Metallic device welding repair process

Abstract

The application relates to the field of equipment repair, and particularly discloses a metal equipment welding repair process, which comprises the following steps: S1, surface pretreatment; S2, selecting welding glue satisfying m0>=m1 and m0 and m1 both being not greater than 0.5 as the welding glue to be used; S3, constructing a glue smearing area: for the observation shape of the contact surface of an inlay block, a similar polygon is drawn in the surface of the contact surface of the inlay block, the distance between the similar polygon and the corresponding side of the inlay block is kept between 3-10 mm, an equivalent figure is constructed in the similar polygon, the equivalent figure area S0 of the equivalent figure is calculated, and the welding glue is smeared on the contact surface of the inlay block, and the smearing area of the welding glue is S; S4, smearing the welding glue: the welding glue is smeared on the contact surface of the inlay block according to the smearing area S0; then the inlay block is contacted with the equipment repair part and a load is loaded; S5, welding; and S6, surface treatment. The application has the characteristics of improving the shearing resistance of the repaired part and improving the welding quality.

Description

Technical Field

[0001] This application relates to the field of equipment welding technology, and more specifically, to a welding repair process for metal equipment. Background Technology

[0002] As equipment ages or operates under fatigue, it typically requires maintenance. To extend the service life of devices and various types of equipment, welding repair technology has increasingly attracted attention.

[0003] For certain critical equipment, especially when the surface wear is severe and sufficient shear resistance is required, it is common practice to weld the insert directly to the repair area. However, when the repair is challenging, such as when the insert shape is extremely irregular, the insert thickness is large, or the stress conditions are complex, welding the insert directly to the repair area is unreliable. The main reason is that a gap always exists between the bottom of the insert and the repair area, and the fixation relies entirely on the weld strength. Equipment repaired using this method is prone to operational risks due to poor shear resistance, and the repair quality is unreliable. Summary of the Invention

[0004] To improve the shear resistance of the repaired area and enhance welding quality, this application provides a welding repair process for metal equipment.

[0005] This application provides a welding repair process for metal equipment, employing the following technical solution: A welding repair process for metal equipment includes the following steps: S1. Surface pretreatment of the repair area; S2. Selection of welding adhesive: Calculate the risk factor m0 of the compressive strength of the welding adhesive. In the above formula, σ max This represents the maximum compressive stress of the welding adhesive. Calculate the risk factor m1 for the shear resistance of the welding adhesive. In the above formula, τ0 is the shear stress borne by the insert, τ max This represents the maximum shear stress resisted by the welding adhesive. Select a welding adhesive that satisfies m0≥m1 and both m0 and m1 are not greater than 0.5 as the welding adhesive to be used; S3, Attachment application area: Observe the shape of the surface to be contacted by the insert, make similar polygons on the surface of the surface to be contacted by the insert, keep the distance between the similar polygons and the corresponding sides of the insert between 3-10mm, construct an equivalent shape in the similar polygons, calculate the area of ​​the equivalent shape S0, and apply welding adhesive to the surface to be contacted by the insert, the area of ​​welding adhesive application is S. S4. Apply welding adhesive: Apply the welding adhesive selected in step S2 to the contact surface of the insert according to the application area S, with a thickness of 1-3mm. Then, the contact surface of the insert is brought into contact with the part of the equipment being repaired, and a load is applied to the surface of the insert until the welding adhesive has solidified; S5. Welding: Welding is used to fill the gap between the insert and the equipment; S6. Surface treatment is performed after welding.

[0006] By adopting the above technical solution, this application uses a combination of welding adhesive and welding for the welding repair of equipment. First, welding adhesive with sufficient connection strength is applied to the bottom of the insert. Then, the insert is bonded to the equipment using the welding adhesive, solving the problem of fixing the contact surface between the insert and the repaired part. Next, a load is applied to the insert to further improve the adhesion effect of the welding adhesive and improve the shear resistance of the contact surface. Finally, after the welding adhesive has solidified, the insert is welded, effectively solving the shear resistance problem of the repaired part, significantly improving the shear resistance of the repaired part, and improving the quality of welding repair.

[0007] Furthermore, this application focuses on the selection of welding adhesive and the welding area. Firstly, a welding adhesive with suitable bonding strength is selected to provide a basic guarantee for the adhesion between the insert and the equipment surface. Secondly, practical experience shows that the area of ​​the welding adhesive application significantly affects the final bonding effect, thus impacting the quality of the welding repair and the safe operation of the equipment. If the welding adhesive application area is small, less adhesive is applied, the weld strength is weak, and its effect is limited. This can lead to the insert suddenly detaching from the equipment surface, damaging surrounding equipment and personnel, posing a safety hazard. However, when the bonding area is large, excess welding adhesive overflows from the insert edge under load and is difficult to remove after drying and curing, requiring manual grinding. In some working conditions, such as inside a wind turbine tower, where space is confined and equipment occupies a portion of the space, it is impossible to remove the overflowing welding adhesive with a grinding wheel. If the overflowing welding adhesive is not removed, or even if it does not overflow but is very close to the insert edge, the high welding temperature can cause the already solidified welding adhesive to melt and vaporize, forming numerous small and dense pores at the weld, resulting in a substandard weld with insufficient strength, threatening the safe operation of the equipment. Therefore, in this application, by constructing the area for applying welding adhesive, a similar polygon is made for the contact surface of the insert, and the distance between the similar polygon and the corresponding side of the insert is controlled. In addition, an equivalent graphic with a larger area is constructed within the similar polygon. The area for applying welding adhesive is based on the effective area of ​​the equivalent graphic. This not only ensures that more welding adhesive is applied to the contact surface of the insert to guarantee the subsequent bonding strength, but also reduces the probability of the welding quality being affected by local overflow of welding adhesive. Ultimately, this improves the shear resistance of the welded repair part and ensures the quality of the weld repair.

[0008] Optionally, when similar polygons are divided into several triangles, the area to be covered is smeared onto each triangle according to a smeared area S. The smeared area S of each triangle is obtained by the following method: S31: Constructing an equivalent figure using triangles: S311: Determine the axis, specifically including the following steps: S3111: First, select two angles, and draw a circle on the angle bisector of each angle. The circle is tangent to the two sides of the angle. Shorten the corresponding endpoints of the two angles of the triangle by 10-30% along the direction of the angle bisector to get the center of the two circles. Then connect the centers of the two circles to make a line connecting the centers. S3112: The extensions of the two ends of the line connecting the centers intersect the two circles at points A and B respectively, and the line segment AB serves as axis 1; S3113: Starting from the third endpoint C of the triangle, draw a perpendicular line to axis 1. The perpendicular line is axis 2. The perpendicular point O divides axis 1 into axis a and axis b. The length of axis a is a, denoted by AO; the length of axis b is b, denoted by BO. S3114: Point C is shortened by 20% along the vertical direction to obtain point D, which satisfies DO = 0.8CO. DO is the c-axis, and the length of the axis is c, denoted by DO. S312: Constructing an equivalent graphic: With O as the origin of the ellipse and 2a and 2c as axes, draw an ellipse, keeping only the AOD part, and denote it as equivalent figure A; with 2b and 2c as axes, draw an ellipse, keeping only the BOD part, and denote it as equivalent figure B. S313: The equivalent figure consists of equivalent figure A and equivalent figure B, and the area of ​​the equivalent figure is... S314: The area S of the welding adhesive application is 0.85S0.

