JPS61226192A - Production of clad metal plate - Google Patents

Abstract

PURPOSE:To attemper drastically the butt accuracy of joining face and to increase the quality by performing enclosed welding in a vacuum with feeding at the specified angle with the beam axis of electron beam the brazing filler metal at the rear part of the welding progressing direction of the joining face of cladded metal plate. CONSTITUTION:The joining face on which >= two sheets of the metallic plate 2, 3 of the same kind or different kind are overlapped is subjected to the enclosed welding in a vacuum by irradiating electron beam 5 in parallel or with slant angle of the joining face with feeding brazing filler metal 6 frm the rear part of the welding progressing direction. In this case the brazing filler metal 6 is collided with the electron beam inside the beam hole to be formed on the joining face by the electron beam and yet is fed so as to make the angle a with the beam axis of the electron beam 5 deg.<=a<=(65-0.4d) deg., [provided d(mm): depth of welding penetration]. The sound welding zone without any welding defect is obtainable irrespective of how the base metal and cladding metal being combined and the clad metal plate of high quality can therefore be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing clad metal plates, and more particularly to a method for appropriately performing assembly and welding of raw metal plates by electron beam welding.

[Prior art] A clad metal plate made by laminating and bonding two or more metal plates is
It is used in a wide range of fields as an inexpensive structural material with excellent corrosion resistance, wear resistance, and heat resistance, and high strength.

Methods for producing clad metal plates include the 11!1 method, overlay method, rolling method, etc., but the rolling method is most commonly used because it can produce large-area products with high efficiency and at low cost.

The rolling method is a method in which the parts to be joined are cleaned and rolled in v4Fm hot or warm conditions to metallurgically join them.

When manufacturing cladding by the rolling method, an important point to keep in mind is the cleanliness of the atmosphere between the joint surfaces. That is, even if the bonding surfaces are clean, if the atmosphere exists between the bonding surfaces, oxides and the like will be formed during heating and rolling, which will impede metallurgical bonding and cause insufficient bonding strength to be obtained. Therefore, in order to manufacture a clad metal plate with sufficient bonding strength, it is necessary to exhaust the atmosphere existing between the bonding surfaces as much as possible during the clad assembly stage to maintain a low pressure state. Another method is to replace the atmosphere between the joint surfaces with an inert gas, but since the gas between the joint surfaces expands during heating and acts in a direction that hinders crimping, the former method lowers the pressure between the joint surfaces. It is inferior to.

Sealed welding using electron beam welding has been proposed as a method for efficiently assembling and welding cladding while maintaining a low pressure state between joint surfaces. In this method, parts to be assembled and welded are set in a vacuum chamber, the vacuum is evacuated to a predetermined degree of vacuum, and then the periphery of the parts is hermetically welded using electron beam welding.

[Problems to be Solved by the Invention] In the method of hermetic welding using an electron beam, as shown in FIG. (5) Vertical irradiation method and the same figure (
As shown in B), the beam (5) is parallel to the joint surface (4).
), but currently both methods have the problems described below, and overcoming them is a major challenge for practical application.

1) In the method of irradiating the beam perpendicularly to the joint surface, the shear force generated during heating and rolling must be supported by the weld metal width at the joint surface position. However, the weld metal width in electron beam welding is at most 5 to 6JI.
Il is the limit, and there is an extremely high risk that the electron beam welding bead (1a) will break due to shearing force and the sealing property will be broken. Furthermore, depending on the combination of the base material (3) and the laminate material (2), cracks may occur in the weld metal during welding. For example, when the base material is carbon steel and the composite material is austenitic stainless steel, the microstructure of the weld metal consists of a mixed structure of austenite and martenrite, so the weld cracking susceptibility is extremely high and cracks may occur. .

2) Irradiate the beam parallel to the joint surface
In one method, the shearing force during rolling is supported by the penetration depth of the weld bead (1b), so that this shearing force can be sufficiently withstood by adjusting the penetration depth.

Therefore, this method can be said to be more practical than the method of irradiating the beam perpendicularly to the joint surface. However, this method has more problems than the vertical beam irradiation method in terms of forming a good hermetic weld bead.

