JPS58110195A - Production of flux cored wire electrode for stainless steel - Google Patents

Abstract

PURPOSE:To remove the fats and oils and moisture thoroughly from the surface of a flux cored welding wire electrode in the stage of producing said wire by packing a flux in a stainless steel hoop by conducting electricity to the wire with power feed rolls thereby heating the wire. CONSTITUTION:A wire W for welding of stainless steel produced by packing a flux into a hoop made of ferritic stainless steel is drawn out from a let-off machine 1 and is passed through a sizing machine 2, whereby the wire is trimmed to a linear shape. Said wire is passed through power feed rolls (a), (b), (c) and guiding rolls (d), (e), (f) which suppress the oscillations of the wire. Electricity is conducted to the rolls (a), (b), (c), to heat the wire at 500-750 deg.C and after the wire is held at these temps. for 0.08-2.0sec, the wire is cooled down to <=300 deg.C with a cooler 3 consisting of double pipe and is coiled on a coiler 5 with a take- up machine 4. The fats and oils such as lubricating oils on the wire surface are thoroughly removed, and the welding work is carried out stably on account of improvement in current conducting characteristics.

Description

Detailed Description of the Invention The present feather is made by drawing the top of a wire with franks for stainless steel, and is capable of absorbing moisture in oils and fats such as sludge oil attached to the wire.
Efficient removal by electrical heating.

This relates to a method for manufacturing a flux-cored wire that has good feedability during welding and has excellent characteristics. Solid wire as shown in Figure 71g2 or flux-cored wire as shown in Figure 71g2 is used.

Since there are problems such as oxidation of the solid wire A bead surface and a decrease in the ease of embroidery, the common place is used as ilJM.On the other hand, the 7-wire wire does not have the above-mentioned drawbacks,
Shira also manufactures a wide variety of 9-year products by mixing flux.1!1. There is an advantage that the wires can be used differently depending on the type of base material, etc. However, these wires are sent into the conduit via a straightening roller and a selection roller, and the wires are energized at the welding tip portion and are connected to the base material. Welding is performed while generating an arc between the welds, but in order to perform stable welding and obtain high-quality weld metal, the wire must be fed at a constant rate. Oil and moisture such as lubricant attached to the wire surface must be completely removed in the final finishing stage, and heat treatment is essential.There are two heat treatment methods for wire: patch method and strand method. Patch type systems account for most of the raw flow;
In this method, wire rods are bundled into coils and put into a heating furnace and heated in an inert atmosphere for several hours to several tens of hours, but because the convection of inert gas is insufficient, There is a problem in that the flux changes locally depending on the degree of contact with the atmospheric gas.Therefore, especially in the case of a 7-lattice-cored wire, there is a problem in that the flux deteriorates locally. In addition, under the above escape conditions, an annealing effect is also applied, but since the temperature inside the furnace is not necessarily uniform, the annealing effect is uneven, resulting in uneven tensile strength. It has also been pointed out that due to the curling, the wire forms a single layer at the exit of the feed roller during welding.

On the other hand, the strand method heats the pipe indirectly by passing a wire through it, so it is less efficient and raw. ! 1
The book @'JA8 and others focused on the above-mentioned complicated circumstances, and made flux-cored wires efficiently without creating a messy interlayer.
The present invention was completed as a result of such research and consists of a ferritic stainless steel hoop filled with 7 lux. When producing flux-cored wire f for stainless steel, the black-cored wire is drawn to the product diameter and then energized through a plurality of power supply rollers to heat the wire at 500 to 750°C while passing between the electrodes. The gist lies in heating the flux-cored wire by holding it for 0.08 to 0 seconds and heating it with electricity.In the present invention, the flux-cored wire is heated using the regular iron heating method, which is a heating method in which the wire is While running in the direction of the wire, it is brought into contact with a power supply roller and heated by electricity, and the heat generated inside the wire can be used to raise the temperature at home, and it heats up continuously in a very short period of time, only a few seconds. Since the wire is heated evenly while traveling in the axial direction, there is no bending during local heating, and high quality product wire can be obtained. can.

