JPH0762375A - Hot lubrication method for steel materials - Google Patents

Abstract

(57) [Summary] [Purpose] In hot rolling, roll wear is reduced, seizure on rolling rolls is prevented, and rolling product quality and work efficiency are improved without causing slipping or biting defects. How to hot lubricate. [Structure] During hot rolling of thick plates, hot rolling of shaped steels such as H-section steel, and pipe making of seamless steel pipes, a highly basic metal salt sulfonate (eg, base number 200 mg-KOH / A lubricant composition containing 20 to 70% by weight of g or more of highly basic Ca sulfonate) is supplied to the surface of a rolling roll.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a steel material in various shapes such as hot rolling of thick plate, H rolling of a H-shaped steel by a universal mill or hot rolling of a shaped steel by a hole type roll, and hot manufacturing of a seamless steel pipe. The present invention relates to a lubrication method in hot rolling. More specifically, even in hot rolling of stainless steel where seizure is likely to occur, it is possible to prevent wear and seizure of rolls, reduce roll unit consumption, improve operating rate, prevent product defects, etc. The present invention relates to a lubrication method in hot rolling, which exhibits a lubrication effect.

[0002]

2. Description of the Related Art In the hot rolling of steel materials such as thick plates,
Since rolling is performed under conditions of high temperature and high pressure, roll wear is large, and particularly in hot rolling of stainless steel, in addition to roll wear, roll surface roughness due to seizure and rolled product flaws are also major problems. Was there.

High Cr steel represented by stainless steel generally contains 13% by weight or more of Cr and is excellent by forming a stable Cr oxidation protective film on the surface of the steel and passivating the surface. Exhibits corrosion resistance and oxidation resistance. However, since this surface oxide film is significantly thinner than that of carbon steel and has high resistance to hot deformation, it easily peels off when subjected to plastic working during hot rolling. When the surface oxide film peels off,
Metal-to-metal contact occurs between the work material and the rolling roll, seizure occurs, and roughening of the roll surface occurs, which is transferred to the rolled product, causing flaws in the rolled product.

Such a phenomenon has been recognized not only in thick plate production lines but also in hot rolling in production lines for various rolled products. For example, H-section steel is a steel material used for building structures and the like, and in its finish rolling,
Hot rolling is performed by a universal mill for H-section steel rolling, which includes a pair of horizontal rolls and a pair of vertical rolls. This H
In the hot rolling of shaped steel, a high temperature is applied between the side surface of the horizontal roll and the inner surface of the H-shaped steel flange that is rolled by it, and between the outer peripheral surface of the vertical roll and the outer surface of the H-shaped steel flange that is rolled by it. Due to sliding friction, seizure is likely to occur. In fields such as chemical plants where corrosion resistance is required, stainless H-section steel is adopted, but in H-section steel rolling of stainless steel, the high resistance to hot deformation of stainless steel itself causes a particularly high surface area. Pressure is applied and severe seizure occurs. The same problem also occurs in the hot rolling of shaped steel by means of hole-type rolls.

Further, in the Mannesmann system seamless steel pipe production line, at the time of hot pipe making by a roll for roll rolling such as sizer or reducer, the edge portion of the roll for rolling roll having the severest friction with the work material is produced. Seizure occurred around the periphery, flaws in the rolled product occurred, and roll wear was large. Such seizure and roll wear were particularly remarkable when the material to be processed was stainless steel.

The occurrence of roll surface roughness and rolling product flaws due to such roll wear and seizure reduces the amount of cycle rolling due to early roll change, deteriorates the roll unit consumption, decreases the operating rate, and reduces the quality of rolled products. This leads to a decrease and an increase in flaw maintenance costs.

Conventionally, as a measure against this problem, a lubricant is applied to the rolling roll for the purpose of preventing seizure and reducing wear by reducing the frictional force between the rolling roll and the workpiece. It is being supplied.

