CN113579431A

CN113579431A - Medium plate monofilament submerged arc welding method

Info

Publication number: CN113579431A
Application number: CN202111002279.3A
Authority: CN
Inventors: 罗雄; 刘宝辉; 温必贵; 毛文全; 刘流明
Original assignee: Guangzhou Shipyard International Co Ltd
Current assignee: Guangzhou Shipyard International Co Ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2021-11-02

Abstract

The invention provides a medium plate monofilament submerged-arc welding method without a Y-shaped groove, which comprises the following steps: (1) assembling two plates to be welded, wherein the assembling clearance is 0-2 mm; (2) welding the front surface by adopting single-wire submerged-arc welding during welding; (3) after the front side is welded, turning over the steel plate, and performing carbon planing on the back side, wherein the depth of the carbon planing is 3-7 mm, and the width of the carbon planing is 9-15 mm; (4) and (3) filling the capping surface by adopting single-wire submerged arc welding with the diameter of 4.1-5 mm and using current larger than 850A for one time. The single-wire submerged-arc welding method for the medium plate does not need double-wire submerged-arc welding, the single-wire submerged-arc welding can also realize no need of forming a Y-shaped groove, the welding equipment is lighter, and the welding process requirement is looser.

Description

Medium plate monofilament submerged arc welding method

Technical Field

The invention belongs to the technical field of ship manufacturing and welding, and particularly relates to a medium plate monofilament submerged arc welding method.

Background

Submerged arc welding was produced in 1935 and is suitable for straight-through welds of medium and thick plate structures due to its large penetration depth, high productivity and reliable mechanization. Therefore, submerged arc welding has wide application in the fields of shipbuilding industry, pressure vessel industry, bridges, railway vehicles, engineering machinery, pipelines, nuclear power plant structures, marine structures, building steel structures and the like, and is one of the most commonly used fusion welding methods in welding production at present. The development process of the submerged-arc welding technology is to develop the submerged-arc welding technology such as double-wire submerged-arc welding, three-wire submerged-arc welding and the like from single-wire submerged-arc welding, multi-wire submerged-arc welding is adopted during thick plate welding, the filling amount is large, the welding efficiency is high, and multi-wire submerged-arc welding can be generally adopted as much as possible.

In the ship building process, the joint of the jointed steel plate with the thickness of 15mm-22mm is mostly subjected to double-sided submerged arc welding with a Y-shaped groove, the edge of the steel plate is cut into the Y-shaped groove by adopting flame or plasma, and the truncated edge is 6-8 mm; firstly welding the upper end of a Y-shaped groove by using submerged-arc welding, then turning over a steel plate, carrying out carbon planing on the lower end of the groove, planing to remove the depth of 4-8 mm, polishing and flattening, and then welding for one pass. Through the arrangement of the Y-shaped groove, the front surface of the groove is welded for multiple times, so that the full penetration of the welding of the medium plate can be ensured. Although the mode of adopting the Y-shaped groove can guarantee full penetration of welding of the medium plate, the Y-shaped groove also has the following technical problems:

1. adopting a Y-shaped groove requires adding a previous process, and a steel plate needs to cut the groove;

2. the Y-shaped groove is adopted, the groove is cut by flame or plasma at the steel plate blanking stage, so that the labor cost is increased, a large amount of smoke and dust are generated during cutting, the electric energy and the water resource are consumed, and the resource cost is increased;

3. in the cutting process of the groove, the welding quality of submerged-arc welding is influenced due to the fact that the accuracy influences the groove and the root is not uniform;

4. the welding process needs to carry out multilayer multi-pass welding, and the welding time is longer.

In order to solve the technical problems, the prior art also has a plurality of welding processes without grooves, the welding can be carried out without grooves by using a double-wire welding process, and the double-wire welding process is easier to realize the welding without Y-shaped grooves compared with a single-wire submerged arc welding method, and can realize the technical effect of full welding without Y-shaped grooves and multi-pass welding because the welding can ensure that the welding is deeper.

However, the twin-wire welding process needs two welding power supplies (one direct current and one alternating current), the weight of the twin-wire submerged arc welding is only 50kg, the operation is heavy, the distance between 2 welding wires has strict adjustment requirements, and the welding process requirement is high. For example, patent publication No. CN 111906417 a discloses a submerged arc welding non-groove welding process method for a medium plate joint, which comprises the following steps: horizontally placing a steel plate to be welded on a steel plate gasket for pairing; and welding the steel plate to be welded by adopting a double-wire welding process, wherein the distance between the front wire and the rear wire is kept at 30mm, the front wire and the rear wire are staggered by 3-5mm, and the rear wire is inclined by 10-15 degrees.

