JPS61255789A - Manufacture of consumable welding insert and consumable welding insert - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to materials used in welding and, in particular, to a method for producing welding inserts or spacers to be utilized between surfaces to be joined by a welding process.

PRIOR ART AND ITS PROBLEMS Consumable inserts are generally well known and have been used for many years in complex welds, such as welding pipe or tubular bore products, where access to the weld point is restricted due to size. It's here.

Specifications for consumable inserts are well known and described in various industry publications. Such publications include American Welding Society Specification AWS A5.30-79, entitled "Consumable Insert Specification," published by the American Welding Society, Miami, Florida, which is incorporated herein by reference. As stated in that publication, when attempting to maintain consistently high quality welds even under adverse welding conditions, or minimizing the presence of obstructions inside a tubular perforated joint. Consumable inserts are used when welding from one side of a joint between two metal surfaces when necessary.

As can be seen from the above-mentioned publications, the most consumable inserts are annular in shape and are therefore used to form joints in tubes or tubular perforated members. The well-known cross-sectional shapes of Maki are used, and the cross-sectional shapes are described in publications of the American Welding Society (AWS) and are selected depending on the particular shape of the surfaces to be joined. . For example, if the cross-sectional shape is "T-shaped" and reeded, such a shape is shown in FIG. Similarly, other shabby shapes include the ``1-character'' shape shown in the diagram.
There is. Each shape is suitable for a particular application, and all shapes must be manufactured to precise tolerances on the order of about 0.005 inches or less.

The dimensional requirements for consumable inserts are particularly stringent when manufacturing these inserts in all relatively hard metals such as chromium-molybdenum steels, austenitic chromium-nickel steels, nickel alloys including copper-nickel alloys, and mild steels. is important. Since the hardness of the materials from which these inserts were made precluded the use of cold processing techniques, consumable inserts were generally manufactured by machining to the desired tolerances. Additionally, the raw material wire that is converted into consumable inserts must meet a standard hardness standard known as the Rockwell B scale, especially 60
Must be compatible with a hardness of ~80.

Therefore, the extremely high hardness and low processability of the materials required to manufacture consumable inserts, the precise tolerances in manufacturing such inserts, and the fact that the finished product meets known standard values Therefore, the necessary tensile strength and Rockwell hardness make it difficult to employ any metal forming technology, whether processed at room temperature or at low temperature. A particular drawback and problem is the known fact that metals undergo work hardening. Consumable inserts have a specific hardness range,
That is, approximately 5 to 7031 kg/ad (72 to 100,0
Early attempts to manufacture such spacers or inserts by forming techniques were thwarted because the tensile strength must be in the range of 0.00 psi). This is because the tensile strength of the final product is outside the tolerance range for the particular product, rendering the bending range unsuitable for forming the insert ring and rendering the material impossible to process.

Therefore, as mentioned at the outset, machining techniques are generally used in the industry for manufacturing consumable inserts. Although this technique produces generally acceptable products, it also has a number of drawbacks. The disadvantages are that there is a burr on the edge of the ring, that the surface that is in direct contact with the surface of the objects to be joined has irregularities that require correction, and that the efficiency of metal removal, that is, machining, is low. That's a bad thing.

The resulting surface irregularities, known as "lands," create gaps in the joint surface, which can lead to cracks and other imperfections in the weld seam. adversely affects the weld fusing properties and integrity, resulting in weld defects.

Therefore, in order to develop the technology for manufacturing consumable inserts, it is important that the technology is more efficient and capable of producing reliable products with the desired tensile strength and dimensional stability required for the product. is necessary.

SUMMARY OF THE INVENTION A method is disclosed for forming metal wire shapes for use as consumable welding inserts, a method of the present invention. This method draws successive circular cross-sectional metal wires through an appropriately shaped drawing die, forming the metal wire into multiple thickness cross-sectional shapes for ultimate use in forming circular rings. Preferably, the drawing is carried out in two buses, the first drawing converting the cross-section of the metal wire by at least 80-90% to form the desired shape of the insert metal wire. The method according to the invention is characterized in that the metal flows in a radial direction. This flow causes the insert metal wire to elongate by 15 to 20% of the completed cross-sectional shape.

