JP2010111767A - Borate-free lubricant for dry wire drawing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a borate-free lubricant for dry wiring drawing which can be used even under severe wire drawing conditions of high temperature, high pressure, and high speed, which can respond to processes of diameter reduction into a broad range of diameters from a small diameter to a large diameter or processes at line speeds in a broad range from a low speed to a high speed, which shows excellent performances in lubricating property, traceability, spreading property, adhesion property, heat resistance, processability, workability, durability, and the like, comparable or superior to a lubricant for dry wire drawing containing a borate, even without using a harmful boron-containing compound such as a borate, and which is safe for the environment and a human body. <P>SOLUTION: The borate-free lubricant for dry wire drawing contains 30 to 90 wt.% of a metal soap of a saturated fatty acid and 10 to 40 wt.% of a borate-free water-soluble inorganic condensate compound, and/or the condensation precursor of the compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is used when a metal such as steel or non-ferrous metal is drawn and drawn into a wire or bar by using a die, and is fired by direct contact between the die and a workpiece base material. The present invention relates to a boric acid-free dry wire drawing lubricant used to prevent sticking and maintain a stable processing state.

  Pressing a metal such as iron and non-ferrous metals such as aluminum, drawing it from a die steel such as a die, drawing it, and then drawing and plastically deforming it into a wire or bar, the die and workpiece base A dry-drawing lubricant is widely used at the site of contact with the material.

  This lubricant prevents the workpiece base and die from coming into direct contact and seizes, and maintains the stable machining shape by making the workpiece matrix slippery and easy to pull out from the die. belongs to.

  Most of the commercially available dry wire drawing lubricants contain metal soaps such as saturated fatty acid sodium soaps and calcium soaps as main active ingredients, and further contain inorganic substances and additives. Among them, dry wire drawing lubricants containing alkali metal soaps such as sodium soaps are excellent in terms of forming a water-soluble lubricating film that is excellent in slipperiness and easy to remove by washing with water. Due to the low melting point of the soap, the lubricant film liquefies when exposed to high temperatures, so that it contains 10 to several tens of weight percent of an inorganic compound, particularly a water-soluble borate compound as an additive. What was not used is used. For example, in Patent Document 1, an element tube is immersed in an aqueous solution containing an alkali metal salt of boric acid and an alkali metal salt of fatty acid, and an alkali metal salt of boric acid and an alkali metal of fatty acid are formed on the inner and outer surfaces of the element tube. A method is described in which a film with salt is formed, a liquid lubricant is applied thereon, and cold drawing is performed.

  Recently, the adverse effects of borate compounds on the environment and the human body have become a problem, and since the use regulations are becoming stricter, boron-containing compounds such as borate compounds are not included, and at the time of wire drawing A water-soluble dry-drawing lubricant that is excellent in lubricity and removability in the plating process after wire drawing and in the pre-heat treatment step is desired.

JP 2002-192220 A

  The present invention was made to solve the above-mentioned problems, and can be used under severe wire drawing conditions under high temperature, high pressure, and high speed. Can handle a wide range of linear speeds from high to high speed, and without using harmful boron-containing compounds such as borate, lubricity, followability, spreadability, adhesion, heat resistance, workability, work Provides borate-free dry wire-drawing lubricants that are high in performance and durability that are equivalent to or better than borate-containing dry wire-drawing lubricants and that are safe for the environment and the human body The purpose is to do.

  The borate-free dry wire drawing lubricant according to claim 1, which is made to achieve the above object, comprises 30 to 90% by weight of a saturated fatty acid metal soap, It is characterized by containing 10 to 40% by weight of the contained water-soluble inorganic condensation compound and / or its condensation precursor compound.

  The dry-drawing lubricant according to claim 2 is the lubricant according to claim 1, wherein the water-soluble inorganic condensation compound comprises a plurality of repeating units derived from the condensation precursor compound in a linear, cyclic and cyclic manner. It is characterized by being condensed in a branched chain form.

