JP2944445B2 - High temperature plastic working lubricant and high temperature plastic working method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant for high-temperature plastic working, which can prevent seizure of the steel on the tool surface, abrasion of the tool surface, and roughening of the surface of the tool in high-temperature plastic working of steel. And a high-temperature plastic working method.

[0002]

2. Description of the Related Art In recent years, in high-temperature plastic working such as hot rolling and hot forging of steel materials, a lubricant for high-temperature plastic working has been used to protect tools, and the effect has been reduced. Examples of the lubricant for high-temperature plastic working include solid lubricants such as graphite, water glass, boron nitride, mica, molybdenum disulfide, iron oxide, calcium carbonate, fluorinated graphite, and metallic soap which have a lubricating effect at high temperatures; Fats and oils, zinc dialkyldithiophosphate,
Extreme pressure lubricants such as phosphate esters; oiliness improvers such as mineral oils, fats and oils, synthetic esters and alcohols; at least one kind of adhesion improvers and pour point depressants such as methacrylate copolymers and butylene butadiene copolymers, or If necessary, an antioxidant such as ditertiarybutylcresol or alpha naphthylamine is generally used.

[0003] In high-temperature plastic working such as hot rolling and hot forging, the temperature of a steel material reaches a high temperature of 800 to 1100 ° C. When the extreme pressure additive or the oiliness improver is used as a lubricant at such a temperature, oxidation or thermal decomposition occurs, and a sufficient effect on the lubricating surface cannot be exerted.
For this reason, a large amount of oil is supplied to the lubricated surface in the high-temperature plastic working compared to the low-temperature plastic working, but it is difficult to obtain a sufficient effect. Therefore, solid lubricants such as graphite and iron oxide, which are hardly decomposed even at a high temperature of 800 ° C. or more, are used as a lubricant for high-temperature plastic working, and exhibit a sufficient effect. However, solid lubricants such as graphite and iron oxide have the following two disadvantages.

First, since a solid lubricant such as graphite or iron oxide is composed of solid particles, it must be dispersed in a liquid when used as a lubricant. However, since these solid particles have a high density, they are separated and settled from the liquid when stored in a dispersed state for a long time. Therefore, a liquid lubricant containing a solid lubricant such as graphite or iron oxide cannot be stored for a long period of time, and it is necessary to re-disperse the solid lubricant separated by stirring periodically in the liquid.
However, some solid lubricants are difficult to re-disperse due to secondary aggregation of particles and the like. In this case, the performance of the lubricant may be degraded, or a solid lubricant that cannot be redispersed may clog the strainer, the oil supply valve, or the like. In order to solve such a problem, when a solid lubricant is dispersed in a liquid, addition of a dispersant, stabilization of the surface of solid lubricant particles, and the like are performed. However, all of them are expensive and require complicated steps in manufacturing. Also, if the viscosity of the lubricant is increased to prevent the sedimentation and sedimentation of the solid lubricant particles, it becomes difficult to apply it to equipment that supplies a general low-viscosity liquid lubricant, and new lubrication for high-viscosity lubricants Equipment must be provided.

[0005] Furthermore, solid lubricants such as graphite, iron oxide, and molybdenum disulfide are black, and there is a problem that a lubricant containing the same significantly contaminates a refueling place. Although there are white solid lubricants, fluorinated graphite and boron nitride, which have good lubricity, are extremely expensive. White and inexpensive solid lubricants include calcium carbonate and mica.
Insufficient lubricity. Therefore, although the lubricant for high-temperature plastic working has the problem of contaminating the surroundings with black,
At present, graphite, iron oxide, molybdenum disulfide and the like which are inexpensive and have good lubricity are used.