In other words, since electron beam welding uses a narrowly focused beam, if there is a gap between the butt surfaces that are to be hermetically welded, most of the electron beam will pass through this gap and the welding will not be completed, as shown in Figure 8. Almost no weld bead is formed where it should be. A weld bead (1C) may be formed at the point where the beam that passed through the gap diverges and spreads, but in this case the bead throat thickness is not large enough to withstand the shearing force, and this part is Since the bead is cut off, the yield is reduced, and the location where the bead is formed is also uncertain, which is extremely problematic in practice.

According to experiments conducted by the present inventors, in order to hermetically weld the base material and the cladding material without any trouble, the gap between the abutting surfaces must be suppressed to within 0.5 mm, but in actual clad assembly members, There is a gap greater than that, and it is almost never the case that the gap is less than 0.5as+ over the entire weld line. In order to control the gap within 0.5ff1, it is necessary to strictly control the flatness of the joint surface between the base material and the laminate material. To achieve this, it is necessary to machine the entire joint surface of both the base material and the laminate material to finish it into a single surface, but this requires an investment in serious grinding equipment and a large amount of man-hours, making it difficult to apply in practice. is almost impossible.

Further, even if the butt gap between the joint surfaces is within 0.5a1, there is a very high possibility that cracks will occur in the weld metal during welding, depending on the combination of the base material and the laminate material, as described above.

[Means for Solving the Problems] The present inventors solved the above problems based on the idea that the latter method of irradiating an electron beam parallel to the joint surface is the method used by Jitsukawachi as a hermetic welding method. We have considered this as much as possible. As a result, they discovered that by performing electron beam welding while supplying a filler metal such as filler wire to the weld under specific conditions, it is possible to perform good hermetic welding without strictly controlling the butt accuracy of the joint surfaces. It has also been found that by performing such welding, the component values of the weld metal can be freely adjusted and optimized.

In electron beam welding, it has traditionally been difficult to weld while stably supplying filler metal to the welding area, and for this reason, no attempt has been made to put welding using filler metal into practical use. This has led to strict requirements for the butt precision of the groove surfaces. The inventors conducted detailed experiments on continuous filler metal supply electron beam welding, and found that even in electron beam welding, by appropriately controlling the supply angle and position of the filler metal, it is possible to stably form the welded part. It was discovered that it is possible to supply filler metal, and its basic configuration is to supply filler metal from the rear in the welding direction to the joint surface of stacked metal plates, parallel to or at an angle to the joint surface. The filler material is collided with the electron beam inside the beam hole formed in the joint surface by the electron beam, and the angle α with respect to the beam axis of the electron beam is set to 5. °≦α≦(6
5-0,4d)'' (where d (mm): welding depth).

FIG. 1 shows the implementation status of the present invention, in which (1) is a weld bead and (6) is a filler metal.

In the present invention, the bonding surface of the overlaid base material (3) and laminate material (2) is bonded with an electron beam (5) while supplying the filler material (6).
) to perform hermetic welding by irradiating. Electron beam (5
) is irradiated parallel or obliquely to the joint surface,
Perform welding along the joint surface.

When the material to be welded is irradiated with an electron beam, the material will be heated and
It is melted and partially evaporated. At this time, a beam hole (8) is formed in the molten pool (7) due to the evaporation reaction force, and the filler metal (6) is supplied into this beam hole (8) from the rear side of the beam in the welding direction. and collides with the electron beam (5) within the beam aperture. As the filler material (6), in addition to a so-called filler wire, a material having an appropriate shape such as a band shape or a rod shape can be used.

The filler metal (6) supplied from the rear of the beam in the welding direction needs to have a predetermined angle α with respect to the beam axis of the electron beam (5). Specifically, the supply angle α (d13 (II), when the penetration depth is d (m), 5°≦α≦(65-0,4d
)) must be within the range. If the supply angle is less than 5°, even a small change in the supply position of the filler metal will cause the collision position with the beam to change significantly, making it difficult to stably melt the filler metal. In addition, if the feeding angle exceeds (65-0,4d)'', the filler metal will come into contact with or rush into the molten pool (7) due to minute fluctuations in the feed position of the filler metal, which will prevent the filler metal from melting. For this reason, the feeding angle α is regulated within the above range. Figure 3 shows the relationship between the penetration depth d and the filler metal feeding angle α. [I
The area I is the proper area.