  The dry-drawing lubricant according to claim 3 is the lubricant according to claim 2, wherein the water-soluble inorganic condensation compound is obtained by condensation-bonding the condensation precursor compound under heating. And

  The dry-drawing lubricant according to claim 4 is the lubricant according to claim 1, wherein the water-soluble inorganic condensation compound is a silicate and / or a condensed phosphate. .

  The dry-drawing lubricant according to claim 5 is the lubricant according to claim 4, wherein the water-soluble inorganic condensation compound comprises condensed phosphate sodium salt, condensed phosphate potassium salt, condensed phosphate acidic salt, And a composite metal salt thereof, and at least one selected from a sodium silicate salt, a potassium silicate salt, and a composite metal salt thereof.

  The dry-drawing lubricant according to claim 6 is the lubricant according to claim 4, wherein the condensed phosphoric acid constituting the condensed phosphate is pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, ultrapolyphosphoric acid. And / or hexametaphosphoric acid.

  The dry drawing lubricant according to claim 7 is the lubricant according to claim 4, wherein the saturated fatty acid is butyric acid, caproic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic. It is characterized by being acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and / or melicic acid.

  The dry-drawing lubricant according to claim 8 is the lubricant according to claim 1, wherein the saturated fatty acid metal soap is a saturated fatty acid sodium salt, a saturated fatty acid potassium salt, and / or a composite thereof. It is a metal salt.

  The dry-drawing lubricant of the present invention can be used conveniently when the workpiece is drawn and drawn from a steel die under high temperature, high pressure and high speed conditions. This lubricant does not contain boron-containing compounds such as harmful borates and is safe. This water-soluble dry wire drawing lubricant contains a water-soluble inorganic condensate or a precursor compound that can be condensed under heating or pressurization, so that it can be lubricated under severe conditions of high temperature and high pressure during wire drawing. It improves the thermal characteristics of the agent, forms a flexible lubricating film on the surface of the wire, exhibits lubricity, followability, spreadability, and adhesion, and facilitates wire drawing.

  This dry wire drawing lubricant is equivalent to or better than the conventional water-soluble dry wire drawing lubricants containing boron-containing compounds such as borates. High performance with good workability, workability, workability, durability, etc., especially useful when drawing wire under a wide range of wire diameters, from heavy to thin, under severe wire drawing conditions at high temperatures and pressures It is.

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples.

  A preferred embodiment of the borate-free dry wire drawing lubricant of the present invention includes a lubricating component composed of a saturated fatty acid metal soap and a water-soluble inorganic condensation compound, and an additive. Is. This borate-free dry wire drawing lubricant is prepared as follows.

  45 to 65 parts by weight of saturated fatty acid and 15 to 20 parts by weight of tap water are mixed and heated to melt, and 5 to 15 parts by weight of condensed phosphoric acid, 10 to 30 parts by weight of caustic soda aqueous solution and about 50 parts by weight. 5% to 15 parts by weight aqueous caustic potassium solution, and after heating and stirring, drying, and then pulverizing the resulting solid, sodium potassium composite metal salt of saturated fatty acid which is metal soap of saturated fatty acid and water-soluble inorganic Containing a condensed phosphate, which is a condensed compound, as a main lubricating component, a dry drawing lubricant containing no borate is obtained.

  The dry wire drawing lubricant has been pulverized, but may be in the form of powder, granule, lump, or solid.

An example of a condensed phosphate is shown as a water-soluble inorganic condensation compound in a dry wire drawing lubricant. Specific examples thereof include a salt of condensed phosphoric acid generated by dehydration condensation of 2 to 6 molecules of phosphoric acid. And [(MO-) PO-O] (M is hydrogen or metal), for example, triphosphoric acid which is diphosphoric acid pyrophosphoric acid, triphosphoric acid which is linear or cyclic A condensed phosphoric acid exemplified by tetraphosphoric acid, a linear or 8-membered cyclic or branched 6-membered cyclic tetrapolyphosphoric acid, a linear, unbranched cyclic or branched ultrapolyphosphoric acid, hexametaphosphoric acid, The compound which became a salt is mentioned. Any of condensed phosphoric acid sodium salt, condensed phosphoric acid potassium salt, condensed phosphoric acid acidic salt (for example, pyrophosphoric acid acidic salt Na ₂ H ₂ P ₂ O ₇ ), or a composite metal salt thereof may be used.

