JP2003253284A - Lubricating oil composition for processing iron-based metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil for processing a metal, without containing a chlorine-based extreme pressure additive, low smelling, not corroding a processing machine and its surrounding nonferrous metals, and also exhibiting a sufficient performance in processing a hard to process iron-based metal material. <P>SOLUTION: This lubricating oil for processing the metal of the iron-based metal material is characterized by containing a thiadiazole derivative. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil composition suitable for processing iron-based metallic materials such as carbon steel and stainless steel.

[0002]

2. Description of the Related Art Conventionally, metal working lubricants used for metal cutting, grinding, cutting, or plastic working such as extrusion, drawing, ironing, pressing, bending, roll forming, and drawing have a lubricating property. For the purpose of imparting properties, oiliness agents such as fats and oils, fatty acids, higher alcohols and esters, and extreme pressure additives containing elements such as sulfur, chlorine and phosphorus have been used. Of these, extreme pressure additives for chlorine compounds such as chlorinated paraffins containing chlorine as an element and chlorinated fatty acid esters are cheaper than other extreme pressure additives and are chemically stable. It has been widely used in a large amount in the field of metalworking because of its excellent lubricating performance. Particularly, in the field where processing performance is emphasized, a lubricating oil composition for metal processing containing a large amount of these chlorine-based extreme pressure additives has been used.

On the other hand, the metal to be processed has a relatively soft material such as aluminum, copper, and alloys thereof, and is easily processed, so-called non-ferrous metal materials such as stainless steel and There are even iron-based metallic materials such as chrome molybdenum steel that are hard to process and difficult to process. In order to process such iron-based metallic materials, the use of chlorine-based extreme pressure additives was essential.

[0004]

However, regarding chlorine-based compounds, for example, in the United States, a specific chlorinated paraffin is recognized as a carcinogenic substance, and the PL law is enforced, and a carcinogenic warning display is obligatory. , A problem was pointed out in terms of safety to the human body. Also, when incinerating waste liquid of metalworking lubricating oil containing chlorine compounds, hydrogen chloride (HCl), which causes air pollution during combustion, is generated, or dioxin is generated depending on the combustion temperature during combustion. It has been pointed out that there is a risk of causing environmental pollution due to such measures. Under such circumstances, the use of lubricating oils for metalworking containing extreme pressure additives of chlorinated compounds such as chlorinated paraffins and chlorinated fatty acid esters is being shunned in many countries. In order to deal with this situation, it is possible to use sulfur compounds instead of chlorine extreme pressure additives, but highly reactive sulfur compounds are non-ferrous metals used in the pipes and seals of processing machines. There has been a problem that metal is corroded, or it becomes a mist and scatters in the use environment, and corrodes copper alloys used in electric parts such as motors and switches. Further, many of the additives themselves have an odor, and there is a problem that the odor is further increased especially in a high temperature environment associated with processing.
On the other hand, there is a problem in that a sulfur-based compound having a low reactivity, which does not cause a problem of corrosion and odor of non-ferrous metals, has insufficient lubrication performance and cannot obtain sufficient processing performance.

Therefore, the present invention does not contain a chlorine-based extreme pressure additive, has a low odor, does not corrode a processing machine and non-ferrous metal parts around the processing machine, and processes a difficult-to-process ferrous metal material. It is an object of the present invention to provide a processing lubricating oil composition capable of exhibiting sufficient performance in the above.

[0006]

Means for Solving the Problems As a result of intensive studies by the inventors of the present invention, in the processing of iron-based metal materials that are difficult to process, a lubricating oil composition for metal processing containing a thiadiazole derivative as an extreme pressure additive has been proposed. It has been found that, when used, a lubricating performance far superior to that of the conventional processing oil containing a large amount of chlorine-based extreme pressure additive can be obtained. It was also found that this thiadiazole derivative has a low odor even in a high concentration state and does not corrode non-ferrous metal materials.

A first aspect of the present invention is a lubricating oil composition for processing an iron-based metallic material, characterized by containing a thiadiazole derivative. In this aspect, the thiadiazole derivative acts as an extreme pressure additive in the lubricating oil composition for processing. In this embodiment, other known extreme pressure additives such as phosphorus-based extreme pressure additives and sulfur-based extreme pressure additives may be used in combination without departing from the objects and effects of the present invention.

