WO2015146466A1 - Steel wire rod having coating film that has excellent corrosion resistance and workability and method for producing same - Google Patents

Abstract

The present invention provides: a steel wire rod having a lubricating coating film, which is capable of achieving a good balance between workability such as wire drawability, spiking properties and ball ironing properties and corrosion resistance such as long-term rust prevention properties; and a method for producing this steel wire rod. A steel wire rod having a coating film that does not contain phosphorus, which is characterized in that the coating film is composed of, sequentially from the steel wire rod side, a lower coating film that is formed of a zirconium oxide and/or a zirconium hydroxide and has a film thickness of 1-200 nm and an upper coating film that contains silicon and tungsten so that the tungsten/silicon mass ratio is within the range of 1.3-18. A method for producing this steel wire rod, which is characterized in that the lower coating film is formed by bringing an aqueous chemical conversion liquid into contact with the surface of the steel wire rod, said chemical conversion liquid having a pH within the range of 2.5-5.0 and being obtained by dissolving a water-soluble zirconium compound.

Description

Steel wire having a film excellent in corrosion resistance and workability and method for producing the same

The present invention relates to a steel wire having a film containing no phosphorus on its surface and a method for producing the same.

In plastic processing of steel wires and steel wires, friction generated when metal surfaces (especially dies and workpieces) rub against each other violently increases processing energy, generates heat, and causes seizure. Various targeted lubricants have been used. Oil and soap have been used for a long time as lubricants, and by supplying them to the friction surface, the frictional force has been reduced as a fluid lubrication film, but plasticity that slides under high surface pressure with large heat generation due to surface area expansion In processing, seizure phenomenon is likely to occur due to lack of lubricity or running out of the lubricating film. For this reason, borate films, phosphate crystal films, etc. that have sufficient film strength and that are less likely to cause lubrication film breakage due to being present at the interface between the die and the workpiece even under high surface pressure, and avoid direct contact between metals A technique of previously coating a metal material surface with a solid film such as an inorganic film is commonly used. In particular, a composite film composed of a zinc phosphate film and a soap layer (hereinafter sometimes referred to as a chemical conversion film) has high processability and corrosion resistance and is widely used.

On the other hand, in recent years, the processing energy has been further reduced, the degree of processing has been increased, difficult-to-process materials can be handled, and the environmental protection of the coating process (for example, phosphating has caused a large amount of industrial waste such as sludge. There is a problem in terms of maintenance), and immersion of phosphorus such as bolts (if phosphorus of the coating component remains after header processing of high-strength bolts, phosphorus enters the steel during heat treatment and causes brittle fracture). The demands are increasing rapidly in various fields, and while considering environmental protection for these demands, solid coatings having high lubricity are being developed. This technique is to form a film having high lubricity by a simple process of applying a water-based plastic processing lubricant to the surface of a workpiece and drying it.

Patent Document 1 discloses a composition in which (A) a water-soluble inorganic salt and (B) wax are dissolved or dispersed in water, and the solid content weight ratio (B) / (A) is in the range of 0.3 to 1.5. An aqueous lubricating film treating agent for plastic working of metal materials and a method for forming the film are disclosed.

Patent Document 2 discloses an aqueous lubricant film treatment agent containing an alkali metal borate (A), wherein the alkali metal borate (A) contains lithium borate, The molar ratio of lithium to alkali metal is 0.1 to 1.0, and the molar ratio (B / M) of boric acid B to alkali metal M of the alkali metal borate (A) is 1.5. An aqueous lubricating film treating agent for plastic working of metal materials and a method for forming the film are disclosed. This technique can form a film having not only workability but also high corrosion resistance by suppressing the crystallization of the film that occurs when the film absorbs moisture.

Patent Document 3 contains an A component: an inorganic solid lubricant, a B component: a wax, and a C component: a water-soluble inorganic metal salt, and a solid content mass ratio between the A component and the B component (A component / B component). ) Is 0.1 to 5, and the solid content mass ratio of the C component to the total amount of the A component, the B component, and the C component (C component / (A component + B component + C component)) is 1 to 30% A water-soluble lubricant for non-phosphorous plastic working is disclosed. This technique is a lubricant that does not contain phosphorus, and is said to be able to realize corrosion resistance equivalent to that of a chemical conversion coating.

Patent Document 4 contains a water-soluble inorganic salt (A), one or more lubricants (B) selected from molybdenum disulfide and graphite, and a wax (C), and these are dissolved in water or Aqueous lubrication in which (B) / (A) is 1.0 to 5.0 in terms of solids weight ratio and (C) / (A) is in the range of 0.1 to 1.0 in terms of solids weight ratio A film treatment agent and a method for forming the film are disclosed. In this technology, high workability equivalent to that of a chemical conversion coating can be realized by blending molybdenum disulfide or graphite with a conventional water-based lubricant coating.

Patent Document 5 discloses silicate (A), polycarboxylate (B), water-compatible polymer and / or water-compatible organic lamellar structure (C), molybdate and / or tungstate. (D) and the film formation agent whose mass ratio of each said component is a predetermined | prescribed ratio is disclosed.

As described in Patent Documents 1 to 5, a water-soluble inorganic salt is an essential component of a solid film of a water-based lubricating film treatment agent. The reason is that a lubricating film composed of a water-soluble inorganic salt has a sufficient film strength, and as described above, it is difficult to cause the lubricating film to break by intervening at the interface between the die and the workpiece even under high surface pressure. This is because direct contact can be avoided. Therefore, in the case of a water-based lubricating film treatment agent, a good lubricating state can be maintained during plastic processing by combining a solid film made of a water-soluble inorganic salt or a water-soluble resin with an appropriate lubricant capable of reducing the friction coefficient.

The film formation mechanism of the water-based lubricating film composed of water-soluble components will be described. The water-soluble inorganic salt of the water-soluble component is in a state of being dissolved in water in the lubricant treatment liquid. When the lubricant is applied to the surface of the metal material and dried, the solvent water evaporates to form a lubricating film. At that time, the water-soluble inorganic salt is deposited as a solid on the surface of the metal material to form a solid film. The solid coating formed in this way has a coating strength that can withstand plastic processing, and exhibits good lubricity during plastic processing by incorporating an appropriate lubricant that reduces the friction coefficient.

International Publication No. 02/012420 JP 2011-246684 A JP 2013-209625 A International Publication No. 02/012419 JP 2002-363593 A

However, the lubricating coatings of Patent Documents 1 to 5 are significantly inferior in long-term rust prevention for 4 months or more as compared with the chemical conversion coating described above, and cannot be increased to a practical level. This is because the main component of the film is a water-soluble component, so that moisture in the atmosphere can be easily absorbed or permeated, and the steel material can easily come into contact with moisture. In Patent Document 2, although corrosion resistance is improved by suppressing crystallization of the film due to moisture absorption, moisture absorption itself is not suppressed, and sufficient corrosion resistance is not obtained. Moreover, it is described that the water-based lubricating film described in Patent Document 3 exhibited a corrosion resistance equivalent to or higher than that of the chemical conversion coating film in a corrosion resistance test in a laboratory in which rusting was accelerated using a thermo-hygrostat. However, the actual environment in which the lubricant film is used is usually in a state where dust, dust, and pickling chemical mist can adhere, and in such a harsh environment, the corrosion resistance is better than the chemical conversion film. The actual situation is inferior. As described above, there has been no water-based lubricating film that does not contain phosphorus that has a rust prevention property equal to or higher than that of the chemical conversion film.