The radial flow that occurs during the drawing operation in the present invention facilitates the use of starting materials of smaller diameter than the diameter of the largest cross-sectional dimension of the final insert product. Therefore,
There is less waste or scrap than conventional machining or 7-rice processing previously utilized, and as mentioned at the outset, the size of the starting material can also be reduced.

Another aspect of the invention is that dimensional stability can be achieved with minimal metal forming, thereby reducing the cost of the product. Similarly, the defects of prior art products, namely edge burrs, uneven irregularities and non-vertical lips, can be eliminated.

Although the process of the invention can be carried out at various drawing speeds, a drawing speed of 30.5 CIIL per minute is preferred. The method can generally be carried out in two baths, with the first bath converting 80-90% of the cross-section to form the final cross-sectional shape, as mentioned at the beginning.

The products produced by the process of the present invention undergo minimal work hardening due to the relatively little processing and therefore can be made from starting materials with the desired hardness in the final product.

The method of the present invention unexpectedly eliminates work hardening of the product and therefore allows the correct hardness of the final insert product to be accurately determined and controlled.

The inserts of the present invention have smooth, precise surfaces that do not produce surface defects such as scallops associated with machining in the prior art. Furthermore, the radial flow that occurs in practice 9 of the process of the invention is approximately 15-20% relative to the diameter of the starting material.
Increases diameter and does not cause surface distortion. The resulting inserts met all of the specifications set by the American Welding Society;
Or better.

OBJECTS OF THE INVENTION Accordingly, a primary object of the present invention is to provide a method for manufacturing a dimensionally accurate and surface-uniform consumable insert.

Another object of the invention is to provide a method by which consumable inserts can be manufactured from less starting material.

Another object of the invention is to provide a method for manufacturing inserts that reduces work hardening of the metal material during product formation.

Still another object of the present invention is to provide a method for manufacturing inserts that can minimize the waste of raw materials generated during operation.

. By now describing the invention with reference to the accompanying drawings,
Other objects and advantages of the invention will become apparent.

EXAMPLE As mentioned at the outset, this product is known as a consumable insert and is described in the publication AWS
This product is defined in composition and substance (according to standards or specifications for consumable inserts established by the American Welding Society as set forth in A5.30-79). 2 in Figures 1 and 2
A cross section of a typical consumable insert is shown. In Figure 1, a typical inverted T-shaped cross-section insert is shown, typically 11! of the adjacent tubular perforated product. It is used when joining edges (by welding). The insert ring is positioned between the edges of the tubular article. The product itself has its edges flared or beveled outward, or machined on the inside to form a predetermined angle therebetween. Therefore,
A welding torch is applied to the outer periphery of the insert to fuse the respective abutting ends of the insert and tubular product together.

When it is necessary to weld a tubular perforated product to another tubular product or component whose end shape is not similar, use the "J" shown in Figure 2.
Shaped consumable inserts are commonly utilized. In this case, “J
The elongated flat side of the "" shape is placed against a dissimilar, larger thickness member, and the thin tubular hole is adjacent to what is essentially a "5" shaped recess on the opposite side of the "J" shape. Accommodate the edges.

The composition of the consumable insert may vary, and the consumable insert contains a variety of well-known metals, all selected to match the base metal during the welding operation. Therefore, most metals for inserts contain iron in various combinations as a major composition. Iron has the effect of preventing radial flow. In the case of mild steel, the typical composition is manganese 0.
．． 90-1.85%, carbon 0.07-0.15%, phosphorus 0
．． 025%, sulfur 0.035%, silicon 0.40-1.1
5%, aluminum O, OS~o, 1sX, zirconium 0.02~0.12Xs titanium 0.05~0.15%
, the remainder is iron. In contrast, chromium-molybdenum steel contains, in addition to the above-mentioned components, chromium up to 6.0X, molybdenum up to 1.2X, silicon in excess of the above-mentioned values, and manganese slightly below the above-mentioned range. do. Finally, austenitic chromium nickel steel Hachrome 18-32
X, nickel 9-23X1 containing nickel increased to about 2-5X and optionally about 2-3X molybdenum.

All of the alloys mentioned above have certain properties in common. That is, it must be a hard metal, and it must be a metal that is difficult to form even during high-temperature treatment or room-temperature treatment. When cold processing is utilized, alloys often experience severe work hardening.

