JP2009287023A - Lubricant composition for processing seamless steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant composition for processing a seamless steel pipe totally satisfying various properties such as storage stability, transferability inside an apparatus piping, sprayability to lubrication sites and property of uniform adhesion to a high-temperature mandrel bar without losing non-carburizability or excellent lubricity to hard-to-work materials such as 13 chromium steel and stainless steel. <P>SOLUTION: There is provided a lubricant composition whose viscosity characteristics are represented by the approximate expression: Y=a×X<SP>b</SP>, wherein Y is viscosity (mPa s); X is shear rate (s<SP>-1</SP>); and during stationary storage, a is 4,000 to 40,000 and b is -1.0 to -0.3; while 90 sec after shear termination, a is 1,000 to 20,000 and b is -1.0 to -0.15. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lubricant for hot pipe rolling used mainly in the manufacture of seamless steel pipes by the Mannesmann pipe manufacturing method.

  As is well known, in the manufacture of seamless metal pipes by the Mannesmann pipe method, a heated solid billet or bloom is made into a hollow pipe by a piercing machine, and then the hollow pipe is drawn or rolled. To finish the product tube. In the stretching process of the Mannesmann tube method, the tube inner surface is forcibly lubricated with a lubricant to prevent seizure. As the lubricant, a graphite-based lubricant mainly composed of granular graphite, scaly graphite, earthy graphite or the like is used in a solid state or in a liquid state in which a binder is mixed.

  When a graphite-based lubricant is used, there is no problem in lubrication performance even when the material to be rolled is a difficult-to-work material such as stainless steel or high alloy steel. However, in these materials, the corrosion resistance is hindered by carburization. That is, when the inner surface of a pipe is lubricated with a graphite-based lubricant in stainless steel or high alloy steel, the inner surface of the pipe is carburized, resulting in selective corrosion of the grain boundary and its vicinity due to grain boundary precipitation of chromium carbide. The corrosion resistance is reduced, and the performance of the product is impaired.

  In order to improve this point, instead of the conventional graphite-based lubricant, Patent Document 1 proposes a composition comprising an oxide-based layered compound and a combination of boric acid and an alkali metal borate. Patent Document 2 proposes a composition comprising a combination of natural or artificial mica, vermiculite, bentonite and boric acid Li, Na, K, metaborate, pyroborate and hydrates thereof. A composition comprising a combination of these oxide-based layered compound and boric acid is effective as a non-carburizing lubricant having excellent lubricity.

  On the other hand, ordinary graphite lubricants do not require non-carburization. Therefore, these graphite-based lubricants can give the above-mentioned properties by sufficiently adding ordinary organic thickeners (for example, water-soluble acrylic resin, water-soluble cellulose such as sodium carboxymethyl cellulose). Is possible. For example, Patent Document 3 discloses a lubricant that satisfies the above properties by blending a large amount of both a water-soluble polymer and a water-dispersible polymer.

Japanese Unexamined Patent Publication No. 64-16894 JP-A-5-171165 JP-A-2-51592

  However, these lubricants disclosed in the above-mentioned Patent Documents 1 and 2 are supplied to the lubrication surface as a solid, or dispersed in water and applied to a tool (mandrel) for use. Therefore, in order to adapt these to actual mandrel mill equipment, storage stability after manufacturing the lubricant, transportability in the equipment piping, sprayability to the lubrication site, uniform adhesion to the high temperature mandrel bar, etc. Properties are needed comprehensively. However, it is not easy to comprehensively satisfy these properties.

  Further, in the drawing and rolling of stainless steel and high alloy steel, non-carburization is absolutely necessary for ensuring corrosion resistance, and the above-described polymer cannot be blended in a large amount.

  Therefore, the present invention is non-carburizing, storage stability, transportability in equipment piping, sprayability to lubrication points, without impairing excellent lubricity for difficult-to-work materials such as 13 chromium steel and stainless steel, It is an object of the present invention to provide a seamless steel pipe working lubricant composition that comprehensively satisfies various properties such as uniform adhesion to a high-temperature mandrel bar.