More specifically, the chain condensed phosphoric acid is represented by the following chemical formula (I):
M ¹ O — [(M ² O—) PO—O] _m —M ³ (I)
(Formula (I) ^in, M 1 ~M ³ are the same or different at least one said metal selected from a metal and H of Na or ^{K, [(M 2 O-)} PO-O] m its repetitive M ² in the unit is the same or different and m = 2 to 6. The unbranched cyclic condensed phosphoric acid has the following chemical formula (II)
-[(M ⁴ O-) PO-O] _n- (II)
(In the formula (II), n is 2 to 6, and [(M ⁴ O—) PO—O] _n is bonded at both ends to form a ring, and M ⁴ in the repeating unit is the same. Alternatively, it is selected from a metal of Na or K and H, and at least any M ⁴ in the repeating unit is represented by the above metal).

In this dry-drawing lubricant, instead of or together with the condensed phosphate which is a water-soluble inorganic condensation compound, a condensation precursor compound thereof, for example, phosphoric acid H ₃ PO ₄ which forms a condensed phosphate by dehydration or its A salt may be included. The condensation precursor compound, such as phosphoric acid, is dehydrated under heating at 200 to 1200 ° C. to become a water-soluble inorganic condensation compound, that is, condensed phosphoric acid, before or during use of the water-soluble dry wire drawing lubricant. . The condensed phosphoric acid is one in which a linear structure type, or a branched or cyclic multimer is mainly formed by heating or pressurizing the condensation precursor.

  Although examples of condensed phosphates have been shown as water-soluble inorganic condensation compounds in dry wire drawing lubricants, they may be chain, branched chain, or cyclic silicates. It may be a mixture with an acid salt.

As a specific example of a silicate, it consists of silicon dioxide and a metal oxide, and has the following formula (III)
^{_{pM 5 2 O · qSiO 2 (}} III)
(Formula (in III), p, q is 2-4, at least one metal ^{M 5} is Na or K)
It is a compound shown by these.

More specifically, the chain silicate is represented by the following chemical formula (IV):
^{M 6 O - {[(M} 7 O-) Si (-OM 8)] - O} r -M 9 (IV)
(In the formula (II), M ^{6 to} M ⁹ are the same or different and are selected from Na or K metal and H, and at least one of the metals, {[(M ⁷ O—) Si (—OM ⁸ )] — O} _r is such that M ⁷ and M ⁸ in the repeating unit are the same or different but are the same or different, and r = 2 to 4).

  The silicate may be cyclic.

  Since these water-soluble inorganic condensation compounds and condensation precursor compounds thereof are other than boron-containing compounds such as borates, the dry wire drawing lubricant does not contain boron at all.

  The dry wire drawing lubricant preferably contains 10 to 40% by weight of a water-soluble inorganic compound or a precursor thereof. Outside this range, characteristics such as heat resistance and lubricity will be insufficient.

  The saturated fatty acid constituting the saturated fatty acid metal soap has 4 to 30 carbon atoms, and examples thereof include linear, branched, or cyclic saturated fatty acids. More specifically, butyric acid, caproic acid, capryl Examples include acids, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and melicic acid. These may be used alone or in combination. Natural fats and oils such as animal fats and vegetable fats and oils containing saturated fatty acid esters may be hydrolyzed by hydrogenation.

  Specifically, the saturated fatty acid metal soap in the dry wire drawing lubricant may be a sodium salt, a potassium salt, a single metal salt, or a composite metal salt thereof. Also good.

  The metal soap of saturated fatty acid is preferably contained in the dry wire drawing lubricant in an amount of 30 to 90% by weight. When it deviates from this range, characteristics such as film property and lubricity become insufficient.

  The dry wire drawing lubricant may contain additives such as preservatives and anticorrosives as necessary.