[0009] Optionally, in step S3, when similar polygons are divided into several triangles and quadrilaterals, each triangle and quadrilateral is coated with a coating area S. The coating area S of the quadrilateral is obtained by the following method: S32: Constructing an equivalent figure using quadrilaterals: S321: Determine the axis, including the following steps: S3211: First, select two angles on the diagonal. Draw a circle on the angle bisector of each angle, with the circle tangent to both sides of the angle. Then, shorten the corresponding endpoints of the two angles by 10-30% along the direction of the angle bisector to form the centers of the two circles. Finally, connect the centers of the two circles to form a line connecting the centers. S3212: The extensions of the two ends of the line connecting the centers intersect the two circles at points A and B respectively, and the line segment AB serves as axis 1; S3213: Starting from the other two points of the quadrilateral, draw perpendicular lines to axis 1. The perpendicular lines intersect the sides of the quadrilateral. Take the longest perpendicular line as axis 2. The perpendicular point O divides axis 1 into axis a and axis b. The length of axis a is a, denoted by AO; the length of axis b is b, denoted by BO. The perpendicular point O divides axis 2 into axis c and axis d. The length of axis c is c, denoted by C0; the length of axis d is d, denoted by DO. S322: Constructing an equivalent graphic: With O as the origin of the ellipse and 2a and 2c as axes, draw an ellipse, keeping only the AOC portion, which is denoted as equivalent figure 1; with 2b and 2c as axes, draw an ellipse, keeping only the BOC portion, which is denoted as equivalent figure 2; with 2a and 2d as axes, draw an ellipse, keeping only the AOD portion, which is denoted as equivalent figure 3; with 2b and 2d as axes, draw an ellipse, keeping only the BOD portion, which is denoted as equivalent figure 4; S323: The equivalent figure is composed of equivalent figure 1, equivalent figure 2, equivalent figure 3, and equivalent figure 4; S324: Calculate the welding adhesive application area S: S3241: Take a point a0 on the a-axis, satisfying Oa0 = 0.9a; take a point b0 on the b-axis, satisfying Ob0 = 0.9b; take a point c0 on the c-axis, satisfying Oc0 = 0.9c; take a point d0 on the d-axis, satisfying Od0 = 0.9d; S3242: Draw a straight line through point a0 parallel to the c-axis and d-axis, intersecting the equivalent figure at two points, with a length of L1 between the two points; draw a straight line through point b0 parallel to the c-axis and d-axis, intersecting the equivalent figure at two points, with a length of L2 between the two points; draw a straight line through point c0 parallel to the a-axis and b-axis, intersecting the equivalent figure at two points, with a length of L3 between the two points; draw a straight line through point d0 parallel to the a-axis and b-axis, intersecting the equivalent figure at two points, with a length of L4 between the two points; S3243: Distinguish between the values ​​of (L1+L2)(c+d) and (L3+L4)(a+b), and keep only the larger one; S3244: Based on the discrimination result, if (L1+L2)(c+d) is larger, compare the sizes of L1 and L2, and record the larger one as H and the smaller one as h; if (L3+L4)(a+b) is larger, compare the sizes of L3 and L4, and record the larger one as H and the smaller one as h. S3245: If (L3+L4)(a+b) is large, the adhesive bonding area S = (0.98h+H)(a+b)×θ. If (L1+L2)(c+d) is large, the adhesive bonding area S = (0.98h+H)(c+d)×θ. θ is the deviation coefficient, which ranges from 0.45 to 0.69.

[0010] By adopting the above technical solution and determining the area of ​​the welding adhesive applied to the insert according to the above method, the final adhesion effect of the welding adhesive is better, while minimizing the overflow of welding adhesive and reducing the probability of the weld quality being affected by local overflow of welding adhesive. Ultimately, this improves the shear resistance of the welded repair part and ensures the quality of the weld repair.

[0011] Optionally, in step S4, the loading force F0 for the load applied to the surface of the insert is: F0=K0m0Sσ0 In the above formula, K0 is 0.01-0.03, σ0 is the compressive stress borne by the insert, m0 is the risk coefficient of the compressive performance of the welding adhesive, and S is the area of ​​the welding adhesive application.

[0012] By adopting the above technical solution and applying an external load to the insert after the welding adhesive is applied, the bonding effect between the insert and the repair area is significantly improved, thereby significantly improving the shear resistance of the final repair area and improving the quality of welding repair.

[0013] Optionally, in step S4, after applying the welding adhesive, the temperature of the welding adhesive area is controlled to be 30-120℃.

[0014] Optionally, after welding in step S5, a cleaning process to remove welding pores is performed. The specific steps are as follows: Repair agent A is used to fill the pores smaller than 3mm. Repair agent A is welding electrode coating powder. Repair agent B is used to fill the pores with a size greater than or equal to 3 mm. Repair agent B is a mixture of welding electrode coating powder and metal powder. Then, use 1.1-1.5mm welding material to weld and repair the porosity area.

[0015] By adopting the above technical solution, when the welding adhesive melts and vaporizes, it is very easy to generate pores at the root of the weld, which reduces the welding quality. Therefore, in this application, welding pores are cleaned after welding.

[0016] Conventional porosity removal mainly involves directly welding at the pore location or grinding away the pores before welding. However, direct welding has several drawbacks. First, when dealing with small or densely packed pores, while welding can reduce the number of pores, it also enlarges the pores, resulting in poorer weld quality. Furthermore, direct welding can cause the adhesive to regenerate new pores due to secondary heating, potentially increasing the overall number of pores. Second, grinding away the pores before welding presents challenges. In confined spaces, removing pores with a grinding wheel is difficult. Even in larger spaces where grinding is feasible, the resulting pores can still create problems. This indicates that the welding adhesive is very close to the ground area. Therefore, when welding again after grinding, the welding adhesive will still decompose due to heat, producing gas and forming new pores. Moreover, after multiple grinding and welding repairs, the bonding area and bonding effect of the welding adhesive will be affected, thereby reducing the quality of the welding repair. Therefore, these two conventional repair methods are not applicable to the working conditions of the welding adhesive-welding combination used in this application. Therefore, this application uses a repair agent to fill the pores, and then fills the pore positions during the melting of the welding rod. The powder is removed from the air by the action of the electric arc, thus achieving pore cleaning.

[0017] Optionally, in the welding porosity cleaning process, the metal powder in the repair agent B is the metal powder obtained after grinding the welding core of the welding rod. The metal powder and the welding rod coating powder are mixed at a mass ratio of 1:(1.5-3) to obtain the repair agent B.

[0018] By adopting the above technical solution, small pores are filled with flux powder. First, the flux powder occupies the air that was originally occupied by gas. Then, during the melting of the welding material, it fills the position of the small pores. With the help of the arc blowing force, the powder is gradually removed from the small pores, thus cleaning the small pores. During the process, the melted and vaporized part of the flux powder plays a role in protecting the transition of the welding droplets. For large pores, since the space of the large pores is relatively large, the flux powder alone is not enough with the pushing force of the welding arc. Therefore, for the repair of large pores, this application adopts a mixture of metal powder and flux powder. First, the flux powder and metal powder occupy the air that was originally occupied by gas. Then, during the melting of the welding material, they fill the position of the pores. With the help of the arc blowing force, the flux powder is gradually removed from the pores. The melted metal powder automatically remains in the pores. The melted and vaporized part of the flux powder plays a role in protecting the transition of the welding droplets, thus achieving the cleaning and repair of welding pores.

[0019] Optionally, the surface pretreatment of the repaired area in step S1 may be an oil removal and rust removal operation; After welding in step S6, the surface treatment is to polish it smooth.

[0020] In summary, this application has the following beneficial effects: 1. In this application, the welding repair of the equipment adopts a combination of welding adhesive and welding. First, welding adhesive with sufficient connection strength is applied to the bottom of the insert. Then, the insert is bonded to the equipment with the welding adhesive, which solves the problem of fixing the contact surface between the insert and the repair part. Then, the insert is loaded with load to further improve the adhesion effect of the welding adhesive and improve the shear resistance of the contact surface. Finally, after the welding adhesive has solidified, the insert is welded. This effectively solves the problem of shear resistance of the repair part, significantly improves the shear resistance of the repair part, and improves the quality of welding repair. 2. In this application, by constructing the application area of ​​the welding adhesive, a similar polygon is made for the contact surface of the insert, and the distance between the similar polygon and the corresponding side of the insert is controlled. In addition, an equivalent graphic with a larger area is constructed within the similar polygon. The welding adhesive application area is based on the effective area. This can ensure that more welding adhesive is applied to the contact surface of the insert to ensure the subsequent bonding strength, and also reduce the probability of the welding quality being affected by local overflow of welding adhesive. Ultimately, this improves the shear resistance of the welded repair part and ensures the quality of the weld repair.