As a lubricant used for this purpose, for example, JP-A-47-18907 discloses a natural fatty oil containing a small amount of a water displacing agent of 10% by weight or less (eg, oil-soluble sulfonate salt).
A lubricant composition containing the above is proposed. Also, 10μ
A lubricant composition in which about m of finely divided calcium carbonate is dispersed in water or a lubricating base oil is disclosed in Japanese Examined Patent Publication No. 62-14598.
It is disclosed in JP-B-62-39198 and JP-B-62-39199.

However, these lubricants are intended for lubrication during rolling of carbon steel, and when they are used for hot rolling of stainless steel, the work material is severely seized on the surface of the rolling roll, and the rolled product is flawed. Cause Further, there is a problem that the rolling efficiency is extremely lowered because the rolling roll is largely worn.

As a lubricant for rolling stainless steel, a lubricant in which iron oxide powder is dispersed is disclosed in Japanese Patent Laid-Open No. 63-2541.
Japanese Patent Laid-Open Publication No. Hei 1-167396 discloses a method in which graphite powder is dispersed in a viscous aqueous solution.

However, even if the iron oxide powder is dispersed in order to suppress the direct contact between the metal of the rolling roll and the material to be processed, the effect of sufficiently preventing seizure and wear has not been obtained. Further, since graphite has an extremely low coefficient of friction, it may cause biting failure and slip during rolling, and it was not possible to include graphite in an amount sufficient to sufficiently exhibit the seizure prevention effect and wear reduction effect. .

Further, especially in the hot rolling of thick plates,
When the lubricant is supplied to reduce the coefficient of friction between the rolling roll and the work material, slippage is likely to occur during biting. The defective biting due to the slip is noticeable when a thick plate having a thickness of 6 mm or more is rolled by a large-diameter roll. Therefore, with a conventional lubricant that prevents roll wear and seizure due to a reduction in the friction coefficient, slip may occur and rolling itself may not be possible before sufficient seizure prevention and wear reduction are realized. Even in the case of shaped steel rolling or pipe manufacturing of seamless steel pipe, if the friction coefficient becomes too low, slip and bite failure still occur.

The above-mentioned problems are particularly remarkable in the hot rolling of stainless steel, but even in the hot rolling of carbon steel and other special steels, under severe rolling conditions in which a high load is applied to the work material, Similar problems occur to varying degrees. As the rolling speed increases to improve productivity, roll wear and seizure problems are expected to increase in importance even in hot rolling of carbon steel.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce roll wear without causing slipping or biting failure in hot rolling of various steel materials including stainless steel.
It is an object of the present invention to provide a lubrication method in hot rolling of a steel material, which can improve the quality of rolled products and work efficiency by preventing seizure of a material to be rolled onto a rolling roll.

Another object of the present invention is to perform hot rolling of thick plates, hot rolling of H-section steel by a universal mill or rolling of section steel by means of hole-type rolls, and hot pipe making of seamless steel pipes. The object is to achieve the above-mentioned object, and even if the material is stainless steel, the material to be rolled is a rolling roll.
(EN) In the case of pipe manufacturing, it is possible to provide a lubricating method in hot rolling of steel material, which can prevent seizure on the edge portion of a holed roll and can significantly reduce roll wear.

[0016]

DISCLOSURE OF THE INVENTION As a result of searching for a lubricant capable of achieving the above object, the present inventors lubricated a highly basic metal salt sulfonate developed as a detergent / dispersant for internal combustion engine lubricating oils. The inventors have found that a lubricant as a main component is optimal, and have reached the present invention.

The gist of the present invention is as follows. In the hot rolling of thick plates, a lubricant composition containing 20 to 70% by weight of a highly basic metal salt sulfonate is supplied to the surface of a rolling roll, and a lubricating method in hot rolling of thick plates of steel. In the hot rolling of shaped steel, a lubricant composition containing 20 to 70% by weight of a highly basic metal salt sulfonate is supplied to the surface of a rolling roll for lubrication. In the hot production of a seamless steel pipe, a lubricant composition containing 20 to 70% by weight of a highly basic metal salt sulfonate is supplied to the surface of a holed roll for rolling. Lubrication method in manufacturing.

