Welding methods

Abstract

The present application relates to the technical field of welding, in particular to a welding method. A welding wire is used to perform backing layer welding between the gap distance of the bevel formed by a first steel plate and a second steel plate to form a backing transition welding layer, a welding wire is used to perform intermediate transition layer welding between the first steel plate and the second steel plate on the outer surface of the backing transition welding layer, the outer surface of the intermediate transition layer is non-coplanar with the side surface of the first steel plate and the side surface of the second steel plate; a welding wire is used to perform cover layer welding between the first steel plate and the second steel plate on the outer surface of the intermediate transition layer, the outer surface of the cover layer is flush with the side surface of the first steel plate and the side surface of the second steel plate, or the outer surface of the cover layer protrudes from the side surface of the first steel plate and the side surface of the second steel plate. The welding method can realize the welding of dissimilar steel plates, the welding process can effectively solve the process adaptability and material matching problems caused by large mechanical property difference, and can improve the reliability of dissimilar steel plate welding.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding, in particular to a welding method. BACKGROUND

[0002] With the increasing requirements of ship and ocean engineering equipment service, especially in the harsh environment such as deep sea, torrent, dangerous shoal and the like, in order to ensure the structural safety, the steel used in the design also presents the trend of high strength and high toughness. The 10CrNi3MoV steel and the EH550 steel are both high-strength steels for ship and ocean engineering, both of which have high strength, toughness and seawater corrosion resistance. The 10CrNi3MoV steel is widely used in the pressure-resistant and collision-resistant hull of the ship, and the EH550 steel is mainly used in the important load-bearing structure of the ocean engineering equipment. In order to meet the stability requirements of the special customized ship and platform under the harsh factors such as inherent static load, working dynamic load, water pressure, impact and collision, the structural design of the related ship and platform will select different steels according to the functional requirements of the specific structural modules. The 10CrNi3MoV steel is mainly used in the design of the pressure-resistant and impact-resistant hull structure, and the EH550 steel is mainly used in the design of the load-bearing structure which plays a supporting role and transmits load. Therefore, the welding of the 10CrNi3MoV steel and the EH550 steel becomes an indispensable production process.

[0003] However, the carbon equivalent of both the 10CrNi3MoV steel and the EH550 steel is relatively large, and both of them are prone to welding cracking. In addition, the alloy composition and mechanical properties of the two steels are quite different, and the welding of dissimilar materials puts higher requirements on the process adaptability and the matching of welding materials.

[0004] Therefore, there is an urgent need for a welding method to solve the above technical problems. SUMMARY

[0005] The purpose of the present application is to provide a welding method which can realize the welding of two kinds of dissimilar steels.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] The welding method is used for welding between a first steel plate and a second steel plate, the first steel plate is an EH550 steel plate, and the second steel plate is a 10CrNi3MoV steel plate, and the method comprises the following steps:

[0008] A backing layer is welded between the first steel plate and the second steel plate using a welding wire to form a bottom transition welding layer;

[0009] An intermediate transition layer is welded between the first steel plate and the second steel plate using a welding wire on the outer surface of the bottom transition welding layer, and the outer surface of the intermediate transition layer is non-coplanar with the side surface of the first steel plate and the side surface of the second steel plate;

[0010] Welding a cap layer between the first steel plate and the second steel plate on the outer surface of the intermediate transition layer using a welding wire, wherein the outer surface of the cap layer is flush with the side surface of the first steel plate and the side surface of the second steel plate, or the outer surface of the cap layer protrudes from the side surface of the first steel plate and the side surface of the second steel plate;

[0011] The welding wire used is a flux-cored welding wire with a diameter of 1.2 mm. The welding wire contains the following components by mass fraction: carbon content 0.04% to 0.05%, silicon content 0.30% to 0.35%, manganese content 1.55% to 1.65%, nickel content 1.70% to 1.80%, and the rest is iron.