The present invention is a seamless steel pipe working lubricant composition whose viscosity characteristics are represented by the following approximate formula.
Y = a · X ^b Y: Viscosity (mPa · s)
X: shear rate (s ⁻¹ )
During stationary storage a: 4000 to 40000
b: -1.0 to -0.3
90 seconds after the end of shearing a: 1000-20000
b: -1.0 to -0.15
Here, “after 90 seconds from the end of shearing” means that the composition is stirred and sheared, and measurement is started at a predetermined shear rate 30 seconds after the end of the operation. It means another 60 seconds after the start. Therefore, “after 90 seconds” corresponds to the total value of 30 seconds and 60 seconds. Further, “at the end of shearing” refers to the time when the rotation of the propeller for the stirring operation is stopped.

  The seamless steel pipe processing lubricant composition comprises 10 to 40% by mass of an oxide-based layered compound, 5 to 30% by mass of one or more alkali metal salts or amine salts of boric acid, and the alkali metal salt or amine salt of boric acid. It is preferable that 0.11 to 3.0 mass% of one or more water-soluble polymers soluble in one or more aqueous solutions of the above, and the balance water.

  The seamless steel pipe processing lubricant composition includes a pseudoplastic fluid water-soluble polymer, or a pseudoplastic fluid water-soluble polymer and a thixotropic fluid water-soluble polymer as the water-soluble polymer. It is preferable.

  Alternatively, the seamless steel pipe processing lubricant composition is a water-soluble polymer, 0.01 to 1.0% by mass of a pseudoplastic fluid water-soluble polymer based on the total amount of the composition, and a thixotropic fluid water-soluble polymer. It is preferable to contain 0.1-2.0 mass%.

  According to the present invention, storage stability, transportability in equipment piping, and sprayability to lubricated parts are not impaired without impairing non-carburization properties and excellent lubricity for difficult-to-work materials such as 13 chromium steel and stainless steel. It is possible to provide a seamless steel pipe working lubricant composition that comprehensively satisfies various properties such as uniform adhesion to a high-temperature mandrel bar.

It is a figure which shows an ideal viscosity form as a seamless steel pipe processing lubricant composition. It is a figure which shows the chemical structure model of an example of a pseudo plastic fluidity water-soluble polymer. It is a figure which shows the chemical structure model of the long-chain polymer in which glucose was glucoside-bonded as an example of a thixotropic fluidity water-soluble polymer. It is a figure which shows the viscosity characteristic of the static state of a pseudoplastic fluid water-soluble polymer, and a dynamic state. It is a figure which shows the viscosity characteristic of a static state and a dynamic state of a thixotropic fluidity water-soluble polymer.

The oxide-based layered compound used as the main component in the seamless steel pipe processing lubricant composition of the present invention is, for example, natural or artificial mica. As mica, potassium tetrasilicon mica {KMg _2.5 (Si ₄ O ₁₀ ) F ₂ }
Sodium tetrasilicon mica (NaMg _2.5 (Si ₄ O ₁₀ ) F ₂ )
Natural gold mica {KMg ₃ (AlSi ₂ O ₁₀ ) (OH) ₂ }
and so on. One or more of these can be used in the seamless steel pipe processing lubricant composition of the present invention. Further, vermiculite, bentonite or the like can be used instead of or together with mica. Most preferred for the seamless steel pipe working lubricant composition of the present invention is sodium tetrasilicon mica.

  The average particle diameter of the oxide-based layered compound is 1 to 40 μm, preferably 5 to 30 μm. If the average particle size is too small, the effect of slipping between layers is reduced. On the other hand, if the average particle size is too large, problems such as nozzle clogging during spraying occur. The addition amount of the oxide-based layered compound is 10 to 40% by mass, preferably 20 to 30% by mass, in the composition of the seamless steel pipe processing lubricant of the present invention. If the added amount of the oxide-based layered compound is too small, the seizure resistance is lowered, which causes a problem in lubricity. On the other hand, when the amount of the oxide-based layered compound added is too large, the viscosity of the composition becomes too high, causing a problem in workability.

The alkali metal borate salt or amine salt in the composition assists its spreadability in the high-temperature mandrel bar along with the oxide-based layered compound as the main agent, and acts as an auxiliary lubricant by itself. Examples of the alkali metal borate include lithium borate, sodium borate, and potassium borate. Further, metaborates or pyroborates and / or hydrates such as borax (Na ₂ B ₄ O ₇ · 10H ₂ O) can also be used.