In the present invention, thiadiazole refers to a 5-atom heterocycle composed of 1 sulfur atom, 2 nitrogen atoms and 2 carbon atoms. There are four isomers shown below, depending on the position of the heteroatom in the ring.

[0009]

[Chemical 1]

[0010]

[Chemical 2]

[0011]

[Chemical 3]

[0012]

[Chemical 4]

Basically, since the structure of these thiadiazoles does not contain chlorine (Cl), there is no fear that hydrogen chloride (HCl) or dioxin will be generated at the time of incineration.

The thiadiazole derivative in the lubricating oil composition for processing according to the embodiments of the present invention is represented by the following general formula (5)

[0015]

[Chemical 5]

(In the formula, R ¹ and R ² represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably 1 to 14 carbon atoms. R ¹ and R ² may be the same or different. A and b each represent an integer of 0 to 8, preferably 1 to 3, and most preferably 1 or 2, which may be the same or different.) 1,3,4-thiadiazole , The following general formula (6)

[0017]

[Chemical 6]

(In the formula, R ³ and R ⁴ represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably 1 to 14 carbon atoms. R ³ and R ⁴ may be the same or different. Further, a and b each represent an integer of 0 to 8, preferably 1 to 3, most preferably 1 or 2,
It may be the same or different. ) 1, 2, 4
-Thiadiazole, the following general formula (7)

[0019]

[Chemical 7]

(In the formula, R ⁵ and R ⁶ represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably 1 to 14 carbon atoms. R ⁵ and R ⁶ may be the same or different. Further, a and b each represent an integer of 0 to 8, preferably 1 to 3, most preferably 1 or 2,
It may be the same or different. ) 1, 4, 5
-Thiadiazole, the following general formula (8)

[0021]

[Chemical 8]

(In the formula, R ⁷ and R ⁸ represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, preferably 1 to 9 carbon atoms. R ⁷ and R ⁸ may be the same or different. 2,5-bis (N, N-dialkyldithiocarbamyl) -1,3,4-thiadiazole represented by the formula (1) and a mixture of two or more of the compounds represented by the above general formula are preferably used. .

R in equations (5), (6) and (7)
^1-6Specific examples of the alkyl group represented by
Group, ethyl group, n-propyl group, isopropyl group, n-
Butyl group, isobutyl group, sec-butyl group, tert
-Butyl group, various pentyl groups, various hexyl groups, various hexyl groups
Butyl group, various octyl groups, various nonyl groups, various decyl groups
Group, various undecyl groups, various dodecyl groups, tridecyl
Group, tetradecyl group, pentadecyl group, hexadecyl group
Group, heptadecyl group, octadecyl group, nonadecyl group,
An eicosyl group etc. can be mentioned. Equation (8)
R in⁷And R ⁸Specific examples of the alkyl group represented by
Specifically, methyl group, ethyl group, n-propyl group, isop
Ropyl group, n-butyl group, isobutyl group, sec-butyl
Group, tert-butyl group, various pentyl groups, various hex groups
Syl group, various heptyl groups, various octyl groups, various nonyl
Group, various decyl groups, various undecyl groups, various dodecyl groups
Etc. can be mentioned.

Specific examples of such a thiadiazole derivative include 2,5-bis (n-hexyldithio) -1,
3,4-thiadiazole, 2,5-bis (n-octyldithio) -1,3,4-thiadiazole, 2,5-bis (n-nonyldithio) -1,3,4-thiadiazole,
2,5-bis (1,1,3,3, -tetramethylbutyldithio) -1,3,4-thiadiazole, 3,5-bis (n-hexyldithio) -1,2,4-thiadiazole, 3 , 5-bis (n-octyldithio) -1,2,4
-Thiadiazole, 3,5-bis (n-nonyldithio)
-1,2,4-thiadiazole, 3,5-bis (1,
1,3,3, -tetramethylbutyldithio) -1,2,
4-thiadiazole, 4,5-bis (n-hexyldithio) -1,2,3-thiadiazole, 4,5-bis (n
-Octyldithio) -1,2,3-thiadiazole,
4,5-bis (n-nonyldithio) -1,2,3-thiadiazole, 4,5-bis (1,1,3,3, -tetramethylbutyldithio) -1,2,3-thiadiazole,
And alkyl thiadiazoles such as.

