JPS58179598A - Production of flux cored wire for stainless steel - Google Patents

Abstract

PURPOSE:To obtain a wire having high buckling strength, by conducting electricity to the wire and annealing the same for a prescribed time at a prescribed temp. thereby restoring the ductility of the flux cored wire which is hardened in a drawing stage and removing the impurities stuck on the surface efficiently. CONSTITUTION:A flux is packed in an austenitic stainless steel hoop, whereafter the hoop is drawn down to a product diameter. Such flux cored wires is passed through plural pieces of power feed rolls and electricity is conducted therein. The wire is then electrically annealed by holding the same for 0.05-2sec at 800-1,000 deg.C. The ductility of the wire hardened in the drawing stage is thus restored, the impurities stuck on the surface are removed and the wire having high buckling strength is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a flux-cored wire for stainless steel, and more specifically, to recover the ductility of a flux-cored wire that has been hardened during the wire drawing process, and to reduce the amount of oil and moisture attached to the surface. A method for efficiently manufacturing a 79-thick shear wire for stainless steel by efficiently removing it by electric annealing, having good feedability during bath welding, and giving a high-quality #welded metal.
M.

For shielding gas welding of stainless steel, generally solid wire as shown in Figure 1 or v wire with black wire as shown in Figure 2 is used, but the former has a bead
Oxidation on one side and x! Since there is @ during performance deterioration, etc., the places where it can be applied are limited. On the other hand, the latter does not have the above-mentioned disadvantages, and it also has the advantage of being able to manufacture multi-purpose oak wires by using the hair-sharpening process of Futsukus MA, so it can be used differently depending on the type of base material, etc. .

By the way, these wires are sent from the wire reel through the straightening rope and feeding lobe into the conduit tube, and then energized at the MW tip to prevent arcing between them and the base metal before being fed to the welding part. (However, in order to stabilize f# contact spinning and produce high quality #weld metal, the wire must always be fed at a constant speed. To do this, the wire drawing process is necessary. In addition to restoring the ductility of the hardened wire and making it easier to straighten the wire, it also removes the oil and fat on the wire surface (mainly IIIl-lI agent), which causes slippage.
It is necessary to completely remove water and moisture with the final finish J9Wi. In particular, flux-cored shear wire has slightly lower rigidity than solid wire, and it is difficult to completely remove oil and fat that has adhered to the wire, so problems often arise due to poor feeding. It has occurred.

In order to deal with such problems, a method has been used in which the drawn flux-cored shear wire is heat treated to restore the ductility of the casing Ving through an annealing effect and to burn off oil and fat. There are two types of heat treatment methods available: the batch method and the strand method, and the batch method is currently the mainstream. In this method, wires are bundled into a coil V shape, charged into a heating furnace, and heated in an electric current in an inert gas atmosphere for several hours to several tens of hours. Because it is sufficient, there is a difference in the degree of contact with the atmospheric gas, making it easy to meet. Therefore, the quality of the flux may change locally, or the bulk of the oil and fat in the wire overlap portions becomes legs, and this is Mf! There is also the problem that it mixes into the 1-coupled material and causes f# cracks. Moreover, in the batch type, the temperature inside the furnace is not necessarily uniform, so the annealing effect is uneven, and the tensile strength is likely to vary, and cracks are likely to form.Additionally, bending due to the end handle occurs, so the exit part of the feed roller is used for entertainment. It has also been pointed out that the wire buckles at the bottom.

The 10,000 strand type is a method in which the wire is inserted into the pipe and heated indirectly, so the thermal effect is poor (productivity is extremely reduced).

The present inventors focused on the above-mentioned Kenji, and the above-mentioned
The present invention was completely defeated as a result of such research, and its composition was as follows: In order to manufacture a shear wire containing a hoop for stainless steel painting by filling flux into an austenite thread stainless steel hoop and then processing it into a wire, after drawing the flux shear wire to the product diameter, The gist is that current is passed through the lobe and the wire passing between the electrodes is held at 800 to 1000° C. for 0.05 to 2.θ seconds to conduct current annealing.