Here, "highly basic" means JIS K 2501.
The base number measured by (potentiometric titration) is 40 mg-KOH / g
It means that it is above. When two or more highly basic metal salt sulfonates are used, the average value of the base numbers in consideration of the amount of each component in the mixture should be 40 mg-KOH / g or more.

[0019]

The highly basic metal salt sulfonate used in the present invention is obtained by sulfonating an alkyl aromatic with fuming sulfuric acid or SO ₃ gas and converting the obtained petroleum sulfonic acid into an alkaline earth metal (eg, Ca, Ba, Mg). It is produced by neutralizing with a carbonate or hydroxide to give a metal salt (normal salt), and further reacting this metal salt with a carbonate or hydroxide of an alkaline earth metal in the presence of carbon dioxide gas. In addition, you may use an alkali metal as some or all of an alkaline-earth metal. This highly basic metal salt sulfonate contains a large amount of excess alkaline earth metal, which is 3 to 15 times as large as that of the normal salt, mainly as carbonate fine particles having a particle size of 150 Å or less. These ultrafine carbonate particles are naturally deposited during the production process of the highly basic metal salt sulfonate, and when the highly basic metal salt sulfonate is mixed with the lubricating base oil, the fine particles colloid in the base oil. Form a dispersion.

The highly basic metal salt sulfonate is excellent in heat resistance and can contribute to lubrication in a fluid or a state close to a fluid without being completely combusted or decomposed even at the hot rolling temperature of steel. Furthermore, the highly basic metal salt sulfonate is also highly reactive with the oxides on the surface of the steel material, and it is possible to form a lubricious chemical reaction coating that is difficult to peel off on the surface during plastic working, and these effects are unclear. It was found that the lubricity during hot rolling can be significantly improved.

Also, the particle size contained in the highly basic metal salt sulfonate to form a colloidal dispersion in oil 1
Carbonate fine particles of 50 Å or less have an effect of physically suppressing direct metal-to-metal contact between the workpiece and the rolling roll. By introducing the ultrafine solid particles into the surface irregularities of the friction surface, direct contact between the metals is thoroughly suppressed, and seizure is prevented. Further, roll wear is significantly reduced due to the above-mentioned effect of improving lubricity.

Note that the ultrafine solid particles of carbonate do not have a function of relieving the friction of the interface to a large extent, unlike the solid shear-type lubricant represented by graphite. Instead, it acts like a roller at the friction interface to ensure that the minimum friction coefficient required for stable rolling without slipping is reduced and maintained. Therefore, since the friction coefficient does not unnecessarily decrease significantly, it is not found in conventional lubricants that the effects of seizure prevention and roll wear reduction can be exhibited without causing slipping or biting failure. It has been found that such an excellent lubricating action is exhibited.

As a result, seizure that occurs in rolls during thick plate rolling, horizontal roll side faces during H-shaped steel rolling and H-shaped rolling, while maintaining the frictional force required for stable rolling without slips or biting defects. Effectively prevent seizure that occurs on the inner surface of the steel flange, the outer peripheral surface of the vertical roll, and the outer surface of the H-shaped steel flange, as well as seizure that occurs on the hole-type roll edge when manufacturing a seamless steel pipe. Therefore, roll wear can be significantly reduced, and good rolled product quality can be obtained.

In the present invention, a lubricant containing 20 to 70% by weight of a highly basic metal salt sulfonate in a base oil during hot rolling of steel products such as thick plate rolling, shaped steel rolling, or seamless steel pipe making. By feeding the composition to the rolling roll,
The above effects are obtained. If the amount of the highly basic metal salt sulfonate in the lubricant composition is less than 20% by weight, seizure cannot be sufficiently prevented and roll wear is large. On the other hand, if this amount exceeds 70% by weight, the above effect is saturated. A more preferable amount of the overbased metal salt sulfonate is 30 to 60% by weight. The amount of this highly basic metal salt sulfonate is
It is the weight% based on the total weight of the undiluted solution of the lubricant composition, that is, the composition before dilution when diluted with water or the like.

