JP6569145B2 - Heat treated oil composition - Google Patents

Description

  The present invention relates to a heat-treated oil composition.

  Metal materials such as steel are subjected to heat treatment such as quenching, tempering, annealing, and normalization for the purpose of improving their properties. Among these heat treatments, quenching is a treatment in which a heated metal material is immersed in a coolant and transformed into a predetermined quenching structure, and the treated product becomes very hard by this quenching. For example, when a heated steel material in an austenite state is immersed in a coolant and cooled at an upper critical speed or higher, it can be transformed into a quenched structure such as martensite.

  As the coolant, oil-based or water-based heat treatment agents are generally used. The quenching of the metal material using the oil-based heat treatment agent (heat treatment oil) will be described. When the heated metal material is put into the heat treatment oil as a coolant, it is usually cooled through three stages. Specifically, (1) a first stage (vapor film stage) in which the metal material is covered with a vapor film of heat-treated oil, (2) a second stage (boiling stage) in which the vapor film is broken and boiling occurs, (3) This is a third stage (convection stage) in which the temperature of the metal material is equal to or lower than the boiling point of the heat-treated oil and heat is taken away by convection. In each stage, the cooling rate is different because the atmosphere around the metal material is different, and the cooling rate in the second stage (boiling stage) is the fastest.

Generally, in the heat-treated oil, the cooling rate is rapidly increased when shifting from the vapor film stage to the boiling stage. When the metal material is not a simple planar shape, the vapor film stage and the boiling stage are likely to be mixed on the surface of the metal material. When the mixture occurs, a very large temperature difference is generated on the surface of the metal material due to a difference in cooling rate between the vapor film stage and the boiling stage. And this temperature difference generates thermal stress and transformation stress and causes distortion in the metal material.
Therefore, in heat treatment of metal materials, especially quenching, it is important to select heat treatment oils suitable for the heat treatment conditions. If the selection is inappropriate, the metal materials will be distorted and sufficient hardened May not be obtained.

On the other hand, heat-treated oil is classified into 1 to 3 types according to JIS K2242: 2012, and 1 type 1 oil, 2 oil, 2 types 1 oil and 2 oil are used for quenching. is there. Among them, in JISK2242: 2012, a cooling time from 800 ° C. to 400 ° C. is defined as a measure of cooling performance, and for Type 1 No. 2 it is 4.0 seconds or less, for Type 2 No. 1 it is 5.0 seconds or less, 2 types In No. 2, it is set to 6.0 seconds or less. The shorter the cooling time, the higher the cooling performance and the harder the metal material.
Generally, the hardness and strain of a metal after quenching are in a trade-off relationship, and the harder the strain, the greater the strain.

Industrially, 300 ° C. seconds are also used as an index indicating the cooling property of the oil. The number of seconds at 300 ° C. is a cooling time from 800 ° C. to 300 ° C. of the cooling curve obtained in accordance with the cooling performance test method of JIS K2242: 2012.
In order to obtain the desired hardness and distortion, the user selects the quenching oil based on the above-mentioned indices. For example, the above-mentioned Type 2 No. 1 oil is widely used for quenching of gear parts for automobiles in which distortion is a problem. This is because the above-mentioned type 1 oil increases the strain and, depending on the part, the hardness is too high. In addition, although the type 2 No. 2 oil has less strain, the hardness is insufficient.

By the way, most parts such as automobile transmissions and reduction gears are mass-produced, and so-called group quenching is performed in which a large amount of processed products are stacked on one tray and quenched at a time. At that time, there is a problem that the cooling performance varies depending on the position where the stacked components are set, and the hardness and strain of each component vary. For example, the hardness of the part set in the lower part is high, and the hardness of the part set in the upper part is low.
In view of the above situation, techniques of Patent Documents 1 to 6 have been proposed.

JP 2003-286517 A JP 2002-38214 A JP 2001-152243 A JP 2002-327191 A JP 2007-9238 A JP 2013-194262 A

In order to reduce variations in hardness and strain for each part during group quenching, Patent Document 1 proposes to add special equipment such as a vibrator and an injection device.
However, adding the above equipment to a conventional apparatus is costly and it is difficult to modify the equipment depending on the equipment. For this reason, the technique which can reduce the dispersion | variation in hardness and a distortion only by the characteristic of heat-processed oil composition, without investing in equipment like patent document 1 was desired.

