A welding method for a base of a cable guide

Abstract

The invention relates to the technical field of welding of a fairlead base, and in particular to a method for welding a fairlead base. The fairlead base comprises an upper base and a lower base, wherein a dummy shaft is installed between the upper base and the lower base. After the dummy shaft is installed, the fairlead base is hoisted onto a ship. The entire fairlead base is welded to an outer plate of the ship via a horse plate. The upper base of the fairlead is welded for the first time. After the upper base of the fairlead is welded for the first time, the lower base of the fairlead is welded. After the welding of the lower base of the fairlead is completed, the upper base of the fairlead is welded for the second time to fill the groove. The invention reduces the welding deformation of the fairlead base, the deformation is well controlled, and the welding precision of the fairlead base is improved.

Description

Technical Field

[0001] The invention relates to the technical field of fairlead base welding, and in particular to a fairlead base welding method. Background Art

[0002] Many large offshore engineering products require cable-assisted mooring and positioning during production operations, and the installation of their fairleads is a key and difficult control project in the construction process.

[0003] Common fairleads are installed on the outer plate below the fairlead hole and fixed by the upper and lower bases and bearings of the fairlead. The welding deformation of the upper and lower bases of the fairlead affects the assembly of its bearings. The assembly accuracy of the bearings is very high. When welding the base of the fairlead, the upper base of the fairlead is welded first, and then the lower base of the fairlead is welded. At this time, the welding deformation of the upper and lower bases is large, and the dummy shaft cannot be loosened. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a method for welding a fairlead base to solve the problem of large welding deformation of the fairlead base.

[0005] Based on the above purpose, the present invention provides a method for welding a fairlead base, wherein the fairlead base comprises an upper fairlead base and a lower fairlead base, and a dummy shaft is installed between the upper fairlead base and the lower fairlead base; the method comprises:

[0006] Lift the fairlead base onto the ship;

[0007] Weld the base of the fairlead to the outer plate of the ship through the horse plate;

[0008] The first welding of the upper base of the fairlead is performed. The welding amount of the first welding of the upper base of the fairlead shall not be greater than half of the total welding amount of the upper base of the fairlead, including:

[0009] Perform the first fill welding on the first weld between the upper plate on the upper base of the fairlead and the outer plate, filling to the groove depth range of 1 / 4 to 3 / 4,

[0010] Perform the first filling welding on the second weld between the upper horizontal plate on the upper base of the fairlead and the outer plate, and the first filling range of the groove of the second weld is 1 / 4 to 3 / 4;

[0011] After the first welding of the upper base of the fairlead, the lower base of the fairlead is welded, including:

[0012] First filler weld on the lower base of the fairlead, including:

[0013] Perform the first fill welding on the third weld between the lower horizontal plate on the lower base of the fairlead and the outer plate, filling the groove to a depth ranging from 1 / 4 to 3 / 4.

[0014] Perform the first filling welding on the fourth weld between the lower vertical plate on the lower base of the fairlead and the outer plate, and fill it to the depth of the groove in the range of 1 / 4 to 3 / 4;

[0015] Second filler welding of the lower base of the fairlead, including:

[0016] Perform a second fill welding on the third weld to fill the groove.

[0017] Perform a second fill welding on the fourth weld to fill the groove;

[0018] After the welding of the lower base of the fairlead is completed, the upper base of the fairlead is welded for the second time, including:

[0019] Perform a second fill welding on the first weld to fill the groove.

[0020] Perform a second fill welding on the second weld to fill the groove.

[0021] Optionally, the first weld includes a second upper section and a first upper section from bottom to top, and the welding order is the first upper section, the second upper section, and both the second upper section and the first upper section are welded from bottom to top.

[0022] Optionally, the groove depth of the first fill welding of the first weld is 1 / 3.

[0023] Optionally, the second weld includes an upper left section, an upper left second section, an upper right section and an upper right second section from left to right, and the upper left section, the upper left second section, the upper right section and the upper right second section are all welded from left to right or from right to left, and the welding order is upper right section, upper left section, upper right second section and upper left second section.

[0024] Optionally, the groove depth of the first filling welding of the second weld is 2 / 3.

[0025] Optionally, the third weld includes the lower left section, the lower left second section, the lower right section, and the lower right second section from left to right, and the lower left section, the lower left second section, the lower right section, and the lower right second section are all welded from left to right or from right to left, and the welding order is the lower right section, the lower left section, the lower right second section, and the lower left second section.

