TW201634682A - Heat treatment oil composition - Google Patents

Abstract

Provided is a heat treatment oil composition capable, when heat-treating a metal material by quenching, etc., of maintaining cooling performance on the same level as JIS K2242:2012 Type 2 Number 1 oil while reducing variation in cooling performance for each part during batch quenching and capable of limiting changes over time in cooling performance when said heat treatment is performed repeatedly. The heat treatment oil composition is characterized in that: the composition comprises (A) a base oil, and (B) at least one resin selected from petroleum resins and/or petroleum resin derivatives; the specified number of seconds obtained from a cooling curve determined in accordance with the JIS K2242:2012 cooling performance test method is 1.00 second or less; and the 300 DEG C number of seconds, which is the cooling time from 800 DEG C to 300 DEG C on the cooling curve, is 6.00 seconds to 14.50 seconds.

Description

Heat treatment oil composition Field of invention

This invention relates to heat treated oil compositions.

Background of the invention

In the case of metal materials such as steel, heat treatment such as quenching, tempering, annealing, and normalization is applied for the purpose of improving the properties thereof. In these heat treatments, quenching is a treatment in which a heated metal material is immersed in a coolant to be transformed into a predetermined quenched structure, and the treated material becomes very hard by the quenching. For example, if the heated steel material in the Wolsfield state is immersed in the coolant and cooled above the upper critical cooling rate, it can be transformed into a quenched structure such as 麻田散铁.

As the coolant, an oil-based or water-based heat treatment agent can be generally used. In the case of quenching a metal material using an oil-based heat treatment agent (heat treatment oil), in the case where a heat-treated oil belonging to a coolant is supplied to a heated metal material, it is usually cooled in three stages. Specifically, (1) the first stage (vapor film stage) in which the metal material is coated with the heat-treated oil vapor film, (2) the second stage in which the vapor film is broken to cause boiling (boiling stage), and (3) the metal material. The temperature becomes below the boiling point of the heat treatment oil, and the heat is taken away by the convection in the third stage (convection stage). Then, in each stage due to the surrounding metal material The cooling rate varies depending on the ambient gas, and the cooling rate in the second stage (boiling stage) is the largest.

In general, in the heat-treated oil, the cooling rate is rapidly accelerated from the vapor film stage to the boiling stage. If the metal material is not a simple planar shape, the vapor film stage and the boiling stage are likely to be intermixed on the surface of the metal material. Then, in the case where the mixing occurs, a large temperature difference occurs on the surface of the metal material due to the difference in the cooling rate between the vapor film stage and the boiling stage. Then, due to the temperature difference, thermal stress or abnormal stress is generated, so that the metal material is strained.

Therefore, in the heat treatment of the metal material, especially in the quenching, it is important to select the heat treatment oil suitable for the heat treatment condition. If the selection is not appropriate, there is a case where the metal material is strained and at the same time, sufficient hardening hardness cannot be obtained.

On the one hand, the heat-treated oil is classified into one to three kinds according to Japanese JIS K2242:2012, and the one used for quenching is one type 1 oil, one type of No. 2 oil, two kinds of No. 1 oil, and two kinds of two. No. oil. In Japan, JIS K2242:2012 has standardized the cooling seconds from 800 °C to 400 °C as an indicator of cooling performance. One type 2 is set to be 4.0 seconds or less, and two types of 1 number are set to 5.0 seconds or less. Two types of No. 2 are set to be below 6.0 seconds. The shorter the number of cooling seconds, the higher the cooling performance and the harder the metal material becomes.

In general, the hardness of the metal after quenching is in balance with the strain system. The harder the strain, the greater the strain.

Further, in terms of industrial properties, the number of seconds at 300 ° C was also used as an index indicating the cooling property of the oil agent. The so-called 300 ° C seconds is in accordance with Japanese JIS The cooling time from 800 ° C to 300 ° C in the cooling curve obtained by the cooling performance test method of K2242: 2012.