Also, the non-uniformity of the film is mentioned as a point where the water-based lubricating film is inferior to the chemical conversion film. For example, when a wire coil is processed by a batch method, if there is a portion where the wires overlap each other or a binding portion, the coating treatment liquid does not reach the portion, and the coating becomes thin. Since the thickness of the film has a significant effect on the corrosion resistance, for example, a phenomenon is observed in which rust starts to be generated from the coil binding site. The decrease in corrosion resistance due to the non-uniformity of the film is a big problem for the conventional water-based lubricating film.

Examples of water-soluble inorganic salts that can provide relatively high corrosion resistance include alkali metal salts of silicates (hereinafter sometimes referred to as silicates), alkali metal salts of tungstates and / or ammonium salts (hereinafter referred to as May be described as tungstate). These water-soluble inorganic salts are also described in Patent Document 1, Patent Document 4 and Patent Document 5. However, they are also inferior in practical corrosion resistance compared to the chemical conversion coating.

Water-soluble silicate has a property that it hardly permeates moisture in water-soluble inorganic salt and has very high adhesion to the material. Because of this property, it is a material that can exhibit relatively high corrosion resistance, although not as much as the chemical conversion coating. This is because the water-soluble silicate is crosslinked and forms a network structure in the process of forming a film in which water as a solvent of the lubricant volatilizes. However, because of this network structure, the water-soluble silicate film is too brittle as a lubricating film. For this reason, when a base material is processed, a film | membrane may crack and it may not fully follow. In addition, due to the network structure, the adhesiveness is too high, film removal failure may occur, and various problems may be caused in subsequent processes. For example, in the case where plating is performed in a subsequent process, not only does the film component enter and contaminates the plating solution, but also causes defective plating in the portion where the film component remains.

In addition, water-soluble tungstate does not easily absorb moisture from the outside air when a film is formed. This is because when the water-soluble tungstate forms a film, it forms particulate crystals. Furthermore, water-soluble tungstate has the property of forming a passive film having a self-repairing function on the metal surface, and it can be expected to form a highly corrosion-resistant film by using it as a film component. Moreover, since water solubility itself is high, it can be easily removed with an aqueous solution. However, since the water-soluble tungstate is crystalline, it has poor adhesion to the material and cannot form a uniform film, so that the expected corrosion resistance and workability cannot be obtained. For example, the adhesion and uniformity of the film can be improved by adding a synthetic resin component to the lubricant, but the corrosion resistance is still inferior to that of the chemical conversion film.

In addition, the water-based lubricating film treatment agents containing water-soluble inorganic salts described in Patent Documents 1 to 3 have in common poor processability compared to the chemical conversion film. This is particularly noticeable in severe processing where the surface area expansion ratio is several tens of times (hereinafter sometimes referred to as “strong processing”), such as insufficient deformation of the material, reduction in mold life, and seizure. Occur.

The water-based lubricating film treating agent described in Patent Document 4 contains molybdenum disulfide and graphite, so that it is possible to obtain a workability equivalent to or higher than that of the chemical conversion film even during strong working. However, when these components are blended, the color of the lubricating liquid becomes black, and the apparatus, its surroundings and workers are significantly contaminated. Molybdenum disulfide and graphite are liable to settle, and over time, they may harden at the bottom of the treatment tank and become difficult to redisperse, making stable operation difficult. Furthermore, these two components are factors that greatly reduce the corrosion resistance, and the corrosion resistance is inferior to that of the lubricating film of Patent Documents 1 to 3 as well as the chemical conversion coating.

In Patent Document 5, a coating material containing silicate (A) as a main component and containing too much corrosion-resistant agent (D) or the like has seizure when the extrusion load is high. Since it is inferior, stable work becomes difficult, and long-term rust prevention is not sufficient.

Thus, the water-based lubricating film could not form a film having both high corrosion resistance over a long period of about 4 months or more and workability at the time of strong processing, comparable to the chemical conversion film even in a practical environment. In particular, with respect to corrosion resistance, since the film tends to be non-uniform, rusting from the thin film portion becomes a problem. Further, when the silicate is contained in the water-based lubricating film treating agent, defective film removal becomes a problem.

Accordingly, the present invention provides a steel wire having a lubricating film capable of achieving both workability such as wire drawing, spikeability, ball ironing, and corrosion resistance such as long-term rust prevention, and a method for producing the same. It was raised as an issue.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that if a later-described upper layer film and lower layer film are formed on a steel wire as a lubricating film, both workability and corrosion resistance can be achieved. It is. Specifically, a film made of zirconium oxide and / or hydroxide is formed as the lower layer film, and a specific ratio of silicate and tungstate, that is, a mass ratio of tungsten / silicon is set as a predetermined ratio. It was found that by forming a composite upper film, high corrosion resistance and workability that could never be achieved with these components alone were obtained.

The present invention is configured as follows to solve the above-mentioned problems.

The steel wire rod of the present invention is a steel wire rod having a coating containing no phosphorus, and the coating is made of zirconium oxide and / or hydroxide in order from the steel wire side, and has a film thickness of 1.0 to It is summarized in that it includes a lower layer film having a thickness of 200 nm and an upper layer film including silicon and tungsten and having a mass ratio of tungsten / silicon of 1.3 to 18.

It is preferable that the silicon is derived from a water-soluble silicate and the tungsten is derived from a water-soluble tungstate.

The silicon is derived from at least one selected from lithium silicate, sodium silicate, and potassium silicate, and the tungsten is at least selected from lithium tungstate, sodium tungstate, potassium tungstate, and ammonium tungstate. It is preferably derived from one or more.

It is preferable that the upper layer film contains a resin and the mass ratio of resin / (silicon + tungsten) is 0.01 to 3.2.

The resin is preferably at least one selected from vinyl resins, acrylic resins, epoxy resins, urethane resins, phenol resins, cellulose derivatives, polymaleic acid, and polyester resins.

It is preferable that the upper layer film contains a lubricant, and the mass ratio of the lubricant / (silicon + tungsten) is 0.01 to 3.2.

The lubricant is preferably at least one selected from wax, polytetrafluoroethylene, fatty acid soap, fatty acid metal soap, fatty acid amide, molybdenum disulfide, tungsten disulfide, graphite, and melamine cyanurate.

The film mass per unit area of the upper film is preferably 1.0 to 20 g / m ² .

The method for producing a steel wire according to the present invention is that the lower layer film is formed by bringing a water-based chemical conversion solution in which a water-soluble zirconium compound is dissolved into contact with the surface of a steel wire in the range of pH 2.5 to 5.0. Have

In the steel wire of the present invention, since the lubricating film including the upper layer film and the lower layer film is configured as described above, it has excellent workability such as wire drawability, spike property, ball ironing property, and corrosion resistance such as long-term rust prevention property. Steel wire rod is obtained. In addition, their performance is superior to that of a conventional water-based lubricant film in that all of the performance is equal to or higher than that of a steel wire having a chemical conversion coating. In particular, it is a feature that the conventional water-based lubricating film does not have in that high corrosion resistance can be obtained even when the water-based lubricating film becomes thin due to external factors such as overlapping or binding of materials.

The present invention relates to a steel wire having a film containing no phosphorus, wherein the film is composed of an oxide and / or hydroxide of zirconium in order from the steel wire side, and has a thickness of 1 to 200 nm. And a steel wire material comprising an upper film containing silicon and tungsten and having a tungsten / silicon mass ratio in the range of 1.3-18.

In the present invention, the steel used for the steel wire includes carbon steel, alloy steel, special steel and the like. As such steel, carbon steel having a carbon content of 0.2% by mass or less (excluding 0% by mass) to carbon steel having a carbon content of more than 0.2% by mass and not more than 1.5% by mass, and depending on the use of carbon steel Alloy steel or special steel containing at least one selected from silicon, manganese, phosphorus, sulfur, nickel, chromium, copper, aluminum, molybdenum, vanadium, cobalt, titanium, zircon and the like. In the present invention, the steel wire generally refers to steel processed into a wire by hot working. The steel wire material of the present invention includes a steel wire. With steel wire, steel wire was further processed, such as steel wire drawn to a specified size (wire diameter, roundness, etc.), steel wire or drawn steel wire plated, etc. Say things.