In the present invention, an electric heating method is used to heat the flux-cored shear wire, and this is necessary by heating the wire by heating it by electric current by making it contact with a power supply roller while running in the axial direction of the wire. Since it can be heated continuously in an extremely short period of several seconds, productivity is high. Moreover, since the wire is heated uniformly while running in the axial direction, a high-quality product wire can be obtained without local heating or bending.

FIG. 8 is a conceptual diagram showing an embodiment of the present invention, and shows a WO heat treatment process for a flux shear wire drawn to a product diameter t. That is, the processing equipment includes a wire feeding section A, a heat treatment section tn
It consists of part 1 B1 wire take-up part C, and feeding part A.
Then, the wire W pulled out from the feeding ml is the straightener 2.
After that, it is led to heat treatment 11B.

The heat treatment section B is divided into a feeding section B1 and a cooling section 2, and there are three feeding rollers a, b, and c, and three guide rollers d% al f for suppressing wire runout, and the method shown in Fig. 5g4. Powered by The number and arrangement of ceramic power supply lobes and guide rollers, voltage a11 flow adjustment during energization heating, etc. can be set in the notice according to the composition and diameter of the wire W (hoop and 7 lux). In the example shown in FIG. 4, the power supplied between power supply rollers a and b and between b and c is
, P2 - by warning si, wire WO heat g & bu IM
You can control the degree. Cooling part B2 has 2
The heavy pipe 8 is arranged so that the wire W passing through the inner pipe is cooled by flowing cold water to the outer pipe side, so that the temperature of the wire W at the exit part becomes below FJaoo°C. 2. Set the length and inner diameter of the electric tube 8. However, the cooling method itself is of course not limited to this; any method may be used as long as it is a sand-blowing method, such as an air cooling method.

The cooled wire W is sent to the argument section CK and is taken up at the receiving section 4.
The film is then wound onto a winder 4115.

The heat pattern in the above heat treatment process is, for example, as shown in FIG.
Zeng is suitable for twisting or evaporating these depending on the noodles and adhesion neck, etc., such as Omagari fat that adheres to the wire surface. Adjustments may be made so that uniform heating conditions can be obtained.

By the way, the present inventors investigated the feed resistance during gas-shielded arc welding using a flux-cored wire using an austenitic stainless steel hoop. It is recommended to design 749 strength based on this. Also 7
The relationship between the tensile strength and buckling strength of Otsutas filled shear wire is shown in the sixth
- If the wire tensile strength becomes less than 45 tow, the buckling retention of the welding wire will fall below the maximum resistance (approximately 8.0 kg' above), causing buckling, etc. It can be seen that feeding defects are more likely to occur. Figure 7 shows the effect of heating holding time on the wire tensile strength in each type of energized heating knitting.As the M degree increases, the tensile strength sharply decreases even when held for a short time. Because it drops to seven! I'm having trouble adjusting.

Therefore, in order to stably obtain a tensile strength of 46 kg/Ilj or more, it is necessary to set the electric heating temperature of the wire to 1000° C. or less and the heat retention time to 2.0 seconds or less.

On the other hand, the present inventor has discovered that when the tensile strength of the shear wire with blacks exceeds 116 kg/-, the wire
It can be confirmed that it is easy to cause disintegration at the / part and cause poor feeding. Looking at Figure 7 from this perspective, in order to make the tensile strength less than 120 kg/let, the heating temperature It is understood that it is extremely hot when the temperature is 800°C or more and the holding time is 0.05 seconds or more.

That is, the tort pattern during electrical heating in the present invention is not particularly limited as described above, but from the viewpoint of tensile strength to reach the buckling strength KM of the wire, the upper limits of the heat retention temperature and heat retention time are 1000°C and 2.0°C, respectively. On the other hand, the lower limits of the heat retention temperature and time are limited to 800° C. and 0.06 seconds, respectively, from the viewpoint of the amount of hydrogen that is directly linked to hot spots. In other words, the energization heating conditions are the above preferred/1! By setting the temperature and time, high quality shear wire for austenitic stainless steel can be stably produced.

Furthermore, Figure 1g8 shows hydrogen II derived from the #4 beak oil and water in the wire depending on the heat retention time and heat retention/ai degree of the wire.
It is an experimental result graph showing a situation where k changes.