[0021] 3. In this application, a self-made repair agent is used to fill the welding pores. Then, during the melting process of the welding rod, the pores are filled. The powder is removed from the air by means of the electric arc treatment, thereby achieving pore cleaning and repair. Attached Figure Description

[0022] Figure 1This is a schematic diagram of constructing the equivalent graphic in Embodiment 1 of this application; Figure 2 This is a schematic diagram of constructing the equivalent graphic in Embodiment 2 of this application; Figure 3 This is a schematic diagram of constructing the equivalent graphic in Embodiment 3 of this application. Detailed Implementation

[0023] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0024] Welding inserts to the repair surface is a common repair process when repairing equipment. However, when the inserts are irregular in shape, thick, or subjected to complex stress conditions, there will always be a gap between the bottom of the insert and the repaired area. This results in the bottom of the insert and the repaired surface of the equipment being unable to connect. When the insert encounters large shear stress, the insert can easily peel off locally or completely from the equipment, posing a significant operational risk. In particular, when this process is used for inserts thicker than 12mm, the probability of quality accidents occurring within the next two years exceeds 50%.

[0025] To improve connection strength and effectively address the shear resistance of the repaired area, this application, based on practical verification, first adheres the bottom surface of the insert to the repair surface using welding adhesive, followed by subsequent welding to achieve a connection and improve the quality of the welded repair. In this process, the area covered by the welding adhesive significantly impacts the final adhesive bonding effect, thereby affecting the quality of the welded repair and the safe operation of the equipment.

[0026] If the area covered by the welding adhesive is small, the amount of adhesive applied will be insufficient, resulting in weak weld strength and limited effectiveness. This can lead to the insert suddenly detaching from the equipment surface, damaging surrounding equipment and personnel, and posing a safety hazard. However, when the application area is large, excess welding adhesive overflows from the edge of the insert under load and becomes difficult to remove after drying and curing, requiring manual grinding. In some operating conditions, such as inside a wind turbine tower, where space is limited and equipment occupies a portion of the space, it is impossible to remove the overflowing welding adhesive with a grinding wheel. If the overflowing welding adhesive is not removed, or if it is very close to the edge of the insert even if it has not overflowed, the high welding temperature will cause the already solidified welding adhesive to melt and vaporize, forming numerous small and dense pores at the weld, resulting in a substandard weld with insufficient weld strength, threatening the safe operation of the equipment.

[0027] To address the issue of the welding area of ​​the welding adhesive, ensuring it remains within a suitable range to achieve better bonding strength while minimizing overflow, this application determines the effective area of ​​the welding adhesive by constructing an ellipse. Specifically, firstly, a similar polygon is created within the surface of the insert to be in contact, with the distance between the similar polygon and the corresponding edge of the insert maintained between 3-10 mm. Then, an equivalent shape is constructed within the similar polygon. This firstly limits the equivalent shape, ensuring that after the welding adhesive is applied and a load is applied, the adhesive will flow to the periphery, allowing sufficient distance to control the degree of overflow and reduce the amount of welding adhesive spillage.

[0028] Furthermore, to enhance the application effect of the welding adhesive, the inventors, based on practical experience, found that applying the welding adhesive within similar polygons yielded better results, with more stable adhesion and less impact on subsequent welding.

[0029] As for the construction of the equivalent graphic, since the shape of the inlay is usually a polygon, it can be decomposed into multiple triangles or a combination of triangles and quadrilaterals. Therefore, the construction of the equivalent graphic in this application is also to decompose similar polygons into triangles or a combination of triangles and quadrilaterals. Thus, the construction in this application is mainly for the construction of triangles and quadrilaterals. The application area and application region of the welding adhesive are carried out separately in the decomposed triangles and quadrilaterals.

[0030] This application uses proof by contradiction to prove that equivalent figures can be constructed from triangles and quadrilaterals with angles not exceeding 180°, as follows: For a triangle, first choose two angles, ∠B and ∠C. Draw a circle on the angle bisector of each angle, tangent to the two sides of the angle. Then connect the centers of the two circles. Assume the radii of the two circles are small enough that their centers coincide approximately with ∠B and ∠C. When drawing a perpendicular line from the other angle, ∠A, to the line connecting the centers, the point of perpendicularity lies on the extension of that line, indicating that either ∠B or ∠C is an obtuse angle. Similarly, if AB, BC, and AC cannot be perpendicularly drawn, it means at least two angles are obtuse angles greater than 90°. This contradicts the rule that the sum of the interior angles of a triangle is 180°. Therefore, at least one perpendicular line must exist.

[0031] For a quadrilateral, connect diagonal AC. Choose two angles, ∠A and ∠C. Draw a circle on the angle bisector of each angle, tangent to the two sides of the angle. Then connect the centers of the two circles to form a line connecting their centers. If a perpendicular line cannot be drawn from points B and D, it means ∠B and ∠D are both greater than 90 degrees. Similarly, connect diagonal BD. Choose two angles, ∠B and ∠D. Draw a circle on the angle bisector of each angle, tangent to the two sides of the angle. Then connect the centers of the two circles to form a line connecting their centers. If a perpendicular line cannot be drawn from points A and C, it means ∠A and ∠C are both greater than 90 degrees. In this case, the sum of the four angles must be greater than 360 degrees. This contradicts the fact that the sum of the interior angles of a quadrilateral is 360 degrees. Therefore, at least one set of perpendicular lines must exist.

[0032] By using the above proof by contradiction, it can be proven that a perpendicular line can be drawn from a triangle and a quadrilateral with an angle not exceeding 180°, and thus an equivalent figure satisfying the requirements of this application can be created.

[0033] σ in this application max σ0 is the maximum compressive stress of the welding adhesive (MPa), σ0 is the shear stress borne by the insert (MPa), and τ0 is the maximum compressive stress of the welding adhesive (MPa). max σ0 represents the maximum shear stress of the welding adhesive (MPa) and the compressive stress (Pa) borne by the insert. Both are provided by the material manufacturer or can be determined by the company itself.

[0034] Example 1 A welding repair process for metal equipment includes the following steps: S1. Surface pretreatment of the repaired parts: Degreasing and derusting are performed on the surface of the repaired parts of the inserts and equipment to expose the metallic luster. S2. Selection of welding adhesive: Provides the maximum compressive stress σ of the welding adhesive max The maximum shear stress τ of the welding adhesive is 75 MPa. max The shear stress τ0 of the insert is 16 MPa; the compressive stress σ0 of the insert is 2.45 MPa.