The steel wire of the present invention comprises at least two layers of a lubricating film, that is, a lower layer film and an upper layer film in order from the surface of the steel wire. Each of the upper layer film and the lower layer film may be a single layer or two or more layers. Further, if necessary, further layers may be formed on the upper film, between the upper film and the lower film, and between the steel wire and the lower film.
None of the coatings contains phosphorus, and the composition used for forming the coating does not contain a component containing phosphorus. However, in the present invention, it is not excluded that a component containing phosphorus is inevitably mixed in the coating on the surface of the steel wire in the operation process or the like. That is, even if phosphorus is contaminated as an inevitable impurity in actual operation, if phosphorus is contained in an amount of about 1% by mass or less, it is unlikely that the steel wire will be brittlely broken by such phosphorus. It can be assumed that phosphorus does not occur.

Hereinafter, each component, composition, etc. of the lubricating film in the steel wire according to the present invention will be described in order.

The upper layer film should contain silicon and tungsten, and the film should have a tungsten / silicon mass ratio in the range of 1.3-18. By containing in this range, it is possible to form a film having high corrosion resistance, workability and sufficient adhesion, which could not be achieved with silicate or tungstate alone or other water-soluble inorganic salts described later.

For example, when a water-soluble silicate and a water-soluble tungstate described later are combined to form a film, the tungstate is taken into the network structure formed by the silicate. As described above, the disadvantage of the tungstate is largely due to the formation of a crystalline film, but the tungstate can be present uniformly and finely by being incorporated into the silicate network structure. become able to. As a result, the properties of the silicate that hardly permeate moisture and the passive film having the self-repairing function of the tungstate are compatible, and the corrosion resistance is remarkably improved.

Further, as an influence of the tungstate on the silicate, an improvement in film removal property can be mentioned. As described above, the cause of poor processability and film removal of the silicate is due to the formation of a strong continuous film by polymerizing the silicate. Is moderately hindered from forming a strong network structure and can improve processability and film removal properties.

The mass ratio of tungsten / silicon is 1.3 or more, preferably 1.8 or more, more preferably 2.0 or more. The mass ratio is 18 or less, preferably 10 or less, more preferably 5.4 or less.
When the mass ratio of tungsten / silicon is less than 1.3, sufficient corrosion resistance and workability cannot be obtained, and a film having poor film removal properties is obtained. This is because the amount of the tungstate is relatively reduced, the passive film is not sufficiently formed, and the amount of the silicate is relatively increased to form a strong network structure. To do. When the mass ratio of tungsten / silicon exceeds 18, a film in which sufficient corrosion resistance and workability cannot be obtained. This is due to the fact that the amount of silicate becomes relatively small and moisture can easily permeate, the crystals of the tungstate precipitate, and the adhesion and uniformity of the film are lowered. In the present invention, the mass ratio of tungsten / silicon is preferably based on the ratio of the tungsten element derived from the water-soluble tungstate and the silicon element derived from the water-soluble silicate in the film. It can be calculated as follows.

The lower layer film is made of zirconium oxide and / or hydroxide, preferably zirconium oxide. In the present invention, the lower layer film may be referred to as a zirconium film.
The film thickness of the lower layer film is 1.0 nm or more, preferably 5 nm or more, more preferably 20 nm or more. The film thickness is 200 nm or less, preferably 150 nm or less, more preferably 130 nm or less. When the film thickness is less than 1.0 nm, the zirconium film becomes too thin and sufficient corrosion resistance cannot be exhibited. On the other hand, when the film thickness is larger than 200 nm, there is no influence on the corrosion resistance, but the adhesion failure of the film occurs and the workability is lowered.

Thus, the corrosion resistance can be improved by forming the zirconium film. This is because the addition of a zirconium film as a lower layer film changes the network structure of the silicate by the zirconium film and strengthens the bond. By improving. In addition, since the zirconium film is much thinner than the upper film, it is easy to form a uniform film even in a place where a normal water-based lubricating film tends to be a thin film, which leads to improvement in corrosion resistance. Further, as described above, the network structure of the upper layer film and the bond strengthened portion of the zirconium film are important for improving the corrosion resistance, so that it is hardly affected by the film thickness of the entire upper layer film. Therefore, the corrosion resistance can be sufficiently exhibited even at a location where the water-based lubricating film as described above tends to be a thin film. A single zirconium film causes defects in the film and becomes a failure because it becomes a starting point of corrosion and processing performance cannot be obtained.

Thus, by combining the silicate and tungstate films and the zirconium film in this way, it is possible to realize high workability that could not be achieved in the past and high corrosion resistance in a practical environment.

In the present invention, it is preferable that the silicon is derived from a water-soluble silicate and the tungsten is derived from a water-soluble tungstate.

Examples of the water-soluble silicate include sodium silicate, potassium silicate, lithium silicate, and ammonium silicate. These may be used alone or in combination of two or more.

Examples of the water-soluble tungstate include sodium tungstate, potassium tungstate, lithium tungstate, and ammonium tungstate. These may be used alone or in combination of two or more.

Examples of the zirconium supply source in the coating agent for forming a zirconium film according to the present invention include zirconium sulfate, zirconium oxysulfate, ammonium zirconium sulfate, zirconium nitrate, zirconium oxynitrate, ammonium zirconium nitrate, zirconium acetate, zirconium lactate, and chloride. Zirconium, fluorozirconic acid, fluorozirconium complex salt and the like can be mentioned. These may be used alone or in combination of two or more.

Next, the resin will be described. The resin is blended in the upper layer film for the purpose of binder action, improvement of adhesion between the substrate and the film, imparting leveling property by thickening action, and stabilization of the dispersed component.
Examples of resins having such functions and properties include vinyl resins, acrylic resins, epoxy resins, urethane resins, phenol resins, cellulose derivatives, polymaleic acid, and polyester resins. These may be used alone or in combination of two or more.

In the present invention, the upper layer film contains a resin, and the mass ratio of resin / (silicon + tungsten) is preferably 0.01 or more, more preferably 0.1 or more. The mass ratio is preferably 3.2 or less, more preferably 2.1 or less. If it is less than 0.01, the above-mentioned action is not sufficiently exerted, and if it exceeds 3.2, the amounts of silicon and tungsten are relatively reduced, and the high corrosion resistance and workability characteristic of the present invention are exhibited. become unable.

Next, the lubricant will be described. The lubricant itself is slippery and has a function of reducing the frictional force. In general, when the frictional force increases during plastic processing, processing energy increases, heat generation, seizure, etc. occur.However, when a lubricant is included in the upper layer coating of the steel wire of the present invention, it exists in a solid form in the lubricating coating. An increase in frictional force is suppressed. Examples of the lubricant having such functions and properties include wax, polytetrafluoroethylene, fatty acid soap, fatty acid metal soap, fatty acid amide, molybdenum disulfide, tungsten disulfide, graphite, and melamine cyanurate. These may be used alone or in combination of two or more.

Specific examples of the wax include polyethylene wax, paraffin wax, microcrystalline wax, polypropylene wax, and carnauba wax. Specific examples of the fatty acid soap include sodium myristate, potassium myristate, sodium palmitate, potassium palmitate, sodium stearate, and potassium stearate. Specific examples of the fatty acid metal soap include calcium stearate, zinc stearate, barium stearate, magnesium stearate, and lithium stearate. The fatty acid amide is, for example, an amide compound having two fatty acids. Specific examples thereof include ethylene bislauric acid amide, ethylene bis stearic acid amide, ethylene bisbehenic acid amide, N, N′-distearyl adipic acid amide, ethylene bis oleic acid. Amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N, N′-dioleyl adipic acid amide.