Alkyl aromatics as raw materials for highly basic metal salt sulfonates include mineral oil lubricating oil fractions, synthetic compounds,
For example, alkylbenzene, a product obtained by alkylating polyolefin with benzene, and dinonylnaphthalene can be used.

The metal salt of the highly basic metal salt sulfonate is
It can be selected from alkaline earth metals and alkali metals, but it is preferred to use alkaline earth metal salts such as highly basic Ca sulphonate, highly basic Mg sulphonate, highly basic Ba sulphonate. Highly basic Ca sulfonate has the highest lubricating effect, so it is highly basic.
At least 20% by weight of Ca sulfonate in the lubricant composition
It is more preferable to contain it.

Such highly basic metal salt sulfonates may be used either individually or in combination of two or more. In the case of a mixture of two or more, the average base number of the mixture is 40 mg-KO
It should be H / g or higher. Therefore, in this case, if the low basic metal salt sulfonate having a base number lower than 40 mg-KOH / g is mixed with the high basic metal salt sulfonate and the average base number becomes 40 mg-KOH / g or more, Is available.

The highly basic metal salt sulfonate has a base number of
The above effects can be achieved if the amount is 40 mg-KOH / g or more, but the one having a base number of 200 mg-KOH / g or more is particularly excellent in anti-seizure ability and abrasion resistance.

When the base number is less than 200 mg-KOH / g, the content of the ultrafine solid particles of carbonate is relatively small, and therefore the carbonate fine particles necessary for physically preventing direct contact between metals are contained. The amount introduced into the friction interface will be insufficient. Therefore, for example, when the material to be processed is a stainless steel material in which seizure is likely to occur, complete prevention of seizure and sufficient reduction of roll wear may not be achieved.

However, such a base number is 200 mg-KOH / g
A highly basic metal salt of less than sulfonate also exerts a sufficient lubricating effect in hot rolling of carbon steel or special steel in which seizure is relatively unlikely to occur, and prevents seizure and sufficiently reduces roll wear. You can Also, if the lubricant composition is supplied in a state of high viscosity or close to the undiluted solution, the base number of 20
A highly basic metal salt sulfonate of less than 0 mg-KOH / g can be used to exert a sufficient lubricating effect in hot rolling of stainless steel.

When the base number is less than 40 mg-KOH / g, the amount of carbonate fine particles is so small that seizure due to direct contact between metals cannot be prevented and does not function effectively as a lubricant. There is no particular upper limit to the base number of the highly basic metal salt sulfonate, but at present, the base number exceeds 500 mg-KOH / g, and it is not possible to manufacture products with properties such as appropriate viscosity as a lubricant. Is 500 mg-KOH / g.
However, if it becomes possible due to the manufacturing technology, it is possible to use one having a higher base number.

The lubricating oil composition used in the present invention can be prepared by blending a highly basic metal salt sulfonate with a commonly used lubricating base oil. As the lubricating base oil, oils and fats such as mineral oil, synthetic lubricating oil, rapeseed oil, lard oil,
One or more selected from higher fatty acids and their esters can be used.

A mixture of only a highly basic metal salt sulfonate and a lubricating base oil can be used satisfactorily, but if necessary, other solid lubricants, extreme pressure additives, antioxidants, pour point depressants, You may mix | blend a viscosity index improver etc.

Examples of solid lubricants include graphite, molybdenum disulfide, boron nitride, mica, talc and the like. Examples of extreme pressure additives include sulfur-based extreme pressure additives such as sulfurized fats and oils, sulfurized mineral oils, dinonyl polysulfide and the like, and tricresyl phosphate, dioctyl phosphate and other phosphoric acid-based extreme pressure additives. Examples of antioxidants include methylene-
Examples thereof include bisphenols such as 4,4-bis (2,6-di-tert-butylphenol); alkylphenols such as di-tert-butylcresol; and naphthylamines.
Examples of pour point depressants and viscosity index improvers include polymethacrylates and polyolefins.