  This water-soluble dry drawing lubricant is used as follows. A water-soluble dry-drawing lubricant is applied to a metal or non-metal workpiece base material by application, spraying, dipping, or the like as a solid, for example, as a powder. When it is drawn from a steel mold such as a die, plastically deformed and drawn, a desired wire or bar is obtained.

  An example in which a borate-free dry wire drawing lubricant to which the present invention is applied is prepared is shown in Example 1, and an example in which the present invention is applied to a dry wire drawing lubricant is shown as a comparative example. Shown in 1-2.

Example 1
In a reaction vessel equipped with a stirrer, 50 parts by weight of industrial stearic acid and 15 parts by weight of tap water were added, and the mixture was heated and melted with stirring. Then, 9 parts by weight of condensed phosphoric acid shown in claim 6 was added, Further, 17 parts by weight of a 48% caustic soda aqueous solution and 9 parts by weight of a 48% caustic potassium aqueous solution were added. Heating and stirring were continued until the water content became 1.0% or less. The obtained dried crude lubricant was pulverized with a 500 mesh sieve so that the passing rate was about 60%, and each borate-free lubricant for dry wire drawing was obtained.

(Comparative Example 1)
In a reaction vessel equipped with a stirrer, 50 parts by weight of industrial stearic acid and 15 parts by weight of tap water were added, and the mixture was heated and melted with stirring, and then boric acid instead of condensed phosphoric acid as in Example 1. 9 parts by weight were added, and further 17 parts by weight of 48% aqueous sodium hydroxide solution and 9 parts by weight of 48% aqueous caustic potassium solution were added. Heating and stirring were continued until the water content became 1.0% or less. The obtained dried crude lubricant was pulverized with a 500 mesh sieve so that the passing rate was about 60%, to obtain a dry wire drawing lubricant.

(Comparative Example 2)
In a reaction vessel equipped with a stirrer, 50 parts by weight of industrial stearic acid and 15 parts by weight of tap water were added, heated and melted with stirring, cooled, added with 9 parts by weight of phosphoric acid, and an additional 48%. 17 parts by weight of an aqueous caustic soda solution and 9 parts by weight of an aqueous 48% caustic potassium solution were added. Heating and stirring were continued until the water content became 1.0% or less. The obtained dried crude lubricant was pulverized with a 500 mesh sieve so that the passing rate was about 60%, to obtain a dry wire drawing lubricant.

  Using the dry drawing lubricants of Example 1 and Comparative Examples 1 and 2, the wire drawing was performed by a wire drawing machine, and the performance was evaluated.

(Wire drawing)
First, wire drawing was performed using a die. The processing conditions are as follows.
Workpiece material: 72A material Wire speed: 40m / min Wire diameter reduction: 2.8mmφ → 2.5mmφ → 2.25mmφ → 2.00mmφ 3 steps (Repeat 1 pass and extend 3 passes) Lined.)
Pretreatment of workpiece base material: None

  The wire drawing process and its performance evaluation method are as follows.

  The processed wire was pretreated by removing the oxidized scale on the surface of the processed wire by pickling using a 12 wt% aqueous hydrochloric acid solution, followed by washing with water several times and drying.

  Subsequently, an arbitrary amount of the evaluation lubricant was introduced into the die box, and the wire drawing evaluation of the pretreated wire was performed according to the above conditions.

(Average pulling force measurement test)
A load cell was attached to the die, and the difference between the maximum value and the minimum value of the average drawing force when the wire drawing was performed was drawn for 20 to 30 seconds. The results are shown in Table 1.

  As is clear from Table 1, in any wire diameter, when the dry-drawing lubricant of Example 1 was used, the pulling force fluctuation range was the same as that of the lubricant containing the borate of Comparative Example 1. There was excellent wire drawing stability. On the other hand, it was recognized that the lubricant of Comparative Example 2 using a non-condensed inorganic compound had a larger drawing force fluctuation range than Example 1 at any wire diameter and was inferior in wire drawing stability.

(Visual observation test of wire surface after wire drawing)
The drawn wire was washed with a wire drawing wire detergent (manufactured by Kyoeisha Chemical Co., Ltd .; trade name: Light Clean A-3), and the surface was visually observed. The results are shown in Table 2.