In addition, when the vapor film stage is long, the time during which the vapor film stage and the boiling stage are mixed also becomes long, and the distortion tends to increase. For this reason, it is preferable to shorten the number of seconds (characteristic seconds) until reaching the temperature at which the vapor film stage ends (characteristic temperature).
Patent Document 2 proposes a method of quenching with oil after cooling to a characteristic temperature or lower with a gas in order to eliminate the influence of characteristic seconds.
On the other hand, Patent Document 3 proposes a method of once raising the temperature of the processed material from the quenching oil immediately above the martensite transformation start temperature in order to eliminate the temperature difference of the processed material due to uneven cooling.
However, the means of Patent Documents 2 and 3 are more costly and time consuming than simple oil quenching. The means of Patent Documents 2 and 3 are methods for reducing distortion, and it is not possible to reduce variations in hardness and distortion for each part during group quenching.

In Patent Document 4, in the quenching of a metal material, uneven cooling is less likely to occur, and the kneaded viscosity at 40 ° C. is 5 to 60 mm ² as a heat-treated oil composition that can secure the hardness of the quenched product and reduce quenching distortion. A heat-treated oil composition comprising a mixed base oil consisting of 50 to 95% by weight of a low-viscosity base oil of / s and 50 to 5% by weight of a high-viscosity base oil having a kinematic viscosity at 40 ° C. of 300 mm ² / s or more is proposed. ing.
Patent Document 5 proposes a heat-treated oil composition that reduces the variation in cooling performance during group quenching while having a cooling performance comparable to that of Type 2 No. 1 oil. Specifically, 5% by mass of a low boiling point base oil having a 5% distillation temperature of 300 ° C. or more and 400 ° C. or less and less than 50% by mass, and 50% by mass of a high boiling point base oil having a 5% distillation temperature of 500 ° C. or more. A heat-treated oil composition comprising a mixed base oil comprising more than 95%.
However, since the heat-treated oil compositions of Patent Documents 4 and 5 do not use a vapor film breaker, the characteristic seconds are long, and it is not possible to reduce variations in hardness and strain for each part during group quenching.

In Patent Document 6, a base oil having a 40 ° C. kinematic viscosity of 5 mm ² / s to 60 mm ² / s is 50% by mass to 95% by mass based on the total amount of the composition, and a 40 ° C. kinematic viscosity is 300 mm ² / s or more. A heat-treated oil composition is proposed that can reduce variation in cooling performance during group quenching by blending 5% by mass to 50% by mass of the base oil, based on the total amount of the composition, and an α-olefin copolymer. ing.
However, the heat-treated oil composition of Patent Document 6 has a problem that the cooling performance decreases with time due to repeated quenching.

  The present invention has been made under such circumstances, and when heat-treating a metal material by quenching or the like, while maintaining the same cooling performance as JIS K2242: 2012 Type 2 No. 1 parts, parts during group quenching It is an object of the present invention to provide a heat-treated oil composition that can reduce the variation in cooling performance of each and can suppress the change with time of the cooling performance when the heat treatment is repeated.

  In order to solve the above-mentioned problem, in the embodiment of the present invention, the cooling performance test method of JIS K2242: 2012 includes (A) base oil and (B) one or more selected from petroleum resin and / or petroleum resin derivatives. The characteristic seconds obtained from the cooling curve obtained according to the above are 1.00 seconds or less, and the cooling time from 800 ° C. to 300 ° C. of the cooling curve is 6.00. Provided is a heat-treated oil composition characterized by being at least 14 seconds and not longer than 14.50 seconds.

  The heat-treated oil composition of the present invention has a cooling performance equivalent to that of JIS K2242: 2012 Type 2 No. 1 oil when heat-treating a metal material by quenching or the like, and variation in cooling performance for each part during group quenching. Can be reduced. Furthermore, the heat-treated oil composition of the present invention can suppress the change in cooling performance with time when the heat treatment of the metal material is repeated.

  Embodiments of the present invention will be described below. The heat-treated oil composition of the present embodiment includes (A) a base oil and (B) one or more selected from petroleum resins and / or petroleum resin derivatives, and conforms to the cooling performance test method of JIS K2242: 2012. The characteristic seconds obtained from the obtained cooling curve is 1.00 seconds or less, and the cooling time from 800 ° C. to 300 ° C. of the cooling curve is 6.00 seconds or more and 14. It is 50 seconds or less.

