CN111761176A

CN111761176A - Fixed-position T-shaped full penetration joint welding process

Info

Publication number: CN111761176A
Application number: CN202010625684.XA
Authority: CN
Inventors: 杨伟锋; 黄楚畅; 王孟果; 许斌
Original assignee: Guangzhou Wenchong Shipyard Co Ltd
Current assignee: Guangzhou Wenchong Shipyard Co Ltd
Priority date: 2020-07-01
Filing date: 2020-07-01
Publication date: 2020-10-13

Abstract

The invention discloses a fixed position T-shaped full penetration welding joint welding process, which comprises the following steps: designing two sides of a web plate of the T-shaped full penetration joint to be in a groove-shaped structure, wherein two sides of the groove-shaped structure are symmetrically or approximately symmetrically arranged; step two: welding overhead fillet welding in a lower side bevel of a web plate of the T-shaped full penetration joint by using a flux-cored wire CO2 semi-automatic welding method; step three: and (3) welding flat fillet welding in the side groove on the web plate of the T-shaped joint by using a double-wire submerged arc automatic welding method. The invention saves the auxiliary work of back chipping, grinding and the like of the root part of the groove of the T-shaped full penetration joint, and introduces an automatic welding method for welding, thereby improving the integral welding construction efficiency of the T-shaped joint, improving the welding environment of a welder and reducing the labor intensity of the welder.

Description

Fixed-position T-shaped full penetration joint welding process

Technical Field

The invention relates to a welding process of a T-shaped full penetration joint at a fixed position.

Background

At present, the coaming of the ship hatch, i.e. the steel plate structure which is perpendicular to the deck of the ship and surrounds the hatch, plays the role of preventing water from entering the cargo hold and supporting the hatch cover. In the container ship, longitudinal hatch coamings also participate in the longitudinal strength calculation in the ship body, the web plate is thicker and reaches 25-50mm, and the welding workload is large. The longitudinal hatch coaming structure is generally manufactured separately and then assembled (combined) with the side sections of the main hull by taking the outer plate as a base surface, and the hatch coaming web and the main deck of the side sections are combined into a T-shaped joint (hereinafter referred to as a horizontal T-shaped joint) which is fixed by taking the web as a horizontal position. The horizontal T-shaped joint in the product adopts a double-sided groove full penetration welding design, and in the process of the total assembly operation, because the hatch coaming web plate is parallel to the horizontal plane, and the groove at the upper side of the web plate is in a flat fillet welding position, the welding operation is easier, the requirement on the skill of a welder is relatively lower, and the welding quality is also relatively easy to ensure; and the groove on the lower side of the web plate is in an overhead fillet welding position, so that molten steel in a welding pool can flow down under the influence of gravity during welding, the formation of a welding seam is difficult to control, and the requirement on the welding skill of a welder is high. Due to the narrow space of the groove root and the shallow welding penetration of the common welding method, the narrow space area of the groove root is difficult to completely weld through in the welding process. In general, after welding is completed on one side of the T-joint, a carbon gouging operation is performed on the back-welded side to gouge the non-penetration area of the groove root and obtain a groove shape suitable for welding by a general welding method, which is commonly referred to as back gouging. The carbon planing operation process can generate sparks, waste residues and harmful smoke, can harm workers and pollute the environment. The groove size after the carbon planing is enlarged, and the welding workload and the polishing and cleaning work before groove welding can be additionally increased.

In the prior art, a groove on the lower side of a T-shaped joint web plate is subjected to fillet welding by using a flux-cored wire CO2 welding process method. And (3) performing carbon planning back gouging operation on the root of the groove on the upper side of the web plate by a welder, planning till the groove is completely white, seeing weld joint tissues on the back side, avoiding the defects of incomplete penetration and the like, and generally planning to the depth of about 4-6 mm. And then, grinding the planed part by using a grinding wheel grinder to clean oxidation slag, oxide skin and a hardened layer in the groove. And finally, welding the upper groove by using a CO2 welding method or a technology of welding two layers by using a CO2 welding method and then using a single-wire submerged arc welding method for capping. The process has the defects that after the groove at one side is welded, the groove at the other side needs to be subjected to carbon planing and polishing operation at the root part of the groove before connection, the welding auxiliary workload is large, spark, waste residue and harmful smoke are generated in the carbon planing operation process, workers are injured, and the environment is polluted.