[0026] Optionally, the fourth weld is welded from bottom to top.

[0027] Optionally, preheating is performed before all welding. After all welding stages are completed, preheating is terminated and the welding side is wrapped with insulation cotton to slow cooling. The reverse side is carbon planed to whiten. When all welds are cooled, check whether the dummy shaft can move and rotate freely up and down. If the dummy shaft can move and rotate, then continue with subsequent welding.

[0028] Optionally, the welding includes first performing positioning welding, the positioning welding is located on the upper part of the base layer, and then performing base welding on the base layer. After the base welding is completed, the lower filling welding is performed on the lower filling layer below the base layer. After the lower filling welding is completed, the positioning welding place on the upper part of the base layer is a carbon planing layer, and the carbon planing layer is carbon planed to remove the white. After natural cooling, the upper filling layer on the upper part of the base layer is performed with an upper filling welding. After the upper filling welding is completed, the upper cover layer at the upper end of the upper filling layer and the lower cover layer at the lower end of the lower filling layer are filled.

[0029] Optionally, round steel can be placed on the primer layer before welding.

[0030] Beneficial effects of the present invention: the present invention provides a method for welding a fairlead base, in which the welding amount of the fairlead upper base is large, and after completing the welding of about half of this part, the welding deformation of the fairlead upper base is reduced, thereby reducing the misalignment between the dummy shaft and the shaft sleeve on the upper base of the fairlead, and then the lower base of the fairlead is welded to make up for the misalignment between the dummy shaft and the shaft sleeve, and finally the remaining welding amount of the fairlead upper base is completed, and by adjusting the welding sequence of the fairlead base, the welding deformation of the fairlead base is reduced, and the deformation is well controlled, and after the upper base of the fairlead is subjected to post-weld heat treatment, the dummy shaft can still be well installed, and the shaft sleeve is well protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a structural schematic diagram of the present invention;

[0033] Figure 2 for Figure 1 Structural diagram of the AA section;

[0034] Figure 3 for Figure 1 Structural diagram of the middle BB section;

[0035] Figure 4 It is a structural schematic diagram of the welding filling primer layer and the lower filling layer of the present invention;

[0036] Figure 5 It is a structural schematic diagram of welding of the present invention;

[0037] Figure 6 It is a structural schematic diagram of the upper base of the fairlead of the present invention.

[0038] In the figure: 1, upper base of the fairlead; 2, lower base of the fairlead; 11, upper vertical plate; 12, upper horizontal plate; 13, first weld; 14, second weld; 21, lower vertical plate; 22, lower horizontal plate; 23, third weld; 24, fourth weld; 31, base layer; 32, lower filling layer; 33, upper filling layer; 34, upper cover layer; 35, lower cover layer; 36, carbon planing layer. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0040] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0041] like Figures 1 to 6 As shown, a method for welding a fairlead base, the fairlead base comprises an upper fairlead base 1 and a lower fairlead base 2, a dummy shaft is installed between the upper fairlead base 1 and the lower fairlead base 2; the method comprises:

[0042] Step 1: After installing a dummy shaft between the upper base 1 of the fairlead and the lower base 2 of the fairlead, the fairlead base is hoisted onto the ship as a whole;

[0043] Step 2: Fix the base of the fairlead to the outer plate of the ship by tack welding through the horse plate; before tack welding between the base of the fairlead and the outer plate of the ship, place round steel at the root of the tack weld and then tack weld. The setting of round steel is convenient for reducing welding shrinkage deformation. Carbon planing can be carried out after welding of other areas.

[0044] Step 3, make a fairlead measuring tool and draw inspection lines for measuring welding deformation on the fairlead base, the outer plate and the fairlead measuring tool, measure the vertical distance or horizontal distance between the inspection line on the fairlead base and the inspection line on the outer plate, the inspection line on the fairlead base and the inspection line on the fairlead measuring tool as original data, and after subsequent welding, measure the real-time data of the vertical distance or horizontal distance between the inspection line on the fairlead base and the inspection line on the outer plate, the inspection line on the fairlead base and the inspection line on the fairlead measuring tool, and make a corresponding comparison with the original data at the same place, and adjust the welding position and direction in time according to the size of the difference in the comparison data;