The amount of water in the wire is closely related to welding defects such as blowholes and pinholes.
It is said that exceeding the above-mentioned welding defects is likely to occur if the hydrogen content exceeds pm Vt, but within the range of temperature and holding time of the high current annealing mentioned above, the above hydrogen amount is 100 pm.
The following shows that υ, the amount of hydrogen, is not a problem.

The basic principle of the present invention is the above-mentioned energization, but the quality of the flux-cored wire is J! In order to improve this, it is important to take measures that take into account the following problems. In other words, flux-cored wire is as shown in Figure 2 (because it has seams, it tends to twist during the wire drawing process, and its straightness is worse than that of solid wire. Also, it has to be wetted before heat treatment).
Cleaning is sometimes performed to roughly remove the lil' fat, but since it is not possible to thoroughly remove the grout that has entered the joint of the hoop, conductive Bad lubricant, etc. adheres to the power supply rope and accumulates. Then, the sudden contact between the power supply rope and the wire causes sparks, causing spark flaws on the wire surface, which can even lead to wire breakage. The constant V feed is obstructed, causing the arc length to fluctuate, causing f# large defects such as blowholes, and sometimes leading to failure in feed.

However, the above problems can be easily solved by the following steps.

That is, as a first measure against sparks, as shown in Fig. 2, a straightener 2 is placed in front of the energization heating section, and the wire W is twisted and the large crookedness caused by the bobbin is corrected. The straightness of the wire in the furnace is improved, and lubricant at the wire seam is removed as much as possible by inserting slippery members inside the straightener 2, thereby suppressing energization failures. As a second means, guide rollers d%e%f in the energized heating furnace are used to prevent twisting runout during high-speed operation, thereby preventing energization failures caused by wire runout. I! As the eighth means.

As shown in FIG. 4, tlO<supply power Pi between feeding lobes.

Adjust so that PgK and Pl)Pg, and quickly burn out the lubricant on the wire surface that prevents the four-electrity between the power supply rollers a and b, and improve the compatibility between the power supply row 9b and the wire W. Improve the quality of the class Tsumugi woman. That is, in the energization heating process, the current 1 is divided into the current 5Iti □ in the direction of the power supply row 9b and the current i1 in the direction of the power supply roller C, and the current flowing through the power supply row 9b is the largest ( , since sparks are most likely to occur at roller bs,
If sparks in the power supply row 55 can be suppressed by the above means, sparks in the entire electrical heating system can be substantially eliminated. In the present invention, by taking the above-mentioned eight spark prevention measures, electric heating can be performed more stably and efficiently.

The present invention is roughly constructed as described above, and the heat treatment after wire drawing is carried out using Jo-V heat by energizing.
Skaisan itself is made continuous, lubricating oil etc. are almost completely and efficiently removed, and the buckling strength is increased to 2k1.
We have succeeded in producing a blacks-containing shear wire for stainless steel with ausbunite yarn having a low m content.

4. Figure 1 is a cross-sectional view of a solid wire, Figure 2 is a cross-sectional view of a flat shear wire, and Figure 8 is a cross-sectional view of an embodiment of the present invention. Figure 4 shows the preferred electrification heating method.
Figure 6 is a diagram illustrating the heat pattern of electrical annealing.
The figure is a graph showing the relationship between the buckling strength of the wire and the tensile strength of the wire, and the 8g7 figure is a graph showing the relationship between the tensile strength of the wire and the heat retention time. FIG. 8 is a graph showing the heat retention time and the influence of the heat retention time on the hydrogen content in the wire.

1... Wire feeding pipe 2... Straightener 3... Double tube for cooling 4... Tensile wire 5... Winding device W... Wire "sb*"...・Electrification row a9
Tun e, f...Guide roller applicant Kobe Steel, Ltd.

Claims (1)

[Claims] 11) Filling an austenitic stainless steel hoop with blanks and then drawing them to produce blacks-filled shear wire for stainless steel painting. Electricity is passed through the power supply roller, and the wire passing between the electrodes is 80θ to 10
JIIla method for 7-lux shear wire for stainless steel, characterized by carrying out electrical annealing while holding at 00°C for 0.05 to 2.0 seconds.