[0006] On the other hand, the present inventors previously prepared an iron oxide powder by dispersing iron oxide powder and calcium carbonate powder in an aqueous solution or a base grease in which 1 to 5% by weight of a water-soluble polymer was dissolved in water. A lubricant for high-temperature plastic working characterized by a content of 3 to 30% by weight and a content of calcium carbonate powder of 0.13 to 18.8% by weight has been developed (Japanese Unexamined Patent Publication No.
-234991). This high-temperature plastic working lubricant has 9
It has satisfactory performance in preventing seizure of the rolled material on the roll surface when the stainless steel is rolled at a temperature of 00 ° C. or more. However, this lubricant is black and has a NLGI consistency of no. 00 or more, or because the viscosity is as high as 3000 centipoise or more,
The purpose of the lubricant for high-temperature plastic working, which is transparent liquid, does not contaminate the lubricating point, and can be lubricated by the conventional liquid lubricating oil lubricating equipment conventionally used, cannot be achieved.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high-temperature plastic working performed in a temperature range of 800 ° C. to 1100 ° C., which is effective in suppressing tool wear and rough skin. An object of the present invention is to provide a high-temperature plastic working lubricant which is free from contamination and is inexpensive, and a high-temperature plastic working method using the lubricant.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for preparing a highly basic alkaline earth metal salicylate at a temperature of 800.degree.
This is achieved by a high temperature plastic working lubricant performed in the region of 00 ° C. The lubricant composition for high-temperature plastic working of the present invention may be a highly basic alkaline earth salicylate alone,
It may be one obtained by adding at least one kind of mineral oil and ester to a highly basic alkaline earth salicylate. In a preferred embodiment of the present invention, there is provided a lubricant for high-temperature plastic working comprising 3 to 90% by weight of a highly basic alkaline earth metal salicylate and 10 to 97% by weight of at least one selected from the group consisting of mineral oils and esters. Is done. The highly basic alkaline earth metal salicylate used in the present invention,
Those having a base number of 40 or more, preferably 100 or more, more preferably 150 or more are suitable.

Specific examples of the overbased alkaline earth salicylate used in the lubricant of the present invention include overbased calcium salicylate, overbased magnesium salicylate, and overbased barium salicylate. The same effect can be obtained by using any of them. Therefore,
Hereinafter, a highly basic calcium salicylate will be described in the present specification, but the present invention is not limited thereto. The overbased calcium salicylate used in the present invention is a known substance. For example, commercially available products include OSCA431, OSCA453, and
OSCA435, OSCA438; SA of Shell Chemical Company
P005Ca salicylate and the like. The high basic calcium salicylate is, for example, dissolving a neutral calcium salt of alkyl salicylic acid in a predetermined solvent (for example, aromatic hydrocarbons such as benzene and toluene, alcohol solvents such as methanol and ethanol, and mineral oil). Calcium hydroxide corresponding to the base number required as a highly basic calcium salicylate is added to this solution and mixed. Then, after passing an excess carbon dioxide gas sufficient to carbonate the added calcium hydroxide, a filter aid such as activated clay is added and the mixture is filtered, and the filtrate is distilled under reduced pressure to remove volatile solvents. Can be manufactured. The highly basic calcium salicylate produced by this method is a transparent liquid in which calcium carbonate is stably dispersed, and can be applied to liquid rolling oil refueling equipment conventionally used compared to solid lubricants. . The overbased calcium salicylate can be optionally dissolved in mineral oil or ester. Calcium carbonate is a known solid lubricant, and has the advantage of not polluting the environment during refueling because it is white.

Among the highly basic calcium salicylates used in the present invention, those represented by the following formula are particularly preferred. [R ¹ R ² C ₆ H ₃ (OH) -COOCaOOC-C ₆ H ₃ (OH) R ¹ R ² ] n ・ (CaCO ₃ ) m wherein R ¹ is an alkyl group having 5 to 28 carbon atoms or carbon Number 6 ~
30 represents an aryl group, R ² is a hydrogen atom, and has 1 to 2 carbon atoms.
8 represents an alkyl group or an aryl group having 6 to 30 carbon atoms. The lubricant of the present invention preferably contains at least 3% by weight of a highly basic calcium salicylate. If the content is 3% by weight or less, sufficient lubricity cannot be exhibited.

The highly basic calcium salicylate used in the present invention has a base number of 40 or more, preferably 1 or more.
It is preferable to contain CaCO ₃ of 00 or more, more preferably 150 or more. The base number is the number of mg of potassium hydroxide equivalent to hydrochloric acid required to neutralize all base components contained in 1 g of a sample. This base number is determined by JI
In SK2501, it is defined as the total base number. Therefore, the base number of a highly basic calcium salicylate increases as the content of CaCO ₃ as a base component increases. When the base number of the highly basic calcium salicylate of the present invention is less than 40, sufficient lubricity cannot be obtained.