[0035] Calculate the risk factor m0 of the compressive strength of the welding adhesive. In the above formula, σ max This represents the maximum compressive stress of the welding adhesive. Calculate the risk factor m1 for the shear resistance of the welding adhesive. In the above formula, τ0 is the shear stress borne by the insert, τ max This represents the maximum shear stress resisted by the welding adhesive. If the requirement that m0≥m1 and both m0 and m1 are not greater than 0.5 is met, this welding adhesive is selected as the welding adhesive to be used. S3. Constructing the adhesive application area: Observing the shape of the insert's contact surface, which is a triangle with no angle exceeding 180°, construct similar triangles within the surface of the insert's contact surface. The lengths of the three sides of the similar triangles are 85.9mm, 58.3mm, and 100.1mm, respectively. The distance between the similar triangles and the corresponding sides of the insert is maintained at 3mm. Construct an equivalent shape within the similar triangles, calculate the equivalent shape area S0, and apply welding adhesive to the insert's contact surface. The welding adhesive application area is S. The specific operation includes the following steps: S31: Constructing an equivalent figure using triangles: S311: Determine the axis, specifically including the following steps: S3111: Reference Figure 1 First, select two angles of similar triangles, draw a circle on the angle bisector of each angle, with the circle tangent to both sides of the angle, and then connect the centers of the two circles to form a line connecting their centers. S3112: The extensions of the two ends of the line connecting the centers intersect the two circles at points A and B respectively, and the line segment AB serves as axis 1; S3113: Starting from the third endpoint C of the triangle, draw a perpendicular line to axis 1. The perpendicular line is axis 2. The perpendicular point O divides axis 1 into axis a and axis b. The length of axis a is a = 63.8 mm, and the length of axis b is b = 25.1 mm.

[0036] S3114: Point C is shortened by 20% along the vertical direction to obtain point D, which satisfies DO = 0.8CO. DO is the c-axis, and the length of the axis is c = 35.5mm.

[0037] S312: Constructing an equivalent graphic: With O as the origin of the ellipse and 2a and 2c as axes, draw an ellipse, keeping only the AOD portion, which is denoted as equivalent figure A (that is, drawing a quarter region of the ellipse with 2a and 2c as axes); with 2b and 2c as axes, draw an ellipse, keeping only the BOD portion, which is denoted as equivalent figure B (that is, drawing a quarter region of the ellipse with 2b and 2c as axes, the same below).

[0038] S313: The equivalent figure consists of equivalent figure A and equivalent figure B, and the area of ​​the equivalent figure is... =0.785×(63.8+25.1)×35.5=2477.4mm 2 ; S314: The area S of the welding adhesive application is 0.85S0 = 0.85 × 2477.4 mm. 2 =2105.8mm 2 ; S4. Apply welding adhesive: Apply the welding adhesive selected in step S2 to an area of ​​S = 2105.8 mm as described in step S3. 2 Apply the coating to the inside of similar triangles, with a thickness of 2mm. Then, the contact surface of the insert is brought into contact with the part of the equipment to be repaired, the temperature of the adhesive area is controlled at 30°C, and a load is applied to the surface of the insert until the welding adhesive solidifies. The loading force F0 for the surface load of the insert is: F0=K0m0Sσ0=0.03×0.5×0.0021058×2.45×10 6 =77.4N In the above formula, K0 is 0.03, σ0 is the compressive stress (Pa) borne by the insert, m0 is the risk coefficient of the compressive strength of the welding adhesive, and S is the area of ​​the welding adhesive application (m²). 2 ); S5. Welding: Welding is used to fill the gap between the insert and the equipment; After the above steps, the porosity within the first weld pass (200mm in length) was counted, resulting in 28 small pores (less than 3mm) and 11 large pores (3mm or larger). Welding porosity cleaning was then performed on these pores, specifically as follows: In this embodiment, the insert is a Q345 steel plate. E5015 welding rod and ENiCrMo-3 welding rod are prepared. After the coating of the E5015 welding rod is peeled off, it is collected and processed into coating powder, which is used as repair agent A. The metal part of the ENiCrMo-3 welding electrode, namely the welding core, is ground to obtain metal powder. At the same time, the front 30mm of the welding core is processed into a welding core with a diameter of 1.5mm. The metal powder obtained from grinding the welding core is mixed with the coating powder at a mass ratio of 1:2 and made into a paste to obtain repair agent B. Repair agent A was filled into small pores with a pore size of less than 3 mm, and repair agent B was filled into large pores with a pore size of 3 mm or more. Then, ENiCrMo-3 welding rods with a diameter of 1.5 mm, after grinding, were used to weld and repair the pore areas. After the first repair, there were 6 small pores with a pore size of less than 3 mm and 1 large pore with a pore size of 3 mm or more. After the second repair, the number of large and small pores was 0.

[0039] S6. After welding, the surfaces of the inserts and welds are ground and cleaned to meet the requirements for smoothness and roughness.

[0040] Example 2 A welding repair process for metal equipment is performed according to the method in Example 1, except that in step S2, the maximum compressive stress σ of the welding adhesive is provided. max The maximum shear stress τ of the welding adhesive is 80 MPa. max The shear stress τ0 of the insert is 20 MPa; the compressive stress σ0 of the insert is 2.1 MPa.

[0041] Calculate the risk factor m0 of the compressive strength of the welding adhesive. In the above formula, σ max This represents the maximum compressive stress of the welding adhesive. Calculate the risk factor m1 for the shear resistance of the welding adhesive. In the above formula, τ0 is the shear stress borne by the insert, τ max This represents the maximum shear stress resisted by the welding adhesive. If the requirement that m0≥m1 and both m0 and m1 are not greater than 0.5 is met, this welding adhesive is selected as the welding adhesive to be used. In step S3, the shape of the surface to be contacted by the insert is observed to be quadrilateral. A similar quadrilateral is then constructed within the surface of the insert, with the distance between the similar quadrilateral and the corresponding side of the insert maintained at 6mm. The lengths of the four sides of the similar quadrilateral are 66.8mm, 50.6mm, 102.6mm, and 65.8mm, respectively. The coating area S of the similar quadrilateral is obtained using the following method: S32: Constructing an equivalent figure using quadrilaterals: S321: Determine the axis, including the following steps: S3211: Reference Figure 2 First, select two angles on the diagonal, draw a circle on the angle bisector of each angle, with the circle tangent to both sides of the angle, and then connect the centers of the two circles to form a line connecting their centers. S3212: The extensions of the two ends of the line connecting the centers intersect the two circles at points A and B respectively, and the line segment AB serves as axis 1; S3213: Starting from the other two points of the quadrilateral, draw perpendicular lines to axis 1. The perpendicular lines intersect the sides of the quadrilateral. Take the longest perpendicular line as axis 2. The perpendicular point O divides axis 1 into axis a and axis b. The length of axis a is a = 21.6 mm, and the length of axis b is b = 77.9 mm. The perpendicular point O divides axis 2 into axis c and axis d. The length of axis c is c = 58.5 mm, denoted by C0, and the length of axis d is d = 11.5 mm, denoted by DO. S322: Constructing an equivalent graphic: With O as the origin of the ellipse and 2a and 2c as axes, draw an ellipse, keeping only the AOC portion, which is denoted as equivalent figure 1; with 2b and 2c as axes, draw an ellipse, keeping only the BOC portion, which is denoted as equivalent figure 2; with 2a and 2d as axes, draw an ellipse, keeping only the AOD portion, which is denoted as equivalent figure 3; with 2b and 2d as axes, draw an ellipse, keeping only the BOD portion, which is denoted as equivalent figure 4; S323: The equivalent figure is composed of equivalent figure 1, equivalent figure 2, equivalent figure 3, and equivalent figure 4; S324: Calculate the welding adhesive application area S: S3241: Take a point a0 on the a-axis, satisfying Oa0 = 0.9a; take a point b0 on the b-axis, satisfying Ob0 = 0.9b; take a point c0 on the c-axis, satisfying Oc0 = 0.9c; take a point d0 on the d-axis, satisfying Od0 = 0.9d; S3242: Draw a straight line through point a0 parallel to the c-axis and d-axis, intersecting the equivalent figure at two points. The length between the two points is L1 = 43.3 mm. Draw a straight line through point b0 parallel to the c-axis and d-axis, intersecting the equivalent figure at two points. The length between the two points is L2 = 43.1 mm. Draw a straight line through point c0 parallel to the a-axis and b-axis, intersecting the equivalent figure at two points. The length between the two points is L3 = 30.5 mm. Draw a straight line through point d0 parallel to the a-axis and b-axis, intersecting the equivalent figure at two points. The length between the two points is L4 = 30.5 mm. S3243: Distinguish between the values ​​of (L1+L2)(c+d)=(43.3+43.1)(58.5+11.5)=86.4×70=6048 and (L3+L4)(a+b)=(30.5+30.5)(21.6+77.9)=61×99.5=6069.5, and keep only the larger one (L3+L4)(a+b); S3244: According to the discrimination results, L3 = 30.5mm, L4 = 30.5mm, L3 = L4; S3245: If (L3+L4)(a+b) is large, the adhesive bonding area S = (0.98h+H)(a+b)×θ, where θ is the deviation coefficient, ranging from 0.45 to 0.69. Therefore, S = (0.98h+H)(a+b)×θ = 1.98 × 30.5 × 99.5 × 0.55 = 3304.8 mm. 2 ; In step S4, the welding adhesive selected in step S2 is applied to an area of ​​3304.8 mm as described in step S3. 2 Apply the coating to the inside of similar quadrilaterals, with a thickness of 3mm. Then, the contact surface of the insert is brought into contact with the part of the equipment to be repaired, the temperature of the adhesive area is controlled at 75℃, and a load is applied to the surface of the insert until the welding adhesive solidifies. The loading force F0 for the surface load of the insert is: F0=K0m0Sσ0=0.02×0.49×0.003305×2.7×10 6 =87.45N In the above formula, K0 is 0.02, σ0 is the compressive stress (Pa) borne by the insert, m0 is the risk factor of the compressive strength of the welding adhesive, and S is the area of ​​the welding adhesive application (m²). 2 ); In step S5, after the above processing, the porosity within the first weld length of 200mm is counted, resulting in 25 small pores with a size less than 3mm and 12 large pores with a size greater than or equal to 3mm. Welding porosity cleaning is then performed on these pores, specifically as follows: In this embodiment, the insert is made of cast iron QT400. Z308 welding rod and ENiCrFe-3 welding rod are prepared. After the coating of Z308 welding rod is peeled off, it is collected and processed into coating powder, which is used as repair agent A. The metal part of the ENiCrFe-3 welding electrode, namely the welding core, is ground to obtain metal powder. At the same time, the front 30mm of the welding core is processed into a welding core with a diameter of 1.3mm. The metal powder obtained from grinding the welding core is mixed with the coating powder at a mass ratio of 1:3 and made into a paste to obtain repair agent B. Repair agent A was filled into small pores with a pore size less than 3 mm, and repair agent B was filled into large pores with a pore size greater than or equal to 3 mm. Then, ENiCrFe-3 welding rods with a diameter of 1.3 mm, after grinding, were used to weld and repair the pore areas. After the first repair, there were 5 small pores with a pore size less than 3 mm and 0 large pores with a pore size greater than or equal to 3 mm. Using the same method, after the second repair, the number of both large and small pores was 0.