FIG. 3 is a conceptual diagram showing an embodiment of the present invention, and shows a heat treatment process of a flux-cored wire W that has been drawn to a product diameter of 30%. That is, the processing device S is composed of a wire feeding section A, a heat treatment section B, and a wire take-up section C.The wire W, which has been drawn out from 1, is advanced through the 1m feeding section. Part B receives 4.

The heat treatment @it is divided into a ring electric motor and a cooling part B2, and power supply rollers a, b, and c and guide rollers d, @, and f for suppressing wire crinkling are arranged respectively.

Power is supplied by the method shown in FIG. In addition, the arrangement of the power supply row 2 and the guide rollers, and the voltage and illumination during energization heating
The flow adjustment etc. may be set appropriately according to the composition, diameter, etc. of the wire W (7-wire and flux), and in the example of FIG. The heat treatment temperature of the wire W can be controlled by adjusting the power supply t□, P2 between the power supply rollers a and b and between the power supply rollers b and e. Cooling section Nx
SC is equipped with a tube 3, and the wire W passing through the inner tube is cooled by flowing cold water to the outer tube side.
Set the length and inner diameter of the a1 tumor 3 that will be 0″C or less. However, the cooling method itself is of course not limited to this,
- Any method may be used as long as it is to be cooled. For example, an air cooling method may be mentioned.

The cooled wire W is sent to the take-off section C and taken off at the take-off section 11.
4 and is wound up by winding III&.

The heat pattern in the above heat treatment process is as shown in FIG. 5, for example, but this turn can be arbitrarily changed by controlling the energization as described above.
In short, t14II should be performed so as to obtain the optimum heating conditions for burning or evaporating the oil and fat, depending on the type and amount of the oil and fat attached to the wire surface.

By the way, the present inventors have developed ferritic stainless steel LIII.
Targeting flux-cored wire using 47-pu,
When we investigated the feed resistance during gas V-rudo arc welding, it was found to be inferior to II. It is approximately 3.0148 degrees under the above conditions, and it is recommended to set the wire strength based on this.
The relationship between the tensile strength and buckling strength of flux-cored wire is as shown in Figure jI6, and the wire tensile strength is 45
It can be seen that when the welding wire becomes less than ky/am2, the Wi bending strength of the welding wire falls below the maximum resistance (approximately LOk@ of e above), causing buckling, etc., resulting in failure of feeding and formation of islands.Furthermore, Fig. 7 is an experimental graph showing the effect of heating holding time on wire tensile strength at each energization time, and heat treatment a
As the WL increases, the tensile strength rapidly decreases even if held for a short period of time, so the quantity key 1 becomes 1 female. Therefore 451w/-
In order to stably obtain a tensile strength of m2 or more, the wire heating process must be set to 760° C. or less and the heat retention time must be set to LO seconds or less.

on the other hand! 1118FIA is an experimental result graph showing how the amount of hydrogen derived from pre-laid moisture in the wire changes depending on the heat retention time and am retention degree of the wire.・The tD hydrogen amount during the ry ear changes due to blowholes and Welding defects such as pinholes! FIIIf: Skin-friendly, the above water volume is IQ
It has been confirmed that if the welding temperature exceeds Oppm, welding defects as described above are likely to occur. From this perspective, the 8th v! J
Looking at jk, in order to reduce the hydrogen content to lOOppm or less, the kawaki temperature f! The temperature should be s00℃ or higher and the heat retention time should be 0.
It is understood that the meeting is longer than 0@seconds.

That is, the heat pattern during electrical heating in the present invention is not particularly limited as described above, but from the viewpoint of tensile strength related to the buckling strength of the wire, the upper limits of the heat retention temperature and heat retention time are 750°C and 2.0°C, respectively. On the other hand, the lower limits of heat retention time and heat retention time are limited to 500° C. and 0.08 seconds, respectively, due to the amount of hydrogen directly linked to welding defects. In other words, 1
By setting the instant heating conditions within the above preferred a'lA degree and time, it is possible to stably obtain high quality ferritic stainless steel vXH flux-cored wire with high productivity.

The basic configuration of the present invention is as described above.