  The addition amount of the alkali metal borate or amine salt in the composition is 5 to 30% by mass, preferably 10 to 20% by mass. When there is too much addition amount of these salts, the lubricity of a main ingredient will be disturbed. Moreover, when the addition amount of these salts is too small, the spreading effect of the main agent, which is the main agent, on the mandrel bar is impaired, and insufficient lubrication is induced as a result of insufficient fluid lubrication.

  As the water-soluble polymer used in the seamless steel pipe processing lubricant composition of the present invention, a natural, semi-natural, or synthetic water-soluble polymer alone or in a range that satisfies the viscosity condition defined in the present invention, or Multiple combinations can also be used. These water-soluble polymers will be specifically described later.

Next, an ideal viscosity form found by the present inventors is shown in FIG. Figure 1 shows viscosity on the vertical axis and time on the horizontal axis.
(I): Standing (ii)-(iii): Constant-speed shearing (iii)-(iv): Viscosity changing with time under the respective conditions of shear stop.

The inventors of the present application, when the seamless steel pipe working lubricant composition has the viscosity characteristics shown in the following (1) to (4), in producing a seamless metal pipe by the Mannesmann pipe method, good lubricity It was found that can be obtained. That is, (1) In order to store solid particles such as an oxide-based layered compound uniformly and stably, it is necessary that the viscosity at the time of (i) standing is high. This is because if the viscosity is low, the solid particles will settle.
(2) In order to ensure fluidity and sprayability in the piping, it is necessary that the viscosity during shearing (ii) to (iii) is low.
(3) For the dense and uniform adhesion of the fluid having the greatest influence on the lubricating performance to the high-temperature bar, the viscosity of (ii) needs to be high. When viewed microscopically, the lubricant is continuously sprayed onto the tool surface. At that time, the lubricant that has arrived next is sprayed onto the lubricant film that has arrived and adhered first. That is, since the lubricating film that was first attached is sheared, if the viscosity of (ii) is low, it is scraped off or scattered by the spray pressure.
(4) In order to ensure uniform and stable retention of solid particles on the tool surface, it is necessary to immediately start to increase in viscosity after the end of shearing in (iii) to (iv). This is because it takes time until the viscosity is recovered, or the lubricant flows down from the tool surface if the viscosity does not recover.

The viscosity form of FIG. 1 satisfying various properties such as storage stability, transportability in equipment piping, sprayability to lubrication, and uniform adhesion to a high temperature mandrel bar without adding a large amount of polymer. In order to realize, the present inventors have found that it is necessary to satisfy the following formula. That is, as a result of measuring the viscosity characteristics of the lubricant composition of the present invention satisfying the above-mentioned properties by the viscosity measuring method described in the examples described later, the obtained viscosity characteristic curves are represented by the following approximate expressions a and b. It was within the range.
Y = a · X ^b Y: Viscosity (mPa · s)
X: shear rate (s ⁻¹ )
During stationary storage, a: 4000 to 40000
b: -1.0 to -0.3
90 seconds after the end of shearing a: 1000-20000
b: -1.0 to -0.15
In the approximate expression Y = a · X ^b , during stationary storage a: 4000 to 40000,
b: -1.0 to -0.3
It was. This is because if the a is less than 4000, the viscosity of the lubricant composition upon standing is low, and the oxide-based layered compound settles during storage. On the other hand, if a exceeds 40000, the fluidity of the lubricant composition is almost lost, causing a problem in transportation.

Furthermore, when b is larger than −0.3, the difference between the viscosity of the lubricant composition when it is left stationary and the viscosity when it is sheared (when transporting or spraying) is small, which causes problems in transportation and spraying. On the other hand, if b is less than -1.0, the viscosity of the lubricant composition drops too much when sprayed, and when applied to the tool, the adhered lubricant is scraped off or scattered by the pressure of the lubricant itself. . More preferably,
a: 7000-30000
b: -0.5 to -0.8
It is.

Here, the approximate expression Y = a · ^Xb will be described with reference to FIG. 1. When the stationary storage (that is, when the value of X is close to 0), the value of a is larger and the value of b is smaller. The viscosity of 1 (i) is high and the stability is good. For example,
X = 0.01, a = 100000, b = −1
Then, Y = 10,000,000 mPa · s.