Disclosure of Invention

The invention aims to provide a welding process of a T-shaped full penetration joint at a fixed position, which omits auxiliary work such as back chipping and polishing of the root part of a groove of the T-shaped full penetration joint, introduces an automatic welding method for welding, improves the integral welding construction efficiency of the T-shaped joint, improves the welding environment of welders, and reduces the labor intensity of the welders.

In order to achieve the purpose, the invention provides a fixed-position T-shaped full penetration welding joint welding process, which comprises the following steps: designing two sides of a web plate of the T-shaped full penetration joint to be in a groove-shaped structure, wherein the two sides of the groove-shaped structure are symmetrically or approximately symmetrically arranged; step two: welding overhead fillet welding in a lower side bevel of a web plate of the T-shaped full penetration joint by using a flux-cored wire CO2 semi-automatic welding method; step three: flat fillet welding in a slope on the upper side of a T-shaped joint web plate is welded by using a double-wire submerged arc automatic welding method, and a direct-current power supply is used for front wire welding; the back wire bonding uses an ac power source.

In the welding process of the T-shaped full penetration joint at the fixed position, in the second step, the welding current of the first welding seam at the root of the groove by using the flux-cored wire CO2 for semi-automatic welding is 190-210A, the welding voltage is 27-29V, and the welding speed is 25 cm/min.

In the fixed-position T-shaped full penetration joint welding process, in the second step, the welding arc is aligned with the root of the groove to perform linear track welding in the first welding line welding process of the root of the groove.

In the fixed position T-shaped full penetration joint welding process, in the second step, the welding current of the flux-cored wire CO2 for the filling and cap weld bead semi-automatic welding is 220-240A, the welding voltage is about 28-30V, and the welding speed is about 45 cm/min.

In the welding process of the T-shaped full penetration joint at the fixed position, in the third step, the front welding wire and the rear welding wire are serially connected on a straight line, the front-rear distance is 80-100mm, the front welding wire and the rear welding wire share one welding trolley, and the welding speed of all welding passes is 65 cm/min.

In the welding process of the fixed-position T-shaped full penetration joint, in the third step, the first welding current and voltage of the wire before the double-wire submerged arc automatic welding are respectively 800-; the welding current and voltage of all welding passes of the back wire are respectively 550-600A and 30-32V.

In the welding process of the fixed-position T-shaped full penetration joint, in the third step, the length of the front wire of the double-wire submerged arc automatic welding is 45-55mm, and the length of the rear wire is 50-60 mm.

In the fixed position T-shaped full penetration joint welding process, in the third step, the angle between the welding wire and the horizontal position plate in the double-wire submerged arc automatic welding method is adjusted to 70-75 degrees.

In the welding process of the fixed-position T-shaped full penetration joint, in the second step, the welding material for CO2 semi-automatic welding is a flux-cored wire of GB/T10045E 501T-1 model, and the specification is phi 1.2 mm.

In the welding process of the fixed-position T-shaped full penetration joint, in the third step, the front welding wire and the rear welding wire of the double-wire submerged arc automatic welding are the same welding wire, the diameter specifications of the welding wires are phi 4.0mm, and the welding material of the submerged arc automatic welding is a combination of a submerged arc welding wire and a welding flux of GB/T5293F 5A2-H10Mn2 model.