Further, 2,5-dimercapto-1,3,4
-Thiadiazole, 3,5-dimercapto-1,2,4
-Thiadiazole, 3,4-dimercapto-1,2,5
-Thiadiazole, 4,5-dimercapto-1,2,3
-Dimercaptothiadiazoles such as thiadiazole are also preferably used. Furthermore, mixtures of these can also be used.

In the present invention, the term "iron-based metal" means carbon steel, stainless steel, heat-resistant steel, tool steel, spring steel, bearing steel, cast iron, etc. , Nickel (Ni), manganese (M
n), molybdenum (Mo), silicon (Si), tungsten (W), niobium (Nb), vanadium (V), and the like. Refers to the metal material. In the present invention, “ferrous metal” is a concept corresponding to “non-ferrous metal” such as aluminum, copper or brass. While non-ferrous metals are relatively easy to process, many of the ferrous metals are generally more difficult to process than non-ferrous metals because of their hard materials, etc. The standard is also high.

Further, in the present invention, "machining" means, for example, "cutting", "grinding", "cutting", or "extrusion", "pulling", "drilling", "drawing", "rolling". , "Rolling", "forging", "punching",
This refers to processing that involves permanent deformation of the metal to be processed, such as plastic working such as "ironing", "pressing", "bending", and "roll forming".

A second aspect of the present invention is a lubricating oil composition for metalworking of iron-based metallic materials containing only a thiadiazole derivative as an extreme pressure additive. Since the lubricating oil composition for metalworking of this aspect contains only thiadiazole as an extreme pressure additive, there is an advantage that the production work and the control of the oil used can be facilitated by simplifying the composition.

In any of these embodiments, the basic component of the lubricating oil composition for metalworking is a so-called base oil, and in each of the above embodiments, it is premised that the base oil contains a predetermined amount of the thiadiazole derivative. There is. In any of the embodiments, the amount of the thiadiazole derivative added is not particularly limited, but is preferably 1% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, most preferably 15% by mass or more, based on the entire lubricating oil composition. It is preferably 20% by mass or more. By such blending, it is possible to obtain lubricity superior to that of a conventional lubricating oil composition for metalworking containing an extreme pressure additive of a chlorine compound such as chlorinated paraffin.

In the lubricating oil composition for metalworking of the present invention, mineral oil, fats and oils or synthetic oils can be used as the base oil. Of these, when mineral oil is used as a base oil, the present invention is not particularly limited to crude oil as a raw material, but from the viewpoint of oxidative stability and availability, for example, Arabian light, marban, berries produced in the Middle East, etc. The use of paraffinic crude oil or naphthenic crude oil from Australia or Venezuela is recommended. With respect to the vacuum distillation fraction obtained by subjecting such crude oil to atmospheric distillation and vacuum distillation, solvent degassing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, Among the refining treatments such as clay treatment, paraffinic or naphthenic mineral oils obtained by appropriately combining one or more refining treatments can be used as the base oil. These mineral oil-based base oils are commercially available under general names such as "spindle oil", "machine oil", "turbine oil", "cylinder oil", and "liquid paraffin".

Examples of fats and oils include beef tallow, lard,
Use soybean oil, rapeseed oil, rice bran oil, coconut oil, palm oil, palm kernel oil, sheep fat (lanolin), olive oil, tall oil, castor oil, cottonseed oil, safflower oil, shark liver oil, or hydrogenated products of these. be able to.