[0012] As a preferred technical solution of the above welding method, if the welding wire is in any of the flat welding, vertical welding or overhead welding positions, the welding wire is inclined 5° to 10° toward the second steel plate side;

[0013] If the welding wire is in the horizontal welding position, the welding wire is inclined toward the second steel plate, and the angle between the welding wire and the horizontal plane is 10° to 15°.

[0014] As a preferred technical solution of the above-mentioned welding method, in the process of performing base layer welding between the groove spacing formed by the first steel plate and the second steel plate using a welding wire to form a bottom transition weld layer: if the welding wire is in any of the flat welding, horizontal welding or overhead welding positions, the welding current is 170A to 175A, the arc voltage is 24V to 25V, the welding speed is 12.3cm / min to 12.8cm / min, the welding wire extension length is 12mm to 15mm, the shielding gas flow rate is 15L / min to 20L / min, wherein the welding wire swing amplitude in the flat welding position is 6mm to 8mm, the welding wire does not swing in the horizontal welding position, and the welding wire swing in the overhead welding position is 4mm to 6mm;

[0015] If the welding wire is in the vertical welding position, the welding current is 175A~180A, the arc voltage is 21V~22V, the welding speed is 8.5cm / min~9.0cm / min, the welding wire extension length is 12mm~15mm, the shielding gas flow rate is 15L / min~20L / min, and the welding wire swing amplitude is 6mm~8mm.

[0016] As a preferred technical solution of the above welding method, during the process of welding the intermediate transition layer between the first steel plate and the second steel plate using a welding wire on the outer surface of the bottom transition weld layer:

[0017] If the welding wire is in any one of the flat welding, horizontal welding or overhead welding position, the welding current is 205A-210A, the arc voltage is 25V-27V, the welding speed is 17.5cm / min-21.5cm / min, the wire extension length is 12mm-15mm, and the shielding gas flow rate is 15L / min-20L / min, wherein the flat welding position wire swing range is 6mm-10mm, the horizontal welding position wire does not swing, and the overhead welding position wire swings 4mm-8mm;

[0018] If the welding wire is in the vertical welding position, the welding current is 185A-190A, the arc voltage is 23V-24V, the welding speed is 11.3cm / min-12.3cm / min, the wire extension length is 12mm-15mm, the shielding gas flow rate is 15L / min-20L / min, and the wire swing range is 8mm-12mm;

[0019] Wherein the interpass temperature during welding of the intermediate transition layer is less than 150℃.

[0020] As a preferred technical scheme of the above welding method, during welding of the cover layer between the first steel plate and the second steel plate using the welding wire on the outer surface of the intermediate transition layer:

[0021] If the welding wire is in any one of the flat welding, horizontal welding or overhead welding position, the welding current is 190A-200A, the arc voltage is 24V-25V, the welding speed is 25.0cm / min-29.0cm / min, the wire extension length is 12mm-15mm, the shielding gas flow rate is 15L / min-20L / min, and the wire does not swing;

[0022] If the welding wire is in the vertical welding position, the welding current is 170A-175A, the arc voltage is 22V-23V, the welding speed is 9.0cm / min-10.0cm / min, the wire extension length is 12mm-15mm, the shielding gas flow rate is 15L / min-20L / min, and the wire swing range is 8mm-12mm;

[0023] Wherein the interpass temperature during welding of the cover layer is less than 190℃.

[0024] As a preferred technical scheme of the above welding method, the bottom transition welding layer is welded in one pass, and the intermediate transition layer is welded in multiple passes.

[0025] As a preferred technical scheme of the above welding method, before the bottom layer welding is performed using the welding wire between the gap distance of the bevel formed by the first steel plate and the second steel plate to form the bottom transition welding layer, it further includes:

[0026] Opening a welding bevel at the edge of the first steel plate and the second steel plate;

[0027] Assembling a first steel plate and a second steel plate, wherein the groove root of the first steel plate and the groove root of the second steel plate are arranged opposite to each other to form a groove spacing, wherein the groove spacing is a preset distance;

[0028] A welding pad is installed, wherein the central axis of the welding pad overlaps the central axis of the groove spacing.

[0029] As a preferred technical solution of the above welding method, the groove spacing ranges from 4 mm to 6 mm.