[0042] Example 3 A welding repair process for metal equipment is carried out according to the method in Example 2, except that in step S2, the maximum compressive stress σ of the welding adhesive is provided. max The maximum shear stress τ of the welding adhesive is 95 MPa. max The shear stress τ0 of the insert is 27 MPa; the compressive stress σ0 of the insert is 3.0 MPa.

[0043] Calculate the risk factor m0 of the compressive strength of the welding adhesive. In the above formula, σmax This represents the maximum compressive stress of the welding adhesive. Calculate the risk factor m1 for the shear resistance of the welding adhesive. In the above formula, τ0 is the shear stress borne by the insert, τ max This represents the maximum shear stress resisted by the welding adhesive. If the requirement that m0≥m1 and both m0 and m1 are not greater than 0.5 is met, this welding adhesive is selected as the welding adhesive to be used. In step S3, the shape of the surface to be contacted by the insert is observed to be pentagonal. A similar pentagon is constructed within the surface of the insert, with the distance between the similar pentagon and the corresponding side of the insert maintained at 10mm. The lengths of the similar pentagons are 131.9mm, 148.4mm, 221.4mm, 123.4mm, and 126.5mm, respectively. Figure 3 The similar pentagon is divided into triangles and quadrilaterals by connecting the diagonals. The lengths of the three sides of the triangles are 131.9mm, 126.5mm and 211mm, and the lengths of the quadrilaterals are 211mm, 148.4mm, 221.4mm and 123.4mm. The area S of welding adhesive is calculated for the triangles and quadrilaterals respectively, and then applied to the equivalent figures constructed by the triangles and quadrilaterals respectively. For the triangle, the length of the a-axis is 78.8 mm, the length of the b-axis is 81.3 mm, and the length of the c-axis is 50 mm. Therefore, the area of ​​the equivalent figure is S0 = 0.785 × (78.8 + 81.3) × 50 = 6284 mm². 2 Therefore, the area S of the welding adhesive applied inside the triangle is 0.85S0 = 5341.4 mm. 2 ; For the quadrilateral, the length of axis a is 48.1 mm, the length of axis b is 174 mm, the length of axis c is 124 mm, the length of axis d is 39.5 mm, the length of L1 is 71.3 mm, the length of L2 is 71.3 mm, the length of L3 is 96.9 mm, and the length of L4 is 96.8 mm. Distinguish between the values ​​of (L1+L2)(c+d) and (L3+L4)(a+b), and keep only the larger one; (L1+L2)(c+d)=(71.3+71.3)(124+39.5)=142.6×163.5=23315.1; (L3+L4)(a+b)=(96.9+96.8)(48.1+174)=193.7×222.1=43020.77, therefore, keep (L3+L4)(a+b); L3 > L4, L3 is denoted as H, L4 as h, and the area of ​​adhesive bonding inside the quadrilateral is S = (0.98h + H)(a + b) × θ = (0.98 × 96.8 + 96.9)(48.1 + 174) × 0.55 = 23424.9 mm 2 ; In step S4, the welding adhesive selected in step S2 is applied to an area of ​​S = 5341.4 mm as described in step S3. 2 Apply the coating to the inside of similar triangles, with a thickness of 1 mm, and apply it to an area of ​​S = 23424.9 mm² as described in step S3. 2 Apply the coating to the inside of similar quadrilaterals, with a thickness of 1mm. Then, the contact surface of the insert is brought into contact with the part of the equipment to be repaired, the temperature of the adhesive area is controlled at 120℃, and a load is applied to the surface of the insert until the welding adhesive solidifies. The loading force F0 for the surface load of the insert is: F0=K0m0Sσ0=0.01×0.46×(0.0053414+0.0234249)×3.0×10 6 =397N In the above formula, K0 is taken as 0.01, σ0 is the compressive stress (Pa) borne by the insert, m0 is the risk coefficient of the compressive strength of the welding adhesive, and S is the area of ​​the welding adhesive application (m²). 2 ); In step S5, after the above processing, the porosity within the first weld length of 200mm is counted, resulting in 31 small pores with a size less than 3mm and 9 large pores with a size greater than or equal to 3mm. Welding porosity cleaning is then performed on these pores, specifically as follows: In this embodiment, the insert is made of 304 stainless steel. E9018-B9 welding rod and A102 welding rod are prepared. After the coating of E9018-B9 welding rod is peeled off, it is collected and processed into coating powder, which is used as repair agent A. The metal part of the A102 welding electrode, namely the welding core, is ground to obtain metal powder. At the same time, the front 30mm of the welding core is processed into a welding core with a diameter of 1.1mm. The metal powder obtained from grinding the welding core is mixed with the coating powder at a mass ratio of 1:1.5 and made into a paste to obtain repair agent B. Repair agent A was filled into small pores with a pore size of less than 3 mm, and repair agent B was filled into large pores with a pore size of 3 mm or more. Then, A102 welding rods with a diameter of 1.1 mm, after grinding, were used to weld and repair the pore areas. After the first repair, there were 6 small pores with a pore size of less than 3 mm and 0 large pores with a pore size of 3 mm or more. After the second repair, the number of large and small pores was 0.

