CN112025037B

CN112025037B - Welding method based on deep fusion welding machine

Info

Publication number: CN112025037B
Application number: CN202010868314.9A
Authority: CN
Inventors: 杨卫东; 凌波; 陈建; 陈娜娜; 易冉; 向明
Original assignee: CRRC Zhuzhou Vehicle Co Ltd
Current assignee: CRRC Zhuzhou Vehicle Co Ltd
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2022-04-15
Anticipated expiration: 2040-08-26
Also published as: CN112025037A

Abstract

The invention belongs to the technical field of welding, and discloses a welding method based on a deep fusion welding machine, which comprises the following steps of: the electric arc is stopped at a first welding point of the welding line to form a first molten pool; performing arc advancing operation, advancing the arc to a second welding point, moving the arc to unwelded base metal to directly melt the base metal and then form a second molten pool, and simultaneously stirring the metal solution in the first molten pool to promote the overflow of impurities in the molten pool metal; and continuing to perform the arc advancing operation until the advancing arc reaches the Nth welding point, so that the arc moves to unwelded base metal to directly melt the base metal and then form an Nth molten pool, and simultaneously stirring the metal solution in the Nth-1 th molten pool to promote the overflow of impurities in the molten pool metal. The welding method provided by the invention can solve the problems that the welding process of the deep fusion welding machine for reducing the groove angle and the gap is easy to cause narrow and deep welding seam section shape and generate heat cracks.

Description

Welding method based on deep fusion welding machine

Technical Field

The invention relates to the technical field of welding, in particular to a welding method based on a deep fusion welding machine.

Background

In the prior art, the design standard of the angle groove angle of the fillet weld of the steel structure T-shaped joint is as follows: the single side is 35-60 degrees, and the gap is 2-4 mm. In actual production, however, in order to ensure full penetration of the root of the weld, the actual groove angle is basically 45-55 degrees, and the gap is 4 mm; this results in a large increase in the filling amount of the weld, an increase in the heat input of the weld, an increase in the welding deformation, and a large increase in the consumption of welding materials and the welding workload. For the purpose, a deep fusion welding machine can be adopted to increase the fusion depth, so that the groove angle and the gap can be reduced to a certain extent, the heat input is reduced, and the thermal deformation is inhibited; however, the design of the groove parameters causes the problems of narrow and deep weld section shape and hot cracks.

Disclosure of Invention

The invention provides a welding method based on a deep fusion welding machine, which solves the technical problems that the welding process for reducing the angle and the gap of a groove by the deep fusion welding machine in the prior art is easy to cause narrow and deep weld joint section shape and generate hot cracks.

In order to solve the technical problem, the invention provides a welding method based on a deep fusion welding machine, which comprises the following steps of adopting a linear strip conveying method in the process of welding a bottoming layer and executing the following pendulum welding operation:

the electric arc is stopped at a first welding point of the welding line, so that molten iron is fused with the bevel face to form a first molten pool;

performing an arc advancing operation, advancing the arc to a second welding point, moving the arc to unwelded base metal to directly melt the base metal and then form a second molten pool, and simultaneously stirring the metal solution in the first molten pool to promote the overflow of impurities in the molten pool metal;

and continuing to perform the arc advancing operation until the arc is advanced to an Nth welding point, so that the arc is moved to unwelded base metal to directly melt the base metal and then form an Nth molten pool, and simultaneously stirring the metal solution in the Nth-1 th molten pool to promote the overflow of impurities in the molten pool metal, wherein N is an integer more than 2.

Further, in the pendulum welding operation:

executing the pause operation at the peak current to enlarge the melting depth;

and performing the arc advancing operation at the base current, reducing the transition of the filler metal into the welding seam and promoting the arc to directly melt the base metal.

Further, in the arc advancing operation, the advancing amplitude of the arc was a distance of 1/2 molten pool widths.

Further, the width of the molten pool is 10-12 mm.

Further, in the pendulum welding operation, the back rake angle between the welding gun and the welding seam is controlled to be 75-80 degrees, and the included angle between the welding gun and the unbevelled flat plate is controlled to be 30-35 degrees.

Further, during the priming welding process, the dry elongation of the welding wire is 20 mm.

Further, in the process of welding the vertical plate and the flat plate, the angle of the bevel face is 30 degrees, the gap between the vertical plate and the flat plate is 3 millimeters, the back of the bevel face is welded by adding a process base plate, the bottoming current is 295-300A, and the capping current is 255-260A.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

according to the welding method based on the deep fusion welding machine, aiming at the welding operation of the bottom layer of a welding seam, a first molten pool is formed at a first welding point in the linear strip conveying process, an electric arc is rapidly moved forwards after the first molten pool is stabilized, the first molten pool is swung to the next welding point, and the unwelded base metal is directly heated to enable the base metal to be at the highest temperature of a welding state, so that deeper fusion depth is conveniently formed; the condition that the highest temperature is always in a mixed liquid after the base metal and the welding material metal are melted but not in the base metal in the conventional strip conveying operation is avoided, and the condition can cause the high-temperature solution to indirectly heat the base metal, so that the depth of the melting depth is not enough, a narrow and deep welding seam section is generated, and hot cracks are easily induced to form; therefore, the base metal can be melted under the conditions of less accumulated heat input and shorter welding time, and the formation of hot cracks is further inhibited. It is worth saying that the arc is removed from the first molten pool quickly and stably, the metal solution in the first molten pool can be stirred to a certain extent, so that the impurities in the molten pool metal are enabled to overflow, the risk of crack formation is reduced, and the quality of the welding seam is ensured. The method has the advantages that the method is rapid in forward movement, the welding seam base metal is directly heated by the high temperature of the electric arc, only the welding seam molten pool metal with less filling metal is mixed, the maximum penetration is achieved by using shorter welding time, the welding seam thickness is smaller, the probability of forming a deep and narrow welding seam section is reduced, and the hot crack tendency is reduced.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic diagram illustrating an arrangement state of welding objects in a welding method of a deep fusion welding machine according to an embodiment of the present invention;

FIG. 2 is a schematic view of a first perspective of a position of a welding gun according to an embodiment of the present invention;

FIG. 3 is a schematic view of a second perspective of the position of the torch according to the exemplary embodiment of the present invention;

FIG. 4 is a schematic diagram of a pendulum welding operation provided by an embodiment of the present invention.