[0030] As a preferred technical solution of the above welding method, during the process of forming the welding groove on the edges of the first steel plate and the second steel plate:

[0031] For flat welding, vertical welding and overhead welding, both the first and second steel plates shall have a 20° groove;

[0032] If the welding position is horizontal, the first steel plate at the bottom has a 15° groove, and the second steel plate at the top has a 25° groove.

[0033] As a preferred technical solution of the above welding method, the gasket is fixed by aluminum foil tape.

[0034] As a preferred technical solution of the above welding method, after welding is completed, the back pad is removed and the card used to support the first steel plate and the second steel plate is cut off.

[0035] Beneficial effects of the present invention:

[0036] The proportions of iron, carbon, silicon, manganese, and nickel in the welding wire effectively ensure that the transition metal achieves sufficient strength and toughness. This patented invention effectively addresses the process adaptability and material matching issues caused by significant differences in alloy composition and mechanical properties, and can improve the reliability of welding dissimilar materials such as 10CrNi3MoV steel and EH550 steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without any creative work.

[0038] Figure 1 The welding method provided by the embodiment of the present invention Figure 1 ;

[0039] Figure 2The first steel plate and the second steel plate provided in the embodiment of the present invention are grooves welded by flat welding, vertical welding or overhead welding;

[0040] Figure 3 The first steel plate and the second steel plate provided in the embodiment of the present invention are grooves of horizontal welding;

[0041] Figure 4 The welding method provided by the embodiment of the present invention Figure 2 .

[0042] In the picture:

[0043] 1. First steel plate; 2. Second steel plate. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0045] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0046] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0047] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0048] With existing technology, both 10CrNi3MoV and EH550 steels are high-strength steels for shipbuilding and marine engineering applications. Therefore, dissimilar welding of these two materials is essential. However, both 10CrNi3MoV and EH550 steels have high carbon equivalents, making them susceptible to weld cracking. Furthermore, the alloy composition and mechanical properties of these two steels differ significantly, placing higher demands on process adaptability and welding material compatibility when welding dissimilar materials.

[0049] To this end, the present invention provides a welding method that can be used for welding 10CrNi3MoV steel plates and EH550 steel plates to solve the problem that the alloy composition and mechanical properties of the two steels are quite different, and higher requirements are placed on process adaptability and welding material matching when welding dissimilar materials.

[0050] like Figure 1 As shown, the welding method is used for welding a first steel plate 1 and a second steel plate 2, wherein the first steel plate 1 is an EH550 steel plate and the second steel plate 2 is a 10CrNi3MoV steel plate. The method comprises the following steps:

[0051] S101, using a welding wire to perform base layer welding between the groove formed by the first steel plate 1 and the second steel plate 2 to form a bottom transition welding layer;

[0052] S102, welding an intermediate transition layer between the first steel plate 1 and the second steel plate 2 using a welding wire on the outer surface of the bottom transition weld layer, wherein the outer surface of the intermediate transition layer is not coplanar with the side surface of the first steel plate 1 and the side surface of the second steel plate 2;

[0053] S103. Use welding wire to weld a cover layer between the first steel plate 1 and the second steel plate 2 on the outer surface of the intermediate transition layer, and the outer surface of the cover layer is flush with the side surface of the first steel plate 1 and the side surface of the second steel plate 2, or the outer surface of the cover layer protrudes from the side surface of the first steel plate 1 and the side surface of the second steel plate 2.

[0054] The proportion of iron, carbon, silicon, manganese, nickel and other elements in the welding wire is matched, so that the strength and toughness of the transition layer metal can be effectively ensured; the process adaptability and material matching problem caused by the large difference in alloy composition and mechanical property can be effectively solved, and the reliability of the welding of the 10CrNi3MoV steel and the EH550 steel dissimilar materials can be improved.

[0055] In some embodiments, if the welding wire is in any one of the flat welding, vertical welding or overhead welding position, the welding wire is inclined to the second steel plate side by 5-10°; if the welding wire is in the horizontal welding position, the welding wire is inclined to the second steel plate, and the included angle between the welding wire and the horizontal plane is 10-15°. By adjusting the angle of the welding wire, the flowability of the molten metal is controlled to avoid the problems of poor weld fusion and forming.