The amount of the solid lubricant added is about 1 to 10% by weight, the amount of the extreme pressure additive is about 1 to 15% by weight, and the amount of the antioxidant is about 0.01 to 1.0% by weight. The addition amount of the point depressant and the viscosity index improver is 1 to 5% by weight, respectively.
It is a degree.

According to the present invention, in the hot rolling of a thick plate, the hot rolling of a shaped steel, or the hot pipe making of a seamless steel pipe, the above-mentioned lubricant composition (hereinafter simply referred to as lubrication) is applied to the surface of the rolling roll. Supply agent). As a result, as described above, seizure is prevented without causing slippage or defective biting,
Roughness of the roll and flaws of the rolled product due to seizure do not occur, and at the same time roll wear is significantly reduced, improving the quality and working efficiency of the rolled product. This effect is particularly remarkable when the material to be processed is a ferritic or austenitic stainless steel material, but it can sufficiently exhibit the effect even in the general hot rolling of carbon steel.

The specific method of supplying the lubricant is, according to the required viscosity and concentration, an air atomizing method in which the lubricant is mixed with compressed air and supplied in the form of a spray, or a water injection method in which it is mixed with water and supplied. The method of the present invention can be appropriately selected from known methods such as a steam atomization method of atomizing with heated steam and supplying, and any method can sufficiently obtain the effects of the present invention. Of course, the method of supplying the undiluted solution as it is may be used, and other general oil supply methods can also be used. When supplied in undiluted solution, the lubricant may be made non-flammable, for example, by making it water-soluble, if necessary. The supply amount of the lubricant largely varies depending on the rolling condition, and therefore it may be determined in advance by experiments so as to prevent seizure during hot rolling.

It is not always necessary to supply the lubricant to all of the rolling rolls, but the lubricant may be supplied to at least one rolling roll. That is, in the case of multi-pass rolling, the object of the present invention can be sufficiently achieved by supplying the lubricant only to the rolling rolls of some of the stands where seizure is likely to occur. Further, it is not necessary to supply the lubricant to the entire surface of each rolling roll in contact with the workpiece. The lubricant may be supplied only to the site where seizure easily occurs.

In the case of hot rolling of thick plates, the lubricant may be directly supplied to the upper and lower rolling rolls, or may be indirectly supplied to the rolling rolls through the reinforcing rolls. In some cases, the lubricant may be supplied to the thick steel plate (workpiece) just before rolling. An example of a lubricant supply method that can be used in the case of plate rolling is shown in FIG. In FIG. 1, the lubricant is directly supplied from the nozzle 11 to the rolling roll 12.
Reference numeral 13 is a reinforcing roll, 14 is a thick steel plate, 15 is a roll cooling water supply nozzle, and 16 is a drainer.

In the hot rolling of H-section steel by the universal mill, it is preferable to directly or indirectly supply the lubricant to the side surface of the horizontal roll and the outer peripheral surface of the vertical roll used in the finish rolling mill. In this case, seizure is likely to occur between the side surface of the horizontal roll and the inner surface of the H-section steel flange rolled by it, and between the outer peripheral surface of the vertical roll and the outer surface section of the H-section steel flange section rolled thereby. By supplying a lubricant, it is possible to completely prevent seizure and product defects at this portion.

FIG. 2 shows how H-section steel is rolled by a universal mill. 22 is horizontal roll, 23 is vertical roll, 24
Indicates an H-shaped steel, and 25 indicates a portion where seizure easily occurs. An example of the lubricant supply method in this case is shown in FIG. In this example, the lubricant is directly supplied from the nozzle 21 to the side surface of the horizontal roll 22 and the outer peripheral surface of the vertical roll 23, that is, a portion where seizure easily occurs.

Of course, also in hot rolling of shaped steels other than H-shaped steel by means of hole-shaped rolls or the like, the same effect can be obtained by directly or indirectly supplying the above lubricant to all or part of the rolling rolls. Can be obtained.