While the alloy is under tension, work hardening occurs as a result of the formation of crystals, so that the alloy rapidly becomes brittle. This condition is undesirable when forming the alloy as a consumable insert.

This is because the insert needs to be responsive and fluid within a carefully defined temperature range in order to achieve accurate and rapid welding.

If excessive work hardening occurs, as measured by the Rockwell B scale, the alloy will not flow properly at welding temperatures, resulting in incomplete welds and defects.

As mentioned at the outset, the manufacture of consumable inserts may place greater demands on their dimensional stability. That is, even if the insert has the desired hardness and exhibits the desired flow properties, edge ridges and uneven lands (these surfaces are referred to as 2.4.6 in Figures 1 and 2)
．． Surface defects such as 8.1O112 and 14) constitute gaps between adjacent abutting surfaces of the articles to be welded, resulting in incomplete welds, cracks, etc.

The present invention solves the above-mentioned problem by forming a consumable insert wire by performing a straight forward drawing operation.

Alloy drawing is well known and can be traced back to the techniques of silversmiths. Pultrusion techniques are often used for precious metals and other metals that exhibit relatively high ductility and formability. Thus, ductile alloys, such as aluminum, are well known for their good pultrusion and formability, whereas they have significantly higher hardness and tensile strength, such as the steels and copper-based alloys mentioned above. High alloys resist pultrusion forming operations and are difficult to pultrude.

Most pultrusion forming operations are "cold processing" techniques. That is, this operation is carried out on unheated materials at room temperature. Particularly evident in the case of materials of high hardness, the extremely high stresses created in the drawing die are generally a barrier to the suitability of drawing as a forming operation for these hard alloys.

Particularly in the case of alloys (such as the steels and cage copper-based alloys discussed herein), attempts to introduce pultrusion operations have consistently failed. The surface of the drawn material often exhibits irregularities or craters known as "scallops" due to the stress applied by the die and the relatively treacherous nature of the metal stock. Attempts have been made to use various lubricants to alleviate this phenomenon, but no results have been obtained that are commercially viable.

Because of the shape of this product, which varies in thickness, it seems particularly unsuitable for this type of forming operation. 1st and 2nd
It is clear from the figure that any attempt to extract something of this cross-section would be met with difficulty. Nevertheless, the present invention is based on the idea of reshaping the metal starting material so that cross-sectional shapes of various thicknesses of this consumable insert can be formed by a drawing operation utilizing two preferred drawing passes. . Applicants are aware that early attempts to draw hard metals with shapes of varying thickness have been successful, but it is important to note that the number of dies between each thickness of the desired varying thickness product is The angle varies and the shape of the drawing die is extremely precise to prevent distortion and surface damage. However, the present invention may be practiced with a drawing die that is not critical to the specific cross-sectional shape desired in the final product, or to the specific die surface or angle.

According to the invention, a round starting material is drawn into several shapes (two of which are shown in Figures 1 and 2) by the following process.
(indicates the number of items). The process involves at least one, preferably two passes through a suitable drawing die at an average speed of up to za+m (1 inch) per minute. The first pass, referred to as a "luffing" pass, provides the starting material with a cross-sectional reduction of 80% to 90X relative to the final cross-sectional shape. In the 1st vA, the illustrated "inverted T-section" comprises laterally opposed lands 2.4 and adjacent abutment surfaces 6.8 arranged essentially vertically.

As mentioned at the beginning, this shape is utilized when two tubes of equal wall thickness are joined end-to-end.

The regularity and tolerances of the lands 2.4 and edges 6.8 are tight, which ensures that air gaps and other discontinuities are avoided.

Furthermore, the lands 2.4 are perfectly aligned and correspondingly aligned between the respective tubes or tubular holes to ensure proper weld formation.

FIG. 2 shows a "J-shaped cross section" which is basically half the shape shown in FIG. That is, 2nd 1
0 and an abutting end 12 are provided to accommodate a tube of a predetermined wall thickness,
Adjacent members of greater wall thickness abut broad surfaces 14. In the case of inserts with the cross-sectional shape shown in FIG.
need to be prepared.