[0056] In some embodiments of the present application, during the process of welding the backing layer between the grooves formed by the welding wire between the first steel plate 1 and the second steel plate 2 to form the backing transition welding layer: if the welding wire is in any one of the flat welding, horizontal welding or overhead welding position, the welding current is 170-175A, the arc voltage is 24-25V, the welding speed is 12.3-12.8cm / min, the welding wire extension length is 12-15mm, and the protective gas flow is 15-20L / min, wherein the welding wire swing range in the flat welding position is 6-8mm, the welding wire does not swing in the horizontal welding position, and the welding wire swing in the overhead welding position is 4-6mm; by matching the welding arc parameters, the problems of element burning loss and coarse organization transformation caused by improper welding heat input are avoided.

[0057] If the welding wire is in the vertical welding position, the welding current is 175-180A, the arc voltage is 21-22V, the welding speed is 8.5-9.0cm / min, the welding wire extension length is 12-15mm, the protective gas flow is 15-20L / min, and the welding wire swing range is 6-8mm.

[0058] In this way, the welding of the backing transition layer is controlled according to different welding positions, which avoids the formation of incomplete fusion and incomplete penetration welding defects due to insufficient back forming, and avoids the formation of welding porosity, burning and other problems due to excessive arc impact force and heat, and comprehensively ensures the welding forming of the backing transition welding layer to ensure the welding quality of the back of the transition welding layer.

[0059] In some embodiments of the present application, when welding an intermediate transition layer between a first steel plate 1 and a second steel plate 2 using a welding wire on the outer surface of a bottom transition layer: if the welding wire is in any of the flat welding, horizontal welding, or overhead welding positions, the welding current is 205A to 210A, for example, 205A, 206A, 207A, 208A, 209A, or 300A. The arc voltage is 25V to 27V, for example, 25V, 26V, or 27V. The welding speed is 17.5cm / min to 21.5cm / min, for example, 17.5cm / min, 18cm / min, 18.5cm / min, 19cm / min, 19.5cm / min, 20cm / min, 20.5cm / min, 21cm / min, or 21.5cm / min. The welding wire extension length is 12 mm to 15 mm, for example, the welding wire extension length is 12 mm, 13 mm, 14 mm, or 15 mm; the shielding gas flow rate is 15 L / min to 20 L / min, for example, the shielding gas flow rate is 15 L / min, 16 L / min, 17 L / min, 18 L / min, 19 L / min, or 20 L / min; wherein, the welding wire swing amplitude in the flat welding position is 6 mm to 10 mm, for example, the welding wire swing amplitude is 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm; the welding wire does not swing in the horizontal welding position, and the welding wire swing in the overhead welding position is 4 mm to 8 mm, for example, the welding wire swing in the overhead welding position is 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm.

[0060] If the welding wire is in the vertical welding position, the welding current is 185A to 190A, for example, the welding current is 185A, 186A, 187A, 188A, 189A, or 190A. The arc voltage is 23V to 24V, for example, the arc voltage is 23V or 24V. The welding speed is 11.3cm / min to 12.3cm / min, for example, the welding speed is 11.3cm / min, 11.4cm / min, 11.5cm / min, 11.6cm / min, 11.7cm / min, 11.8cm / min, 11.9cm / min, 12.0cm / min, 12.1cm / min, 12.2cm / min, or 12.3cm / min. The welding wire extension length is 12mm~15mm, for example, the welding wire extension length is 12mm, 13mm, 14mm or 15mm; the shielding gas flow rate is 15L / min~20L / min, for example, the shielding gas flow rate is 15L / min, 16L / min, 17L / min, 18L / min, 19L / min or 20L / min; the welding wire swing amplitude is 8mm~12mm, for example, the welding wire swing amplitude is 8mm, 9mm, 10mm, 11mm or 12mm; with this arrangement, the welding of the intermediate transition layer is controlled according to different welding positions, preventing element burning and coarse structure transformation problems caused by excessive welding heat input, and poor fusion problems caused by insufficient welding heat input, and comprehensively avoiding the malignant transformation of weld formation and structure morphology of the intermediate transition weld layer, thereby ensuring the welding quality of the transition weld layer.