(A) Base oil (A) As a base oil of a component, mineral oil and / or synthetic oil are mentioned.
Mineral oils include paraffin-based mineral oils, intermediate-based mineral oils and naphthenic-based mineral oils obtained by ordinary refining methods such as solvent refining and hydrogenation refining, or waxes produced by the Fischer-Tropsch process (gas (Turi Liquid Wax) and mineral oil-based waxes.
Examples of synthetic oils include hydrocarbon synthetic oils and ether synthetic oils. Examples of the hydrocarbon-based synthetic oil include alkylbenzene and alkylnaphthalene. Examples of ether synthetic oils include polyoxyalkylene glycol and polyphenyl ether.

  (A) The base oil of component may be a single system using one of the above-described mineral oil and synthetic oil, but a mixture of two or more mineral oils, a mixture of two or more synthetic oils, It may be a mixed system such as a mixture of one or more of mineral oil and synthetic oil.

40 ° C. The kinematic viscosity of the base oil of the component (A), is preferably 40 mm ² / s or more 500 mm ² / s or less, more preferably at most 50 mm ² / s or more 350mm ² / s, 60mm ² / More preferably, it is s or more and 200 mm ² / s or less.
By setting the 40 ° C. kinematic viscosity of the base oil of component (A) within the above range, it is possible to ensure essential cooling performance based on component (A) and to make the characteristic seconds and 300 ° C. seconds within the ranges described below. it can.
When the base oil of the component (A) is a base oil in which two or more kinds of base oils are mixed, the kinematic viscosity of the mixed base oil preferably satisfies the above range.
In this embodiment, the kinematic viscosity of the base oil and heat-treated oil composition can be measured according to JIS K2283: 2000.

The content ratio of the base oil of the component (A) with respect to the total amount of the heat-treated oil composition is preferably 10 to 99.9% by mass, more preferably 50 to 98% by mass, and 80 to 95% by mass. More preferably it is.
By making the content ratio of the component (A) 80% by mass or more, the essential cooling performance based on the component (A) can be secured, and the content ratio of the component (A) should be less than 100% by mass. Thereby, the usage-amount of the petroleum resin of a (B) component and / or the derivative | guide_body of a petroleum resin can be ensured, and the effect based on the (B) component mentioned later can be acquired easily.

(B) Petroleum Resin and / or Petroleum Resin Derivative The heat-treated oil composition of the present embodiment comprises (B) one or more petroleum resins and / or petroleum resin derivatives. The component (B) petroleum resin and / or petroleum resin derivative has a role as a vapor film breaker.
By using petroleum resin and / or petroleum resin derivatives as the vapor film breaker, the vapor film stage can be shortened, and the cooling performance of the heat-treated oil composition can be easily made comparable to JISK2242: 2012 Type 2 No. 1 oil. .
Moreover, since the vapor film stage can be shortened by using petroleum resin and / or petroleum resin derivatives, it is difficult to mix the vapor film stage and the boiling stage on the surface of the metal material. For this reason, by using petroleum resins and / or petroleum resin derivatives, it is possible to make it difficult for variations in cooling performance (variations in hardness and strain) to occur between parts during group quenching. In addition, by using petroleum resin and / or a derivative of petroleum resin, when a component has a complicated shape, it is difficult to cause variation in cooling performance at each location of the component, so that distortion of each component can be suppressed.
Furthermore, by using petroleum resin and / or a derivative of petroleum resin, when the heat treatment of the metal material is repeatedly performed, it is possible to suppress a change with time in the cooling performance of the heat-treated oil composition. Specifically, when the heat treatment of the metal material is repeated, the number of seconds (characteristic seconds) until the vapor film stage is reached and the kinematic viscosity decreases over time. Can be suppressed. That is, the lifetime of the heat-treated oil composition can be extended by using petroleum resin and / or petroleum resin derivatives.
Further, the characteristic seconds in the initial stage of the heat treatment can be shortened by the petroleum resin and / or the petroleum resin derivative. Excellent cooling performance can be imparted from the initial stage.
The reason why petroleum resins and / or petroleum resin derivatives can exert the above-described effects is considered to be the thermoplastic characteristics of petroleum resins and petroleum resin derivatives, and the excellent solubility in base oils.