It may come as a surprise in the above context that a pull-out operation of the type utilized here can yield good results. Also, particularly because machining has traditionally been utilized to manufacture consumable inserts, the diameter of the starting material for conventional consumable inserts must correspond to the largest dimensions of the final product. In contrast, the pulling operation utilized in the present invention is
A starting material of reduced diameter can be introduced. It has been found that during the drawing operation, the starting material stretches radially to an extent of about 15-20X beyond the minimum diameter of the material. The following table shows how a blank material of a specific diameter is formed into a standard size and shape according to the present invention.

Original material Changed shape (Diameter) (Diameter inch) (Main dimension Dragon) (Main dimension inch) 2
．． 794 0.110 3.175 ynJ section / “J section 3.632 0.143 3.96
88mJ cross section Winter “J cross section 2.921 0.115
3.175 direction J section and “J section 3.759 0
．． 148 3.9688wJl! ! ti face child “J
It should be noted that the longitudinal dimension of the resulting transformed shape is greater than the maximum cross-sectional dimension of the starting material, ensuring radial flow or elongation. This is therefore clearly advantageous compared to conventional machining, which produces large amounts of scrap and is therefore costly. Utilizing the method of the present invention, it is possible to purchase material with a reduced diameter and correspondingly lower costs, and at the same time reduce the generation of scrap by effectively dispersing the metal during the forming process. be able to.

As stated at the beginning, the drawing process of the present invention utilizes the first "luffing pass" to form the final cross section of 80 to 90X. Figure 3 shows the first "
Figure 3 shows the cross-sectional shape of the starting material of circular cross-section which has undergone a 'ruffing pass'. The imaginary lines diagrammatically show the flow of the nine metals produced. The nature of the drawing process can be better appreciated by looking at FIG. 4, which diagrammatically shows the die elements utilized to form the cross-sections of FIGS. 1 and 3.

In FIG. 4, the main die element 20 is shown so as to reveal an essentially semi-circular surface 22 forming a "T-shaped""cap".
It shows. A second rectangular element 24,26 is applied to the round surface of the starting material to form a land 2 as shown in FIG.
．． Start forming 4. The modular nature of the die components shown in Figure 4 facilitates fine tuning of the die set and maintains basic dimensional accuracy such as parallelism of the ends 6.8 and linear correspondence between the two ends 2.4. Make it certain.

The components of the die set shown in Fig. 4 have sufficient hardness,
It can be constructed from a variety of well-known materials that have dimensional stability in use.

Of course, if the drawing operation is essentially a "cold processing" operation, there will be enough heat generated by friction during the drawing operation that the material from which the die set is made must resist deformation. No. A variety of such materials are known in the metalworking industry and can be utilized in the manufacture of this die set.

Further, in FIGS. 3 and 4, the method features radial metal flow during the drawing operation. Fourth
The structure of the die shown extends a T-shaped "stem" within the area 28 defined between elements 24,26. Typically, this type of radial flow occurs to the detriment of the product during the drawing operation. That is, when this type of metal flow occurs, it results in twisting and the resulting product exhibits surface or dimensional non-uniformity. However, one of the features of the present invention is that even when subjected to radial flow, uniform cross-sectional dimensions and surfaces are maintained, so that the resulting The product requires at most one or two additional drawings.

The method of the present invention is carried out by passing the wire through a die at a rate of 25.4 m (1 inch) per minute, which is preferred. When carrying out the method of the invention at this speed, the insert surface remains smooth and dimensionally accurate to achieve the desired radial metal flow. Inserts made by the method of the invention also generally do not suffer from undesirable work hardening, and moreover, it is possible to select a starting material with a hardness range closer to that desired in the final product than was previously possible. can. Since the consumable inserts of the present invention desirably have a hardness range of 60 to 80 on the Rockwell B scale, minimal work hardening when carrying out the method of the present invention means that the hardness is lower than that which could be used with conventional methods. It is possible to produce sufficient products with wire starting materials having a hardness range higher than the range.

If the final product has excessive hardness, the hardness can be reduced by any known technique such as annealing the respective materials within known parameters. Generally, annealing is performed by heating the product at a specific temperature for a specific time in an atmosphere designed to reduce stress in the metal and correspondingly reduce the product hardness. The exact details of the annealing vary, but are not part of this invention and will not be discussed in detail.