In order to obtain the hardness and strain of the purpose, the user selects the quenching oil based on the above indexes. For example, in the quenching of automobile gear parts and the like which have a problem in strain, the above-mentioned two types of No. 1 oil are widely used. This is because the strain is increased by the above-mentioned one type of oil, and the hardness of the parts is too high, and the strain is small, but the hardness is insufficient. The reason.

However, parts such as an automobile transmission or a speed reducer are almost mass-produced, and so-called group hardening in which a large amount of processing material is stacked on one carrier and quenched once is performed. In this case, depending on the position where the stacked parts are placed, there is a problem that the cooling performance is uneven, and the hardness or strain of each part is uneven. For example, the hardness of the parts placed in the lower part is high, and the hardness of the parts placed in the upper part is low.

In view of the above situation, there are proposals for the techniques of Patent Documents 1 to 6.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2003-286517

Patent Document 2: Japanese Laid-Open Patent Publication No. 2002-38214

Patent Document 3: Japanese Laid-Open Patent Publication No. 2001-152243

Patent Document 4: Japanese Laid-Open Patent Publication No. 2002-327191

Patent Document 5: Japanese Laid-Open Patent Publication No. 2007-9238

Patent Document 6: Japanese Laid-Open Patent Publication No. 2013-194262

In order to reduce unevenness in hardness or strain of each part during quenching, Patent Document 1 proposes to add special equipment such as a vibrating machine or an injection device.

However, it is costly to add the above-mentioned equipment to the conventional device, and it is difficult to retrofit the device. Therefore, there is a need to have a technique that does not require investment in equipment as in Patent Document 1, but uses only heat treatment oil composition characteristics to reduce unevenness in hardness or strain.

Further, once the vapor film stage is elongated, the time during which the vapor film stage and the boiling stage are mixed is also elongated, and the strain is liable to become large. Therefore, it is desirable to shorten the number of seconds (characteristic seconds) until the temperature (characteristic temperature) at which the vapor film stage ends.

In order to eliminate the influence of the number of characteristic seconds, Patent Document 2 proposes a method of cooling with a gas to a temperature lower than a characteristic temperature and then performing oil quenching.

On the other hand, in order to eliminate the difference in the temperature of the treated material caused by the uneven cooling, Patent Document 3 proposes a method of uniformly raising the treated material from the quenching oil at a temperature above the initial temperature of the metamorphic iron of the granulated iron.

However, the methods of Patent Documents 2 and 3 are more costly or time-consuming than simple oil quenching. Further, the methods of Patent Documents 2 and 3 are methods for reducing strain, and it is not possible to reduce unevenness in hardness or strain of each part during group quenching.

Patent Document 4 proposes a heat-treating oil composition which can be used as a heat-treating oil composition which can prevent the unevenness of cooling from being generated on the quenching of a metal material, can ensure the hardness of the quenched material and can reduce the quenching strain, and the heat-treating oil composition It is composed of a mixed base oil which is 50~95% by weight of a low viscosity base oil having a dynamic viscosity of 5 to 60 mm ² /s at 40 ° C and a dynamic viscosity of 300 mm ² at 40 ° C / More than s high viscosity base oil 50~5 wt%.

Further, Patent Document 5 proposes a heat-treating oil composition which has the same cooling performance as the above-mentioned two types of No. 1 oil, but which can reduce the unevenness in cooling performance during group quenching. Specifically, the heat-treated oil composition contains a mixed base oil which is 5% by mass or more and less than 50% by mass based on a low-boiling base oil having a 5% distillation temperature of 300 ° C or more and 400 ° C or less. And a high-boiling base oil having a 5% distillation temperature of 500 ° C or more is more than 50% by mass and is composed of 95% or less.

However, since the heat treatment oil compositions of Patent Documents 4 and 5 do not use a vapor film breaker, the number of characteristics is long, and the unevenness of hardness or strain of each part during group quenching cannot be reduced.