The hot rolling lubrication method of the present invention can be applied, for example, in the hot manufacturing process of the Mannesmann system seamless steel pipe,
It can be carried out by supplying the above-mentioned lubricant to a roll for roll rolling used as a sizer, a reducer or the like. In this case, it is desirable that the roll of the lubricant is supplied directly to the periphery of the roll edge where seizure is likely to occur.

FIG. 4 shows an example of a method of supplying a lubricant to a hole-type rolling roll in producing such a seamless steel pipe. The lubricant is directly supplied from the nozzle 41 to the edge portion 44 of the grooved rolling roll 42 where seizure easily occurs. 43 is a rolled steel pipe.

[0045]

Examples Example 1 (Hot rolling of thick plate) Twelve kinds of lubricant compositions Nos. 1 to 12 shown in Table 1 were prepared. Of these, Nos. 1 to 9 were examples of the present invention, Nos. 10 to 11 were comparative examples, and No. 12 was a conventional example. The lubricant compositions of the present invention and comparative examples were prepared by mixing a high-viscosity refined mineral oil and a fat / oil at a ratio of 1: 1 with a base oil of a lubricating oil and a highly basic metal salt sulfonate at a predetermined ratio with a homomixer. It was prepared by the above. The lubricant composition of the conventional example has almost the same viscosity as that of the example of the present invention (80 cS at 40 ° C).
It is a commercially available general hot rolling oil having t).

In the four-stage rolling of the hot rolling line for thick plates, the lubricant supply equipment shown in FIG. 1 is arranged and each prepared lubricant composition is applied to an austenitic stainless steel plate (JIS
SUS304) rolling chance (rolling amount 3000 tons, rolling temperature 110
It was supplied to the upper and lower rolling rolls (made of ductile cast iron) at 0 ° C. Lubricant is mixed with water by water injection method, pressure is 5 kgf / mm ² , concentration
0.5% by weight was applied directly to each rolling roll. Table 2 shows the results of an investigation of the occurrence of troubles during rolling, the seizure and wear of rolling rolls after rolling (maximum roll wear depth), and the extent of product defects.

[0047]

[Table 1]

[0048]

[Table 2]

According to the hot rolling lubrication method of the present invention, rolling troubles such as slipping at the time of biting do not occur,
It was possible to almost completely prevent seizure from occurring on the rolling rolls and reduce the amount of roll wear. In another experiment, the amount of lubricant supplied by the water injection method was increased to a concentration of 1.0%, but rolling troubles such as slip, which was a problem during conventional thick plate rolling, did not occur at all. Example 2 (Hot rolling of H-section steel) Each of the same lubricant compositions prepared in Example 1 were tested in the hot rolling of H-section steel in a universal mill.
In the finishing universal mill of the H-section steel rolling line shown in Fig. 2, the lubricant supply piping equipment was installed as shown in Fig. 3, and each prepared lubricant composition was rolled into austenitic stainless steel (JIS SUS 304). It was supplied to each rolling roll (made of high alloy cast iron) at the chance (rolling amount 500 tons, rolling temperature 900 ° C). Each lubricant is, as shown in FIG.
The stock solution was atomized directly from the inlet side of the rolling to the side surface of the horizontal roll and the outer surface of the vertical roll at a flow rate of 500 cc / min and 100 cc / min, respectively. Table 3 shows the results of examining the degree of seizure and wear of the rolling roll after rolling and the degree of surface flaw of the H-shaped steel product.

[0050]

[Table 3]

As in Example 1, according to the hot rolling lubrication method of the present invention, even during H-section steel rolling, seizure that occurs on the rolling rolls is almost completely prevented and the amount of roll wear is reduced. Was. In the hot lubrication method of the present invention, rolling troubles such as slippage during biting did not occur during hot rolling of H-section steel.