Detailed Description

The embodiment of the application provides a welding method based on a deep fusion welding machine, and solves the technical problems that in the prior art, the welding process for reducing the groove angle and the gap through the deep fusion welding machine is easy to cause the narrow and deep weld joint section shape and generate thermal cracks.

In order to better understand the technical solutions, the technical solutions will be described in detail below with reference to the drawings and the specific embodiments of the specification, and it should be understood that the embodiments and specific features of the embodiments of the present invention are detailed descriptions of the technical solutions of the present application, and are not limitations of the technical solutions of the present application, and the technical features of the embodiments and examples of the present application may be combined with each other without conflict.

Referring to fig. 4, an embodiment of the present application provides a welding method based on a deep fusion welding machine, including that a linear bar conveying method is adopted in a bottoming layer welding process, and the following swing welding operations are performed:

The first welding point is not limited to the first welding point of the whole welding operation, but relative to the second welding point, the first welding point is understood as the last welding point, and the corresponding second welding point is the next welding point.

The actual first spot of the weld involved in this embodiment is not actually on the object to be welded, but is provided on an auxiliary plate fixed to the object to be welded, continuous with the weld, facilitating quality control of the weld on the object to be welded. The welding of the welding seam in the embodiment needs to be strictly welded according to the method, so that the depth and heat control of each molten pool are ensured; but the first welding point can not ensure the condition of direct heating of the base material, so that an auxiliary plate needs to be arranged; of course, a similar reciprocating welding mode can be adopted, and the details are not described here.

The rapid forward movement operation can ensure that the electric arc directly heats the base metal, so that the temperature of the electric arc is higher than that of the electric arc which indirectly heats the base metal through molten metal liquid caused by continuous strip conveying along the welding line, and deeper fusion depth is conveniently formed; and the relative heat accumulation input is smaller, and the welding time is shorter, so that the shape of the section of a narrow and deep welding seam can be avoided, and the generation of hot cracks is inhibited.

In order to further improve the welding quality, the section shape of a narrow and deep welding seam is avoided, and the risk of generating thermal cracks is reduced; the above-described pendulum welding operation further optimizes the welding operation in combination with the current pulse frequency of the weld.

Further, in the pendulum welding operation:

executing the pause operation at the peak current to enlarge the melting depth;

Further, in the arc advancing operation, the advancing amplitude of the arc was a distance of 1/2 molten pool widths. The width of the molten pool is 10-12 mm. In the present embodiment, in the rapid advancing operation, the advancing amplitude of the arc is a distance of 1/2 molten pool widths; correspondingly, the width of the molten pool can be 10-12 mm. Therefore, the problem that the weld thickness is increased due to excessive accumulation of weld metal caused by too small forward movement can be avoided; the problems that the forward movement is too large, the welding seam is disjointed and the welding seam penetration is influenced can also be avoided.

Referring to fig. 2 and 3, in the welding process, the back rake angle of the welding gun and the welding seam is controlled to be 75-80 degrees, and the included angle of the welding gun and a flat plate which is not beveled is controlled to be 30-35 degrees; the maximum weld penetration is closer to the root of the weld, which is easy to weld quality and form large penetration.

And in the process of welding the priming layer, the dry elongation of the welding wire is 20 mm.

Referring to fig. 1, in the process of welding the vertical plate 1 and the flat plate 2, the angle of the bevel face 4 is 30 degrees, the gap between the vertical plate 1 and the flat plate 2 is 3 mm, the process backing plate 3 is added on the back of the bevel face 4 for welding, the priming current is 295-.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims

1. A welding method based on a deep fusion welding machine is characterized by comprising the following steps of adopting a linear bar conveying method in the process of welding a bottom layer and executing the following pendulum welding operation:

2. A welding method based on a deep fusion welding machine as claimed in claim 1, characterized in that in said pendulum welding operation:

executing the pause operation at the peak current to enlarge the melting depth;

3. A welding method based on a deep fusion welder according to claim 1, characterized in that in the arc advancing operation the advancing amplitude of the arc is a distance of 1/2 puddle widths.

4. The welding method based on the deep fusion welding machine as claimed in claim 3, wherein the width of the molten pool is 10-12 mm.

5. The welding method of claim 1, wherein in the swing welding operation, the back rake angle of the welding torch and the welding seam is controlled to be 75-80 degrees, and the included angle of the welding torch and the ungrooved flat plate is controlled to be 30-35 degrees.

6. A welding method as defined in claim 5, wherein during said primer welding, the wire has a dry length of 20 mm.

7. The welding method based on the deep fusion welding machine as claimed in claim 1, wherein in the welding process of the vertical plate and the flat plate, the angle of the bevel face is 30 degrees, the gap between the vertical plate and the flat plate is 3 mm, the back of the bevel face is welded by a process base plate, the bottoming current is 295-300A, and the capping current is 255-260A.