[0061] Furthermore, the interpass temperature during welding of the intermediate transition layer is less than 150° C. This can avoid the problem of element burning and coarse structure transformation caused by excessively high temperatures of the first steel plate 1 and the second steel plate 2 during welding.

[0062] In some embodiments of the present application, when welding a cap layer between a first steel plate 1 and a second steel plate 2 using a welding wire on the outer surface of the intermediate transition layer: if the welding wire is in any of the flat welding, horizontal welding, or overhead welding positions, the welding current is 190A to 200A, 191A, 192A, 193A, 194A, 195A, 196A, 197A, 198A, 199A, or 200A; the arc voltage is 24V to 25V, for example, the arc voltage is 24V or 25V; the welding speed is 25.0cm / min to 29.0cm / min, for example, the welding speed is 25.0cm / min, 26cm / min, 27cm / min, 28cm / min, or 29cm / min; and the welding wire extension length is 12mm to 15mm, for example, the welding wire extension length is 12mm, 13mm, 14mm, or 15mm. The shielding gas flow rate is 15 L / min to 20 L / min. For example, the shielding gas flow rate is 15 L / min, 16 L / min, 17 L / min, 18 L / min, 19 L / min, or 20 L / min. The welding wire does not swing during welding.

[0063] If the welding wire is in the vertical welding position, the welding current is 170A to 175A, for example, 170A, 171A, 172A, 173A, 174A, or 175A. The arc voltage is 22V to 23V, for example, 22V or 23V. The welding speed is 9.0cm / min to 10.0cm / min, for example, 9.0cm / min, 9.1cm / min, 9.2cm / min, 9.3cm / min, 9.4cm / min, 9.5cm / min, 9.6cm / min, 9.7cm / min, 9.8cm / min, 9.9cm / min, or 10cm / min. The wire extension length is 12mm to 15mm, for example, 12mm, 13mm, 14mm, or 15mm. The shielding gas flow rate is 15L / min to 20L / min, 15L / min, 16L / min, 17L / min, 18L / min, 19L / min, or 20L / min. The wire swing amplitude is 8mm to 12mm, for example, 8mm, 9mm, 10mm, 11mm, or 12mm. This configuration controls the welding of the cap layer according to different welding positions, ensuring the fluidity of the weld bead in a molten state, while also ensuring reliable fusion between weld beads and between the weld bead and the base material, avoiding the formation of undercuts and other problems. This comprehensively ensures the weld formation of the cap layer and thus the welding quality of the front of the transition layer.

[0064] Furthermore, the interpass temperature during the cap layer welding process is less than 190° C. This setting can avoid the problems of element burnout and coarse structure transformation caused by excessive temperature.

[0065] It should be noted that, in this embodiment, the bottom transition layer is welded in one pass, and the middle transition layer is welded in multiple passes.

[0066] In some embodiments of the present application, before performing base layer welding between the groove spacing formed by the first steel plate 1 and the second steel plate 2 using a welding wire to form a bottom transition weld layer, the method further includes:

[0067] A welding groove is provided at the edges of the first steel plate 1 and the second steel plate 2 ; the welding groove can accommodate more molten solder to ensure that the first steel plate 1 and the second steel plate 2 are connected by solder.

[0068] The first steel plate 1 and the second steel plate 2 are assembled, and the root of the groove of the first steel plate 1 and the root of the groove of the second steel plate 2 are arranged relative to each other to form a groove spacing, and the groove spacing is a preset distance; the groove spacing is a preset distance in order to accommodate the solder and prevent the solder from protruding from the groove formed by the first steel plate 1 and the second steel plate 2. Specifically, the first steel plate 1 and the second steel plate 2 are fixed by a card horse.