[0045] After the full welding of the horse plate is completed, the fairlead measuring tool is welded on both sides of the fairlead base. The fairlead measuring tool includes an upper plate and a middle plate located below the upper plate on both sides of the fairlead upper base 1, and a lower plate is arranged on both sides of the fairlead lower base 2. The two upper plates, the two middle plates and the two lower plates are all arranged symmetrically about the fairlead base. The upper plate is located on the oblique upper side of the fairlead upper base 1, the middle plate is located on the oblique lower side of the fairlead upper base 1, and the lower plate is located on the oblique lower side of the fairlead lower base 2. The lower plate, the upper plate and the middle plate can all be provided with diagonal braces, and the lower plate, the upper plate and the middle plate are all welded to the outer plate of the ship;

[0046] The inspection lines on both sides of the upper base 1 of the fairlead are symmetrically arranged. The inspection lines on one side of the upper base 1 of the fairlead include: two inspection lines vertically arranged on the upper outer wall and the middle outer wall of the upper base 1 of the fairlead, two inspection lines vertically arranged on the outer plate of the ship on one side of the upper base 1 of the fairlead, the two inspection lines vertically arranged on the outer plate of the ship are respectively at the same height as the two inspection lines vertically arranged on the upper outer wall and the middle outer wall of the upper base 1 of the fairlead, an inspection line perpendicular to the outer plate is arranged on the middle plate, and two mutually perpendicular inspection lines are horizontally arranged on the upper end surface of the bottom plate of the upper base 1 of the fairlead;

[0047] The inspection lines on both sides of the lower base 2 of the fairlead are symmetrically arranged, and the inspection lines on one side of the lower base 2 of the fairlead are as follows: an inspection line perpendicular to the outer plate is arranged on the lower plate, and two mutually perpendicular inspection lines are arranged horizontally and vertically on the upper surface of the bottom plate of the lower base 2 of the fairlead, and an inspection line on the upper surface of the bottom plate of the lower base 2 of the fairlead is arranged parallel to the inspection line on the lower plate, and a horizontally arranged inspection line is arranged on the outer plate on one side of the lower base 2 of the fairlead, and another inspection line on the upper surface of the bottom plate of the lower base 2 of the fairlead is arranged parallel to the horizontally arranged inspection line on the outer plate;

[0048] Step 4: Perform the first welding on the upper base 1 of the fairlead. The welding amount of the first welding on the upper base 1 of the fairlead is not more than half of the total welding amount of the upper base 1 of the fairlead. The total welding amount of the upper base 1 of the fairlead includes the welding amount of the first welding on the upper base 1 of the fairlead plus the welding amount of the second welding on the upper base 1 of the fairlead.

[0049] The method comprises: performing a first filling welding on the first weld 13 between the upper plate 11 on the upper base 1 of the fairlead and the outer plate, the filling depth ranges from 1 / 4 to 3 / 4 of the groove, and the thickness of the welded filling layer is at least 14 mm;

[0050] The first weld 13 includes a second upper section and a first upper section from bottom to top, the first upper section is welded first, and then the second upper section is welded, and both the second upper section and the first upper section are welded from bottom to top;

[0051] Further, the groove depth of the first fill welding of the first weld 13 is preferably 1 / 3;

[0052] Performing the first filling welding on the second weld 14 between the upper horizontal plate 12 on the upper base 1 of the fairlead and the outer plate, the first filling range of the groove of the second weld 14 is 1 / 4 to 3 / 4;

[0053] The second weld 14 includes an upper left section, an upper left second section, an upper right section, and an upper right second section from left to right. The upper left section, the upper left second section, the upper right section, and the upper right second section are all welded from left to right or from right to left. The welding order is upper right section, upper left section, upper right second section, and upper left second section.

[0054] Furthermore, the groove depth of the first filling welding of the second weld 14 is preferably 2 / 3.

[0055] Step 5: After the first welding of the upper base 1 of the fairlead, the lower base 2 of the fairlead is welded, including:

[0056] The first filling welding of the lower base 2 of the fairlead,

[0057] The third weld 23 between the lower horizontal plate 22 on the lower base 2 of the fairlead and the outer plate is filled with welding for the first time, and the depth of the groove is in the range of 1 / 4 to 3 / 4.

[0058] The third weld 23 includes a lower left section, a lower left section 2, a lower right section 1 and a lower right section 2 from left to right. The lower left section 1, the lower left section 2, the lower right section 1 and the lower right section 2 are all welded from left to right or from right to left. The welding order is the lower right section 1, the lower left section 1, the lower right section 2 and the lower left section 2.

[0059] Further, the groove depth of the first filling welding of the third weld 23 is preferably 1 / 3;

[0060] The fourth weld 24 between the lower vertical plate 21 on the lower base 2 of the fairlead and the outer plate is filled with welding for the first time, and the depth of the groove is in the range of 1 / 4 to 3 / 4.