The welding type of the steel plates with the thickness of 15mm-22mm in the ship building process is more, and the trolley type welding is more convenient to use single-wire submerged arc welding compared with heavy double-wire submerged arc welding with strict process requirements. However, single wire submerged arc welding is very difficult to achieve to eliminate the Y-groove process and satisfy the welding effect compared with double wire submerged arc welding.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a medium plate monofilament submerged arc welding method without a Y-shaped groove.

The invention provides a medium plate monofilament submerged arc welding method, which comprises the following steps:

(1) assembling two plates to be welded, wherein the assembling clearance is 0-2 mm;

(2) welding the front surface by adopting single-wire submerged-arc welding during welding;

(3) after the front side is welded, turning over the steel plate, and performing carbon planing on the back side, wherein the depth of the carbon planing is 3-7 mm, and the width of the carbon planing is 9-15 mm;

(4) and (3) filling the capping surface by adopting single-wire submerged arc welding with the diameter of 4.1-5 mm and using current larger than 850A for one time.

Preferably, in the step (3), after the back surface is subjected to carbon planing, the step of grinding the back surface is further included.

Preferably, the monofilament submerged arc welding diameter is 4.8 mm.

Preferably, the thickness of the medium plate is 15mm-22 mm.

Preferably, the monofilament submerged arc welding dry elongation is 25mm-35 mm.

Preferably, the welding current in the step (2) is 700A-850A, the welding direct current voltage is 30V-35V, and the welding speed is 30m/h-35 m/h.

Preferably, in the step (4), the welding current is 860 to 1200A, the welding direct current voltage is 34 to 37V, and the welding speed is 22 to 26 m/h.

Preferably, in the step (4), the welding current is 880A-1200A.

Preferably, in the step (3), the carbon planing depth is 4mm-6mm, and the width is 10mm-12 mm.

Preferably, the assembling clearance in the step (1) is 0.5-2 mm.

Preferably, the front side is welded once to form a front side welding layer, the back side is welded once to fill the cover surface to form a back side welding layer, and the front side welding layer is connected with the back side welding layer.

Preferably, one end of the front welding layer is connected with the back welding layer, and the other end of the front welding layer covers the front assembled by the two plates; one end of the back welding layer is connected with the front welding layer, and the other end of the back welding layer covers the back surface of the two plates.

The welding method for the submerged arc welding of the medium plate monofilament provided by the invention has the following beneficial effects:

1. the invention adopts double-sided submerged arc welding without the Y-shaped groove, thereby avoiding the problem that the Y-shaped groove needs a steel plate to cut the groove at the blanking stage;

2. the invention solves the problem that the welding quality is influenced by the groove precision when the Y-shaped groove is adopted for welding;

3. the invention adopts a mode of not Y-shaped beveling, reduces cutting procedures, can effectively reduce the consumption of resources and labor hours of personnel, and effectively avoids environment pollution caused by smoke dust and arc light generated by cutting;

4. the invention avoids the need of multilayer and multi-pass filling welding in the prior Y-shaped groove technology and improves the welding efficiency.

5. The invention still has better welding effect for the welding of the medium and thick plates by using the single-wire submerged-arc welding under the process of not forming the Y-shaped groove and not adopting multiple welding wires.

Drawings

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. Like reference numerals refer to like parts throughout the drawings, and the drawings are not intended to be drawn to scale in actual dimensions, emphasis instead being placed upon illustrating the principles of the invention.