[0069] In order to prevent the solder from flowing out at the groove and to prevent the solder from acting on other structures, in this embodiment, a welding pad is installed, and the central axis of the welding pad overlaps the central axis of the groove spacing.

[0070] For example, in this embodiment, the groove spacing ranges from 4 mm to 6 mm. For example, the groove spacing is 4 mm, 5 mm, or 6 mm.

[0071] It should be noted that, in the process of forming the welding groove on the edges of the first steel plate 1 and the second steel plate 2, Figure 2 and Figure 3 As shown, in this embodiment, if the welding wire is in the flat welding, vertical welding, or overhead welding position, the first steel plate 1 and the second steel plate 2 both have a 20° groove. If the welding wire is in the horizontal welding position, the first steel plate 1 located at the bottom has a 15° groove, and the second steel plate 2 located at the top has a 25° groove. This arrangement allows the welding groove to be matched to different welding positions, avoiding the possibility of a too-small weld groove that affects weld penetration, and the possibility of an too-large weld groove that increases filler metal costs.

[0072] In order to facilitate the removal of the liner, in this embodiment, the liner is fixed by an aluminum foil tape. The aluminum foil tape can also withstand high temperatures and ensure that the liner fits the first steel plate 1 and the second steel plate 2.

[0073] It should be noted that, in this embodiment, after welding is completed, the back gasket is removed and the card used to support the first steel plate 1 and the second steel plate 2 is cut off. In this way, the welding of the two steel plates is completed.

[0074] like Figure 4As shown, the method specifically includes the following steps:

[0075] S201, forming welding grooves on the edges of the first steel plate 1 and the second steel plate 2;

[0076] S202, assembling the first steel plate 1 and the second steel plate 2, with the groove root of the first steel plate 1 and the groove root of the second steel plate 2 being arranged opposite to each other to form a groove spacing, where the groove spacing is a preset distance;

[0077] S203, installing the welding pad, wherein the central axis of the welding pad overlaps the central axis of the groove spacing;

[0078] S204, performing base layer welding between the groove formed by the first steel plate 1 and the second steel plate 2 using a welding wire to form a bottom transition welding layer;

[0079] S205, welding an intermediate transition layer between the first steel plate 1 and the second steel plate 2 using a welding wire on the outer surface of the bottom transition weld layer, wherein the outer surface of the intermediate transition layer is not coplanar with the side surface of the first steel plate 1 and the side surface of the second steel plate 2;

[0080] S206. Welding a cap layer between the first steel plate 1 and the second steel plate 2 on the outer surface of the intermediate transition layer using a welding wire, wherein the outer surface of the cap layer is flush with the side surface of the first steel plate 1 and the side surface of the second steel plate 2, or the outer surface of the cap layer protrudes from the side surface of the first steel plate 1 and the side surface of the second steel plate 2;

[0081] S207, after welding is completed, the back gasket is removed, and the card used to support the first steel plate 1 and the second steel plate 2 is cut off.

