A high-strength steel full penetration fillet joint welding method

Abstract

The application provides a high-strength steel full penetration fillet welding method, comprising the following steps: preparing a groove of a web plate, the single-side angle of the groove is 40-50 DEG, and a root face of the groove is reserved; positioning welding is performed to make the web plate and a face plate keep a 2-6mm assembly gap; formal welding is performed, multi-layer and multi-pass welding is adopted on the front and back of the groove, the welding sequence is first welding the front of the groove with the first pass of backing, then welding the back of the groove with the first layer of sealing, when the first pass of backing and the first layer of sealing are welded, the left and right angles of the welding gun are perpendicular to the plate joint, the up and down angles of the welding gun form a 20-40 DEG included angle with the face plate, and a zigzag swinging gesture is adopted for welding; the front and back of the groove are cross-filled and covered, the left and right angles of the welding gun are perpendicular to the plate joint, the up and down angles of the welding gun are adapted to the position of the welding pass, the cross-filled welding and the covered welding are both multi-layer and multi-pass welding, and the interlayer temperature of the welding seam is controlled to be 100-150 DEG C in the whole welding process. The method saves the process of grinding and polishing the back carbon root, and improves the welding efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the field of high-strength steel full penetration welding technology, in particular to a high-strength steel full penetration corner joint welding method. BACKGROUND

[0002] In the shipbuilding process, the ship structure is usually made of high-strength steel material. At present, when high-strength steel is used for full penetration corner joint welding, the welding method is usually to first weld the front surface, then remove the root by carbon planing after the back surface, and then weld the back surface. Since the front surface welding is usually incomplete, with slag and non-fusion defects, carbon planing is required before back surface welding, which increases the processing process, and the carbon planing and polishing work is heavy, resulting in low welding efficiency. In addition, the traditional welding method has high cost in terms of labor hours, energy use and material consumption, which is not conducive to improving the welding efficiency of shipbuilding. SUMMARY

[0003] The purpose of the embodiment of the application is to provide a high-strength steel full penetration corner joint welding method, which effectively controls the welding sequence, welding angle, welding gesture and welding heat input, adopts a double-sided single-arc welding method with front and back welds crossing each other, ensures the fusion of the weld, formulates a high-strength steel full penetration corner joint welding process, and the front and back welds are well formed, and the mechanical properties such as tensile and bending are good, and meet the process requirements. The whole can reduce the welding workload, reduce the construction cost, improve the on-site production efficiency, and ensure the high-strength steel welding process requirements.

[0004] The application provides a high-strength steel full penetration corner joint welding method, which comprises the following steps:

[0005] S1, making a groove of the web plate, the single-side angle of the groove is 40-50°, and a bevel of the groove is reserved;

[0006] S2, positioning welding, so that the web plate and the panel are welded with a 2-6mm assembly gap;

[0007] S3, formal welding, multi-layer multi-pass welding is used on the front and back of the groove, the welding sequence is to weld the front of the groove first, after the first pass of the front is welded, the first layer of the back of the groove is welded, when the first pass of the front and the first layer of the back are welded, the welding gun is perpendicular to the joint, the welding gun is at an angle of 20-40° with the panel, and the welding gun is used to weld with a sawtooth swing gesture; after the first layer of the back is filled and welded, the front and back of the groove are cross-filled and covered, and the filling and covering are welded, when the filling and covering are welded, the welding gun is perpendicular to the joint, the welding gun is at an angle of 20-40° with the panel, and the welding gun is used to weld with a sawtooth swing gesture; during the filling and covering process, the oxidation layer on the surface of each weld is polished, and the filling and covering are welded with multi-layer multi-pass welding, and the interlayer temperature of the weld is controlled at 100-150°C during the whole welding process.

[0008] In an embodiment, in the S3, the welding current of the first pass of the front is 130-180 A, the welding voltage is 20-24 V, and the welding speed is 160-250 mm / min; the welding current of the first layer of the back is 160-230 A, the welding voltage is 21-27 V, and the welding speed is 210-300 mm / min; the welding current of the filling and covering is 170-250 A, the welding voltage is 23-28 V, and the welding speed is 210-300 mm / min.