[0044] Comparative Example 1 A metal equipment welding repair process is carried out according to the method in Example 2, except that step S3 is not performed, and when applying welding adhesive in step S4, the welding adhesive selected in step S2 is directly applied to the bottom of the insert with the same thickness.

[0045] Comparative Example 2 A metal equipment welding repair process is carried out according to the method in Example 2, except that the deviation coefficient θ in step S3 is 0.3.

[0046] Comparative Example 3 A metal equipment welding repair process is carried out according to the method in Example 2, except that the deviation coefficient θ in step S3 is 0.8.

[0047] Comparative Example 4 A metal equipment welding repair process is carried out according to the method in Example 2, except that the loading force F0 of the load applied to the surface of the insert in step S4 is 135N.

[0048] Comparative Example 5 A metal equipment welding repair process is carried out according to the method in Example 2, except that the loading force F0 of the load applied to the surface of the insert in step S4 is 35N.

[0049] Comparative Example 6 A metal equipment welding repair process is carried out according to the method in Example 2, except that in step S2, the maximum compressive stress σ of the welding adhesive is provided. max If the pressure is 30 MPa, then the risk factor m0 of the compressive strength of the welding adhesive is 0.6.

[0050] Comparative Example 7 A metal equipment welding repair process is carried out according to the method in Example 2, except that in step S2, the maximum shear stress τ of the welding adhesive is provided. max If the shear resistance is 12.3 MPa, then the risk factor m1 of the welding adhesive is 0.51.

[0051] Comparative Example 8 A metal equipment welding repair process is carried out according to the method in Example 2, except that in step S5, no welding repair agent is used, and the porosity is removed directly by welding.

[0052] Comparative Example 9 A metal equipment welding repair process is carried out according to the method in Example 2, except that welding repair agent is not used in step S5, but conventional mechanical methods are used to remove the porosity before re-welding.

[0053] I. Performance Testing 1. First, the shear stress of the welded repair part of the equipment after the above welding repair process was tested, and the test results are shown in Table 1 below.

[0054] Table 1: Testing items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Shear stress / MPa 14.8 19.1 25.3 19.2 16.2 19.1 Testing items Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Shear stress / MPa 19.2 15.4 3.7 9.6 19.1 19.0 If the adhesive bonding area is large, the degree and tendency of adhesive overflow during loading will also increase, resulting in more porosity in the weld and thus reducing weld strength, leading to poor shear resistance of the repaired area. If the bonding area is small, although the degree and tendency of adhesive overflow are avoided, the bonding strength of the adhesive also decreases, reducing the shear resistance of the repaired area. Therefore, the adhesive bonding area has a significant impact on the shear resistance of the repaired area. Combining the actual shear stress results of the repaired area in Table 1 above, and referring to the test results of Example 2 and Comparative Examples 1 and 3, it can be seen that the actual shear stress detected in Comparative Examples 1 and 3 is basically equal to the actual shear stress detected in Example 2, indicating that after the bonding area increases to a certain extent, the impact on the adhesive bonding effect is very limited. Referring to the test results of Example 2 and Comparative Example 2, it can be seen that the actual shear stress detected in Comparative Example 2 is less than that detected in Example 2, indicating that a smaller bonding area will affect the adhesive bonding effect. Comparing the results of Comparative Examples 1, 2, and 3 with Example 2, the method for calculating the adhesive bonding area according to the present invention not only ensures that the adhesive can fully exert a good bonding effect, but also reduces the degree and tendency of adhesive overflow, thereby ensuring the shear resistance of the repaired part.

[0055] To enhance the adhesion of the welding adhesive, this invention employs a method of applying a load to the bonding surface to further improve the implementation effect. Excessive loading force increases the degree of adhesive overflow, leading to an increase in porosity during welding, which is detrimental to the overall welding repair effect. Conversely, insufficient loading force affects the adhesion of the welding adhesive, also negatively impacting the overall welding repair effect. Referring to Comparative Example 4, where the loading force applied to the insert is greater than the result obtained by the formula in this application, although the loading force applied to the insert is greater than that in Example 2, the final measured actual shear stress is essentially equal to the actual shear stress measured in Example 2. This indicates that once the loading force reaches a certain level, it has little impact on the adhesion of the welding adhesive. In Comparative Example 5, where the loading force applied to the insert is less than the result obtained by the formula in this application, the smaller loading force results in a lower final measured actual shear stress compared to that measured in Example 2. This demonstrates that increasing the loading force is beneficial for enhancing the adhesion of the welding adhesive. Comparison of Comparative Examples 4 and 5 with Example 2 shows that the method for calculating the surface load of the insert according to the present invention can not only improve the adhesion effect of the welding adhesive, but also reduce the degree of welding adhesive overflow.

[0056] Under alternating loads, the compressive stress resistance of the welding adhesive is crucial. Poor compressive strength increases early fatigue at the bonding site, while poor shear resistance easily leads to disc-like quality issues with the insert. For the welding adhesive itself, its compressive and shear resistance are key parameters affecting its bonding effect. This invention proposes a specific selection method for welding adhesives in the welding repair process. In Comparative Examples 6 and 7, when the risk coefficients for either compressive or shear resistance of the welding adhesives are greater than 0.5, the actual shear stresses detected with both Comparative Example 6 and 7 are significantly lower than those detected with the welding adhesive in Example 2. This indicates a significant reduction in the shear resistance of both Comparative Example 6 and 7, which greatly impacts the quality of the welding repair. Therefore, the method proposed in this invention is more reasonable in selecting welding adhesives.

[0057] Comparative Examples 8 and 9 were identical to Example 2 in terms of the method of selecting the welding adhesive, the bonding area, and the method of applying the load. The actual shear stress data detected were also basically the same, indicating that the shear resistance of the welding adhesive was equally reliable and the implementation effect of the welding adhesive was equally good.

[0058] 2. Secondly, during the welding repair process of the metal equipment using the welding repair process provided in the above embodiments and comparative examples, the number of pores generated in the first layer of weld after welding in step S5 was statistically analyzed. The total weld length was 200 mm and the weld width was 6-10 mm. The results are shown in Table 2 below.

[0059] Table 2: Excessive welding adhesive will increase the formation of weld porosity, which in turn affects the weld quality. The more porosity there is, the worse the weld quality.

[0060] Compared with Example 2, Comparative Example 1 had a larger adhesive application area, resulting in more severe adhesive overflow and many pores during welding; Comparative Example 2 had a relatively smaller adhesive application area, resulting in lower heat exposure and less adhesive decomposition during welding, thus producing fewer pores; Comparative Example 3 had a relatively larger adhesive application area, resulting in higher heat exposure and greater adhesive decomposition during welding, thus producing more pores.

[0061] In Comparative Example 4, the loading force applied to the insert is greater than the result obtained by the formula in this application. In Comparative Example 5, the loading force applied to the insert is less than the result obtained by the formula in this application. Compared with Example 2, Comparative Example 4 has a larger loading force, resulting in a higher degree of solder adhesive overflow, which leads to a greater number and severity of pores compared to Example 2. In Comparative Example 5, the degree of solder adhesive overflow is weaker, and the number and severity of pores are also reduced compared to Example 2.

[0062] In Example 2, both the compressive strength risk coefficient and the shear strength risk coefficient are less than 0.5, and the shear strength risk coefficient is less than the compressive strength risk coefficient. In contrast, the compressive strength risk coefficient or the shear strength risk coefficient of the welding adhesive used in Comparative Examples 6 and 7 is greater than 0.5. Since Comparative Examples 6 and 7 are the same as Example 2 in terms of the method of applying the welding adhesive and the operation steps, the severity of porosity generated by welding is not much different from that of Example 2.

[0063] When conventional methods were used to remove pores in Comparative Examples 8 and 9, compared to Example 2, it can be seen that the methods in Comparative Examples 8 and 9 were far less effective at removing pores than those in Example 2.