According to the method of the present invention, the permissible groove gap width can be expanded to about 3 m8 degrees, thereby making it possible to significantly reduce the butting accuracy of the joint surfaces. Furthermore, according to the present invention, the composition of the weld metal can be optimized by using filler metal, and a sound welded part without welding defects can be obtained regardless of the combination of the base material and the laminate material. .

[Example] The present invention will be explained in detail below.

・Example 1 Base material SM 41 80X 1,0O
OX 500am laminating material S US 304 20
X 1,0OOX 5GGam+For each of the above materials, the surfaces to be bonded were machined and cleaned and then stacked, but the base material and the laminated material were not brought into close contact, and the two layers of rIJIIji were provided and the bonding surfaces were butted. After this, the parts were carried into the vacuum chamber, and after being evacuated for 10 minutes under the degree of vacuum of 15 pa or less, the W4F
Welding was performed around the F4 material by irradiating an electron beam in a direction parallel to the joint surface while continuously supplying filler wire. Welding conditions are acceleration voltage 150kV, beam current 100mA, welding speed 30ca/in1 filler wire SUS 312 (1
, 2φ), a filler wire supply angle α of 40°, and a filler wire supply amount of 16 m/inch, and welding was performed in a horizontal position as shown in FIG.

The bead penetration depth at this time is approximately 30mm. Met.

The material hermetically welded by electron beam welding was uniformly heated at 1250°C and then rolled at a reduction ratio of 3. The temperature at the end of rolling was 1050°C. During heating and rolling, the weld bead sufficiently withstood the shearing force without breaking.

Ultrasonic tests were conducted over the entire joint surface after rolling, but
No defective echoes were detected.

Regarding the material after rolling, 3 each from both ends and the center of the rolled material.
We took out several shear test specimens and found out their shear strength.
A value of 35 to 39Ksf/JIII2 was obtained, and the shear strength specified by JIS (≧20Kgf/1xs2
) were obtained. Front, back, and side bending tests were also conducted, but no peeling was observed at the joint surfaces. The microstructure of the bonded surface is shown in FIG. 4, and the base material and the laminate material are sufficiently bonded.

・Example 2 In Example 1, the base material and the laminated material were f! 2m between joint surfaces without attaching
A gap of m was provided, and filler wire was continuously supplied to perform sealing welding. Here, the types and dimensions of the base material and the laminated material were the same as in Example 1, and the joint surface gap was Oiw, that is, the base material and the laminated material were closely overlapped. In this case, the joint surface between the base material and the laminate material was machined to make it flat. Welding conditions other than vacuum evacuation and feed amount of filler wire were the same as in Example 1.

Although the bead shape does not require the supply of filler wire, when the base material and the laminate were directly electron beam welded without a filler wire, cracks often occurred in the weld metal. To prevent this cracking, 5US312 series filler wire (1
, 2φ) was continuously supplied while electron beam welding was performed.

The minimum supply amount of filler wire required to prevent cracking is 1.2R.
/Win, but when the supply amount of filler wire increases, the molten metal becomes excessive, and the molten metal drips from the welding part surface and creates a cavity defect inside the weld metal, so the upper limit of the supply amount is set to 2.5rrt/ It needed to be below yitn. In actual sealed welding, electron beam welding was performed with the feed rate of filler wire set to 1.8 m/sin. The fi-free welded material was heated uniformly at 1250°C and then rolled at a reduction ratio of 3. The weld bead sufficiently withstood the shear forces during heating and rolling. An ultrasonic test was conducted over the entire joint surface of the rolled material, but no defect echo was detected. Three shear test pieces were taken from both ends and the center of the rolled material, and the shear strength of the joint was examined.34-39
A value of 9f/m2 was obtained and JISjJl rating 1 (upper 20
Good results were obtained that significantly exceeded Kst/llm2).

Front, back, and side bending tests were also conducted, but no peeling was observed at the joint surfaces.

- Example 3 In Examples 1 and 2, the joint surfaces were machined, but in practice, machining a large-area joint surface involves various difficulties. Therefore, without machining the surfaces to be joined, the base material (8M41) and the mating material (S
US 304) were superimposed. In this case, the flatness of the base material and the laminate material was not very good, and the gap between the abutting surfaces varied between 0 and 3 as+, as shown in FIG. The gap was measured in advance, and the filler wire supply car was changed according to the gap to perform sealing welding by electron beam welding. The basic welding conditions are the same as in Example 1. A good bead shape was obtained over the entire weld line, and no weld cracks were observed.