  As is apparent from Table 2, in any wire diameter, a film-like lubricant is uniformly formed on the surface of the wire after drawing in the same manner as in Comparative Example 1 using the lubricant borate for dry drawing in Example 1. In contrast, when the lubricant of Comparative Example 2 using a non-condensed inorganic compound was used, the lubricant was adhering to the surface of the wire after drawing in a powdery or patchy state. In some cases, the lubricant adheres only to the powder and the wire substrate is exposed without adhering to the other part. It is assumed that such a difference appears as a difference in the pulling force fluctuation range in Table 1.

(Microscopic observation test of the surface of the wire after drawing)
The drawn wire was washed with a cleaning agent, and the surface thereof was magnified 400 times with a laser microscope and observed. The results are shown in Table 3.

  As is clear from Table 3, when the dry drawing lubricants of Example 1 and Comparative Example 1 were used, a flat part generated by direct contact between the die and the wire, ie, a microscope, was used at any wire diameter. It was confirmed that the wire drawing state was good because there were very few white streaks or spots observed when observed. On the other hand, when the lubricant of Comparative Example 2 was used, a flat portion, that is, a white streak or a spot-like portion by a microscope, was generated much more than in the case of Example 1 at any wire diameter, It was confirmed that the wire drawing state was poor. Furthermore, it was recognized that the flat part increased as the diameter decreased.

(Measurement of dry wire drawing lubricant adhesion on the surface of the wire after drawing)
Measure the weight of the drawn wire, wash it with a cleaning agent, measure the weight of the wire again, and calculate the amount of adhesion from the weight difference before and after cleaning and the diameter and length of the wire. . The results are shown in Table 4.

  As is clear from Table 4, the lubricant for dry drawing of Example 1 had the same lubricant as that of Comparative Example 1 adhered to the wire drawing at any wire diameter. On the other hand, when the lubricant of Comparative Example 2 is used, it is recognized that the adhesion amount of the lubricant is smaller than that of Example 1 at any wire diameter. It is assumed that such a difference appears as an enlargement of a flat portion observed as a streak or a spot on the surface in the microscopic observation as shown in Table 3.

  The borate-free dry wire drawing lubricant of the present invention is obtained by drawing a workpiece base material such as a metal wire such as steel, a tube, a rod, or a rod from a die steel or other die steel, It is used in the wire drawing process in which a material is plastically deformed to reduce the diameter.

Claims (8)

  30 to 90% by weight of a saturated fatty acid metal soap and 10 to 40% by weight of a boron-free water-soluble inorganic condensation compound and / or its condensation precursor compound are contained in a borate-free dry type A lubricant for wire drawing.   2. The water-soluble inorganic condensation compound is obtained by condensing a plurality of repeating units derived from the condensation precursor compound in a linear, cyclic and / or branched chain. Lubricant for dry wire drawing.   The dry-drawing lubricant according to claim 2, wherein the water-soluble inorganic condensation compound is a product obtained by condensing the condensation precursor compound under heating.   The dry-drawing lubricant according to claim 1, wherein the water-soluble inorganic condensation compound is a silicate and / or a condensed phosphate.   The water-soluble inorganic condensation compound is a condensed sodium phosphate salt, a condensed potassium phosphate salt, a condensed phosphoric acid acid salt, and a composite metal salt thereof, a sodium silicate salt, a potassium silicate salt, and a composite metal salt thereof. The dry drawing lubricant according to claim 4, wherein the lubricant is at least one selected from the group consisting of:   The dry-drawing lubrication according to claim 4, wherein the condensed phosphoric acid constituting the condensed phosphate is pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, ultrapolyphosphoric acid, and / or hexametaphosphoric acid. Agent.   The saturated fatty acid is butyric acid, caproic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and The dry-drawing lubricant according to claim 1, wherein the lubricant is a melicic acid.   The dry-drawing lubricant according to claim 1, wherein the saturated fatty acid metal soap is a saturated fatty acid sodium salt, a saturated fatty acid potassium salt, and / or a composite metal salt thereof.