Further, as a synthetic oil, polyalpha-
Olefin (ethylene-propylene copolymer, polybutene, 1-octene oligomer, 1-decene oligomer,
And their hydrides), alkylbenzenes, alkylnaphthalenes, monoesters (eg, butyl stearate, octyl laurate, etc.), diesters (eg, dioctyl phthalate, diethyl phthalate, di-
2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc.), polyester (for example, trioctyl trimellitate, tetraoctyl pyromellitate, etc.), polyol ester (for example, trimethylolpropane caprylate, Trimethylolpropane pelargonate,
Pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, etc.), polyoxyalkylene glycol, higher alcohol, polyphenyl ether, dialkyldiphenyl ether, phosphoric acid ester (eg tricresyl phosphate, etc.), fluorine compound (eg, Perfluoropolyether, fluorinated polyolefin, etc.), silicone oil, etc. can be used.

In the present invention, one of the above base oils may be used alone, or two or more thereof may be used in combination.

Further, since the above-mentioned two aspects of the lubricating oil composition for metalworking is a composition in which a base oil and an additive are mixed, there is no direct restriction on the viscosity and the flash point of the base oil. But,
The flash point of the lubricating oil composition mixed with the base oil is preferably 70 ° C. or higher from the viewpoint of safety and handling (from the Fire Defense Law). From this viewpoint, the flash point of the base oil itself is preferably 70 ° C or higher. The viscosity of base oil having such a flash point is, in the case of paraffinic mineral oil,
It is usually 1.6 mm ² / S or more at 40 ° C. Under such constraints, it is preferable to select the base oil viscosity so that the finished viscosity of the lubricating oil composition will be a predetermined value.

Generally, a lubricating oil composition for metalworking used for processing such as "cutting", "grinding", "drilling", "rolling" and "punching" has a low viscosity and is used as a base oil. It is recommended to select low viscosity oil. On the other hand, "extrusion", "pulling out", "drawing", "rolling",
Many of the lubricating oil compositions for metalworking used for processing such as "forging" have high viscosity, and it is recommended to select a relatively high viscosity oil as the base oil. Further, when cooling is important in processing, it is advantageous to use a low-viscosity oil, and when importance is attached to lubricity, it is advantageous to use a high-viscosity oil. It is desirable to add consideration from this point of view when selecting the base oil viscosity.

A third aspect of the present invention is a lubricating oil composition for metalworking iron-based metallic materials, which comprises a thiadiazole derivative as a base oil. In this embodiment, the base oil such as the mineral oil, fat or oil or synthetic oil as described above is not required, and the thiadiazole derivative itself can be used as the base oil of the lubricating oil composition for metalworking. In this case, since the thiadiazole derivative itself as the base oil is provided with extreme pressure performance, the thiadiazole derivative alone can form a lubricating oil composition for metalworking of iron-based metals. By adopting such a configuration, the composition can be simplified, so that the manufacturing process can be simplified and the oil used can be easily managed.

On the other hand, other known extreme pressure additives such as phosphorus-based extreme pressure additives and sulfur-based extreme pressure additives, and additions having other functions, within a range that does not deviate from the objects and effects of the present invention. It is also permissible to incorporate agents such as antioxidants, rust preventives, defoamers and the like. Further, it is understood that a material to which a small amount (10% by mass or less) of mineral oil, fat or oil or synthetic oil is simply added as an extender is included in the technical scope of the lubricating oil composition for metalworking of ferrous metals of the present invention. It must be.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below based on Examples and Comparative Examples. However, the present invention is not limited to these examples. The following examples,
The numbers in the comparative examples indicate the mass% of each component in the composition.

[0039]

[Examples] (1) Formulation Table 1 shows an example formulation of the lubricating oil composition for metalworking of the present invention.
Table 2 shows the comparative formulation. The lubricating oil compositions for metalworking obtained by the blending of these Examples and Comparative Examples were heated, mixed and stirred, and brought into a uniform state for evaluation.

[0040]

[Table 1] Example formulation

[0041]

[Table 2] Comparative example formulation

(2) Details of each raw material The specific raw materials in each of the above formulations are shown in Table 3 below.

[0043]

[Table 3] Raw materials

In the above, for example, "S = 10%" means that the sulfur content contained in the raw material is 10% by mass. In addition, “100 ° C. × 1 h: activity” means
The degree to which the pure copper test piece is corroded when the pure copper test piece is immersed in the raw material kept at 100 ° C. for 1 hour is shown. "Activity" indicates a noticeable discoloration of the test piece.
"Inert" indicates that the test piece has little discoloration. 40 ° C viscosity is kinematic viscosity, JIS K228
It is a value measured by the method specified in 3.