Example 3 (Hot Production of Seamless Steel Pipe) Each of the same lubricant compositions prepared in Example 1 were tested by feeding them to a hole-type roll in the production of a seamless steel pipe. In the sizer of the Mannesmann mandrel mill pipe production line, a lubricant supply piping facility was installed as shown in Fig. 4, and each prepared lubricant composition was used to make an austenitic stainless steel (JIS SUS 304) pipe production opportunity (rolling). It was supplied to the edge of the hole-type roll for rolling at a quantity of 1000 tons and a tube rolling temperature of 1200 ° C). Each of the lubricants was directly supplied to the roll edge portion as the undiluted solution at a pressure of 5 kgf / mm ² and a flow rate of 2 to 4 liters / minute. Table 4 shows the results of examining the degree of seizure and wear of the edge portion of the rolling roll (made of high Cr cast steel) after pipe rolling and the degree of product flaw.

[0053]

[Table 4]

As in Example 1, according to the hot pipe rolling lubrication method of the present invention, even in the pipe rolling of a seamless steel pipe,
The seizure that occurs at the edge of the rolling hole roll was almost completely prevented, and the amount of roll wear was significantly reduced. In the hot lubrication method of the present invention, rolling troubles such as slippage during biting during pipe rolling did not occur at all.

From the above results of Examples 1 to 3, whether the lubricant composition contains 30 to 60% by weight of the highly basic metal salt sulfonate or 20% by weight or more of the highly basic Ca sulfonate. Alternatively, it can be seen that when the high basic metal salt sulfonate having a base number of 200 mgKOH / g or more is contained, the seizure prevention effect and the wear reduction effect are further enhanced in any type of hot rolling.

The material of the rolling roll is high carbon type high speed steel (high speed steel) roll, high alloy grain cast iron roll, high roll
It has been confirmed that the same results as above can be obtained with any of the commonly used hot rolling rolls such as Cr cast iron rolls, adamite rolls, and ductile cast iron rolls. Further, in the above examples, the results of hot rolling of stainless steel are shown, but it is clear that even if the material is carbon steel, the effect of preventing seizure and the effect of reducing roll wear can be obtained.

[0057]

As described above, the hot lubrication method of the present invention is the hot rolling of a thick plate and the H by the universal mill.
Hot rolling of shaped steels, rolling of other shaped steels with hole-type rolls, and hot pipe making of seamless steel pipes without seizure of rolling rolls without causing rolling troubles such as slips during biting. It has excellent effects on prevention, reduction of roll wear, etc., and can improve the quality of rolled products and work efficiency.

[Brief description of drawings]

FIG. 1 is an explanatory view illustrating a hot lubrication method of the present invention in plate rolling.

FIG. 2 is an explanatory view of a universal mill for rolling H-section steel.

FIG. 3 is an explanatory view illustrating a hot lubrication method of the present invention for a universal mill.

FIG. 4 is an explanatory view illustrating a hot lubrication method of the present invention for a pipe-making hole type roll of a seamless steel pipe.

[Explanation of symbols]

11, 21, 41: Lubricant supply nozzle, 12: Roll for rolling, 1
3: Reinforcing roll, 14: Thick steel plate, 15: Roll cooling water supply nozzle, 16: Drainer, 22: Horizontal roll for rolling, 23:
Vertical rolls for rolling, 24: H-shaped steel, 25, 44: Site where seizure occurs, 42: Hole type roll for rolling, 43: Steel pipe to be rolled

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C10N 40:24

Claims (4)

[Claims] 1. A hot plate heat treatment for a steel material, characterized in that, in hot rolling of a thick plate, a lubricant composition containing 20 to 70% by weight of a highly basic metal salt sulfonate is supplied to the surface of a rolling roll. Lubrication method in hot rolling. 2. A hot rolling H-shaped steel, characterized in that, in hot rolling of shaped steel, a lubricant composition containing 20 to 70% by weight of a highly basic metal salt sulfonate is supplied to the surface of a rolling roll. Lubrication method in rolling. 3. In the hot production of a seamless steel pipe, a lubricant composition containing 20 to 70% by weight of a highly basic metal salt sulfonate is supplied to the surface of a hole roll for rolling. Lubrication method in hot manufacturing of steel pipe. 4. The base number of the highly basic metal salt sulfonate is
The lubrication method according to any one of claims 1 to 3, wherein the lubrication amount is 200 mg-KOH / g or more and the material to be processed is a stainless steel material.