In the approximate expression Y = a · X ^b , 90 seconds after the end of shearing a: 1000 to 20000
b: -1.0 to -0.15
It was. When a is less than 1000 or b is less than −1.0, the water-soluble polymer is sheared, and it takes time until the viscosity recovers, or when applied to the tool without being recovered by shearing, the lubricant flows down. Because it will end up. Further, if a exceeds 20000, or b exceeds -0.15, a problem occurs during transfer or spraying. More preferably,
a: 3000-20000
b: -0.3 to -0.8
It is.

The viscosity of (ii) to (iii) in FIG. 1 is higher when the value of a is larger and the value of b is smaller during shearing (that is, when the value of X immediately after stirring is large). When “a” is too large and “b” is too small, the viscosity is not lowered and the transportability and sprayability are hindered. For example,
X = 10, a = 100000, b = −1
Then, Y = 10,000 mPa · s After shearing (that is, when the value of X immediately after stirring is small), it is (iv) in FIG. 1, and the values of a and b are the same as those at the time of stationary storage. If it becomes about a degree, the viscosity will be recovered quickly. In this case, when the lubricant adheres to the tool, it becomes difficult to flow down. Therefore, an appropriate viscosity characteristic as described above is required.

  As a result of earnestly examining the conditions for satisfying the above-mentioned viscosity characteristics, the inventors of the present application, as a water-soluble polymer used in the lubricant composition of the present invention, may be satisfied even with a pseudo plastic flowable water-soluble polymer alone. However, it has been found that adding both a pseudoplastic fluid water-soluble polymer and a thixotropic fluid water-soluble polymer is satisfactory.

  Representative examples of pseudo plastic fluid water-soluble polymers include bio gums such as xanthan gum, welan gum, and lamb gum gum. The chemical structure of xanthan gum is a water-soluble polymeric polysaccharide consisting of repeating binding blocks, with the structural component consisting of 2 glucose, 2 mannose and 1 glucuronic acid as a unit. The chemical structure model is shown in FIG.

  Typical examples of thixotropic fluidity water-soluble polymers include carboxymethylcellulose salts (Na salt, K salt, amine salt). As an example, FIG. 3 shows a chemical structure model of a long-chain polymer in which glucose is glucoside-bonded.

  In addition to the above, pseudo plastic fluidity and / or thixotropic fluidity can be used for the following substances that are difficult to distinguish clearly due to the influence of molecular weight, other components (for example, metal (Ca, etc.) ions) and pH, such as duran gum, Biogum such as succinoglucan, natural polysaccharides such as tamarind, tara gum, locust bean gum, carrageenan, cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, and other polyacrylic acid It can also be achieved by blending a salt (Na salt, K salt, amine salt), a salt of alginic acid (Na salt, K salt, amine salt) and the like into the lubricant composition.

  Next, FIG. 4 shows the static and dynamic viscosity characteristics of the pseudoplastic fluid water-soluble polymer, and FIG. 5 shows the thixotropic fluid water-soluble polymer. With only the pseudo plastic flowable water-soluble polymer, the change from the static state to the dynamic state is linear, which is within the scope of the present invention but is not fully satisfactory. On the other hand, the viscosity change of the thixotropic flowable water-soluble polymer is less gradual than the viscosity change of the pseudoplastic flowable water-soluble polymer when the transition from the static state to the dynamic state is small. In addition, the thixotropic fluidity water-soluble polymer requires some time (yield value) from the occurrence of the dynamic state to the decrease in viscosity. In addition, the thixotropic fluidity water-soluble polymer requires time to increase the viscosity when moving from dynamic to static. If it takes a long time to change the viscosity, the lubricant sprayed on the mandrel bar cannot change the viscosity for ideal film formation in the film forming process until drying. As a result, it causes difficulty in uniform adhesion to the mandrel bar. Therefore, only the thixotropic fluidity water-soluble polymer cannot sufficiently satisfy the object of the present invention.

  In order to realize the ideal viscosity form shown in FIG. 1, it is desirable to add both of the two types of polymers described above. Specifically, the addition ratio of the pseudoplastic fluid water-soluble polymer is 0.01 to 1.0% by mass based on the total amount of the composition, and the addition ratio of the thixotropic fluid water-soluble polymer is the composition. It is 0.1-2.0 mass% on the basis of the total amount of things. More preferably, the ratio of the pseudoplastic flowable water-soluble polymer is 0.05 to 0.5% by mass based on the total amount of the composition, and the ratio of the thixotropic flowable water-soluble polymer is based on the total amount of the composition. 0.5 to 1.5 mass%.