[0064] Generally, the same location in a weld should not be repaired more than twice. The number of pores repaired after porosity elimination in step S5 in the above embodiments and comparative examples was statistically analyzed, and the results are shown in Tables 3 and 4 below.

[0065] Table 3: Statistics of pores after the first repair Table 4: Statistics of porosity after the second repair According to the welding porosity removal method of Example 2, and based on the test results in Tables 2 and 3, the number of welding pores in Comparative Examples 1 to 7 was significantly reduced. In Comparative Examples 8 and 9, when traditional methods were used to remove pores, based on the test results in Tables 2 and 3, the methods in Comparative Examples 8 and 9 showed poor pore removal effects, far lower than the treatment effect of Example 2.

[0066] Based on the contents of Tables 1, 2, 3, and 4, the implementation effect of the welding repair process described in this invention is comprehensively analyzed. Compared with Example 2, although the shear stress detected in Comparative Example 1 is approximately equal to that in Example 2, the test data in Tables 2, 3, and 4 show that after the porosity removal treatment, the number of pores inside the weld is still very large. Even after a second repair, defects still exist inside the weld, which greatly affects the welding quality. This indicates that an excessively large welding adhesive application area is not conducive to the welding repair effect. Although the porosity severity in Comparative Example 2 is comparable to that in Example 2 after the porosity removal treatment, the test data in Table 1 shows that the shear stress of the welding adhesive in Comparative Example 2 is significantly lower than that in Example 2. This indicates that a smaller welding adhesive application area results in lower shear stress. The welding repair effect is greatly affected. Although the welding adhesive bonding area of ​​Comparative Example 3 is larger than that of Example 2, the phenomenon or tendency of welding adhesive overflow is more obvious in Comparative Example 3 under load. This will significantly increase the number of pores during the welding process. According to the data in Tables 2, 3 and 4, it not only increases the difficulty of pore removal efficiency and effect, but also affects the welding quality and is not conducive to the welding repair effect. Normally, the repair effect of Comparative Example 3 is not as good as that of Example 2. Through the comparison of Comparative Examples 1, 2 and 3 with Example 2, it can be seen that the welding adhesive bonding area calculation method described in this invention is reasonable and has a good implementation effect.

[0067] Although the loading force of Comparative Example 4 was greater than that of Example 2, Table 2 shows that the severity of porosity generated during welding in Comparative Example 4 was slightly higher than that in Example 2. Tables 3 and 4 show that although the porosity removal treatment was effective, the repair effect of Comparative Example 4 was not as good as that of Example 2. In addition, if the loading force is too large, it will cause local deformation of the repaired part, which is not conducive to the repair quality. The loading force of Comparative Example 5 was small. Compared with Example 2, Comparative Example 5 generated fewer pores during welding and the porosity removal treatment was effective. However, Table 1 shows that the actual shear stress detected in Comparative Example 5 was significantly less than that detected in Example 2. In terms of repair effect, the repair effect of Comparative Example 5 was significantly worse than that of Example 2. By comparing Comparative Examples 4 and 5 with Example 2, the adhesion effect of the welding adhesive gradually improved with the increase of the loading force. However, after the loading force reached a certain level, the adhesion effect of the welding adhesive not only did not improve significantly, but also tended to increase the severity of porosity. Therefore, the loading force should not be too large or too small. The comparison between Comparative Examples 4 and 5 and Example 2 shows that the loading force calculation method for the surface loading load of the insert described in this invention is reasonable and has good implementation effect.

[0068] Although the severity of porosity in Comparative Examples 6 and 7 was not significantly different from that in Example 2, and the porosity removal effect of Comparative Examples 6 and 7 after porosity removal treatment was close to that of Example 2, the compressive strength risk coefficient and shear strength risk coefficient of the welding adhesives used in Comparative Examples 6 and 7 were both greater than 0.5. Combined with the actual shear stress results measured in Table 1, this indicates that the welding adhesives of Comparative Examples 6 and 7 do not meet the requirements of this invention for the compressive strength risk coefficient and shear strength risk coefficient of welding adhesives, which is detrimental to the repair quality of the inserts. Comparing Comparative Examples 6 and 7 with Example 2, the welding adhesive selection method described in this invention is reasonable and has good implementation results.

[0069] Comparative Examples 8 and 9 represent conventional methods for removing porosity. Based on the test results in Tables 2 and 3, the porosity removal effects of Comparative Examples 8 and 9 are not good, resulting in poor implementation. Generally, the same location in a weld should not be repaired more than twice. As shown in Table 4, the porosity removal effects of Comparative Examples 8 and 9 are poor, significantly increasing the difficulty of weld repair. The secondary repair pass rate is extremely low, easily leading to weld quality defects and hindering repair quality. Comparing Comparative Examples 8 and 9 with Example 2, the welding porosity removal method described in this invention can significantly improve the porosity removal effect and weld repair quality, ensuring that the weld quality meets repair requirements and demonstrating good implementation results.

[0070] II. Verification of Repair Results For equipment that has undergone welding repair processes as described in the above embodiments and comparative examples and is put back into operation, regular maintenance is carried out quarterly in the early stage and monthly in the later stage, and the equipment operation status is closely tracked and recorded in detail. Quality accidents caused by the patch being partially detached from the equipment at the repaired part or completely detached from the equipment during operation are all judged as failures. The situation over the three years after being put into operation is statistically analyzed, and the statistical results are shown in Table 5 below.

[0071] Table 5: Verification of Repair Effect Based on the test results in Table 5 above, the inventors analyzed the causes of failure in comparative examples 1 to 9: 1. In Comparative Examples 1, 3, 4, 8, and 9, the failure sites were at the weld seams. The main reason for the failure was that the weld quality remained substandard after secondary repair. Incompletely removed weld porosity served as crack initiation points, and the generation of these crack initiation points was the primary cause of weld fracture. Comparison revealed that the porosity removal method described in this invention ensures effective equipment repair.

[0072] 2. The failure sites in Comparative Examples 2 and 5 were at the adhesive bonding points, mainly due to the small adhesive bonding area and insufficient loading force, resulting in poor adhesive adhesion. This indicates that the calculation methods for both the adhesive bonding area and the loading force affect the final repair quality. Comparison revealed that the adhesive bonding area calculation method and the loading force calculation method described in this invention can ensure the repair effect of the equipment.

[0073] 3. In Comparative Examples 6 and 7, the failure sites were at the welding adhesive, mainly because the maximum compressive stress or maximum shear stress of the welding adhesive did not meet the operating conditions, leading to a higher failure rate. This indicates that the properties of the welding adhesive itself have a significant impact on the final repair quality. Comparison revealed that the welding adhesive selection method described in this invention can ensure the repair effect of the equipment.

[0074] In addition, the inventors found that when conventional porosity elimination technology is used for inserts with a thickness of more than 12mm, the probability of quality accidents within the next two years exceeds 50%. However, when the process described in this application is used, which involves first bonding with welding adhesive and then welding, and then eliminating and repairing the porosity of the weld, no local or complete peeling problems occurred during subsequent operation for inserts with a thickness of 12-16mm.

[0075] In summary, the welding repair process for metal equipment in this application primarily involves first bonding and fixing the insert to the contact surface of the equipment with welding adhesive, and then welding the insert to the repair area using fillet welds. This significantly improves the shear resistance of the insert. However, if the welding adhesive is applied improperly, overflow can easily occur, resulting in porosity and affecting the welding quality of the fillet weld. Therefore, this application addresses this issue by determining the application area and region of the welding adhesive to reduce overflow. Furthermore, to address the porosity problem after welding, this application uses a self-made welding repair agent to remove the porosity before welding repair, thereby improving the final welding quality and enhancing the shear resistance of the repaired area.