Patent Document 6 proposes a heat-treating oil composition in which a dynamic viscosity at 40 ° C of 50% by mass or more and 95% by mass or less based on the total amount of the composition is 5 mm ² /s or more and 60 mm ² /s or less. when the base oil to the composition in a total amount of 5 mass% or more and 50 mass% or less of dynamic viscosity of less than 40 ℃ of 300mm ² / s base oil, and α-olefin copolymer, whereby the quenching group may be reduced Uneven cooling performance.

However, the heat-treated oil composition of Patent Document 6 has a problem that the cooling performance is deteriorated with time by repeated quenching.

The present invention has been made in view of the above, and it is an object of the present invention to provide a heat-treating oil composition which can maintain the same degree as the two types of No. 1 oil of JIS K2242:2012 when heat-treating a metal material by quenching or the like. Cooling performance can reduce the cooling performance of each part during group quenching At the same time, it is possible to suppress the temporal change of the cooling performance which occurs when the heat treatment is repeatedly performed.

In order to solve the above problems, an embodiment of the present invention provides a heat treatment oil composition comprising: (A) a base oil; and (B) one or more selected from the group consisting of petroleum resins and/or petroleum resin derivatives. The characteristic temperature of the heat-treated oil composition obtained from the cooling curve is 1.00 second or less, and the cooling time of the cooling curve from 800 ° C to 300 ° C, that is, 300 ° C seconds is 6.00 seconds or more and 14.50 seconds or less, wherein The cooling curve was obtained in accordance with the cooling performance test method of JIS K2242:2012, Japan.

When the metal material is heat-treated by quenching or the like, the heat-treating oil composition of the present invention can maintain the same cooling performance as the two types of No. 1 oil of JIS K2242:2012, and can reduce the cooling performance of each part during group quenching. All. Further, the heat-treated oil composition of the present invention can suppress the change in the cooling performance which occurs when the metal material is repeatedly subjected to the heat treatment.

Hereinafter, embodiments of the present invention will be described. The heat-treated oil composition of the present embodiment contains: (A) a base oil, (B) one or more selected from the group consisting of petroleum resins and/or petroleum resin derivatives, and the characteristic number of seconds obtained from the cooling curve is 1.00 second or less, and The cooling time of the cooling curve from 800 ° C to 300 ° C, that is, 300 ° C seconds is less than 6.00 seconds and less than 14.50 seconds, wherein This cooling curve was obtained in accordance with the cooling performance test method of JIS K2242:2012, Japan.

[(A) base oil]

The base oil of the component (A) may be mineral oil and/or synthetic oil.

Examples of the mineral oil include a paraffinic hydrocarbon-based mineral oil, an intermediate-based mineral oil, and a naphthenic-based mineral oil obtained by a general refining method such as solvent refining and hydrogen refining; and a wax which has been produced by a Fischer-Tropsch method or the like ( Gas-to-liquid wax), a wax isomerization system oil produced by isomerization of a wax such as mineral oil wax, and the like.

Examples of the synthetic oil include a hydrocarbon-based synthetic oil and an ether-based synthetic oil. The hydrocarbon-based synthetic oil may, for example, be an alkylbenzene or an alkylnaphthalene. Examples of the ether-based synthetic oil include polyoxyalkylene glycol and polyphenylene ether.

The base oil of the component (A) may be a single system using only one of the above-mentioned mineral oils and synthetic oils, or may be a mixture of two or more kinds of mineral oils, or a mixture of two or more types of synthetic oils. A mixed system is used in which one type or two or more types of mineral oil and synthetic oil are mixed.

The 40 ° C dynamic viscosity of the base oil of the component (A) is preferably 40 mm ² /s or more and 500 mm ² /s or less, more preferably 50 mm ² /s or more and 350 mm ² /s or less, and 60 mm ² /s or more and 200 mm ² / s is better below.

By setting the 40 ° C dynamic viscosity of the base oil of the component (A) to the above range, the essential cooling performance achieved by (A) can be ensured, and the characteristic number of seconds and the number of 300 ° C seconds can be easily made in the range described later.