(3) Evaluation test method 1. Lubricity (cutting resistance) test Surface broaching was performed under the following test conditions using a brooching machine manufactured by Fujikoshi, and cutting force during cutting (N)
Was measured using a piezoelectric dynamometer manufactured by Kistler. Processing conditions: depth of cut = 0.08 mm / blade, cutting speed = 4
Material to be cut: Chrome steel (SCr420H), which is characterized by having high hardness, was used. Tool material: SKH55 Tool specifications: 6 blades, rake angle = 15 °, clearance angle = 2 °,
Blade width = 4 mm 2. Corrosion test A test piece of pure copper (C1100P) was immersed in a sample oil prepared based on the composition of each Example and Comparative Example in Tables 1 and 2, and 1
It was kept at 00 ° C for 24 hours. After 24 hours, the test piece was taken out from the sample oil, and the state of surface corrosion was visually observed.
Evaluation was made according to the criteria shown in Table 4.

[0046]

[Table 4] Corrosion test evaluation criteria

3. Odor test Sample oils prepared based on the compositions of Examples and Comparative Examples in Tables 1 and 2 were placed in a sample oil bottle, sealed, and allowed to stand in a constant temperature bath at 50 ° C., and then a sensory test was performed. The evaluation was performed according to the criteria shown in.

[0048]

[Table 5] Odor test evaluation criteria

(4) Evaluation test results of the sample oil prepared based on the composition of each Example and Comparative Example,
Table 6 shows the test results regarding lubricity (cutting resistance), corrosiveness, and odor.

[0050]

[Table 6] Evaluation test results

From the test results shown in Table 6, the following matters were clarified. 1. When the content of the thiadiazole derivative in the lubricating mineral oil was increased, the lubricity became better and the cutting resistance tended to decrease as the content increased. When 20% by mass of the thiadiazole derivative was blended in the mineral oil, a level of lubricity (cutting resistance) sufficiently higher than that of the conventional chlorinated paraffin blended oil (Comparative Example 5) could be obtained. The relationship between the thiadiazole blending amount and the lubricity (cutting resistance) drastically changed between the blending amounts of 1 to 20 mass% and became gradual when the blending amount exceeded 20 mass% (Examples 1 to 4). , And FIG. 1). It is estimated that the blending amount of the thiadiazole derivative that obtains the same level of lubricity (cutting resistance) as that of the chlorinated paraffin-blended oil of Comparative Example 5 is around 5% by mass (see FIG. 1).

On the other hand, an oil containing 10% by mass of sulfurized lactate (Comparative Example 1), an oil containing 2% by mass of dialkyl polysulfides A and B (Comparative Examples 2 and 3), and dialkyl polysulfide A.
70% by mass of the blended oil (Comparative Example 4) could not achieve the same level of lubricity (cutting resistance) as the chlorinated paraffin blended oil (Comparative Example 5).

2. Oils containing corrosive thiadiazole derivatives (Examples 1 to 4)
In No. 4, no discoloration was observed on the surface of the pure copper sample piece. It is recognized that this is at a level much higher than the level of "very slight discoloration" of the conventional oil containing 20% by mass of chlorinated paraffin (Comparative Example 5). On the other hand, 10% by mass of sulfurized butter fat (Comparative Example 1),
In the oil containing 2% by mass of dialkyl polysulfide A (Comparative Example 2), the entire surface of the pure copper sample piece turned black. In addition, 2% by mass of dialkyl polysulfide B
In the blended oil (Comparative Example 3), the surface of the pure copper sample piece was observed to be slightly discolored, and in the blended oil of 70% by mass of dialkyl polysulfide A (Comparative Example 4), the surface of the pure copper sample piece was entirely covered. It was observed that the color changed to black and that the thin film had peeled off.