The products produced by the method of the invention are particularly useful when the drawing process uses an essentially straight starting material to form essentially multiple thickness shapes and when the material is coiled to form a ring. A distinctive feature is that dimensional tolerances and specifications can be obtained close to each other. Forming the ring by the drawing process alone results in surface defects due to the non-uniform nature of metal removal and flow, as well as the multiple thickness shapes of the drawing die. The fact that the multi-thickness profile product of the present invention requires no more than one or two pull-outs and has a smooth, dimensionally stable surface is comparable to that of the prior art. This is one of the distinguishing characteristics.

The method of the invention is carried out as described above by performing a twelfth tuffing pass which forms 80-90% of the final cross-section of the insert. The next pass or buses then complete the formation of the final insert product and ensure uniformity and accuracy to the dimensions of the insert product. This subsequent drawing pass is performed with a drawing die of a different size than the die used in the luffing pass. Accordingly, the method of the invention carries out a first drawing pass and a subsequent drawing pass in succession, whereby the continuous metal material is first passed through a rat-swinging die;
It is then passed through a finishing die (not shown) which defines the final size and shape of the insert product. Alternatively, the coil of wire may be first passed through a twelfth tuffing die and re-wound into a coil. This second or next finishing die may be placed in a separate location and the material in the "luffing draw" condition is passed through the second finishing die to complete the process. Although the precise technique of this multiple drawing method is the best mode for carrying out the method of the present invention, various modifications may be made within the skill of those skilled in the art.

The present invention is not limited to the embodiments shown and described; the embodiments described above are merely illustrative of the best mode of carrying out the invention; Various changes can be made to the details. The invention includes all modifications falling within the scope of the claims.

[Brief explanation of the drawing]

Figure 1 is a diagrammatic cross-section showing a standard "inverted T-section" for consumable inserts; Figure 2 is a diagrammatic cross-section showing a "J-section" for consumable inserts; Figure 3 is a diagrammatic cross-sectional view of the starting wire showing its cross-sectional shape after the first drawing bath; Figure 4 is a diagrammatic view showing the elements of a drawing die suitable for forming a consumable insert with an "inverted T-section"; FIG. 2, 4, 6, 8, 10, 12, 14...
Surface 20... Main die element 22... Semicircular surfaces 24, 26... Second element 28... Section
Regional Patent Applicant Robbon Backing Ring Company 1 Figure 4 Procedural Amendment Request June 27, 1960 Manabu Shiga, Commissioner of the Patent Office (Examiner of the Patent Office) 2. Name of the invention Method for manufacturing consumable welding inserts and consumables Welding insert 3, relationship with the case of the person making the amendment Patent applicant name Robbon Backing Ring Company 4
, Agent Address: Hayakawa Building, 5-14-7 Hakusan, Bunkyo-ku, Tokyo Phone: Tokyo 94G-0531 (Representative) - Showa
Submit an engraving of the monthly statement (with no changes to the contents) as attached.

Claims (1)

Claims: 1. A method of manufacturing a consumable welding insert from a continuous length of metal wire, comprising at least one drawing pass of said metal wire through a drawing die that constitutes a multi-thickness configuration. A manufacturing method for consumable welding inserts featuring features. 2. The method according to claim 1, wherein at least two drawing passes are performed. 3. The method of claim 1 or 2, wherein the first drawing pass forms 80-90% of the final cross-sectional shape of the insert. 4. The method of claim 1 or 2, wherein the metal wire is drawn at a rate of about 25.4 mm (1 inch) per minute. 5. The method of claim 3, wherein the metal wire is drawn at a rate of about 25.4 mm (1 inch) per minute. 6. The method according to claim 1 or 2, wherein the metal wire is caused to flow in a radial direction during the drawing step. 7. The method according to claim 3, wherein the metal wire is caused to flow in a radial direction during the drawing step. 8. The method according to claim 4, wherein the metal wire is caused to flow in a radial direction during the drawing step. 9. The method according to claim 5, wherein the metal wire is caused to flow in a radial direction during the drawing step. 10. The method of claim 6, wherein the metal wire is flowed radially to increase its maximum cross-sectional dimension by 15-20%. 11. The method of claim 1 in which the metal wire is drawn through more than one drawing die. 12. The method of claim 11, wherein the metal wire is subsequently drawn simultaneously through two different drawing dies. 13. A consumable welding insert manufactured by the method according to any one of claims 1 to 12.