When the base oil of the component (A) is a base oil obtained by mixing two or more base oils, the dynamic viscosity of the mixed base oil satisfies the above range.

Moreover, in the present embodiment, the dynamic viscosity of the base oil and the heat-treated oil composition The degree can be measured in accordance with JIS K2283:2000.

The content ratio of the base oil of the component (A) is preferably from 10 to 99.9% by mass, more preferably from 50 to 98% by mass, even more preferably from 80 to 95% by mass, based on the total amount of the heat-treated oil composition.

By setting the content ratio of the component (A) to 80% by mass or more, the essential cooling performance achieved by (A) can be ensured, and the content ratio of the component (A) can be ensured by less than 100% by mass. The amount of the petroleum resin and/or petroleum resin derivative used as the component is easy to obtain the effect achieved by the component (B) described later.

[(B) petroleum resin and / or petroleum resin derivatives]

The heat-treated oil composition of the present embodiment contains one or more (B) petroleum resins and/or petroleum resin derivatives. The petroleum resin and/or petroleum resin derivative of the component (B) has a function as a vapor film breaker.

By using a petroleum resin and/or a petroleum resin derivative as a vapor film breaker, the vapor film stage can be shortened, and the cooling performance of the heat treatment oil composition can be easily made to the same level as the two types of No. 1 oil of JIS K2242:2012.

Further, since the vapor film stage can be shortened by using a petroleum resin and/or a petroleum resin derivative, the vapor film stage and the boiling stage are less likely to be mixed on the surface of the metal material. Therefore, by using a petroleum resin and/or a petroleum resin derivative, uneven cooling performance (uneven hardness or strain) of each part during group quenching is less likely to occur. Further, by using a petroleum resin and/or a petroleum resin derivative, when the parts have a complicated shape, the cooling performance of the parts is less likely to be uneven, so that the strain of each part can be suppressed.

Further, by using petroleum resins and/or petroleum resin derivatives, When the heat treatment of the metal material is repeated, the occurrence of the cooling performance over time can be suppressed. Specifically, when the heat treatment of the metal material is repeated, it is possible to suppress the increase in the number of seconds (characteristic seconds) until the temperature at which the vapor film stage is reached, and to suppress the deterioration of the dynamic viscosity with time. That is, the life of the heat-treated oil composition can be prolonged by using a petroleum resin and/or a petroleum resin derivative.

Further, by the petroleum resin and/or the petroleum resin derivative, the number of characteristics in the initial stage of the heat treatment can be shortened.

The reason why the petroleum resin and/or the petroleum resin derivative exerts the above effects is presumably due to the thermoplastic properties of the petroleum resin and the petroleum resin derivative, and the excellent solubility to the base oil.

The petroleum resin is an aliphatic olefin or an aliphatic diene having a carbon number of 4 to 10 or a carbon number of 8 or more which is obtained by a by-product from the thermal decomposition of petroleum such as petroleum brain. A resin obtained by polymerizing or copolymerizing one or more kinds of unsaturated compounds having an olefinic unsaturated bond. The petroleum resin is, for example, an "aliphatic petroleum resin" obtained by polymerizing an aliphatic olefin or an aliphatic diolefin, and an aromatic petroleum resin obtained by polymerizing an aromatic compound having an olefinic unsaturated bond. An "aliphatic-aromatic copolymerized petroleum resin" obtained by copolymerizing an aliphatic olefin or an aliphatic diolefin with an aromatic compound having an olefinic unsaturated bond.

Examples of the aliphatic olefin having 4 to 10 carbon atoms include pentene, hexene, heptene and the like. Further, examples of the aliphatic diolefin having 4 to 10 carbon atoms include butadiene, pentadiene, isoprene, cyclopentadiene, dicyclopentadiene, and Kelpene and the like. Further, examples of the aromatic compound having a carbon number of 8 or more and having an olefinic unsaturated bond include styrene, α-methylstyrene, β-methylstyrene, vinyltoluene, vinylxylene, anthracene, and methyl group.茚, ethyl hydrazine, etc.