[0009] In an embodiment, in the S3, the covering is welded with multi-layer multi-pass welding, the welding swing gesture is an up-and-down sawtooth gesture, the edge of the molten pool covers the previous weld when each weld is welded, and the edge of the molten pool covers the edge of the groove when the last covering is welded.

[0010] In an embodiment, in the S3, during the formal welding, the wire extension is 10-15 mm, the wire is in front of the molten pool, and the weld height of the back is controlled at 0-2 mm and the width is controlled at 4-8 mm.

[0011] In an embodiment, in the S2, a clamp plate is used to fix the back of the corner joint, and the positioning welding is performed in the groove, the positioning welding length is greater than or equal to 50 mm, the positioning welding interval is less than or equal to 500 mm, a transition slope is polished at the position of the arc pit, and the welding is started from 10-20 mm away from the joint.

[0012] In an embodiment, during the formal welding, the width of the single weld is 6-10 mm, and the thickness of the single weld is less than or equal to 5 mm.

[0013] In an embodiment, before welding, a heating plate or a torch is used to preheat the weld on both sides within a predetermined range, and the preheating temperature is 60-150°C.

[0014] In an embodiment, the protective gas during welding is a mixed gas of 95% Ar and 5% CO2, and the gas flow during welding is 15-30 L / min.

[0015] In an embodiment, the first pass on the front side, the first layer on the back side and the filling cover pass are all welded from right to left.

[0016] In an embodiment, the welding material for welding is a JS80 solid wire with a diameter of 1.2 mm.

[0017] The high-strength steel full-penetration corner joint welding method has the following beneficial effects:

[0018] 1. The welding heat input is effectively controlled during welding, i.e. the welding sequence, welding angle, welding gesture and welding heat input are controlled, and the double-sided single-arc welding method with the front and back welds crossing at the same time is adopted to ensure the weld fusion, strictly control the interlayer temperature of the weld, and make the front and back welds well-shaped and have good mechanical properties such as tensile and bending, and meet the process requirements.

[0019] 2. Compared with the traditional welding method, the back carbon planing and grinding process is saved, the welding workload is reduced, and the welding efficiency of the high-strength steel full-penetration corner joint is improved.

[0020] 3. The welding sequence of the front and back welds crossing at the same time is adopted, and the structural deformation problem is also avoided.

[0021] 4. The double-sided single-arc welding method of the gas-melted electrode is adopted, the weld root fusion is good, the welding efficiency is improved by more than 1 times, the material cost is reduced by 30%, and the labor cost is reduced by 50%. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without creative labor.

[0023] Figure 1 It is a welding assembly schematic diagram of a high-strength steel full-penetration corner joint according to an embodiment of the present application.

[0024] Figure 2 It is a structure schematic diagram of a weld layer weld pass of a high-strength steel full-penetration corner joint according to an embodiment of the present application.

[0025] Figure 3 It is a structure schematic diagram of a groove of a web according to an embodiment of the present application.

[0026] Figure 4 A structural schematic diagram of a positioning welding according to an embodiment of the present application is shown.

[0027] 1, first pass; 2, second pass; 3, third pass; 4, fourth pass; 5, fifth pass; 6, sixth pass; 7, seventh pass; 8, eighth pass; 9, ninth pass; 10, tenth pass; 11, eleventh pass; 12, twelfth pass; 13, thirteenth pass; 14, fourteenth pass; 100, plate; 110, web; 111, first single edge; 112, second single edge; 113, blunt edge; 120, panel; 200, assembly gap; 210, positioning welding length; 220, positioning welding spacing. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0030] Referring to Figures 1-3 , the present application provides a high-strength steel full penetration fillet welding method. The high-strength steel plate 100 is welded. In an embodiment, the high-strength steel plate 100 includes a web 110 and a panel 120. In an embodiment, the high-strength steel plate is selected to be 30mm thick 980A steel of grade 10CrNi5MoV, which is a 785MPa grade high-strength ship hull steel. The comprehensive performance and processability of the material are good, but it is very sensitive to hydrogen and prone to hydrogen-induced cracking, and the welding process is relatively complex. The welding method provided by the present application specifically includes the following steps:

[0031] S1, making a groove of the web 110, the single edge (the first single edge 111 and the second single edge 112) angle of the groove is 40-50°, and a blunt edge 113 is reserved, the blunt edge 113 is 1-2mm; the blunt edge is reserved to easily control the heat input during welding. In an embodiment, the groove form is K-shaped, and the K-shaped groove is easy to process and form;

[0032] S2, positioning welding, welding the root of the web plate and the panel to keep 2-6mm assembly gap 200;

[0033] S3, formal welding, using multi-layer multi-pass welding on the front and back of the groove, in one case, see Figure 2 , the front and back welding is 8 layers and 14 passes, specifically, 8 layers of welding includes: the front first pass 1 (1st layer), the second pass 2 (2nd layer), the third pass 3 (3rd layer), the fourth pass 4 (4th layer), the fifth pass 5 and the sixth pass 6 together form the 5th layer, the seventh pass 7 and the eighth pass 8 together form the 6th layer. The ninth pass 9, the tenth pass 10 and the eleventh pass 11 together form the 7th layer. The twelfth pass 12, the thirteenth pass 13 and the fourteenth pass 14 together form the 8th layer. The welding sequence is to weld the front first pass 1 of the groove first, after the front first pass 1 is welded, the back first layer of the groove is welded, when the front first pass 1 and the back first layer of the groove are welded, the left and right angles of the welding gun are perpendicular to the plate joint, the up and down angles of the welding gun are 20-40° to the panel, and the oblique sawtooth swing gesture is used for welding; after the back first layer of the groove is filled and welded, the front and back of the groove are cross-filled and covered with welding. See Figure 2 , the filling welding includes the second pass 2, the third pass 3, the fourth pass 4, the fifth pass 5, the sixth pass 6, the seventh pass 7 and the eighth pass 8; the covering welding includes the ninth pass 9, the tenth pass 10, the eleventh pass 11, the twelfth pass 12, the thirteenth pass 13 and the fourteenth pass 14. When filling and covering, the left and right angles of the welding gun are perpendicular to the plate joint, the up and down angles of the welding gun are adapted to the position of the pass, the oxidation layer on the surface of each pass is polished during filling and covering, and multi-layer multi-pass welding is used for filling and covering. During the whole welding process, the interlayer temperature of the weld is controlled at 100-150℃.

[0034] Specific welding parameters, the welding current of the first pass of the front side 1 is 130-180 A, the welding voltage is 20-24 V, and the welding speed is 160-250 mm / min; the welding current of the first layer of the back side 1 is 160-230 A, the welding voltage is 21-27 V, and the welding speed is 210-300 mm / min; the welding current of the filling cover is 170-250 A, the welding voltage is 23-28 V, and the welding speed is 210-300 mm / min. In an embodiment, the front side and the back side use the same welding voltage and welding speed, the welding voltage is 23-28 V, and the welding speed is 210-300 mm / min, and different welding currents are used: the welding current of the front side filling is 170-250 A, the welding current of the front side cover is 180-250 A; the welding current of the back side filling is 180-250 A, and the welding current of the back side cover is 180-250 A, so as to accurately control the heat input during the filling and covering welding and improve the welding forming quality.

[0035] In the above implementation process, by reserving a blunt edge and an assembly gap between the web plate and the face plate, and performing welding perpendicular to the plate joint on the front side and the back side of the assembly gap, by controlling the welding angle, the welding gesture and the welding heat input, the welding heat input includes the welding parameters, the welding time and the interlayer temperature of the weld during welding, and by using the double-sided single-arc welding method with the front and back welds crossing at the same time, the weld fusion is ensured, the interlayer temperature of the weld is strictly controlled, the welding process of the high-strength steel full-penetration corner joint is formulated, the front and back welds are well formed, and the mechanical properties such as tensile and bending are good, and the process requirements are met. Compared with the traditional welding method (welding the front side first and then welding the back side), the back side carbon planing, cleaning and polishing process is saved, the welding efficiency of the high-strength steel full-penetration corner joint is improved. In addition, the welding sequence with the front and back welds crossing at the same time also effectively avoids the problem of structural deformation. That is, the method can reduce the welding workload, reduce the construction cost, improve the on-site production efficiency, and also ensure the welding process requirements of high-strength steel.