Compared with the prior art, the welding process for the T-shaped full penetration joint at the fixed position has the beneficial effects that: the welding quantity of the grooves on two sides is symmetrical by setting the symmetrical groove angles, most of welding deformation can be offset, the angular deformation of the welded T-shaped joint is reduced, the root area of the groove can be easily welded through the design of the size of the truncated edge as small as possible, CO2 semi-automatic welding can carry out all-position welding operation, good weld forming can be obtained by the welding overhead fillet welding and the welding quality of the groove on the lower side of the T-shaped joint is ensured, in addition, the liner supporting function can be played when the large-current twin-wire submerged arc welding backing welding is carried out on the root of the groove on the upper side of the welding, and welding penetration is avoided during welding. The double-wire submerged arc automatic welding method can only weld the flat welding, but the welding penetration is large, the front wire of the double-wire submerged arc welding uses a large-current direct-current power supply, the root of the groove can be effectively welded through in the welding of the upper side groove of the T-shaped joint, even the root welding bead of the back side groove is remelted, and the welding penetration of the root area of the groove is ensured; the back wire uses AC power supply, on one hand, the welding efficiency is improved, on the other hand, the welding slag of the front wire is remelted, the solidification surface of the welding slag is kept away from the narrow space of the groove root as far as possible, the slag is easy to remove after the submerged arc welding seam is welded, the generation of sparks, waste slag and harmful smoke dust caused by carbon planing and polishing operation of the groove root is avoided, and the welding environment of a welder is improved. The welding quality of the double-wire submerged arc welding is easy to ensure, and the overall welding efficiency of the T-shaped joint is also improved.

Drawings

FIG. 1 is a general T-joint full penetration design joint;

FIG. 2 is a full penetration design node for a T-joint of the present invention.

Wherein, 1-CO2 semi-automatic welding and 2-double wire submerged arc automatic welding.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Referring to fig. 1-2, the welding process for the T-shaped full penetration weld with fixed position provided by the present invention includes the following steps: designing two sides of a web plate of the T-shaped full penetration joint to be in a groove-shaped structure, wherein two sides of the groove-shaped structure are symmetrically or approximately symmetrically arranged; step two: welding overhead fillet welding in a lower side slope of a T-shaped full penetration joint web by using a flux-cored wire CO2 semi-automatic welding 1 method; step three: flat fillet welding in a slope on the upper side of a T-shaped joint web plate is welded by using a double-wire submerged arc automatic welding 2 method, and a direct-current power supply is used for front wire welding; the back wire bonding uses an ac power source.

Based on the technical characteristics, the groove welding quantity of two sides is symmetrical by setting symmetrical groove angles, most welding deformation can be counteracted, the angular deformation of the welded T-shaped joint is reduced, the root area of the groove can be easily welded through the design of the size of the truncated edge as small as possible, CO2 semi-automatic welding 1 can carry out all-position welding operation, the welding overhead fillet welding can obtain good welding line forming and ensure the welding quality of the groove at the lower side of the T-shaped joint, in addition, the welding line at the lower side can play a liner supporting role when the groove root at the upper side is subjected to high-current twin-wire submerged arc welding backing welding, and welding penetration is avoided during welding. The double-wire submerged arc automatic welding 2 method can only weld the flat welding, but the welding penetration is large, the front wire of the double-wire submerged arc welding uses a large-current direct-current power supply, the root of the groove can be effectively welded through in the upper side groove welding of the T-shaped joint, even the root welding bead of the reverse side groove is remelted, and the penetration of the root area of the groove is ensured; the back wire uses AC power supply, on one hand, the welding efficiency is improved, on the other hand, the welding slag of the front wire is remelted, the solidification surface of the welding slag is kept away from the narrow space of the groove root as far as possible, the slag is easy to remove after the submerged arc welding seam is welded, the generation of sparks, waste slag and harmful smoke dust caused by carbon planing and polishing operation of the groove root is avoided, and the welding environment of a welder is improved. The welding quality of the double-wire submerged arc welding is easy to ensure, and the overall welding efficiency of the T-shaped joint is also improved.