  If the ratio of the pseudoplastic fluid water-soluble polymer added exceeds the ratio of the thixotropic fluid water-soluble polymer, the change in viscosity due to shearing becomes too large, resulting in difficulty in uniform adhesion to the mandrel bar. On the other hand, when the ratio of the thixotropic fluidity water-soluble polymer becomes too large, the dispersion stability of the oxide-based layered compound and the spreadability to the high-temperature mandrel bar are deteriorated, resulting in difficulty in uniform adhesion.

  The viscosity forms of these two types of mixed systems have a composite form of viscosity characteristics shown in FIGS. The qualitative viscosity characteristics are as follows. That is, in FIG. 1, the viscosity at the time of stationary is high in the location of (i) by the property of a pseudo plastic fluid. Thereafter, when shearing is applied, the viscosity decreases of (i) to (iii) having a composite form of a pseudo plastic flow state and a thixotropic flow state are shown. Finally, as soon as the shearing is finished, the viscosity increases as shown in (iv).

  If the total of both polymers exceeds 3.0% by mass based on the total amount of the composition, a problem of carburization occurs, which is not preferable. Further, when the ratio of both polymers is less than 0.11% by mass based on the total amount of the composition, the dispersion stability of the oxide-based layered compound becomes difficult, and the lubricant composition of the present invention is not completed.

  In addition, the addition of general antifoaming agents and dispersants is only allowed to be added in a small amount (0.5% by mass or less based on the total amount of the composition) since organic compounds have a risk of carburization. For inorganic materials that do not contain carbon, addition is permitted as long as the basic performance of the present invention is not affected.

(1) Preparation of Evaluation Samples Eighteen types of Examples shown in Tables 1 and 2 and 10 comparative examples shown in Table 3 were prepared in a total of 28 types. Tables 1 to 3 also show the values of the intrinsic constants “a” and “b” 90 seconds after the stationary storage and the end of shearing in the approximate expression of these samples.

(2) Performance evaluation test 1) Viscosity (i) Measurement conditions Measuring instrument: B-type rotational viscometer was used.
Measurement temperature: set to 25 ° C.
Shearing conditions: Put 500 ml of sample in a 500 ml beaker and put it on a propeller of φ50 mm
The mixture was stirred for 1 minute under the condition of 3000 rpm.
Rotation speed: Low rotation (1.5 rpm) [Shear speed: 0.323 to 0.366 (s ⁻¹ )]
High rotation (60 rpm) [Shear speed: 12.9 to 14.6 (s ⁻¹ )]
Note that the above-mentioned shear rate has a range of numerical values because the cone actually used is different for each sample in the rotational viscometer that measures the viscosity by rotating the cone on the plate.
(Ii) Measurement method static viscosity: a sample that has been allowed to stand for 24 hours after stirring, starts measurement at a low shear rate, and the viscosity obtained by multiplying the scale of the viscometer 60 seconds after the start of measurement by a coefficient, Subsequently, the measurement was started at a high shear rate, and the viscosity obtained by reading the scale after 60 seconds from the start of the measurement and multiplying by the coefficient was recorded as the static viscosity.
Shear viscosity: The sample was stirred with a propeller to give shear, 30 seconds after the end of the operation, the measurement was started at a low shear rate, and the scale of the viscometer 60 seconds after the start of the measurement was read and multiplied by the coefficient. 30 seconds after the sample was stirred again, the measurement was started at a high shear rate, and the scale obtained by reading the scale 60 seconds after the start of the measurement and multiplying by the coefficient was recorded as the shear viscosity.
In the above measurement, “after 90 seconds from the end of shearing” means an operation of stirring the sample composition and applying shear, and after 30 seconds from the end of the operation, measurement is started at a predetermined shear rate. This means 60 seconds after the start of measurement. That is, “after 90 seconds” corresponds to the total value of 30 seconds and 60 seconds. In addition, “at the end of shearing” means when the rotation of the propeller for the stirring operation is stopped.
(Iii) Determination of the values of the intrinsic constants “a” and “b” In the approximate expression Y = a · X ^b , when the logarithm of both sides is taken,
log (Y) = blog (X) + log (a)
On the other hand, for X and Y obtained by the above measurement, log (X) and log (Y) are obtained and plotted in correspondence with the vertical and horizontal axes of the graph, respectively. Relationship) is obtained. From the plotted data, the slope of the linear function “b” and the vertical axis intercept “a” can be obtained by the method of least squares.