In the present invention, the upper layer film contains a lubricant, and the mass ratio of lubricant / (silicon + tungsten) is preferably 0.01 or more, more preferably 0.1 or more, and the mass ratio is 3. It is preferably 2 or less, more preferably 2.1 or less. Here, if the mass ratio of the lubricant / (silicon + tungsten) is less than 0.01, the above performance cannot be exhibited because the lubricant is too small. When it exceeds 3.2, the amounts of silicon and tungsten are relatively small, and the high corrosion resistance and workability that are the characteristics of the present invention cannot be expressed.

In addition to silicon, tungsten, resin, and lubricant, the upper layer film of the steel wire rod of the present invention is intended to impart leveling and thixotropy to ensure a uniform coating state when a lubricant treatment liquid is applied to a substrate. A viscosity modifier can be blended. Specific examples of such viscosity modifiers include smectite clay minerals such as montmorillonite, saconite, beidellite, hectorite, nontronite, saponite, iron saponite and stevensite, and inorganic thickening such as finely divided silica, bentonite and kaolin. Agents.

The upper film may contain an inorganic salt such as a sulfate or borate, or a water-soluble salt such as an organic salt in order to improve adhesion and workability. Examples of the sulfate include sodium sulfate and potassium sulfate. Examples of the borate include sodium metaborate, potassium metaborate, and ammonium metaborate.
Organic salts include formic acid, acetic acid, butyric acid, oxalic acid, succinic acid, lactic acid, ascorbic acid, tartaric acid, citric acid, malic acid, malonic acid, maleic acid, phthalic acid, etc., and alkali metals, alkaline earth metals, etc. Of the salt.

The film of the steel wire rod of the present invention can provide high corrosion resistance before and after processing, but may further contain other water-soluble rust preventives and inhibitors for the purpose of further improving the corrosion resistance. Specific examples include various organic acids such as oleic acid, dimer acid, tartaric acid and citric acid, various chelating agents such as EDTA, NTA, HEDTA and DTPA, mixed components of alkanolamine such as triethanolamine, and pt-butylbenzoic acid. Known amines such as carboxylic acid amine salts, dibasic acid amine salts, alkenyl succinic acid and water-soluble salts thereof, and aminotetrazole and water-soluble salts thereof can be used. These may be used alone or in combination of two or more.

The upper film treatment agent used in the present invention contains the water-soluble silicate and the water-soluble tungstate as essential components, and contains the resin, the lubricant, and the water-soluble salt as necessary.
The water-soluble silicate is preferably more than 5% by mass in 100% by mass of the upper layer film treating agent, more preferably 10% by mass or more, still more preferably 15% by mass or more, and 58% by mass or less. It is preferable that it is preferably 52% by mass or less, and more preferably 45% by mass or less.
The water-soluble tungstate is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and 91% by mass or less, in 100% by mass of the upper film treatment agent. It is preferable that the content is 85% by mass or less, more preferably 80% by mass or less.
When the amount of the water-soluble silicate is 5% by mass or less and the amount of the water-soluble tungstate is more than 91% by mass, sufficient long-term rust preventive property cannot be obtained, and wire drawing property and ball ironing property are obtained. The film is inferior. This is due to the fact that the amount of water-soluble silicate is relatively reduced, so that moisture easily permeates, and tungsten crystals are precipitated, resulting in a decrease in the adhesion and uniformity of the film.
When the amount of the water-soluble silicate is more than 58% by mass and the amount of the water-soluble tungstate is less than 10% by mass, a film with insufficient corrosion resistance and workability cannot be obtained. This is because a relatively thin passive film is not formed due to a relatively small amount of tungsten, and a strong network structure is formed due to a relatively large amount of water-soluble silicate.

The lower layer coating of the steel wire of the present invention can be used as a base lubricating coating for dry lubricants. By using it as an undercoat of a dry lubricant, the lubricity, seizure resistance, and corrosion resistance can be raised. The type of dry lubricant is not particularly limited, and general lubricating powders and wire drawing powders mainly composed of higher fatty acid soap, borax, lime, molybdenum disulfide, etc. can be used.

In the present invention, the liquid medium (solvent, dispersion medium) in the upper film treatment agent and the zirconium film treatment agent is water. The upper layer film treatment agent may be blended with alcohol having a boiling point lower than that of water in order to shorten the drying time of the lubricant in the drying step.

The upper layer film treatment agent may contain a water-soluble strong alkali component in order to increase the stability of the solution. Specific examples include lithium hydroxide, sodium hydroxide, and potassium hydroxide. These may be used alone or in combination of two or more. The blending amount of these is preferably 0.01 to 10% by mass relative to the total solid mass.

Next, a method for manufacturing a steel wire according to the present invention will be described. The method of the present invention includes a steel wire rod cleaning step, a manufacturing step of an upper layer coating agent and a lower layer coating agent (aqueous chemical conversion treatment liquid) as a water-based lubricating coating agent, and a drying step. Hereinafter, each step will be described.

<Cleaning process (pretreatment process)>
Before forming the film on the steel wire, it is preferable to perform at least one cleaning treatment selected from the group consisting of shot blasting, sand blasting, wet blasting, peeling, alkali degreasing and acid cleaning. The purpose of cleaning here is to remove oxide scales and various types of dirt (oil, etc.) grown by annealing or the like.

<Manufacturing process of zirconium film>
The lower layer film has a pH in the range of 2.5 to 5.0, and is formed by bringing an aqueous chemical conversion treatment solution in which a water-soluble zirconium compound is dissolved into contact with the surface of the steel wire. The aqueous chemical conversion treatment liquid only needs to contain the zirconium supply source. The pH is preferably 2.8 to 4.8, more preferably 3.1 to 4.6, and still more preferably 3.4 to 4.4. If the pH is less than 2.5, the etching becomes excessive, and not only the deposition efficiency of the film is lowered, but also the uniform formation of the film may be hindered. If the pH exceeds 5.0, the liquid stability is lowered, and a large amount of zirconium compound or sludge is precipitated, which may adversely affect the film formation.
The aqueous chemical conversion treatment liquid may be a commercially available zirconium chemical conversion treatment agent, and the zirconium concentration (by mass) is preferably 10 ppm or more, more preferably 30 ppm or more, preferably 500 ppm or less, more preferably 300 ppm. It is as follows.

In the present invention, the contact method for forming the zirconium film is not particularly limited, and examples thereof include spray treatment, immersion treatment, and pouring treatment. In order to promote the formation of a film, the temperature of the aqueous chemical conversion solution at the time of contact, that is, the treatment temperature is preferably 20 to 60 ° C., more preferably 30 to 50 ° C. The contact time depends on the material and structure of the steel wire, the concentration of the chemical conversion treatment liquid, and the treatment temperature, but is preferably about 2 to 600 seconds, and can be appropriately adjusted according to the coating amount. . It is preferable that a water washing step is provided after the chemical conversion treatment so that the aqueous chemical conversion treatment liquid adhering to the steel material is not brought into the upper layer film treatment liquid.

<Manufacturing process of upper film>
Next, an upper layer film is formed on the zirconium film obtained as described above. The step of applying the upper layer coating to the steel wire is not particularly limited, but application such as dipping, flow coating, and spraying can be used. The application is not limited as long as the surface is sufficiently covered with the upper film treatment agent as a water-based lubricating film treatment agent. At this time, in order to improve the drying property, the steel wire may be heated to 60 to 80 ° C. and brought into contact with the water-based lubricating film treating agent. Further, an aqueous lubricating film treating agent heated to 40 to 70 ° C. may be contacted. By these, drying property improves significantly and drying may be attained at normal temperature, and the loss of heat energy can also be reduced.