Further, it is not necessary for all of the raw material compounds of the petroleum resin to be a by-product of the production of olefins by thermal decomposition of petroleum oil such as petroleum brain, and chemically synthesized unsaturated compounds may also be used. For example, a dicyclopentadiene-based petroleum resin obtained by polymerization of cyclopentadiene or dicyclopentadiene or a copolymerization of the cyclopentadiene or dicyclopentadiene with styrene may be used. Dicyclopentadiene-styrene petroleum resin.

The petroleum resin derivative may be a hydrogenated petroleum resin which has been added to a hydrogen atom of the above petroleum resin. In addition, the petroleum resin derivative may be an acid-modified petroleum resin in which the petroleum resin is modified with an acidic functional group represented by a carboxylic acid or the like, and the acid-modified petroleum resin is an alcohol, an amine or an alkali metal. A compound which is modified by a compound such as an alkaline earth metal.

The acid-modified petroleum resin is roughly classified into a carboxylic acid-modified petroleum resin and an acid-modified petroleum resin in which a petroleum resin is modified with an unsaturated carboxylic acid or an unsaturated carboxylic anhydride. Examples of the unsaturated carboxylic acid include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; unsaturated polycarboxylic acids such as maleic acid, fumaric acid, isoconic acid, and pyrocitric acid; monomethyl maleate and fumaric acid; A partial ester of an unsaturated polycarboxylic acid such as a monoethyl ester; and the unsaturated carboxylic acid anhydride may, for example, be an unsaturated polycarboxylic acid anhydride such as maleic anhydride or isaconic anhydride.

In the case of the above petroleum resin and petroleum resin derivative, aliphatic - Aromatic copolymerized petroleum resins and hydrogenated aliphatic-aromatic copolymerized petroleum resins tend to shorten the number of characteristic seconds, which is quite suitable in this regard.

The number average molecular weight of the petroleum resin and the petroleum resin derivative is preferably from 200 to 5,000, more preferably from 250 to 2,500, more preferably from 300 to 1,500, from the viewpoint of easily exerting the effect obtained by the present embodiment.

The petroleum resin and/or petroleum resin derivative preferably has a softening point of 40 ° C or more, 60 ° C or more and 150 ° C or less, preferably 80 ° C or more and 140 ° C or less, in accordance with the method of JIS K2207:2006. Above °C and below 130 °C is better.

By making the softening point of the petroleum resin and/or petroleum resin derivative above 40 ° C, the uneven cooling performance (hardness or strain unevenness) of each part during group quenching is less likely to occur, and the parts are complicated shapes. The uneven cooling performance of the parts can be prevented from occurring, and the strain of each part can be suppressed.

Further, by making the softening point of the petroleum resin and/or the petroleum resin derivative 40 ° C or more, it is possible to further suppress the change in the cooling performance over time during the repeated heat treatment (the temporal increase of the characteristic number of seconds and the transit time of the dynamic viscosity) Inferiority), at the same time, can shorten the number of characteristic seconds in the initial stage of heat treatment. That is, by making the softening point of the petroleum resin and/or petroleum resin derivative above 40 ° C, it is not only the initial stage, but even after repeated use, the cooling performance of the heat treatment oil composition can be more easily maintained, and Long-term general suppression of uneven quenching performance of each part and quenching of each part.

Further, by setting the softening point of the petroleum resin and/or the petroleum resin derivative to 150 ° C or lower, it is possible to reduce the stickiness of the surface of the workpiece after cooling the workpiece such as a metal material with the heat treatment oil composition.

The softening point of the petroleum resin and/or petroleum resin derivative can be adjusted according to the degree of polymerization, the modified component, and the degree of upgrading of the petroleum resin.

Further, in the case where two or more materials are used as the petroleum resin and/or the petroleum resin derivative, all of the materials are preferably in the above softening point range.