FIG. 1 is a schematic structural diagram of the present invention for assembling two plates to be welded;

FIG. 2 is a schematic structural view of the front side of the welding process of the present invention using single wire submerged arc welding;

FIG. 3 is a schematic view of a carbon plane structure on the reverse side of the present invention;

FIG. 4 is a schematic view of a reverse side fill cover construction of the present invention;

FIG. 5 is a photograph showing the results of metallographic tests on the welded product according to example 1 of the present invention;

FIG. 6 is a schematic diagram of the test position of the hardness test of the welded product in the embodiment 1 of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element and be integral therewith, or intervening elements may also be present. The terms "mounted," "one end," "the other end," and the like are used herein for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 6, an embodiment of the present invention provides a welding method for submerged arc welding of a medium plate monofilament, including the following steps:

(1) assembling two plates to be welded, wherein the assembling clearance is 0-2mm, and referring to fig. 1;

(2) adopting single wire submerged arc welding to weld the front surface during welding, and referring to fig. 2;

(3) turning over the steel plate after welding the front side, and performing carbon planing on the back side, wherein the depth of the carbon planing is 3-7 mm, and the width of the carbon planing is 9-15 mm, and referring to fig. 3;

(4) the back filling of the cover surface is completed by adopting single-wire submerged arc welding at one time by using current larger than 850A, the diameter of the single-wire submerged arc welding is 4.1mm-5mm, and refer to figure 4.

The monofilament submerged-arc welding method for the medium plate does not need to form a Y-shaped groove, reduces the previous cutting process and reduces the energy loss. Meanwhile, the invention can realize better welding effect only by front and back welding, thereby improving the welding efficiency.

The single-wire submerged-arc welding method for the medium plate does not need double-wire submerged-arc welding, the single-wire submerged-arc welding can also realize no need of forming a Y-shaped groove, the welding equipment is lighter, and the welding process requirement is looser.

The principle of the invention is as follows:

the back surface is subjected to carbon planing with a specific size, and the back surface disposable cover body filling is realized by matching with a large welding wire diameter and a large current. The technical effect of full penetration welding can be realized without opening the Y-shaped groove and using multiple welding.

In a preferred embodiment, the step (3) further comprises the step of grinding the back surface after the back surface is subjected to carbon planing. And a better welding effect is realized.

In the preferred embodiment, the monofilament submerged arc welding diameter is 4.8 mm.

In a preferred embodiment, the thickness of the medium plate is 15mm to 22mm, in a further preferred embodiment, the thickness of the medium plate is 16mm to 22mm, and in a further preferred embodiment, the thickness of the medium plate is 18mm to 22 mm. The thin plate with smaller thickness can realize better welding effect without opening a Y-shaped groove, and the technical effect of penetration welding is difficult to realize by the method of the invention even for thicker plates, such as plates with more than 40 mm. The welding method is particularly suitable for welding medium plates with the thickness of 15mm-22 mm. Particularly in the field of ship manufacturing, when the welding plate is various in types and can not be used well by double-wire submerged arc welding, the effect of the single-wire submerged arc welding method is remarkable.

In a preferred embodiment, the monofilament submerged arc welding dry elongation is 25mm to 35 mm.

In a preferred embodiment, the welding current in the step (2) is 700A-850A, the welding direct current voltage is 30V-35V, and the welding speed is 30m/h-35 m/h. The current and the voltage of the front welding are basically consistent with the conventional welding parameters, so that the energy consumption is saved.

In the preferred embodiment, in the step (4), the welding current is 860-1200A, the welding direct current voltage is 34-37V, and the welding speed is 22-26 m/h. In the invention, after the carbon planing with a certain depth is carried out on the back, in order to better fill the capping surface, the welding current and the welding voltage need to be increased, so that the capping surface can be filled at one time, a better welding effect is ensured, and the number of welding tracks is reduced.

In the preferred embodiment, in step (4), the welding current is 880A-1200A.

In a preferred embodiment, in the step (3), the carbon plane has a depth of 4mm to 6mm and a width of 10mm to 12 mm.

In a preferred embodiment, the assembly gap in step (1) is 0.5-2 mm.

Referring to fig. 4, in the preferred embodiment, the front side is welded together to form a front side welded layer 1, the back side is welded together to fill the cover side to form a back side welded layer 2, and the front side welded layer 1 and the back side welded layer 2 are connected.

In a preferred embodiment, one end of the front welding layer 1 is connected with the back welding layer 2, and the other end covers the front surface of the assembly of the two plates; one end of the back welding layer 2 is connected with the front welding layer 1, and the other end covers the back surface of the assembly of the two plates.

Example 1

The invention provides a welding method of submerged arc welding of medium plate monofilaments, which specifically comprises the following steps:

s1: two sheets to be welded are assembled, see fig. 1.

S2: the front one-pass weld was welded by the single wire submerged arc welding with a wire diameter of 4.8mm, and with reference to fig. 2, the welding parameters were confirmed as shown in table 1.