<Drying process>
Next, it is necessary to dry the upper layer film treating agent. Drying may be performed at room temperature, but may be performed at 60 to 150 ° C. for 1 to 30 minutes.

Here, the film mass of the upper film formed on the surface of the steel wire is appropriately controlled depending on the degree of subsequent processing, but the film mass is preferably 1.0 g / m ² or more, more preferably 2. It is 0 g / m ² or more, preferably 20 g / m ² or less, more preferably 15 g / m ² or less. When the film mass is small, the lubricity is insufficient. On the other hand, if the coating mass exceeds 20 g / m ² , there is no problem in lubricity, but clogging of the dies and the like are not preferable. The film mass can be calculated from the mass difference and surface area of the steel wire before and after the treatment. In order to control so that it may become the above-mentioned film | membrane mass range, solid content mass (concentration) of a water-system lubricating film processing agent is adjusted suitably. In practice, a high-concentration lubricant is often diluted with water and used in the treatment liquid. The water to be diluted is not particularly limited. For example, pure water, deionized water, tap water, ground water, industrial water, and the like can be used.

<Method of film removal>
In the present invention, the upper layer film can be removed by dipping in an aqueous alkaline cleaning agent or by spray cleaning. The alkaline detergent is a solution in which common alkaline components such as sodium hydroxide and potassium hydroxide are dissolved in water. When the upper layer film is brought into contact with this, the upper layer film dissolves in the cleaning solution, so that the film is easily removed. be able to. Moreover, it is a film that is easily removed by heat treatment after processing. Therefore, it is possible to prevent contamination and plating defects in the subsequent process due to defective film removal by alkali cleaning.

Next, a method for analyzing the film composition will be described.

As a method for analyzing the zirconium film, there is a method of directly observing the film thickness in cross-sectional SEM (Scanning Electron Microscope) observation or cross-sectional TEM (Transmission Electron Microscope) observation. At this time, in order to observe the cross section without damaging the film, a method of producing a cross section by CP (Cross-section Polisher) processing or FIB (Focused Ion Beam) processing is effective. As a simple method, a method of analyzing the zirconium film thickness on the steel material surface by fluorescent X-ray analysis (XRF: X-ray Fluorescence) can be mentioned. At this time, the upper layer film is preferably peeled off with an alkaline aqueous solution or the like. The measurement of the film thickness of the lower layer film is performed by randomly selecting three areas for measuring the film thickness on the surface of the steel material after the upper layer film is peeled off, and measuring the film thickness in all the selected areas. And let the average value of the thickness measured in the said 3 places be the film thickness of the base film of steel materials.

As an analysis method of the upper layer film composition, for example, a method using inductively coupled plasma (ICP: Inductively Coupled Plasma) can be mentioned. In this case, the film composition can be analyzed by dissolving the film on the steel material in a strong alkaline aqueous solution or the like and measuring the amount of dissolved silicon and tungsten by ICP.

Also, when it is difficult to dissolve the upper layer film, the film composition can also be analyzed by a method in which the amount of silicon and tungsten on the surface of the steel wire is directly analyzed by fluorescent X-ray analysis (XRF: X-ray Fluorescence).

Hereinafter, the case where the steel wire is used as a target will be described in more detail together with the effect of the present invention by giving examples together with comparative examples. In addition, this invention is not restrict | limited by these Examples. In the following, “part” means “part by mass” and “%” means “% by mass” unless otherwise specified.

(1-1) Production of Upper Layer Coating Agent and Lower Layer Coating Agent as Aqueous Lubricant Coating Agent Each of the following components was used in the combinations and proportions shown in Table 1 in Examples 1-12 and Comparative Examples 2-17. An upper layer coating agent and a lower layer coating agent were prepared as aqueous lubricant coating agents. In order to enhance the liquid stability, lithium hydroxide was added to the upper layer film treatment agents of Examples 1 to 12 and Comparative Examples 3 to 17 at a concentration of 1% in the liquid. In addition, Comparative Example 18 is a phosphate / soap treatment, and no wire drawing powder is used.

A. Upper layer coating agent <water-soluble silicate>
(A-1) Sodium metasilicate (A-2) No. 3 sodium silicate (Na ₂ O.nSiO ₂ n = 3)
(A-3) Lithium silicate (Li ₂ O.nSiO ₂ n = 3.5)
<Water-soluble tungstate>
(B-1) Ammonium tungstate (B-2) Sodium tungstate (B-3) Potassium tungstate <Resin>
(C-1) Polyvinyl alcohol (average molecular weight of about 50,000)
(C-2) Sodium neutralized salt of isobutylene / maleic anhydride copolymer (average molecular weight of about 165,000)
<Lubricant>
(D-1) Polyethylene wax (average particle size 5 μm)
(D-2) Ethylene bis stearic acid amide <water-soluble salt>
(E-1) Sodium metaborate (E-2) Sodium tartrate (E-3) Sodium sulfate (E-4) Sodium pyrophosphate Underlayer coating agent <zirconium underlayer coating>
(F) Zirconium chemical conversion treatment agent (Pulseed (registered trademark) 1500, manufactured by Nihon Parkerizing Co., Ltd.)
<Underlayer coating other than zirconium underlayer>
(G-1) No. ₂ sodium silicate (Na ₂ O.nSiO ₂ n = 2.5)
(G-2) Zinc phosphate

(1-2) Film analysis A test material having a diameter of 3.2 mm × 1 m subjected to the formation process of the lower layer film and the upper layer film was immersed in a 2% aqueous sodium hydroxide solution heated to 60 ° C. for 2 minutes to form the upper layer film. It peeled. Thereafter, the amounts of silicon and tungsten contained in the aqueous sodium hydroxide solution used for peeling were measured by inductively coupled plasma (ICP), and the mass ratio of tungsten / silicon was examined. Then, it was immersed in 2% sodium hydroxide aqueous solution heated at 60 degreeC for 2 minutes, and the excess upper film | membrane was peeled. The film thickness of the zirconium film was measured by performing fluorescent X-ray analysis (XRF) on the test material from which the upper layer coating was peeled off. The measured values are listed in Table 1. Moreover, the thickness of the lower layer film was measured by carrying out cross-sectional SEM analysis, and the film thickness was measured. In the film thickness measurement, the measurement of the film thickness of the lower layer film (that is, the zirconium film) is performed by randomly selecting three areas for measuring the film thickness on the surface of the steel material after peeling off the upper layer film. In all cases, the film thickness was measured. And the average value of the thickness measured in the said 3 places was made into the film thickness of the base film of steel materials.

(1-3) Film treatment The film treatment method is shown below. In addition, although the to-be-processed material is a steel wire rod of φ3.2 mm, in order to reproduce the thinning of the lubricating film in the binding portion, the processing was performed in a state of being bundled with a plastic binding band.