[0061] The fourth weld 24 is welded from bottom to top;

[0062] Further, the groove depth of the first filling welding of the fourth weld 24 is preferably 1 / 3;

[0063] The second filling welding of the lower base 2 of the fairlead,

[0064] Perform a second fill welding on the third weld 23 to fill the groove.

[0065] The fourth weld 24 is subjected to a second filling welding to fill the groove.

[0066] Step 6: After welding the lower base 2 of the fairlead, weld the upper base 1 of the fairlead for the second time.

[0067] Perform a second fill welding on the first weld 13 to fill the groove.

[0068] The second weld 14 is subjected to a second filling welding to fill the groove.

[0069] The welding amount of the upper base 1 of the fairlead is large. After completing about half of the welding of this part, the welding deformation of the upper base 1 of the fairlead is reduced, thereby reducing the misalignment between the dummy shaft and the shaft sleeve on the upper base 1 of the fairlead. Then the lower base 2 of the fairlead is welded to make up for the misalignment between the dummy shaft and the shaft sleeve. Finally, the remaining welding amount of the upper base 1 of the fairlead is completed. By adjusting the welding sequence of the fairlead base, the welding deformation of the fairlead base is reduced and the deformation is well controlled. After the upper base 1 of the fairlead is subjected to post-weld heat treatment, the dummy shaft can still be well installed, and the shaft sleeve is well protected.

[0070] All the above weldings are preheated before welding. After all welding stages are completed, the preheating is ended by turning off the power of the heating plate, and the welding side is wrapped with insulation cotton to slow down the cooling. The reverse side is carbon planed to whiten the weld. When the weld is cooled, check whether the dummy shaft can move and rotate freely up and down. If the dummy shaft can move and rotate, continue with the subsequent welding. If the dummy shaft cannot move and / or rotate, the dimensional change can be reduced by changing the welding sequence to control the accuracy.

[0071] For the welding of the first weld 13, the second weld 14, the third weld 23 and the fourth weld 24, the preheating and interlayer temperature control before welding shall be strictly carried out in accordance with the requirements of WPS-NT-01-332 Rev0. After welding, insulation cotton shall be used for insulation until the weld cools to the ambient temperature.

[0072] The welding includes first performing positioning welding, the positioning welding is located on the upper part of the base layer 31, and then performing base welding on the base layer 31. After the base welding is completed, the lower filling layer 32 below the base layer 31 is subjected to lower filling welding. After the lower filling welding is completed, the positioning welding position on the upper part of the base layer 31 is a carbon planing layer 36, and the upper part of the base layer 31 is carbon planed to remove the white. After natural cooling, the upper filling layer 33 on the upper part of the base layer 31 is subjected to upper filling welding. After the upper filling welding is completed, the upper cover layer 34 at the upper end of the upper filling layer 33 and the lower cover layer 35 at the lower end of the lower filling layer 32 are filled.

[0073] The base structure of the fairlead is very thick. The upper vertical plate 11, the upper horizontal plate 12, the lower vertical plate 21 and the lower horizontal plate 22 are all thick plates. In view of the large shrinkage deformation of the thick plates during welding, which will seriously affect the disassembly and assembly of the dummy shaft, round steel is placed at the root of the positioning weld before welding. The arrangement of the round steel is convenient for reducing the shrinkage deformation of the thick plates during welding, and the carbon planer is used to remove them after welding of other areas.

[0074] Arc striking plates and arc extinguishing plates are added to the beginning and end of all welds, including the first weld 13, the second weld 14, the third weld 23 and the fourth weld 24, to reduce the damage caused by instability in the arc striking stage and concentration of impurities at the arc extinguishing point.

[0075] The fairlead base is a large-scale fairlead base, the height of the fairlead upper base 1 can be 745 mm, and the distance between the fairlead upper base 1 and the fairlead lower base 2 can be 3200 mm.

[0076] A water cooling jacket is arranged outside the shaft sleeve on the upper base 1 of the fairlead and the lower base 2 of the fairlead, and a spiral cold water pipe is arranged inside the water cooling jacket. A water inlet and a water outlet are arranged at both ends of the spiral cold water pipe respectively. Cold water enters the spiral cold water pipe through the water inlet to cool the shaft sleeve, and the water outlet discharges the absorbed water.

