld (101) that is identical to the actual weld; The first thermocouple probe (2) is set on the surface of the simulated plate (1) with n equally spaced reference lines (102) parallel to the simulated weld (101), and one first thermocouple probe (2) is installed on each reference line (102); The first temperature display device (3) is connected to the first thermocouple probe (2) and is used to display the temperature measured by each of the first thermocouple probes (2); After determining the xth baseline as the boundary line of the heat resistance influence range, at least three of the second thermocouple probes (4) are set on the xth baseline in a uniformly spaced manner. The second temperature display device (5) is connected to the second thermocouple probe (4) and is used to display the temperature measured by each of the second thermocouple probes (4).

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