2) Storage stability (i) Test method 500 ml of a sample was stored in a glass container, and the state of separation after standing for 7 days was observed.
(Ii) Evaluation method: Evaluation was performed according to the following evaluation criteria.
A: No generation of supernatant and no sedimentation at the bottom.
○: Occurrence of less than 5% of supernatant and no sedimentation at the bottom.
Δ: Supernatant 5% or more generated, no bottom sedimentation.
X: There is sedimentation at the bottom regardless of the occurrence of supernatant.
However, “supernatant” refers to a substantially transparent liquid portion that does not contain solid matter. The detection was performed by observing from the side surface of a 500 ml beaker and measuring the height of the supernatant from the sample liquid surface. The supernatant height was evaluated as a percentage of the total liquid level.
Further, “bottom sedimentation” means a state where a solid lubricant settles on the bottom and a hard layer having no fluidity can be confirmed.

3) Carburizing property (i) Test method Four types of lubricants of Examples 4, 11, 13 and Comparative Example 6 are spray-coated on a mandrel bar having a material of SKD61, an outer diameter of 140.5 mm, and an effective portion length of 18 m. Then, it was dried and solidified to form a substantially uniform lubricating film having a thickness of 100 μm on the surface of the mandrel bar. The mandrel bar coated with the lubricant was inserted into a blank having the following details, and stretched and rolled into a blank for final rolling using a mandrel mill consisting of 7 stands.
Specifications for raw tube before drawing and rolling Material: Austenitic stainless steel (SUS304L)
Original processing: piercing and rolling with inclined roll piercing and rolling machine Shape: outer diameter 181.0mm, wall thickness 16.0mm, length 7000mm
Shape of tube after drawing and rolling: outer diameter 151.0mm, wall thickness 5.0mm, length 25300mm
After rolling with a mandrel mill, it was subsequently finish-rolled with a stretch reducer comprising 26 stands, and finished into a steel pipe having an outer diameter of 63.5 mm, a wall thickness of 7.0 mm, and a length of 40000 mm. An arc-shaped test piece having a thickness of 5 mm, a width of 25 mm, and a length of 50 mm was collected from this steel pipe. Using this test piece, the sulfuric acid-copper sulfate corrosion test specified in JIS G0575 was performed, and the intergranular corrosion cracking state generated on the inner surface was observed.
(Ii) Evaluation method: Evaluation was performed according to the following evaluation criteria.
(Double-circle): There is no crack.
X: There is a crack.

4) Sprayability (i) Test conditions Spray method: An airless spray was used.
Discharge pressure: set to 3.0 MPa.
Nozzle: 1 / 4MVVP5010 (manufactured by Ikeuchi Co., Ltd.)
Spray pattern: Fan type Spray angle: 50 degrees (An angle that spreads in a fan shape when water is sprayed)
Sample temperature: set to 25 ° C. for evaluation.
(Ii) Evaluation: Spreadability was evaluated by measuring the spray angle. The evaluation results were recorded according to the following evaluation criteria.
A: Sprayed almost at a predetermined angle (50 degrees).
A: Slightly narrower than a predetermined angle (40 to 45 degrees).
(Triangle | delta): It is considerably narrower than a predetermined angle (20-39 degree | times).
X: Almost no spread (less than 20 degrees) or large spray particles.

5) Adhesiveness (attachment amount)
(I) Test conditions Spray method: An airless spray was used.
Discharge pressure: set to 3.0 MPa.
Nozzle: 1 / 4MVVP5010 (manufactured by Ikeuchi Co., Ltd.)
Spray angle: 50 degrees Sample temperature: 60, 80, 100, 120 ° C.
Nozzle-specimen distance: The test was performed with the distance set to 250 mm.
Specimen speed: 2 m / sec.
(Ii) Evaluation method: A specimen (65 mm × 120 mm × 30 mm steel plate) is sprayed under test conditions, and after application, the specimen is heated to 120 ° C. to dry the lubricant, and then released to 20-40 ° C. After cooling, the lubricant film was peeled off with a knife, the weight was measured, and the value divided by the adhesion area (0.0078 m ² ) was defined as the adhesion amount, and evaluation was performed according to the following evaluation criteria.
(Double-circle): It adheres uniformly and the adhesion amount is 50 g / m ² or more.
○: Adhering almost uniformly, and an adhesion amount of 50 g / m ² or more.
(Triangle | delta): It flows down a little and the adhesion amount is 40 g / m < ² > or more.
X: Flowed down violently and the adhesion amount was 30 g / m ² or less.
Xx: Adhesiveness is poor due to repelling, and the adhesion amount is 30 g / m ² or less.