Both the mineral oil and the ester used in the present invention have a function of forming a lubricating film between the roll and the rolled material, lowering the friction coefficient, and suppressing roughening and seizure of the tool.
In addition, when the viscosity of the highly basic calcium salicylate alone is high and it is not possible to lubricate it with a lubricant pump of a general liquid lubricant lubrication facility, a relatively low viscosity mineral oil or ester or a mixture of mineral oil and ester is used. By adding, it becomes possible to adjust the viscosity to allow lubrication by the lubricant pump. As the mineral oil, those having relatively low viscosity such as spindle oil, machine oil and motor oil are preferable. As the ester, at least one OH group in an alcohol such as 2-ethylhexanol, glycerin, trimethylolpropane, pentaerythritol or the like has 4 carbon atoms.
Those having a relatively low viscosity esterified with a carboxylic acid of ~ 22 are preferred. This effect of lowering the coefficient of friction,
In order to sufficiently exert the effect of adjusting the viscosity, it is preferable to contain 10% by weight or more of mineral oil or ester or a mixture of mineral oil and ester.

The lubricant of the present invention includes not only the above-mentioned mineral oils and esters but also extreme pressure agents (for example, tributyl phosphate) and alcohols (for example, oleyl alcohol) which lower the friction coefficient and have a relatively low viscosity. The same effect can be achieved by adding. Further, an adhesion improver, a pour point depressant, an oxidation stabilizer and the like, which are used in conventional lubricants for high-temperature plastic working, can also be added. The lubricant of the present invention preferably has an intrinsic viscosity of not more than 1000 mm ² / s at 40 ° C. Lubricant viscosity of 1000 at 40 ° C
In the case of mm ² / s or less, lubricate both and / or one of the tool and steel by air spray or water injection using a gear or plunger pump, which is generally used as a lubricant pump. Can be. Alternatively, the coating may be directly applied to the surface to be applied without using a pump.

[0014]

The lubricant of the present invention is a transparent liquid, low-viscosity lubricant containing no black solid lubricant, and can be lubricated by a general liquid lubricating oil supply system. And 800 ° C
In high-temperature plastic working performed in the temperature range from 1 to 1100 ° C., it is effective in suppressing tool wear and skin roughness, and does not pollute the environment.

[0015]

EXAMPLE A highly basic calcium salicylate, mineral oil and ester were placed in a stainless steel heating pot having a stirrer, as shown in Table 1.
And the mixture was stirred at 50 to 80 ° C. for 30 to 60 minutes until it became uniform to produce a lubricant. The lubricant was supplied to the roll surface of a double-type hot rolling mill on the surface of a hot-rolling lubrication system using a water-injection lubrication system using a lubrication pump for liquid lubrication oil. And refueled. In the case of the comparative example in which the lubricating oil had a high viscosity and could not be supplied by the liquid lubricating oil supply pump, the lubricant was evaluated by directly applying the lubricant directly to the roll surface. In this case, only the dilution water was injected from the water injection type oil supply equipment so that the temperature of the roll surface was adjusted to be the same as when the liquid lubricating oil was supplied. The roll drainer is for preventing the dilution water from directly adhering to the rolled material and reducing the temperature of the rolled material. The results are shown in Tables 1 to 3.

Hot Rolling Conditions and Lubricating Oil Supply Roll Roll High Carbon High Alloy Cast Iron Roll 150mmΦ × 150mmL Rolled SUS430 Steel Plate Thickness 4mm Width 25mm Length 100mm 10 Rolls (Rolled at the Same Location of Roll) , Speed 10%, 14mpm Steel material heating temperature 1100 ℃ Finished thickness 3.6mm Lubricating oil amount Total 100ml / min for upper and lower rolls Lubricating oil pump type Plunger pump Dilution water total 1000ml / min for upper and lower rolls Roll drainer Rubber Made

[0017]