[0036] In an embodiment, in S3, the welding swing gesture of the cover welding is an up-and-down sawtooth gesture, the molten pool edge line of each weld covers the previous weld, and the molten pool edge line of the last cover welding covers the bevel edge line, that is, the eleventh welding bead 11 and the fourteenth welding bead 14 cover the bevel edge line. By controlling the position of the welding bead, the weld overlap forming and the flatness of the weld can be ensured.

[0037] In an embodiment, in S2, during formal welding, the welding wire is elongated by 10-15 mm, the welding wire is in front of the molten pool, and the back weld height is controlled to be 0-2 mm and the width is controlled to be 4-8 mm. In combination with the size of the assembly gap 200 of the web plate 110, the assembly gap 200 is 2-6 mm, and in an embodiment, the assembly gap 200 is 3 mm, which is matched with the optimal height of the back weld of 0-2 mm and the width of 4-8 mm.

[0038] In an embodiment, in S2, during tack welding, a hot plate is used to reinforce and fix the back of the corner joint, and tack welding is performed in the groove. In an embodiment, referring to FIG. 2B, the web plate 110 and the face plate 120 are matched, the tack welding length 210 is greater than or equal to 50 mm, and the tack welding spacing 220 is less than or equal to 500 mm. A transition slope is ground at the position of the arc pit of the tack welding, and the welding is started from 10-20 mm away from the joint, which can ensure the weld formation of the backing weld and the joint quality. Figure 4

[0039] In an embodiment, in S3, during formal welding, in order to improve the welding quality of multiple layers and multiple passes, the width of a single pass weld is 6-10 mm, and the thickness of a single pass weld is less than or equal to 5 mm.

[0040] In an embodiment, the welding process further includes preheating the welding seam by using a heating plate or a torch gun to preheat a predetermined range on both sides of the welding seam before welding, the preheating temperature is 60-150°C, and the area of 100 mm on both sides of the welding seam is preheated. Because the high-strength steel has a relatively high temperature requirement during welding, too high or too low temperature will affect the mechanical properties of the welding seam, and preheating can prevent cracks during welding. The process further includes grinding the primer and rust and other impurities within 30 mm on both sides of the front and back of the welding seam before welding.

[0041] In an embodiment, the protective gas used during welding is a mixed gas of 95% Ar and 5% CO2, the CO2 content should be controlled within the range of (5±0.50)%, the purity of the mixed gas is >99.99% carbon dioxide mixed gas, and the gas flow during welding is 15-30 L / min. After the front welding is completed, the back does not need to be carbon planed to clear the root and can be directly backfilled. Practice has shown that the high-strength steel full-penetration corner joint adopts the welding method of double-sided single-arc welding of the melting mixed gas, the weld root fusion is good, the welding efficiency is improved by more than 1 times, the material cost is reduced by 30%, and the labor cost is reduced by 50%.

[0042] ​In an embodiment, the first pass of the front side, the first layer of the back side and the filling cover side are all welded by right-to-left welding. Compared with left-to-right welding, right-to-left welding has better gas protection, the weld is relatively flat, and is not easy to be high. In addition, right-to-left welding is more convenient to operate. The use of right-to-left welding makes the overall weld form well, and reduces the amount of work of each layer and each pass of welding during the welding process.

[0043] In an embodiment, the welding material is selected as a JS80 solid core welding wire with a diameter of 1.2 mm. The welding wire has good droplet transfer characteristics relative to manual arc welding, and the welding arc heat is concentrated. The welding material should be placed in a constant temperature room to prevent the welding material from being damp, and to avoid welding defects during welding.