[0076] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A welding repair process for metal equipment, characterized in that, Includes the following steps: S1. Surface pretreatment of the repair area; S2. Selection of welding adhesive: Calculate the risk factor m0 of the compressive strength of the welding adhesive. m0=(300-s max ) / 450 In the above formula, σ max This represents the maximum compressive stress (MPa) of the welding adhesive. Calculate the risk factor m1 for the shear resistance of the welding adhesive. m1=3.0τ0 / τ max In the above formula, τ0 is the shear stress (MPa) borne by the insert, τ max The maximum shear stress (MPa) of the welding adhesive; Select a welding adhesive that satisfies m0≥m1 and both m0 and m1 are not greater than 0.5 as the welding adhesive to be used; S3. Constructing the welding adhesive application area: Based on the shape of the surface to be contacted by the insert, construct a similar polygon within the surface to be contacted by the insert, keeping the distance between the similar polygon and the corresponding side of the insert between 3-10mm; construct an equivalent shape within the similar polygon, calculate the equivalent shape area S0, and determine the welding adhesive application area S using the equivalent shape area S0 as a reference. The welding adhesive is applied to the area defined by the similar polygon according to the application area S. When similar polygons are divided into several triangles, a smearing area S is applied to each triangle. The smearing area S of each triangle is obtained by the following method: S31: Constructing an equivalent figure using triangles: S311: Determine the axis, specifically Includes the following steps: S3111: First, select two angles, draw circles on the angle bisectors of each angle, with the circles tangent to the two sides of the angles. Then, shorten the points corresponding to the two angles of the triangle by 10-30% along the angle bisectors to form the centers of the two circles. Finally, connect the centers of the two circles to form a line connecting their centers. S3112: The extensions of the two ends of the line connecting the centers intersect the two circles at points A and B respectively, and the line segment AB serves as axis 1; S3113: Starting from the third endpoint C of the triangle, draw a perpendicular line to axis 1. The perpendicular line is axis 2. The perpendicular point O divides axis 1 into axis a and axis b. The length of axis a is a, denoted by AO; the length of axis b is b, denoted by BO. S3114: Point C is shortened by 20% along the vertical direction to obtain point D, which satisfies DO=0.8CO. DO is the c-axis, and the length of the axis is c, denoted by DO. S312: Constructing an equivalent graphic: With O as the origin of the ellipse and with lengths 2a and 2c as axes, draw an ellipse, keeping only the AOD part and denoteing it as the equivalent figure A; Draw an ellipse with lengths 2b and 2c as axes, and keep only the BOD part, which is denoted as the equivalent figure B; S313: The equivalent figure is composed of equivalent figure A and equivalent figure B, and the area of ​​the equivalent figure is S0=(π / 4)×(a+b)×c; S314: The area S of the welding adhesive application is 0.85S0; When similar polygons are divided into several triangles and quadrilaterals, each triangle and quadrilateral is coated with a coating area S. The coating area S of the quadrilateral is obtained by the following method: S32: Constructing an equivalent figure using quadrilaterals: S321: Determine the axis. Includes the following steps: S3211: First, select two angles on the diagonal. Draw a circle on the angle bisector of each angle, with the circle tangent to both sides of the angle. Then, shorten the corresponding endpoints of the two angles by 10-30% along the direction of the angle bisector to form the centers of the two circles. Finally, connect the centers of the two circles to form a line connecting the centers. S3212: The extensions of the two ends of the line connecting the centers intersect the two circles at points A and B respectively, and the line segment AB serves as axis 1; S3213: Starting from the other two points of the quadrilateral, draw perpendicular lines to axis 1. The perpendicular lines intersect the sides of the quadrilateral. Take the longest perpendicular line as axis 2. The perpendicular point O divides axis 1 into axis a and axis b. The length of axis a is a, denoted by AO; the length of axis b is b, denoted by BO. The perpendicular point O divides axis 2 into axis c and axis d. The length of axis c is c, denoted by C0; the length of axis d is d, denoted by DO. S322: Constructing an equivalent graphic: With O as the origin of the ellipse and 2a and 2c as axes, draw an ellipse, keeping only the AOC portion, which is denoted as equivalent figure 1; with 2b and 2c as axes, draw an ellipse, keeping only the BOC portion, which is denoted as equivalent figure 2; with 2a and 2d as axes, draw an ellipse, keeping only the AOD portion, which is denoted as equivalent figure 3; with 2b and 2d as axes, draw an ellipse, keeping only the BOD portion, which is denoted as equivalent figure 4; S323: The equivalent figure is composed of equivalent figure 1, equivalent figure 2, equivalent figure 3, and equivalent figure 4; S324: Calculate the welding adhesive application area S: S3241: Take a point a0 on the a-axis, satisfying Oa0=0.9a; take a point b0 on the b-axis, satisfying Ob0=0.9b; take a point c0 on the c-axis, satisfying Oc0=0.9c; take a point d0 on the d-axis, satisfying Od0=0.9d; S3242: Draw a straight line through point a0 parallel to the c-axis and d-axis, intersecting the equivalent figure at two points, with a length of L1 between the two points; draw a straight line through point b0 parallel to the c-axis and d-axis, intersecting the equivalent figure at two points, with a length of L2 between the two points; draw a straight line through point c0 parallel to the a-axis and b-axis, intersecting the equivalent figure at two points, with a length of L3 between the two points; draw a straight line through point d0 parallel to the a-axis and b-axis, intersecting the equivalent figure at two points, with a length of L4 between the two points; S3243: Distinguish between the values ​​of (L1+L2)(c+d) and (L3+L4)(a+b), and keep only the larger one; S3244: Based on the discrimination result, if (L1+L2)(c+d) is larger, compare the sizes of L1 and L2, and record the larger one as H and the smaller one as h; if (L3+L4)(a+b) is larger, compare the sizes of L3 and L4, and record the larger one as H and the smaller one as h. S3245: If (L3+L4)(a+b) is large, the area of ​​welding adhesive application S = (0.98h+H)(a+b)×θ; if (L1+L2)(c+d) is large, the area of ​​welding adhesive application S = (0.98h+H)(c+d)×θ, where θ is the deviation coefficient, ranging from 0.45 to 0.

69. S4. Apply welding adhesive: Apply the welding adhesive selected in step S2 to the contact surface of the insert according to the application area S, with a thickness of 1-3mm. Then, the contact surface of the insert is brought into contact with the part of the equipment being repaired, and a load is applied to the surface of the insert until the welding adhesive has solidified; S5. Welding: The gap between the insert and the equipment is filled by welding; after welding, the weld pores are cleaned. The specific operation is as follows: Repair agent A is used to fill the pores smaller than 3mm. Repair agent A is welding electrode coating powder. Repair agent B is used to fill the pores with a size greater than or equal to 3 mm. Repair agent B is a mixture of welding electrode coating powder and metal powder. Then, welding repair is performed on the porosity areas using 1.1-1.5mm welding material; in the porosity cleaning process, the metal powder in repair agent B is the metal powder obtained after grinding the welding core of the welding rod, and the metal powder and the welding rod coating powder are mixed at a mass ratio of 1:(1.5-3) to obtain repair agent B. S6. Surface treatment is performed after welding.

2. The metal equipment welding repair process according to claim 1, characterized in that: In step S4, the loading force F0 for the load applied to the surface of the insert is: F0=K0m0Sσ0 In the above formula, K0 is 0.01-0.03, σ0 is the compressive stress (Pa) borne by the insert, m0 is the risk coefficient of the compressive strength of the welding adhesive, and S is the area of ​​the welding adhesive application (m²). 2 ).

3. The metal equipment welding repair process according to claim 1, characterized in that: In step S4, after applying the welding adhesive, the temperature of the welding adhesive area is controlled at 30-120℃.

4. The metal equipment welding repair process according to claim 1, characterized in that: In step S1, the surface pretreatment of the repaired area involves degreasing and rust removal. After welding in step S6, the surface treatment is to polish it smooth.

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