  Petroleum resins are aliphatic olefins and aliphatic diolefins having 4 to 10 carbon atoms, which are obtained as by-products during the production of olefins such as ethylene by thermal decomposition of petroleum such as naphtha, or those having 8 or more carbon atoms and having no olefinic properties. A resin obtained by polymerizing or copolymerizing one or more unsaturated compounds selected from aromatic compounds having a saturated bond. Petroleum resins include, for example, “aliphatic petroleum resins” obtained by polymerizing aliphatic olefins and aliphatic diolefins, “aromatic petroleum resins” obtained by polymerizing aromatic compounds having an olefinically unsaturated bond, and aliphatic resins. It can be roughly classified into “aliphatic-aromatic copolymer petroleum resins” obtained by copolymerizing olefins and aliphatic diolefins with aromatic compounds having an olefinically unsaturated bond.

Examples of the aliphatic olefins having 4 to 10 carbon atoms include butene, pentene, hexene, heptene and the like. Examples of the aliphatic diolefin having 4 to 10 carbon atoms include butadiene, pentadiene, isoprene, cyclopentadiene, dicyclopentadiene, and methylpentadiene. Furthermore, examples of the aromatic compound having 8 or more carbon atoms and having an olefinically unsaturated bond include styrene, α-methylstyrene, β-methylstyrene, vinyltoluene, vinylxylene, indene, methylindene, and ethylindene. .
In addition, all of the raw material compounds of the petroleum resin need not be by-products during the production of olefins by thermal decomposition of petroleum such as naphtha, and chemically synthesized unsaturated compounds may be used. Examples thereof include dicyclopentadiene petroleum resins obtained by polymerization of cyclopentadiene and dicyclopentadiene, and dicyclopentadiene-styrene petroleum resins obtained by copolymerizing these cyclopentadiene or dicyclopentadiene and styrene.

Examples of petroleum resin derivatives include hydrogenated petroleum resins in which hydrogen atoms are added to the above petroleum resins. In addition, as a derivative of the petroleum resin, an acid-modified petroleum resin obtained by modifying the petroleum resin with an acidic functional group typified by carboxylic acid, the acid-modified petroleum resin may be alcohol, amine, alkali metal, alkaline earth metal, or the like. And compounds modified by reaction with the above compound.
Acid-modified petroleum resins can be roughly classified into carboxylic acid-modified petroleum resins obtained by modifying petroleum resins with unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides, and acid anhydride-modified petroleum resins. Examples of unsaturated carboxylic acids include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; unsaturated polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid; monomethyl maleate, monoethyl fumarate, etc. Examples of unsaturated carboxylic acid anhydrides include unsaturated polyvalent carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride.

As the above-mentioned petroleum resins and petroleum resin derivatives, aliphatic-aromatic copolymer petroleum resins and hydrogenated aliphatic-aromatic copolymer petroleum resins are preferred because they tend to shorten the characteristic seconds.
The number average molecular weight of the petroleum resin or petroleum resin derivative is preferably 200 to 5000, more preferably 250 to 2500, and more preferably 300 to 1500 from the viewpoint of easily exerting the effect of the present embodiment. More preferably.

The petroleum resin and / or petroleum resin derivative preferably has a softening point of 40 ° C. or higher, more preferably 60 ° C. or higher and 150 ° C. or lower, and 80 ° C. or higher and 140 ° C. or higher, as measured by the ring and ball method of JIS K2207: 2006. More preferably, it is 85 degrees C or less, and it is still more preferable that it is 85 to 130 degreeC.
By setting the softening point of petroleum resin and / or petroleum resin derivatives to 40 ° C. or higher, variation in cooling performance (variation in hardness and strain) between components can be made more difficult during group quenching, and the shape of the component is complicated. In this case, it is possible to make it difficult for variations in the cooling performance of each part location to occur, and to suppress distortion of each part.
Further, by setting the softening point of petroleum resin and / or petroleum resin derivative to 40 ° C. or higher, the change in cooling performance with time (when the heat treatment is repeated) (the increase in characteristic seconds over time and the kinematic viscosity over time) Can be further suppressed, and the characteristic seconds in the initial stage of the heat treatment can be shortened. That is, by making the softening point of petroleum resin and / or petroleum resin derivative 40 ° C. or higher, it is easier to maintain the cooling performance of the heat-treated oil composition not only at the initial stage but also after repeated use. Therefore, it is possible to suppress the variation in the cooling performance of each part during group quenching and the distortion of each part for a longer period.
In addition, by setting the softening point of petroleum resin and / or petroleum resin derivative to 150 ° C. or less, stickiness of the surface of the workpiece after cooling the workpiece such as a metal material with the heat treatment oil composition is reduced. it can.
The softening point of the petroleum resin and / or petroleum resin derivative can be adjusted by the degree of polymerization of the petroleum resin, the modifying component, and the degree of modification.
In addition, when using 2 or more types of materials as a petroleum resin and / or a petroleum resin derivative, it is preferable that all the materials are in the range of the softening point.