In the second step, the welding current of the first welding seam at the root of the groove by using a flux-cored wire CO2 semi-automatic welding 1 is 190-210A, the welding voltage is 27-29V, the welding speed is 25cm/min, and the welding arc aims at the root of the groove to perform linear track welding in the welding process; the welding electric arc does not swing transversely in the welding process, namely the welding electric arc aims at the root of the groove to weld in a straight track in the welding process, so that the energy of the electric arc is concentrated on the root of the groove, and the root of the groove can be melted to the maximum extent. In addition, the weld bead at the root of the groove is subjected to the heat influence of multiple subsequent weld beads in the subsequent welding process, the metallographic structure crystal grains of the welding joint are easy to grow and coarsen due to multiple thermal cycles, so that the low-temperature impact resistance of the joint is reduced, and the flux-cored wire CO2 semi-automatic welding method 1 adopts small linear energy to carry out welding, so that the metallographic structure crystal grains of the welded joint are finer, the coarsening phenomenon of the crystal grains subjected to multiple heating is relieved, and the joint meets the specified impact requirement.

In the second step, the welding current of the filling and cover bead flux-cored wire CO2 semiautomatic welding 1 is 220-240A, the welding voltage is about 28-30V, and the welding speed is about 45cm/min, so that when the filling and cover bead is less affected by thermal cycle, a slightly larger welding parameter can be used to meet the requirement of forming the overhead fillet weld.

In the third step, the front and the rear welding wires are serially connected on a straight line, the front and the rear intervals are 80-100mm, the front and the rear welding wires share one welding trolley, and the welding speed of all welding passes is 65 cm/min; the welding slag melted by the front wire is prevented from influencing the stable combustion of the welding arc of the rear wire due to the excessively fast solidification, the welding arc of the rear wire is convenient to stably obtain good welding seam forming and easy slag removal, and the stability of processing is ensured by setting the uniform speed.

In the third step, the first welding current and voltage of the wire before the double-wire submerged arc automatic welding are respectively 800-; the welding current and voltage of all welding passes of the back wire are respectively 550-600A and 30-32V. The welding current of the front wire backing weld bead is larger, the voltage is smaller, so that the CO2 backing weld bead at the root part of the groove and even at the back side can be remelted, and the penetration of the root part area of the groove is ensured; the welding voltage is small, about 25-26V, and the width of the welding line is mainly controlled and the stability of the welding arc is ensured. The welding current of the filling and cover bead is 600-650A, the welding voltage is 29-30V, and the welding penetration of a welding seam is mainly controlled and the stability of a welding arc is ensured; the back wire welding uses an alternating current power supply to avoid the magnetic blow phenomenon of welding arc caused by the influence of a magnetic field on the front wire, and the influence on the welding quality. The welding current of the backing weld bead is smaller and is 550-600A, the width of the weld joint is mainly controlled, the edge penetration of the weld joint groove is ensured, and the welding deposition efficiency is improved by adding another welding wire; the welding voltage is about 30-32V, the width of a welding seam is mainly controlled, the stability of welding electric arc is guaranteed, the welding seam is easy to deslag after welding, and welding current and voltage parameters of a filling and cover welding bead are unchanged and are consistent with those of a bottoming welding bead.

In the third step, the length of the front wire of the double-wire submerged arc automatic welding 2 is 45-55mm, the length of the rear wire is 50-60mm, the double-wire submerged arc automatic welding 2 is realized, the distance between the double wires is better controlled, and the front wire is preferably 50mm, and the rear wire is preferably 55 mm.

In the third step, the angle between the welding wire and the horizontal plate in the double-wire submerged arc automatic welding 2 method is adjusted to 70-75 degrees, and the welding wire forms an angle of about 90 degrees with the horizontal plate after passing through a copper contact nozzle in the general submerged arc automatic welding, but the T-shaped groove full penetration joint on the hatch coaming is not suitable. The reason is that the T-shaped joint is an angle joint, when the welding wire approaches the inner part of the slope for welding at an angle of 90 degrees, a contact tip of the welding wire can collide with the web plate for short circuit, so that the welding is stopped; in addition, the angle can cause the electric arc of the welding wire to be incapable of symmetrically welding the groove in the 45-degree angle groove, so that welding seam welding is deviated to influence the welding seam forming, and therefore the problem is avoided by setting the included angle of 70-75 degrees.