(3) Test results The results of the above tests 1) to 5) are shown in Tables 1 to 3.

ＣＭＣ^＊（Ａ）：分子量（100,000） 粘度（８００／２％^＊＊）
ＣＭＣ^＊（Ｂ）：分子量（250,000） 粘度（１６００／１％）
ＣＭＣ^＊（Ｃ）：分子量（175,000） 粘度（２５００／２％）
ＣＭＣ^＊（Ｄ）：分子量（195,000） 粘度（３５００／２％）
ＣＭＣ^＊（Ｅ）：分子量（30,000） 粘度（１５／２％）
ポリアクリル酸Ｎａ（Ａ）：分子量（500,000） 粘度（７５／１％）
ポリアクリル酸Ｎａ（Ｂ）：分子量（1,650,000） 粘度（３００／０．２％）
＊ＣＭＣ＝カルボキシメチルセルロースのＮａ塩
＊＊：２％水溶液にした時の、２５℃における粘度が８００ｍ
Ｐａ・ｓであることを表す。

CMC ^* (A): Molecular weight (100,000) Viscosity (800/2% ^** )
CMC ^* (B): Molecular weight (250,000) Viscosity (1600/1%)
CMC ^* (C): Molecular weight (175,000) Viscosity (2500/2%)
CMC ^* (D): Molecular weight (195,000) Viscosity (3500/2%)
CMC ^* (E): Molecular weight (30,000) Viscosity (15/2%)
Polyacrylic acid Na (A): Molecular weight (500,000) Viscosity (75/1%)
Polyacrylic acid Na (B): Molecular weight (1,650,000) Viscosity (300 / 0.2%)
* CMC = Carboxymethylcellulose Na salt
**: 800m viscosity at 25 ° C when 2% aqueous solution
Represents Pa · s.

(4) Conclusion From the above test results, it was confirmed that the lubricating oil compositions of the examples of the present invention had good performance in all aspects of storage stability, sprayability, and adhesion. On the other hand, the composition group shown in the comparative example could not obtain satisfactory performance in these respects.

  Although the present invention has been described with reference to the most practical and preferred embodiments at the present time, the invention is limited to the embodiments disclosed herein. However, the present invention can be changed as appropriate without departing from the scope or spirit of the invention that can be read from the claims and the entire specification, and a seamless steel pipe working lubricant composition with such changes is also within the technical scope of the present invention. Must be understood as encompassed by.

  The seamless steel pipe processing lubricant composition of the present invention can be used mainly for the production of seamless steel pipes by the Mannesmann pipe manufacturing method.

Claims (4)

A seamless steel pipe processing lubricant composition having a viscosity characteristic represented by the following approximate formula:
Y = a · X ^b Y: Viscosity (mPa · s)
X: shear rate (s ⁻¹ )
During stationary storage a: 4000 to 40000
b: -1.0 to -0.3
90 seconds after the end of shearing a: 1000-20000
b: -1.0 to -0.15 Oxide-based layered compound 10-40% by mass, boric acid alkali metal salt or amine salt 5-30% by mass, boric acid alkali metal salt or amine salt one or more aqueous solutions soluble in water The seamless steel pipe working lubricant composition according to claim 1, comprising 0.11 to 3.0% by mass of at least one functional polymer and the balance water. The seamless steel pipe processing lubricant according to claim 2, wherein the water-soluble polymer includes a pseudoplastic fluid water-soluble polymer, or a pseudoplastic fluid water-soluble polymer and a thixotropic fluid water-soluble polymer. Composition. The water-soluble polymer includes 0.01 to 1.0 mass% pseudoplastic fluid water-soluble polymer and 0.1 to 2.0 mass% thixotropic fluid water-soluble polymer based on the total amount of the composition. Item 3. The seamless steel pipe processing lubricant composition according to Item 2.

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