<Pretreatment and Film Treatment of Examples 1 to 12 and Comparative Examples 3 to 15>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: hydrochloric acid, concentration 17.5%, normal temperature, immersion 10 minutes (d) Washing: tap water, normal temperature, immersion 30 seconds (e) Lower layer coating treatment: Commercial zirconium chemical conversion treatment agent (Pulseed®) ) 1500, manufactured by Nihon Parkerizing Co., Ltd.) Concentration 50 g / L, temperature 45 ° C., pH 4.0 Immersion treatment Immersion time is appropriately adjusted according to the amount of film (f) Water washing: tap water, room temperature, immersion 30 seconds (g) Upper layer coating treatment: Upper layer coating agent prepared in (1-1), temperature 60 ° C., immersion 1 minute (h) drying: 100 ° C., 10 minutes

<Pretreatment and film treatment of Comparative Example 1>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: hydrochloric acid, concentration 17.5%, room temperature, immersion 10 minutes (d) Water washing: tap water, room temperature, immersion 30 seconds (e) pure water washing: deionized water, room temperature, immersion 30 ° C.
(F) Drying: 100 ° C., 10 minutes

<Pretreatment and film treatment of Comparative Example 2>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: hydrochloric acid, concentration 17.5%, normal temperature, immersion 10 minutes (d) Washing: tap water, normal temperature, immersion 30 seconds (e) Lower layer coating treatment: Commercial zirconium chemical conversion treatment agent (Pulseed®) ) 1500, manufactured by Nippon Parkerizing Co., Ltd.) Concentration 50 g / L, temperature 45 ° C., pH 4.0 Immersion treatment immersion time is appropriately adjusted according to the amount of film (f) Washing: tap water, room temperature, immersion 30 ° C.
(G) Pure water washing: deionized water, room temperature, immersion 30 ° C.
(H) Drying: 100 ° C., 10 minutes

<Comparative Example 16 (silicate lower layer coating, upper layer coating treatment)>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: Hydrochloric acid, concentration 17.5%, normal temperature, immersion 10 minutes (d) Washing: tap water, normal temperature, immersion 30 seconds (e) Lower layer coating treatment: Commercially available base treatment agent (preparene (registered trademark)) 5557, manufactured by Nihon Parkerizing Co., Ltd.) Concentration 2.5 g / L, temperature 70 ° C., immersion 1 minute (f) rough drying: normal temperature, 60 seconds (g) upper film treatment: upper film produced by (1-1) Treatment agent Temperature 60 ° C, immersion 1 minute (h) Drying: 100 ° C, 10 minutes

<Pretreatment and Film Treatment of Comparative Example 17 (Zinc Phosphate Lower Layer Film, Upper Layer Film Treatment)>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: hydrochloric acid, concentration 17.5%, room temperature, immersion 10 minutes (d) Water washing: tap water, room temperature, immersion 30 seconds (e) Lower layer coating treatment: commercial zinc phosphate chemical conversion agent (Palbond ( (Registered trademark) 3696X, manufactured by Nihon Parkerizing Co., Ltd.) Concentration 75 g / L, temperature 80 ° C., immersion 10 minutes (f) Water washing: tap water, room temperature, immersion 30 seconds (g) Upper film treatment: (1-1) Produced upper layer coating agent Temperature 60 ° C., immersion 1 minute (h) Drying: 100 ° C., 10 minutes

<Pretreatment and film treatment of Comparative Example 18 (phosphate / soap treatment)>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: hydrochloric acid, concentration 17.5%, normal temperature, immersion 10 minutes (d) Washing: tap water, normal temperature, immersion 30 seconds (e) Chemical conversion treatment: commercial zinc phosphate chemical conversion agent (Palbond (registered) (Trademark) 3696X, manufactured by Nihon Parkerizing Co., Ltd.) Concentration 75 g / L, temperature 80 ° C., immersion 10 minutes (f) Water washing: tap water, room temperature, immersion 30 seconds (g) Soap treatment: commercially available reactive soap lubricant (Palube) (Registered trademark) 235, manufactured by Nippon Parkerizing Co., Ltd.) Concentration 70 g / L, temperature 85 ° C., immersion 3 minutes (h) drying: 100 ° C., 10 minutes (i) dry film amount: 10 g / m ²

(1-4) Evaluation test (1-4-1) Workability (drawing property) test Drawing was performed by drawing a test material of φ3.2 mm × 20 m through a die of φ2.76. A missile C40 from Matsuura Kogyo Co., Ltd. was used as a dry lubricant. A dry lubricant was placed in the die box just before the material was pulled out so that it naturally adhered to the material. Evaluation was performed from seizure of the test material after wire drawing and the remaining amount of the lubricating film.
Evaluation criteria A: No seizure and no metallic luster. A lot of film remains on the whole.
○: There is no seizure and no metallic luster is observed, but the remaining film is slightly less than ◎.
Δ: Although there is no seizure, the remaining amount of the film is slightly small, and a metallic luster is recognized in part.
▲: There is no seizure, but metallic luster is observed in many parts.
X: Seizure occurred.

(1-4-2) Corrosion resistance (long-term rust prevention) test The wires subjected to the wire drawing test were exposed indoors in an open atmosphere in the summer for 2 weeks or 4 months, and the state of rust was observed. It was judged that the larger the rusting area, the lower the corrosion resistance.
Evaluation standard A: Remarkably superior to phosphate / soap film (rust area less than 5%)
○: superior to phosphate / soap film (rust area 5% or more and less than 15%)
Δ: Equivalent to phosphate / soap film (rust area 15% or more and less than 25%)
▲: Inferior to phosphate / soap film (rust area 25% or more and less than 35%)
X: Remarkably inferior to phosphate / soap film (rust area 35% or more)

The test results are shown in Table 2. In all the examples, a lot of film remained, the workability was good, and the corrosion resistance was also good. In Comparative Example 1, the same upper layer film and lower layer film as in the present invention were not used, but seizure occurred at the time of wire drawing. Comparative Example 2 was tested at a zirconium film alone, but seizure occurred as in Comparative Example 1, so that workability was insufficient and corrosion resistance was insufficient. In Comparative Examples 3 and 4, the film thickness of the zirconium film was used outside the scope of the present invention. In Comparative Example 3 in which the film thickness of the zirconium film was too thin, the corrosion resistance decreased, and in Comparative Example 4 in which the film thickness of the zirconium film was too thick, the workability tended to decrease. In Comparative Examples 5 to 12, the mass ratio of silicon and tungsten was set outside the range of the present invention, but the workability was poor and the corrosion resistance was poor because the remaining amount of the film after wire drawing was small. Comparative Examples 13 to 15 contain components other than water-soluble silicate and water-soluble tungstate as water-soluble inorganic salts. However, since the remaining amount of the film after wire drawing is small, workability is inferior and corrosion resistance is increased. Was also inferior. In Comparative Example 16, a water-soluble silicate film was applied as the lower layer film, but the corrosion resistance as high as that of the example could not be obtained. In Comparative Example 17, a phosphate film was formed as the lower film. Although the workability and corrosion resistance are at the same level as in the examples, this film is not preferable because it contains phosphorus and has the problem of immersion phosphorus such as bolts as described above. The sample obtained by subjecting the phosphate coating of Comparative Example 18 to the reaction soap treatment has a problem of phosphorus immersion such as bolts as in Comparative Example 17, and the phosphate coating is not preferable. The same applies to the case where phosphoric acid is contained as a water-soluble salt as in Comparative Examples 12 and 13.
Further, even when the materials are bundled with a binding band and the water-based lubricating film becomes thin at the bundled portion, high corrosion resistance can be imparted.

The present invention will be described in more detail together with its effect by giving an example with a comparative example for a steel wire. In addition, this invention is not restrict | limited by these Examples. In the following, “part” means “part by mass” and “%” means “% by mass” unless otherwise specified.

(2-1) Production of Upper Layer Coating Agent and Lower Layer Coating Agent as Aqueous Lubricant Coating Agents Examples 13 to 29 and Comparative Examples 19 to 35 in the combinations and proportions shown in Table 3 below. An upper layer coating agent and a lower layer coating agent were prepared. Comparative Example 36 is a phosphate / soap treatment.