In the second step, the welding material of the CO2 semiautomatic welding 1 is a flux-cored wire of GB/T10045E 501T-1 model, and the specification is phi 1.2 mm; in the third step, the front welding wire and the rear welding wire of the double-wire submerged arc automatic welding 2 are the same welding wire, the diameter specification is phi 4.0mm, the welding material of the submerged arc automatic welding is a combination of a submerged arc welding wire and a welding flux of GB/T5293F 5A2-H10Mn2 model, and the mixed use of the two welding modes is better realized.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A fixed-position T-shaped full penetration joint welding process is characterized by comprising the following steps:

the method comprises the following steps: designing two sides of a web plate of the T-shaped full penetration joint to be in a groove-shaped structure, wherein the two sides of the groove-shaped structure are symmetrically or approximately symmetrically arranged;

step two: welding overhead fillet welding in a lower side bevel of a web plate of the T-shaped full penetration joint by using a flux-cored wire CO2 semi-automatic welding method;

step three: flat fillet welding in a slope on the upper side of a T-shaped joint web plate is welded by using a double-wire submerged arc automatic welding method, and a direct-current power supply is used for front wire welding; the back wire bonding uses an ac power source.

2. The welding process of the T-shaped full penetration joint with the fixed position as claimed in claim 1, wherein in the second step, the welding current of the first welding seam at the root of the groove by using the flux-cored wire CO2 for semi-automatic welding is 190-210A, the welding voltage is 27-29V, and the welding speed is 25 cm/min.

3. The process of claim 2, wherein in step two, the welding arc is aligned with the groove root for straight-line trajectory welding during the first weld at the groove root.

4. The process for welding a full penetration T-shaped fixed position joint as claimed in claim 1, wherein in said step two, the welding current of the flux cored wire CO2 for the filling and cap pass is 220 and 240A, the welding voltage is about 28-30V, and the welding speed is about 45 cm/min.

5. The process for welding a full penetration joint in a T shape at a fixed position according to claim 1, wherein in the third step, the front and the rear welding wires are serially arranged on a straight line, the front and the rear distances are 80-100mm, the front and the rear welding wires share a welding trolley, and the welding speed of all welding passes is 65 cm/min.

6. The process for welding the T-shaped full penetration joint in the fixed position as claimed in claim 5, wherein in the third step, the first welding current and voltage of the wire before the twin-wire submerged arc automatic welding are respectively 800-; the welding current and voltage of all welding passes of the back wire are respectively 550-600A and 30-32V.

7. The process of welding a fixed position T-shaped full penetration joint as defined in claim 5, wherein in step three, the twin wire submerged arc automatic welding has a front wire length of 45-55mm and a rear wire length of 50-60 mm.

8. The process of welding a fixed position T-shaped full penetration joint as defined in claim 1, wherein in step three, the angle of the welding wire of the twin wire submerged arc automatic welding method and the horizontal position plate is adjusted to 70-75 degrees.

9. The welding process of the fixed position T-shaped full penetration joint as claimed in claim 1, wherein in the second step, the welding material of the CO2 semi-automatic welding is a flux-cored wire of GB/T10045E 501T-1 type with specification phi 1.2 mm.

10. The process of welding a fixed position T-shaped full penetration joint as defined in claim 1, wherein in step three, the front and rear welding wires of the twin wire submerged arc automatic welding are the same welding wire, the diameter specification is 4.0mm, and the welding material of the submerged arc automatic welding is a combination of the submerged arc welding wire and the welding flux of GB/T5293F 5A2-H10Mn2 model.