The content ratio of the petroleum resin and / or petroleum resin derivative of the component (B) with respect to the total amount of the heat-treated oil composition is preferably 0.1 to 90% by mass, and more preferably 2 to 50% by mass. 5 to 20% by mass is more preferable.
By making the content rate of (B) component into 0.1 mass% or more, the effect based on the (B) component mentioned above can be made easy to be acquired. In addition, by setting the content ratio of the component (B) to 90% by mass or less, the amount of the base oil of the component (A) that secures the essential cooling performance is secured, and the heat treatment oil composition has the cooling performance. Can be granted.
The total content of the component (A) and the component (B) is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 100% by mass with respect to the total amount of the heat-treated oil composition.
In addition, if it is a range which does not inhibit the effect of this embodiment, you may contain vapor | steam film | membrane breaking agents other than a stone resin and / or a derivative | guide_body of petroleum resin in the heat-treatment oil composition. Other vapor film breakers include terpene resins, terpene resin derivatives, rosin, rosin derivatives, and the like.

(C) Additive The heat-treated oil composition of the present embodiment may contain additives such as an antioxidant and a cooling performance improver.
The content ratio of the antioxidant, the cooling performance improver, etc. is preferably 10% by mass or less, and more preferably 0.01 to 5% by mass with respect to the total amount of the heat-treated oil composition.

Physical property of heat-treated oil composition The heat-treated oil composition of the present embodiment is characterized in that the characteristic seconds obtained from the cooling curve obtained in accordance with the cooling performance test method of JIS K2242: 2012 is 1.00 seconds or less. Cost.
When the characteristic seconds of the heat-treated oil composition exceeds 1.00 seconds, it becomes difficult to reduce variation in cooling performance for each part during group quenching, and it is also difficult to suppress distortion of each part.

The characteristic seconds of the heat-treated oil composition is preferably 0.95 seconds or less, and more preferably 0.90 seconds or less.
More specifically, the characteristic number of seconds can be calculated by the following (1) and (2).
(1) In accordance with the cooling performance test method of JIS K2242: 2012, a silver sample heated to 810 ° C. is charged into the heat-treated oil composition, and cooling is performed with time as the x axis and the temperature of the silver sample surface as the y axis. Find a curve.
(2) From the cooling curve, the number of seconds until reaching the temperature (characteristic temperature) at which the vapor film stage of the heat-treated oil composition ends is calculated by the tangential intersection method, and the number of seconds is defined as the characteristic number of seconds.
In the above (1), the measurement time interval is preferably 1/100 second.

Furthermore, the heat-treated oil composition of the present embodiment is “300 ° C. seconds”, which is a cooling time from 800 ° C. to 300 ° C. of the cooling curve obtained in accordance with the cooling performance test method of JIS K2242: 2012. Is required to be 6.00 seconds or more and 14.50 seconds or less.
If the heat-treated oil composition has 300 ° C. seconds outside the above range, it becomes difficult to make the cooling performance of the heat-treated oil composition comparable to that of JIS K2242: 2012 Type 2 No. 1 oil.

  The heat-treated oil composition preferably has 300 ° C. seconds of 6.50 to 13.50 seconds, and more preferably 7.00 to 12.50 seconds.

  In order to set the characteristic seconds of the heat-treated oil composition and the number of seconds at 300 ° C. within the above range, the content of component (A) and the kinematic viscosity at 40 ° C., and the content, softening point and number of component (B) The average molecular weight is preferably within the range of the above-described embodiment.