[Table 1] Example component 1 2 3 4 5 6 7 8 9 9 10 11 (1)-----------(2) 3-10 30---1.5--100 (3)- − − − 30 − − 1.5 90 − − (4) − 3 − − − 30 30 − − 90 − (5) 97 97 90 70 70 70 60 47 10 5 − (6) − − − − − − 10 50 − 5 − (7) − − − − − − − − − − − (8) − − − − − − − − − − − − (9) − − − − − − − − − − − (10) − − − − − − − − − − − − (11) − − − − − − − − − − − − Viscosity 45 50 55 50 70 140 120 45 980 950 500 Lubricity Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No pollution No No No No No No No No No No Lubricant B B A A A A A A B A A A A

[0018]

[Table 2] Example components 12 13 14 15 16 17 18 19 20 21 (1) − − − − − − 100 − 99 − (2) 1 30 90 90 1 − − − − − (3) 1 30 10 5 − − − 100 − 49 (4) 1 30 − 5 − 1 − − 1 1 (5) 50 5 − − 99 99 − − − 25 (6) 47 5 − − − − − − − 25 (7) − − --------(8)----------(9)----------(10)---------- (11) − − − − − − − − − − −Viscosity 100 950 550 800 43 48 550 1900 560 200 Lubricity Yes Yes Yes Yes Yes Yes Yes Yes No No Yes Yes Stainless No No No No No No No No No No lubricity B A A A C C D A C A

[0019]

[Table 3]

(1) Highly basic calcium salicylate base number 60 (trade name OSCA431) (2) Highly basic calcium salicylate base number 180 (trade name OSCA453) (3) Highly basic calcium salicylate base number 230 (trade name OSCA435) (4) Highly basic calcium salicylate base number 320 (trade name: OSCA438) (5) Refined mineral oil ISO VG5 (6) Trimethylolpropane triolate (7) Triiron tetroxide particles (particle size: 0.5 to 1 μm) ( 8) Heavy calcium carbonate particles (particle size: 10-20μm) (9) Water (10) Sodium alginate (11) Mineral oil-based lithium stone Keng grease

Comparative Example 5: Commercially available lubricant for high-temperature plastic working (Cudol HR20 manufactured by Kyodo Yushi Co., Ltd.) Comparative Example 6: No lubricant Viscosity: 40 ° C., mm ² / s (However, Comparative Examples 1 to 3 are NLGI consistency) No., Comparative Example 4 is cp at 25 ° C) Lubrication: Whether lubrication can be performed by a liquid oil lubricant pump Pollution: Whether there is contamination around the equipment during use Lubrication: Evaluation of roll wear after hot rolling test In addition, the rough skin condition was observed and evaluated according to the following five grades. A: not recognized at all B: hardly recognized C: slightly recognized D: recognized E: significantly recognized

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI // C10N 10:04 30:06 30:08 40:24 (58) Field surveyed (Int.Cl. ⁶ , DB name) C10M 159/20 C10M 101/02 C10M 105/32 C10M 125/10 C10M 129/70 C10N 10:04 C10N 40:24 WPI / L (QUESTEL)

Claims (6)

(57) [Claims] 1. A high-temperature plastic working lubricant containing a highly basic alkaline earth metal salicylate in the range of 800 ° C. to 1100 ° C. 2. The high-temperature plastic working lubricant according to claim 1, comprising at least one member selected from the group consisting of mineral oils and esters. 3. The high-temperature plastic working lubricant according to claim 2, comprising 3 to 90% by weight of a highly basic alkaline earth metal salicylate and 10 to 97% by weight of at least one selected from the group consisting of mineral oils and esters. . 4. The high-temperature plastic working lubricant according to claim 1, wherein the base number of the highly basic alkaline earth metal salicylate is 100 or more. 5. A material having a viscosity of 1000 mm ² / s at 40 ° C.
The lubricant for high-temperature plastic working according to any one of claims 1 to 4, which is: 6. In a high-temperature plastic working of a steel material, after lubricating the tool with the lubricant for high-temperature plastic working according to any one of claims 1 to 5 on the tool surface , the plastic working is performed in a range of 800 ° C. to 1100 ° C. A high-temperature plastic working method for steel material.