A. Upper layer coating agent <water-soluble silicate>
(A-1) Sodium metasilicate (A-2) No. 3 sodium silicate (Na ₂ O.nSiO ₂ n = 3)
(A-3) Lithium silicate (Li ₂ O.nSiO ₂ n = 3.5)
<Water-soluble tungstate>
(B-1) Ammonium tungstate (B-2) Sodium tungstate (B-3) Potassium tungstate <Resin>
(C-1) Polyvinyl alcohol (average molecular weight of about 50,000)
(C-2) Sodium neutralized salt of isobutylene / maleic anhydride copolymer (average molecular weight of about 165,000)
(C-3) Sodium carboxymethylcellulose (average molecular weight of about 30,000)
(C-4) Water-based nonionic urethane resin emulsion <Lubricant>
(D-1) Anionic polyethylene wax (average particle size 5 μm)
(D-2) Ethylene bis-stearic acid amide (D-3) Calcium stearate (D-4) Polytetrafluoroethylene dispersion (average particle size 0.2 μm)
<Water-soluble salt>
(E-1) Sodium metaborate (E-2) Sodium tartrate (E-3) Sodium sulfate (E-4) Sodium pyrophosphate Underlayer coating agent <zirconium underlayer coating>
(F) Zirconium chemical conversion treatment agent (Pulseed (registered trademark) 1500, manufactured by Nihon Parkerizing Co., Ltd.)
<Underlayer coating other than zirconium underlayer>
(G-1) No. ₂ sodium silicate (Na ₂ O.nSiO ₂ n = 2.5)
(G-2) Zinc phosphate

(2-2) Film analysis The SPCC-SD material was processed to form a lower layer film and an upper layer film, and the amount of silicon and tungsten on the surface was measured by direct fluorescent X-ray analysis (XRF) to determine the mass ratio of tungsten / silicon. The value was examined. Then, it was immersed in 2% sodium hydroxide aqueous solution heated at 60 degreeC for 2 minutes, and the upper film was peeled. The film thickness of the zirconium film was measured by performing fluorescent X-ray analysis (XRF) on the test material from which the upper film was peeled off. The measured values are listed in Table 3. The film thickness measured from XRF is consistent with the result of directly measuring the thickness of the zirconium film by performing cross-sectional SEM analysis.

(2-3) Film Treatment <Pretreatment and Film Treatment of Examples 13 to 29 and Comparative Examples 20 to 33>
(A) Degreasing: Commercially available degreasing agent (Fine Cleaner (registered trademark) E6400, manufactured by Nippon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, room temperature, immersion 20 seconds (C) Pickling: 17.5% hydrochloric acid, normal temperature, immersion 20 minutes (d) Washing: tap water, normal temperature, immersion 20 seconds (e) Lower layer coating treatment: Commercial zirconium conversion treatment agent (Pulseed (registered trademark) 1500) (Manufactured by Nihon Parkerizing Co., Ltd.) Concentration 50 g / L, temperature 45 ° C., pH 4.0 Immersion treatment immersion time is appropriately adjusted according to the amount of film (f) Water washing: tap water, room temperature, immersion 20 seconds (g) neutralization : Commercially available neutralizer (preparene (registered trademark) 27, manufactured by Nippon Parkerizing Co., Ltd.)
(H) Upper layer film treatment: Upper layer film treatment agent produced in (2-1), temperature 60 ° C., immersion 1 minute (i) drying: 100 ° C., 10 minutes

<Pretreatment and Film Treatment of Comparative Example 19>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: Hydrochloric acid concentration 17.5%, normal temperature, immersion 10 minutes (d) Washing: tap water, normal temperature, immersion 30 seconds (e) Lower layer coating treatment: Commercial zirconium chemical conversion treatment agent (Pulseed (registered trademark)) 1500, manufactured by Nippon Parkerizing Co., Ltd.) Concentration 50 g / L, Temperature 45 ° C., pH 4.0, Immersion treatment, Immersion time is appropriately adjusted according to the amount of film (f) Washing: tap water, normal temperature, immersion 30 ° C.
(G) Pure water washing: deionized water, room temperature, immersion 30 ° C.
(H) Drying: 100 ° C., 10 minutes

<Comparative Example 34 (silicate lower layer coating, upper layer coating treatment)>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: Hydrochloric acid, concentration 17.5%, normal temperature, immersion 10 minutes (d) Washing: tap water, normal temperature, immersion 30 seconds (e) Lower layer coating treatment: Commercially available base treatment agent (preparene (registered trademark)) 5557, manufactured by Nihon Parkerizing Co., Ltd.) Concentration 2.5 g / L, temperature 70 ° C., immersion 1 minute (f) rough drying: normal temperature, 60 seconds (g) upper layer coating treatment: upper layer coating manufactured in (2-1) Treatment agent, temperature 60 ° C., immersion 1 minute (h) drying: 100 ° C., 10 minutes

<Pretreatment and Film Treatment of Comparative Example 35 (Zinc Phosphate Lower Layer Film, Upper Layer Film Treatment)>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: hydrochloric acid, concentration 17.5%, room temperature, immersion 10 minutes (d) Water washing: tap water, room temperature, immersion 30 seconds (e) Lower layer coating treatment: commercial zinc phosphate chemical conversion agent (Palbond ( (Registered trademark) 3696X, manufactured by Nihon Parkerizing Co., Ltd.) Concentration 75 g / L, temperature 80 ° C., immersion 10 minutes (f) Water washing: tap water, room temperature, immersion 30 seconds (g) Upper layer coating treatment: (2-1) Produced upper layer coating agent, temperature 60 ° C., immersion 1 minute (h) drying: 100 ° C., 10 minutes

<Pretreatment and film treatment of Comparative Example 36 (phosphate / soap treatment)>
(A) Degreasing: Commercial degreasing agent (Fine Cleaner (registered trademark) 6400, manufactured by Nihon Parkerizing Co., Ltd.), concentration 20 g / L, temperature 60 ° C., immersion 10 minutes (b) water washing: tap water, normal temperature, immersion 30 seconds (C) Pickling: hydrochloric acid, concentration 17.5%, normal temperature, immersion 10 minutes (d) Washing: tap water, normal temperature, immersion 30 seconds (e) Chemical conversion treatment: commercial zinc phosphate chemical conversion agent (Palbond (registered) (Trademark) 3696X, manufactured by Nihon Parkerizing Co., Ltd.) Concentration 75 g / L, temperature 80 ° C., immersion 7 minutes (f) Water washing: tap water, room temperature, immersion 30 seconds (g) Soap treatment: Commercially available reactive soap lubricant (Palube) (Registered trademark) 235, manufactured by Nippon Parkerizing Co., Ltd.) Concentration 70 g / L, temperature 85 ° C., immersion 3 minutes (h) drying: 100 ° C., 10 minutes (i) dry film amount: 10 g / m ²

(2-4) Evaluation Test (2-4-1) Workability (Spikeability) Test A spike test was performed as a test assuming forward pressing of a steel wire. The spike test was conducted according to the description in JP-A-5-7969. Lubricity was evaluated by spike height and molding load after the test. The higher the spike height and the lower the molding load, the better the lubricity. According to the above document, the area expansion rate in the spike test is about 10 times. The lubricity of the film was evaluated by measuring the load and spike height during processing.
Test piece for evaluation: S45C spheroidized annealing material 25 mmφ × 30 mm
Evaluation standard A: Remarkably superior to phosphate / soap film B: Superior to phosphate / soap film Δ: Equivalent to phosphate / soap film B: Inferior to phosphate / soap film X: Phosphate / soap Remarkably inferior to film