[0044] In order to verify the welding effect of the method, the plate welded by the above-mentioned high-strength steel full-penetration corner joint welding method is subjected to quality inspection, and the inspection result is that: the appearance inspection of the front and back sides of the weld of the 980A steel structure corner joint is good, and there is no conventional undercut and porosity; according to the standards of GJB4000-2000, GJB64, 1A-97, the mechanical property tests of bending, hardness and macroscopic of the structure weld are carried out, and the test results show that they all meet the requirements of the welding process of 980A steel.

[0045] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method of welding a full penetration fillet joint of a high strength steel, characterized by, The method comprises the following steps: S1, making a groove of the web plate, the single-side angle of the groove is 40-50°, and a bevel of the groove is reserved; S2, positioning welding, the web plate is welded with the panel to keep a 2-6mm assembly gap; S3, formal welding, the front and back of the groove are welded by multi-layer and multi-pass welding, the welding sequence is that the front of the groove is first welded by the first pass of the bottoming, after the first pass of the bottoming is welded, the back of the groove is welded by the first layer of the back sealing, when the first pass of the bottoming and the first layer of the back sealing are welded, the left and right angles of the welding gun are perpendicular to the plate joint, the up and down angles of the welding gun are 20-40° with the panel, and the welding gun is welded by the oblique sawtooth swing gesture; after the first layer of the back sealing is filled and welded, the front and back of the groove are cross-filled and welded, the left and right angles of the welding gun are perpendicular to the plate joint, the up and down angles of the welding gun are adapted to the position of the weld, the oxidation layer on the surface of each weld is polished during the filling and covering process, the filling and covering are all welded by multi-layer and multi-pass welding, the interlayer temperature of the weld is controlled to be 100-150℃ during the whole welding process, the covering is welded by multi-layer and multi-pass welding, the welding swing gesture is the up and down oblique sawtooth gesture, the molten pool edge line covers the previous weld when each weld is welded, and the molten pool edge line covers the groove edge line when the last covering is welded.

2. The high strength steel full penetration fillet weld method of claim 1, wherein, In the S3, the welding current of the first pass of the bottoming is 130-180A, the welding voltage is 20-24V, and the welding speed is 160-250mm / min; the welding current of the first layer of the back sealing is 160-230A, the welding voltage is 21-27V, and the welding speed is 210-300mm / min; the welding current of the filling and covering is 170-250A, the welding voltage is 23-28V, and the welding speed is 210-300mm / min.

3. The high strength steel full penetration fillet weld method of claim 1, wherein, In the S3, during the formal welding, the welding wire is stretched by 10-15mm, the welding wire is in front of the molten pool, and the height of the back weld is controlled to be 0-2mm and the width is controlled to be 4-8mm.

4. The high strength steel full penetration fillet weld method of claim 1, wherein, In the S2, the positioning welding is performed by the M-shaped plate on the back of the corner joint for strengthening and fixing, the positioning welding is performed in the groove, the length of the positioning welding is greater than or equal to 50mm, the spacing of the positioning welding is less than or equal to 500mm, and the transition slope is polished at the position of the arc pit of the positioning welding.

5. The high strength steel full penetration fillet weld method of claim 1, wherein, During the formal welding, the width of the single-pass weld is 6-10mm, and the thickness of the single-pass weld is less than or equal to 5mm.

6. The high strength steel full penetration fillet weld method of claim 1, wherein, Before the welding, the welding seam on both sides in the preset range is preheated by the heating plate or the torch, and the preheating temperature is 60-150℃.

7. The high strength steel full penetration fillet weld method of claim 1, wherein, The protective gas during the welding is the mixed gas of 95% Ar and 5% CO2, and the gas flow during the welding is 15-30L / min.

8. The high strength steel full penetration fillet weld method of claim 1, wherein, The welding methods of the first pass of the bottoming, the first layer of the back sealing and the filling and covering are all from right to left.

9. The high strength steel full penetration fillet weld method of claim 1, wherein, The welding material for the welding is selected from the JS80 solid core welding wire with a diameter of 1.2mm.

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