TABLE 1

Position of

Diameter of welding wire

Thickness of board

Layer road

Current (A)

Voltage (V)

Speed (m/h)

Flat welding

4.8mm

18～22mm

Front side

700～850

30～35

S3: and after the front side is welded, turning over the steel plate, performing carbon planing on the back side, wherein the depth of the carbon planing is 4-6mm, the width of the carbon planing is 10-12mm, and polishing the back side after the carbon planing, referring to fig. 3.

S4: and (3) adopting single-wire submerged arc welding with the welding wire diameter of 4.8mm to weld by high current, completing filling of the cover surface at one time, and referring to fig. 4, wherein welding parameters are shown in table 2.

TABLE 2

Position of

Diameter of welding wire

Thickness of board

Layer road

Current (A)

Voltage (V)

Speed (m/h)

Flat welding

4.8mm

18～22mm

Back side of the panel

880～1200

34～37

22～26

Effects of the embodiment

The welded product of the embodiment 1 is subjected to welding result tests including magnetic powder detection, ultrasonic detection and metallographic phase test, and the specific test method is as follows:

1. magnetic particle testing

The application standard is as follows: DNVGL-CG-0051;

type of magnetic powder: non-fluorescent wet magnetic powder;

magnetic powder material: HD-BO magnetic suspension;

the magnetic powder applying method comprises the following steps: spraying;

and (4) testing standard: refer to ISO 23278 2015 Level 2X.

2. Ultrasonic testing

The application standard is as follows: DNVGL-CG-0051-2015;

and (4) testing standard: refer to EN ISO 11666 and 2018 Level 2.

3. Metallographic test

The erosion agent is 10% nitric acid alcohol solution.

The test results of the magnetic particle test, the ultrasonic test and the hardness test are shown in table 3.

TABLE 3

The test results in table 3 show that the welding method provided by the invention uses single wire submerged arc welding without forming a Y-shaped groove, does not need multiple welding, and the obtained magnetic powder detection and ultrasonic detection are both qualified, and no welding defect is found in metallographic phase test.

The welded product of example 1 was subjected to a hardness test at the test position shown in FIG. 6, and the test results are shown in Table 4.

TABLE 4

The results in table 4 show that the welding method of the present invention has good hardness after welding, and better safety performance when the welded metal plate is used on the ship body.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, reference to the description of the terms "preferred embodiment," "yet another embodiment," "other embodiments," or "specific examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims

1. A welding method of single wire submerged arc welding of a medium plate is characterized by comprising the following steps:

2. The welding method of submerged arc welding with monofilament for medium plate of claim 1, characterized in that the diameter of the submerged arc welding with monofilament is 4.8 mm.

3. The welding method of submerged arc welding with monofilament as medium plate of claim 1, characterized in that the thickness of the medium plate is 15mm-22 mm.

4. The welding method of submerged arc welding with monofilament for medium plate of claim 1, characterized in that the dry elongation of the submerged arc welding with monofilament is 25mm-35 mm.

5. The welding method of monofilament submerged arc welding of medium plate according to claim 1, characterized in that in said step (2), the welding current is 700A-850A, the welding DC voltage is 30V-35V, and the welding speed is 30m/h-35 m/h.

6. The welding method of monofilament submerged arc welding of medium plate according to claim 1, characterized in that in said step (4), the welding current is 860A-1200A, the welding DC voltage is 34V-37V, and the welding speed is 22m/h-26 m/h.

7. The welding method of submerged arc welding with monofilament in medium plate as claimed in claim 6, characterized in that in said step (4), the welding current is 880A-1200A.

8. The welding method of monofilament submerged arc welding of a medium plate according to claim 1, wherein in the step (3), the carbon plane has a depth of 4mm to 6mm and a width of 10mm to 12 mm.

9. The welding method of monofilament submerged arc welding of a medium plate according to claim 1, wherein said front side welding is performed in one pass to form a front side welding layer, said back side welding is performed in one pass to fill the cap side to form a back side welding layer, and said front side welding layer is connected to said back side welding layer.

10. The welding method of monofilament submerged arc welding of a medium plate according to claim 9, wherein one end of the front welding layer is connected to the back welding layer, and the other end covers the front surface of the assembly of two plates; one end of the back welding layer is connected with the front welding layer, and the other end of the back welding layer covers the back surface of the two plates.