[0082] Furthermore, the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are possible for those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A welding method for welding a first steel plate and a second steel plate, wherein the first steel plate is an EH550 steel plate and the second steel plate is a 10CrNi3MoV steel plate, characterized in that: include: Performing base layer welding between the groove spacing formed by the first steel plate and the second steel plate using a welding wire to form a bottom transition weld layer; If the welding wire is in any of the flat welding, horizontal welding or overhead welding positions, the welding current is 170A~175A, the arc voltage is 24V~25V, the welding speed is 12.3cm / min~12.8cm / min, the welding wire extension length is 12mm~15mm, the shielding gas flow rate is 15L / min~20L / min, and the wire swing amplitude in the flat welding position is 6mm~8mm, the wire does not swing in the horizontal welding position, and the wire swing amplitude in the overhead welding position is 4mm~6mm; If the welding wire is in the vertical welding position, the welding current is 175A~180A, the arc voltage is 21V~22V, the welding speed is 8.5cm / min~9.0cm / min, the welding wire extension length is 12mm~15mm, the shielding gas flow rate is 15L / min~20L / min, and the welding wire swing amplitude is 6mm~8mm; If the welding wire is in any of the flat welding, horizontal welding or overhead welding positions, the welding current is 205A~210A, the arc voltage is 25V~27V, the welding speed is 17.5cm / min~21.5cm / min, the welding wire extension length is 12mm~15mm, and the shielding gas flow rate is 15L / min~20L / min. Among them, the welding wire swing amplitude in the flat welding position is 6mm~10mm, the welding wire in the horizontal welding position does not swing, and the welding wire swing in the overhead welding position is 4mm~8mm; If the welding wire is in the vertical welding position, the welding current is 185A~190A, the arc voltage is 23V~24V, the welding speed is 11.3cm / min~12.3cm / min, the welding wire extension length is 12mm~15mm, the shielding gas flow rate is 15L / min~20L / min, and the welding wire swing amplitude is 8mm~12mm; The interpass temperature during welding the intermediate transition layer is less than 150°C; If the welding wire is in any of the flat welding, horizontal welding or overhead welding positions, the welding current is 190A~200A, the arc voltage is 24V~25V, the welding speed is 25.0cm / min~29.0cm / min, the welding wire extension length is 12mm~15mm, the shielding gas flow rate is 15L / min~20L / min, and the welding wire does not swing; If the welding wire is in the vertical welding position, the welding current is 170A~175A, the arc voltage is 22V~23V, the welding speed is 9.0cm / min~10.0cm / min, the welding wire extension length is 12mm~15mm, the shielding gas flow rate is 15L / min~20L / min, and the welding wire swing amplitude is 8mm~12mm; The interpass temperature during welding of the cap layer is less than 190°C; Welding an intermediate transition layer between the first steel plate and the second steel plate using a welding wire on the outer surface of the bottom transition weld layer, wherein the outer surface of the intermediate transition layer is not coplanar with the side surface of the first steel plate and the side surface of the second steel plate; Welding a cap layer between the first steel plate and the second steel plate on the outer surface of the intermediate transition layer using a welding wire, wherein the outer surface of the cap layer is flush with the side surface of the first steel plate and the side surface of the second steel plate, or the outer surface of the cap layer protrudes from the side surface of the first steel plate and the side surface of the second steel plate; The welding wire used is a flux-cored welding wire with a diameter of 1.2 mm. The welding wire contains the following components by mass fraction: carbon content 0.04% to 0.05%, silicon content 0.30% to 0.35%, manganese content 1.55% to 1.65%, nickel content 1.70% to 1.80%, and the rest is iron.

2. The welding method according to claim 1, characterized in that If the welding wire is in any of the flat welding, vertical welding or overhead welding positions, the welding wire is inclined 5° to 10° toward the second steel plate side; If the welding wire is in the horizontal welding position, the welding wire is inclined toward the second steel plate, and the angle between the welding wire and the horizontal plane is 10° to 15°.

3. The welding method according to claim 1, wherein: The bottom transition layer is welded in one pass, and the middle transition layer is welded in multiple passes.

4. The welding method according to claim 1, wherein: Before performing base layer welding between the groove spacing formed by the first steel plate and the second steel plate using a welding wire to form a bottom transition weld layer, the method further includes: Opening welding grooves on the edges of the first steel plate and the second steel plate; Assembling a first steel plate and a second steel plate, wherein the groove root of the first steel plate and the groove root of the second steel plate are arranged opposite to each other to form a groove spacing, wherein the groove spacing is a preset distance; A welding pad is installed, wherein the central axis of the welding pad overlaps the central axis of the groove spacing.

5. The welding method according to claim 4, characterized in that The groove spacing ranges from 4 mm to 6 mm.

6. The welding method according to claim 4, characterized in that When opening the welding groove on the edge of the first steel plate and the second steel plate: For flat welding, vertical welding and overhead welding, both the first and second steel plates shall have a 20° groove; If the welding position is horizontal, the first steel plate at the bottom has a 15° groove, and the second steel plate at the top has a 25° groove.

7. The welding method according to claim 4, characterized in that The gasket is fixed by aluminum foil tape.

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