Heat treatment oil composition of the present embodiment is preferably from 100 ° C. kinematic viscosity of 10 to 30 mm ² / s, more preferably 15 to 20 mm ² / s.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

A. Evaluation and measurement A-1. Hardness and strain Heat treatment is performed under the following conditions using cylindrical case-hardened steel (outer diameter φ85mm, height 44mm, wall thickness 4mm, material SCM415) as a material for quenching evaluation. evaluated.
<Conditions for heat treatment>
Heat treatment conditions: carburizing step 930 ° C. × 150 minutes, CP = 1.1% by mass
Diffusion process: 930 ° C. × 60 minutes, CP = 0.8 mass%
Soaking process: 850 ° C. × 20 minutes, CP = 0.8% by mass
Oil cooling conditions: Oil temperature 120 ° C., oil cooling time 10 minutes, stirring 20 Hz
Tempering conditions: 180 ° C x 60 minutes Setting method: sword rack (8 quenching workpieces, 4 pieces x 2 steps)
<Evaluation items>
・ Average ellipticity (mm)
・ Ellipticity 3σ (mm)
・ Average taper strain (mm)
・ Taper strain 3σ (mm)
・ Average internal hardness (hardened material 1.5mm inside, HV)
・ Average effective hardened layer depth (mm)

A-2. Initial cooling performance In accordance with the cooling performance test method defined in JIS K2242: 2012, a silver sample heated to 810 ° C. is put into the heat-treated oil composition, and a cooling curve of the silver sample is obtained. Number ”and“ 300 ° C. seconds ”were calculated. The oil temperature of the heat-treated oil composition before charging the silver sample was 120 ° C. for all of Examples 1-1 to 1-9, Comparative Example 1, Example 2, and Comparative Examples 2-1 to 2-2.
<Characteristic seconds>
In the above cooling curve, the temperature at which the vapor film stage ends (characteristic temperature) was calculated in accordance with JIS K2242: 2012, and the number of seconds until the vapor film stage was reached was defined as characteristic seconds.
<300 ° C seconds>
The cooling time from 800 ° C. to 300 ° C. in the cooling curve was set to 300 ° C. seconds.

A-3. Stability of cooling performance with time The results of A-2 above were the results before repeated quenching deterioration tests. Next, repeated quenching deterioration tests were performed under the following conditions. After the deterioration test, the same test and evaluation as in A-2 were performed again, and this was taken as the result after repeated quenching deterioration tests. The rate of change before and after the test was calculated by the following equation (2).
[(Value after test−value before test) / value before test] × 100 (2)
<Test conditions>
Test piece: SUS316
Quenching temperature: 850 ° C
Oil volume: 400ml
Oil temperature: 170 ° C
Quenching times: 400 times

A-4. Dynamic viscosity According to JIS K2283: 2000, the 100 degreeC dynamic viscosity of the heat processing oil composition was measured before and after the repeated quenching deterioration test of said A-3.

B. Preparation and evaluation of heat-treated oil composition (Examples 1-1 to 1-9, Comparative Example 1)
The heat-treated oil composition having the composition shown in Table 1 was prepared, and evaluation and measurement of the above A-2 and A-4 were performed. The results are shown in Table 1.

The materials in Table 1 are as follows.
Base oil 1: Mineral oil with a kinematic viscosity of 90 mm ² / s at 40 ° C. 1-1: Partially hydrogenated aliphatic-aromatic copolymer petroleum resin, softening point 110 ° C., number average molecular weight 760
Petroleum 1-2: aliphatic petroleum resin, softening point 99 ° C., number average molecular weight 1300
Petroleum 1-3: aliphatic-aromatic copolymer petroleum resin, softening point 103 ° C., number average molecular weight 900
Petroleum 1-4: Hydrogenated aliphatic petroleum resin, softening point 105 ° C., number average molecular weight 400
Petroleum 1-5: Hydrogenated aliphatic petroleum resin, softening point 125 ° C., number average molecular weight 430
Petroleum 1-6: Hydrogenated aliphatic petroleum resin, softening point 87 ° C., number average molecular weight 370
Petroleum 1-7: Hydrogenated aliphatic petroleum resin, softening point 103 ° C., number average molecular weight 410
Petroleum 1-8: partially hydrogenated aromatic modified aliphatic petroleum resin, softening point 102 ° C., number average molecular weight 500
Petroleum 1-9: aliphatic petroleum resin, softening point 124 ° C., number average molecular weight 430

As is clear from the results in Table 1, the heat-treated oil compositions of Examples 1-1 to 1-9 have a short cooling time of 300 ° C. and the same cooling performance as Type 2 No. 1 oil of JISK2242: 2012. I can confirm that.
Moreover, it can be confirmed that the heat-treated oil compositions of Examples 1-1 to 1-9 have short characteristic seconds. For this reason, when the heat-treated oil composition of Examples 1-1 to 1-9 is used, it can be seen that suppression of variation in cooling performance for each part during group quenching and suppression of distortion of each part can be expected.