(2-4-2) Workability (Upsetting-Ball Ironing) Test A steel wire was subjected to an upsetting-ball ironing test as a test assuming bolt head formation. The upsetting-ball ironing test was conducted according to the description in JP2013-215773A. The maximum area expansion rate in the upsetting-ball ironing test is 150 times or more, and the area expansion ratio is very large compared to the spike test described above. Therefore, for example, it is a test that can reproduce a process requiring high workability such as forming the head of a hexagon bolt with a flange. The anti-seizure performance of the film was evaluated by evaluating the amount of seizure entering the ironing surface.
Test piece for evaluation: S10C spheroidized annealing material 14 mmφ × 32 mm
Bearing ball: 10mmφ SUJ2
Evaluation criteria It was evaluated how much area burned with respect to the entire area of the ironing surface.
◎: Remarkably superior to phosphate / soap coating ○: Superior to phosphate / soap coating △: Equivalent to phosphate / soap coating ▲: Inferior to phosphate / soap coating ×: From phosphate / soap coating Markedly inferior

(2-4-3) Evaluation of corrosion resistance (long-term rust prevention) The test pieces subjected to the above-mentioned upper layer coating and lower layer coating formation treatment were exposed indoors for 2 weeks or 4 months in an open atmosphere in summer to check the degree of rust generation. Observed. It was judged that the larger the rusting area, the lower the corrosion resistance.
Test piece: SPCC-SD 75mm x 35mm x 0.8mm
Evaluation standard A: Remarkably superior to phosphate / soap film (rust area less than 5%)
○: superior to phosphate / soap film (rust area 5% or more and less than 15%)
Δ: Equivalent to phosphate / soap film (rust area 15% or more and less than 25%)
▲: Inferior to phosphate / soap film (rust area 25% or more and less than 35%)
X: Remarkably inferior to phosphate / soap film (rust area 35% or more)

Table 4 shows the test results. As is clear from Table 4, the examples had good workability (spike test, ball ironing test) and corrosion resistance (particularly long-term rust prevention). Comparative Example 19 was a film having only a zirconium film, but the workability and corrosion resistance were greatly inferior. In Comparative Examples 20 and 21, the film thickness of the zirconium film is set outside the range of the present invention. Although the comparative example 20 is a case where the film thickness of a lower layer film | membrane is made thin too much, it resulted in inferior corrosion resistance. Comparative Example 21 was a case where the film thickness of the lower layer film was made too thick, but the processability was inferior. In Comparative Examples 22 to 29, the mass ratio of silicon and tungsten was set outside the range of the present invention, but the results of ball ironing and corrosion resistance tended to be inferior. Comparative Examples 30 to 33 contain components other than water-soluble silicate and water-soluble tungstate as water-soluble inorganic salts, but there was a tendency that the results of ball ironing and corrosion resistance were inferior. In Comparative Example 34, a silicate film was applied as the lower layer film, but the corrosion resistance as high as that of the example could not be obtained. In Comparative Example 35, a phosphate film was formed as the lower film. Although the workability and corrosion resistance are at the same level as in the examples, this film is not preferable because it contains phosphorus and has the problem of immersion phosphorus such as bolts as described above. What performed the reaction soap process to the phosphate membrane | film | coat of the comparative example 36 was inferior to the Example in corrosion resistance. Further, as in Comparative Example 35, there is a problem of phosphorus immersion such as bolts, and a phosphate film is not preferable. The same applies to the case where phosphorus is included as a water-soluble salt as in Comparative Examples 27 and 30.

As is clear from the above description, high workability and sufficient corrosion resistance in a practical environment can be achieved by using a steel wire having a lubricating film including an upper film and a lower film of the present invention. Therefore, the present invention has a great industrial utility value.

The present invention includes the following aspects.
Aspect 1:
A steel wire having a film containing no phosphorus,
The coating comprises, in order from the steel wire side, an oxide and / or hydroxide of zirconium, and has a lower layer coating having a thickness of 1.0 to 200 nm, silicon and tungsten, and has a mass ratio of tungsten / silicon. A steel wire material comprising an upper film in the range of 1.3 to 18.

Aspect 2:
The steel wire according to aspect 1, wherein the silicon is derived from a water-soluble silicate and the tungsten is derived from a water-soluble tungstate.

Aspect 3:
The silicon is derived from at least one selected from lithium silicate, sodium silicate, and potassium silicate, and the tungsten is at least selected from lithium tungstate, sodium tungstate, potassium tungstate, and ammonium tungstate. The steel wire rod according to the aspect 1 or 2 derived from one or more kinds.

Aspect 4:
The steel wire according to any one of aspects 1 to 3, wherein the upper layer film includes a resin, and a mass ratio of resin / (silicon + tungsten) is 0.01 to 3.2.

Aspect 5:
The steel wire according to aspect 4, wherein the resin is at least one selected from vinyl resins, acrylic resins, epoxy resins, urethane resins, phenol resins, cellulose derivatives, polymaleic acid, and polyester resins.

Aspect 6:
The steel wire according to any one of embodiments 1 to 5, wherein the upper layer film contains a lubricant, and the mass ratio of the lubricant / (silicon + tungsten) is 0.01 to 3.2.

Aspect 7:
The steel wire according to aspect 6, wherein the lubricant is at least one selected from wax, polytetrafluoroethylene, fatty acid soap, fatty acid metal soap, fatty acid amide, molybdenum disulfide, tungsten disulfide, graphite, and melamine cyanurate. .

Aspect 8:
The steel wire rod according to any one of embodiments 1 to 7, wherein a film mass per unit area of the upper layer film is 1.0 to 20 g / m ² .

Aspect 9:
A method for producing a steel wire according to any one of aspects 1 to 8, wherein a water-based chemical conversion treatment solution having a pH in the range of 2.5 to 5.0 and having a water-soluble zirconium compound dissolved therein is brought into contact with the surface of the steel wire. And forming a lower layer film.

This application is accompanied by a priority claim based on Japanese Patent Application No. 2014-070445 whose application date is March 28, 2014, and Japanese Patent Application No. 2014-070445 is referred to by reference. Incorporated herein.

Claims (9)

1. A steel wire having a film containing no phosphorus,
   The coating comprises, in order from the steel wire side, an oxide and / or hydroxide of zirconium, and has a lower layer coating having a thickness of 1.0 to 200 nm, silicon and tungsten, and has a mass ratio of tungsten / silicon. A steel wire material comprising an upper film in the range of 1.3 to 18.
2. The steel wire according to claim 1, wherein the silicon is derived from a water-soluble silicate and the tungsten is derived from a water-soluble tungstate.
3. The silicon is derived from at least one selected from lithium silicate, sodium silicate, and potassium silicate, and the tungsten is at least selected from lithium tungstate, sodium tungstate, potassium tungstate, and ammonium tungstate. The steel wire rod according to claim 1 or 2 derived from one or more kinds.
4. The steel wire according to claim 1 or 2, wherein the upper layer film contains a resin, and a mass ratio of resin / (silicon + tungsten) is 0.01 to 3.2.
5. The steel wire according to claim 4, wherein the resin is at least one selected from vinyl resins, acrylic resins, epoxy resins, urethane resins, phenol resins, cellulose derivatives, polymaleic acid, and polyester resins.
6. 3. The steel wire according to claim 1, wherein the upper layer film contains a lubricant, and the mass ratio of lubricant / (silicon + tungsten) is 0.01 to 3.2.
7. The steel according to claim 6, wherein the lubricant is at least one selected from wax, polytetrafluoroethylene, fatty acid soap, fatty acid metal soap, fatty acid amide, molybdenum disulfide, tungsten disulfide, graphite, and melamine cyanurate. wire.
8. The steel wire rod according to claim 1 or 2, wherein a film mass per unit area of the upper film is 1.0 to 20 g / m ² .
9. 3. The method for producing a steel wire according to claim 1 or 2, wherein an aqueous chemical conversion treatment solution having a pH in the range of 2.5 to 5.0 and having a water-soluble zirconium compound dissolved therein is brought into contact with the surface of the steel wire. A method for producing a steel wire, comprising forming a film.