In order to raise the quality of flux-cored wire to record levels.

It is desirable to take countermeasures that take into account problems such as downward twisting.In other words, since 7-lux wire has seams as shown in figure s2, twisting is likely to occur during the wire drawing process, and solid wire In addition, cleaning is sometimes performed to roughly remove lubricants, etc. prior to heat treatment, but it is not possible to sufficiently remove the ffi agent that has entered the joints of the hoop. At the stage of increasing the length of the energized heating pipe, conductive thick lubricants and the like adhere to and accumulate on the energizer. Then, the contact between the power supply roller and the wire becomes poor, causing sparks and spark defects on the wire surface.
Sometimes it even leads to disconnection. When this spark flaw is formed in a protruding shape on the wire surface.

Stable supercharging of the wire is hindered and the arc length fluctuates.

This may cause welding defects such as plowholes, and sometimes lead to failure of the feed.

However, the above-mentioned dose curve can be easily resolved by the method shown below.In other words, as a countermeasure against sparks, the first measure is to install a straightener in front of the energized heating section as shown in Figure 3. 2, the wire W can be straightened in the energized heating furnace by correcting the twist of the wire W and the large bends caused by the bobbin! By increasing the lubricant removal member in the straightening device 2, the lubricant removal member is thoroughly removed at the wire joint, thereby suppressing energization failures. Further, as means 112, the wire runout during high-flow operation is prevented by idle rollers d, e, and f in the four-electric heating furnace, thereby preventing energization failures caused by wire runout. Furthermore, as a third means.

As shown in Figure 4, the supply area between the power supply rollers is %P2.
Contact stability is achieved by adjusting the fence so that Pl>P2 for Pl>P2, and quickly burning off the lubricant on the wire surface that prevents the 4111 property between the power supply rollers C and improving the familiarity between the power supply roller B and the wire W. In other words, in the energization heating process, the electric current fi1 is the electric current in the direction of the feed roller b at the feed roller b! . Since the current flowing through the power supply roller B is divided into the current il in the direction of the power supply roller C, the current flowing through the power supply roller B is the largest, and sparks are most likely to occur in the row 96 portion. If it is possible to suppress the sparks in the entire electric heating system (a), then the sparks in the entire electric heating system can be substantially eliminated.In this way, in the present invention, the above three spark prevention measures and y
By taking this precaution, one current heating can be performed more stably and efficiently.

The present invention is roughly constructed as described above, and since the heat treatment after wire drawing is performed using Joule heat by energizing,
The process itself is made continuous, and the moisture content is completely and efficiently removed, and a flux-cored wire for ferritic stainless steel is produced that has excellent radiance and low water resistance. It happened

[Brief explanation of the drawing]

1st PA is a cross-sectional view of a solid wire, FIG. 2 is a cross-sectional diagram of a 7 lux wire, FIG. 3 is an explanatory diagram showing an embodiment of the present invention, @4 diagram is an explanatory diagram showing a preferred electrical heating method, SS- is a diagram illustrating a heat pattern of electrical heating, 1
Figure 6 is a graph showing the relationship between wire buckling strength and wire O tensile strength, Figure 7 is a graph showing the relationship between wire tensile strength and heat retention time, and Figure 8 is a graph showing the relationship between wire buckling strength and wire O tensile strength. It is a graph showing the influence on the aqueous content in the water. 1... Wire feed-out, 2... Straightener, 3...
211II tube for cooling, 4... Feeling of pulling, 5... Winding device, W... Wire, thorn, b, c... Current roller, d, @, f... Guide roller>~ Nanashima hard! Seven @ shouting eyes (-X) )! SeQ = Tadashi Sakai Ken ■ ＼

Claims (1)

[Claims] 11) Filling a ferritic stainless steel hoop with 7 lux to assemble a stainless steel-brox-cored wire, draw the flux-cored wire until it reaches one piece, and then pass it through a plurality of power supply rollers. The wire passing through the tube between the electrodes was heated to a temperature of SOO to 750 degrees Celsius.
08-Method for making stainless steel 447 rattuce wire by holding it for LO seconds and heating it with electricity to make it Jk4I mold.