3. The sample oils containing 50% by mass or less of the odor thiadiazole derivative (Examples 1 to 3) had the same results (no odor) as the oils containing 20% by mass of chlorinated paraffin (Comparative Example 5).
The thiadiazole derivative alone (Example 4) had a very slight odor. On the other hand, 10% by mass of sulfurized lard
The blended oil (Comparative Example 1) had a strong offensive odor, and 2% by mass of dialkyl polysulfides A and B were blended (Comparative Example 2,
In 3), a very slight odor was recognized. Also, an oil containing 70% by mass of dialkyl polysulfide A (Comparative Example 4).
Was not a bad odor, but a strong odor was recognized.

4. Summary It is possible to replace chlorinated paraffins as extreme pressure additives with thiadiazole derivatives. In the region where the content of thiadiazole is 1 to 20% by mass, when the content of thiadiazole is increased, the lubricity (cuttability) also sharply increases. To obtain the lubrication performance equivalent to that of the oil containing 20% by mass of chlorinated paraffin, the thiadiazole derivative should be added to 5%.
It is necessary to mix it in an amount of about mass%. If the content of the thiadiazole derivative is increased beyond this range, the lubricating performance will increase accordingly. Therefore, by adding a predetermined amount of a thiadiazole derivative, a lubricating oil composition for processing an iron-based metal having a processing performance equal to or higher than that of a processing oil containing an extreme pressure additive of a chlorine-based compound such as chlorinated paraffin. Can be obtained. The corrosiveness of the metalworking lubricating oil composition containing the thiadiazole derivative is superior to that of the metalworking lubricating oil composition containing the chlorinated paraffin. Therefore, where chlorinated paraffin-containing oil is currently used and there is no problem with regard to corrosiveness, even if a metalworking lubricating oil composition containing a thiadiazole derivative is used, pipes and other materials that are susceptible to corrosion are used. There is no risk of corrosion even in the. Further, the odor of the lubricating oil composition for metalworking containing the thiadiazole derivative is at a very low level.

According to the findings of the inventors of the present application, as described above, the thiadiazole derivative has excellent lubricity, is not corrosive, and has a low odor. It is also possible to configure it as a lubricating oil, a lubricating / lubricating oil for sliding surface, a lubricating / lubricating oil for sliding surface, and an oil for hydraulic pressure. In this case, by blending with a base oil having various viscosities, a product having a predetermined viscosity such as ISO-VG32, 68, or 220 can be finished. Further, in this case, it is preferable to add a known antioxidant, rust preventive, antifoaming agent or the like.

Although the present invention has been described above with reference to the presently most practicable and preferred embodiments, the present invention is limited to the embodiments disclosed herein. However, the invention can be appropriately modified within the scope of the gist or concept of the invention that can be read from the claims and the entire specification, and the lubricating oil composition for metalworking of iron-based metal materials accompanied by such modifications is also included. Further, it should be understood as being included in the technical scope of the present invention.

[0058]

As described above, according to the lubricating oil composition for metalworking of iron-based metals of the present invention, since the thiadiazole derivative is adopted as the extreme pressure additive, the composition component contains chlorine. Not in. Therefore, when incinerated as waste oil, hydrogen chloride and dioxin are not generated. Further, due to the excellent extreme pressure performance of the thiadiazole derivative, it is possible to obtain better lubricating performance for processing iron-based metals than when chlorinated paraffin or the like is used as an extreme pressure additive. Furthermore, by using a thiadiazole derivative, corrosion of non-ferrous metal parts in the environment of use,
There is no fear of a bad smell problem in the work environment.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the added amount of a thiadiazole derivative and lubricity (cutting resistance).

Claims (4)

[Claims] 1. A lubricating oil composition for processing an iron-based metallic material, which comprises a thiadiazole derivative. 2. A lubricating oil composition for processing an iron-based metal material, which comprises only a thiadiazole derivative as an extreme pressure additive. 3. The iron according to claim 1, wherein the amount of the thiadiazole derivative added is 1.0 to 99.9 mass% with respect to the entire lubricating oil composition. Lubricating oil composition for processing metal-based materials. 4. A lubricating oil composition for processing an iron-based metal material, which comprises a thiadiazole derivative as a base oil.