(Example 2, Comparative Examples 2-1 to 2-2)
The heat-treated oil composition having the composition shown in Table 2 was prepared, and the above A-1 to A-4 were measured and evaluated. The 100 ° C. kinematic viscosity of A-4 was measured before and after the repeated quenching deterioration test of A-3. The results are shown in Table 2.

The materials in Table 2 are as follows.
Base Oil 2-1: 40 ° C. kinematic viscosity 120 mm ² / s of the mineral base oil 2-2: 40 ° C. kinematic viscosity 60 mm ² / s of the mineral base oil 2-3: 40 ° C. mineral oil resins kinematic viscosity 200 mm ² / s 2: Partially hydrogenated aliphatic-aromatic copolymer petroleum resin, softening point 110 ° C., number average molecular weight 760
α-olefin copolymer: α-olefin copolymer having a kinematic viscosity of 2000 mm ² / s at 100 ° C.

As is clear from the results in Table 2, it can be confirmed that the heat-treated oil composition of Example 2 has a short cooling time of 300 ° C. and has a cooling performance comparable to that of JIS K2242: 2012 Type 2 No. 1 oil. Moreover, the heat-treated oil composition of Example 2 has small values of ellipticity 3σ and taper strain 3σ, and it can be confirmed that variation in strain during group quenching can be suppressed. Furthermore, it can be confirmed that the heat-treated oil composition of Example 2 can suppress deterioration of performance over time (increase in characteristic seconds, increase in 300 ° C. seconds, decrease in kinematic viscosity) when repeated heat treatment is performed.
In addition, the heat-treated oil composition of Example 2 can maintain good performance over a long period after repeated use from the initial stage because the characteristic seconds in the initial stage and 300 seconds at 300 ° C. show good values. I can confirm.

  The heat-treated oil composition of the present embodiment can reduce the variation in cooling performance of parts during group quenching while maintaining the same cooling performance as Type 2 No. 1 oil of JIS K2242: 2012, and heat treatment of metal materials It is possible to suppress the change in cooling performance with time when the above is repeated. For this reason, the heat treatment oil composition of this embodiment is suitable as a heat treatment oil when performing heat treatment such as quenching, annealing, and tempering on alloy steels such as carbon steel, nickel-manganese steel, chromium-molybdenum steel, and manganese steel. In particular, among them, it is preferably used as a heat-treated oil when quenching.

Claims (6)

Characteristic seconds obtained from a cooling curve obtained according to the cooling performance test method of JIS K2242: 2012, including (A) base oil and (B) one or more selected from petroleum resins and / or petroleum resin derivatives. as the number is less than 1.00 seconds, Ri 14.50 seconds der below 300 ° C. the number of seconds more than 6.00 seconds cooling time until 300 ° C. from 800 ° C. of the cooling curve,
JIS K2207: 2006 of was measured by the ring and ball method (B) a petroleum resin and / or heat treatment oil composition having a softening point of derivatives of petroleum resin is characterized der Rukoto 40 ° C. or more components. The heat-treated oil composition according to claim 1 , wherein the softening point of the petroleum resin and / or petroleum resin derivative of component (B) measured by the ring and ball method of JIS K2207: 2006 is 60 ° C or higher and 150 ° C or lower. The heat-treated oil composition according to claim 1 or 2 , wherein the base oil of the component (A) has a 40 ° C kinematic viscosity of 40 to 500 mm ² / s. Based on the total amount of the heat treatment oil composition, (A) a base oil component from 10 to 99.9 wt%, (B) claims a derivative of a petroleum resin and / or petroleum resin component containing 0.1 to 90 wt% Item 4. The heat-treated oil composition according to any one of Items 1 to 3 . The heat-treated oil composition according to any one of claims 1 to 4 , wherein the heat-treated oil composition has a kinematic viscosity at 100 ° C of 10 to 30 mm ² / s. The heat-treated oil composition according to any one of claims 1 to 5, wherein the number average molecular weight of the component (B) petroleum resin and / or petroleum resin derivative is 200 to 5,000.