[0077] When welding the horse plate, the approved appropriate WPS should be used and the welding should be carried out strictly in accordance with the requirements of the WPS;

[0078] Remove the horse plate after all welds are completed and cooled to ambient temperature.

[0079] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. The present invention is not limited to the above-mentioned implementation modes, that is, it does not mean that the present invention must rely on the above-mentioned methods and structures to be implemented. Under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0080] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for welding a fairlead base, wherein the fairlead base comprises an upper fairlead base and a lower fairlead base, a dummy shaft is installed between the upper fairlead base and the lower fairlead base, and the method is characterized in that: include: Lift the fairlead base onto the ship; Weld the base of the fairlead to the outer plate of the ship through the horse plate; The first welding of the upper base of the fairlead is performed. The welding amount of the first welding of the upper base of the fairlead shall not be greater than half of the total welding amount of the upper base of the fairlead, including: Perform the first fill welding on the first weld between the upper plate on the upper base of the fairlead and the outer plate, and fill to the groove depth range of 1 / 4 to 3 / 4, Perform the first filling welding on the second weld between the upper horizontal plate on the upper base of the fairlead and the outer plate, and the first filling range of the groove of the second weld is 1 / 4 to 3 / 4; After the first welding of the upper base of the fairlead, the lower base of the fairlead is welded, including: First filler weld on the lower base of the fairlead, including: Perform the first fill welding on the third weld between the lower horizontal plate on the lower base of the fairlead and the outer plate, filling the groove to a depth ranging from 1 / 4 to 3 / 4. Perform the first filling welding on the fourth weld between the lower vertical plate on the lower base of the fairlead and the outer plate, and fill it to the depth of the groove in the range of 1 / 4 to 3 / 4; Second filler welding of the lower base of the fairlead, including: Perform a second fill welding on the third weld to fill the groove. Perform a second fill welding on the fourth weld to fill the groove; After the welding of the lower base of the fairlead is completed, the upper base of the fairlead is welded for the second time, including: Perform a second fill welding on the first weld to fill the groove. Perform a second fill welding on the second weld to fill the groove.

2. A method for welding a fairlead base according to claim 1, characterized in that: The first weld includes the second upper section and the first upper section from bottom to top, and the welding sequence is the first upper section, the second upper section, and the second upper section and the first upper section are both welded from bottom to top.

3. A method for welding a fairlead base according to claim 1, characterized in that: The groove depth of the first filler weld of the first weld is 1 / 3.

4. A method for welding a fairlead base according to claim 1, characterized in that: The second weld includes the upper left section, the upper left second section, the upper right section and the upper right second section from left to right. The upper left section, the upper left second section, the upper right section and the upper right second section are all welded from left to right or from right to left, and the welding order is the upper right section, the upper left section, the upper right second section and the upper left second section.

5. A method for welding a fairlead base according to claim 1, characterized in that: The groove depth of the first filling weld of the second weld is 2 / 3.

6. A method for welding a fairlead base according to claim 1, characterized in that: The third weld includes the lower left section, the lower left second section, the lower right section, and the lower right second section from left to right. The lower left section, the lower left second section, the lower right section, and the lower right second section are all welded from left to right or from right to left, and the welding order is the lower right section, the lower left section, the lower right second section, and the lower left second section.

7. A method for welding a fairlead base according to claim 1, characterized in that: The fourth weld is welded from bottom to top.

8. A method for welding a fairlead base according to claim 1, characterized in that: Preheating is performed before all welding. After all welding stages are completed, preheating is terminated and the welding side is wrapped with insulation cotton to slow cooling. The reverse side is carbon planed to whiten it. When all welds are cooled, check whether the dummy shaft can move and rotate freely up and down. If the dummy shaft can move and rotate, then continue with subsequent welding.

9. A method for welding a fairlead base according to claim 1, characterized in that: The welding includes first performing positioning welding, the positioning welding is located on the upper part of the base layer, and then performing base welding on the base layer. After the base welding is completed, the lower filling welding is performed on the lower filling layer below the base layer. After the lower filling welding is completed, the positioning welding position on the upper part of the base layer is a carbon planing layer, and the upper part of the base layer is carbon planed to remove the white. After natural cooling, the upper filling layer on the upper part of the base layer is performed with upper filling welding. After the upper filling welding is completed, the upper cover layer at the upper end of the upper filling layer and the lower cover layer at the lower end of the lower filling layer are filled.

10. A method for welding a fairlead base according to claim 9, characterized in that: Before welding, place round steel at the root of the tack weld.

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