An ultrasonic test was conducted on the rolled material rolled under the same conditions as in Example 1, but no defect echo was detected. Three shear test pieces were taken from both ends and the center of the rolled material to examine the shear strength of the joint, and good results were obtained, with values of 9f/as2 ranging from 36 to 40. In addition, front, back, and side bending tests were also conducted, but no peeling of the bonded surfaces was observed.

- In the example, a rolled cladding was produced using a combination of 5M41 and 5US304, but good hermetic welding could be achieved with other combinations by supplying filler wire with appropriate composition.

As described above, by applying the filler metal supply electron beam welding method of the present invention to assembly welding of clad metal plates, a weld bead without weld cracking can be formed regardless of the combination of the base material and laminate materials. can do. At the same time, even if a gap of about 3 seconds occurs on the abutting column surfaces of the joint, it can be sufficiently coped with and a good weld bead can be formed. Therefore, it has been found that by applying the present invention, it is possible to perform good hermetic welding even on the flat marks of the current base material and composite V material, and that the various properties of the joint after rolling are also sufficiently satisfactory. , the effectiveness of the present invention was confirmed.

In addition, various processes can be considered for hermetic welding using an electron beam, such as welding three sides using the conventional arc welding method and then electron beam welding the remaining one side in a vacuum chamber, but in any case, the electron beam In closed welding, it is important to supply filler metal and perform welding, and this is where the present invention is applied.

Note that the above dense r1m contact was performed by irradiating the electron beam parallel to the bonding surface, but it is also effective to irradiate the electron beam at a certain angle to the bonding surface, as shown in Figure 6. there were. However, if the angle (θ) is set to exceed 20°, it becomes difficult to stably supply the filler metal, so the incident angle θ of the electron beam is limited to 20@ or less.

The above is a case where the laminate material and the base material are a combination of different materials, but the present invention naturally applies to the laminate material and the i! It has been confirmed that even a combination of similar materials can be used extremely effectively and the effect will be even greater.

Regarding the welding position, the present invention is fully applicable to welding not only in a horizontal position but also in a downward and vertical position, and it is also possible to weld in a downward or vertical position with the clad member erected.

[Effects of the invention] According to the present invention described above, the permissible groove gap width can be significantly expanded compared to the conventional method, and as a result, the butting accuracy of the joint surfaces can be significantly relaxed, and in addition, The use of a filler metal makes it possible to optimize the composition of the weld metal, and has the excellent effect of making it possible to obtain a sound welded part without welding defects, regardless of the combination of the base material and the laminate.

[Brief explanation of the drawing]

1 and 2 show the state of implementation of the present invention, with FIG. 1 being a perspective explanatory view and FIG. 2 being a partially enlarged view of a welded portion. FIG. 3 shows the relationship between the penetration depth of the weld and the filler metal supply angle. FIG. 4 is an enlarged microscope photograph showing the gold all-weave on the joint surface in Example (1). FIG. 5 is a perspective explanatory view showing the polymerization state of the base material and the laminate material in Example (3). FIG. 6 is a perspective explanatory view showing another implementation situation of the present invention. FIGS. 7(A) and (B) are explanatory diagrams each showing a conventional electron beam welding method.
The figure is an explanatory diagram showing a welding situation in a conventional method. In the figure, (1) is a weld bead, (2) is a cladding material, (
3) is the base material, (5) is the electron beam, (6) is the filler metal, (
8) shows each beam hole. (x200)

Claims (1)

[Claims] In a method of manufacturing a clad metal plate by stacking two or more metal plates of the same or different types, sealingly welding them in a vacuum using an electron beam, and then hot rolling or warm rolling, the stacked metal plates are The joint surfaces are hermetically welded by irradiating an electron beam parallel or at an oblique angle to the joint surfaces while supplying filler metal from the rear in the welding direction, and the filler metal is applied to the joint surfaces by the electron beam. The electron beam is collided with the electron beam inside the formed beam hole, and the angle α of the electron beam with respect to the beam axis is 5°≦α≦(65-0
．． 4d)° (where d (mm): weld penetration depth).