The content ratio of the petroleum resin and/or petroleum resin derivative of the component (B) to the total amount of the heat-treated oil composition is preferably 0.1 to 90% by mass, preferably 2 to 50% by mass, more preferably 5 to 20% by mass. .

By setting the content ratio of the component (B) to 0.1% by mass or more, the effect achieved by the above component (B) can be easily obtained. In addition, when the content ratio of the component (B) is 90% by mass or less, the amount of the component (A) component oil which is responsible for the essential cooling performance can be ensured, and the heat treatment oil composition can be provided with cooling performance.

The content of the component (A) and the component (B) is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 100% by mass based on the total amount of the heat-treated oil composition.

Further, the heat treatment oil composition may contain a vapor film breaker other than the stone resin and/or the petroleum resin derivative as long as it does not inhibit the effects of the embodiment. Other vapor film breakers include terpene resins, terpene resin derivatives, rosins, and rosin derivatives.

[(C) Additives]

The heat-treated oil composition of the present embodiment may contain an additive such as an antioxidant or a cooling performance enhancer.

The content ratio of the antioxidant, the cooling performance enhancer, and the like is preferably 10% by mass or less, and preferably 0.01 to 5% by mass based on the total amount of the heat-treated oil composition.

[The physical properties of the heat-treated oil composition]

In the heat-treated oil composition of the present embodiment, the number of characteristics obtained from the cooling curve must be 1.00 second or less, and the cooling curve is obtained in accordance with the cooling performance test method of JIS K2242:2012.

When the number of seconds of the heat treatment oil composition exceeds 1.00 second, it becomes difficult to reduce unevenness in cooling performance of each part during quenching, and it is also difficult to suppress the strain of each part.

The number of seconds of the characteristic of the heat-treating oil composition is preferably 0.95 seconds or less, more preferably 0.90 second or less.

More specifically, the number of characteristic seconds is calculated based on the following (1) and (2).

(1) According to the cooling performance test method of JIS K2242:2012, a silver sample heated to 810 ° C was placed in a heat treatment oil composition, and a cooling curve in which the time was the x-axis and the surface temperature of the silver sample was the y-axis was obtained.

(2) The number of seconds until the temperature (characteristic temperature) at which the vapor film stage of the heat treatment oil composition ends is calculated from the tangential intersection method, and the number of seconds is the characteristic second.

Further, in the above (1), the interval between the measurement times is preferably 1/100 second.

Further, in the heat-treated oil composition of the present embodiment, the cooling time of the cooling curve from 800 ° C to 300 ° C, that is, "300 ° C seconds" must be 6.00 seconds or more and 14.50 seconds or less, and the cooling curve is in accordance with JIS K2242:2012. The cooling performance test method is obtained.

When the number of seconds of 300 ° C of the heat-treated oil composition is out of the above range, it is difficult to make the cooling performance of the heat-treated oil composition the same as that of the two types of No. 1 oil of JIS K2242:2012.

The heat treatment oil composition has a number of 300 ° C seconds, preferably 6.50 to 13.50 seconds, and preferably 7.00 to 12.50 seconds.

In order to make the characteristic number of seconds of the heat-treated oil composition and the number of seconds of 300 ° C in the above range, the content of the component (A) and the dynamic viscosity at 40 ° C, and the content of the component (B), the softening point and the number average molecular weight are carried out as described above. It is better within the range of morphology.

In the heat-treated oil composition of the present embodiment, the dynamic viscosity at 100 ° C is preferably 10 to 30 mm ² /s, and preferably 15 to 20 mm ² /s.

Example

Next, the present invention will be described in further detail based on examples, but the present invention is not limited by the examples.

A. Evaluation, measurement

A-1. Hardness and strain

For the quenching evaluation material, a cylindrical forged steel (outer diameter φ85 mm, height 44 mm, thickness 4 mm, material SCM415) was used, and heat treatment was performed under the following conditions, and further, the following items were evaluated.

<conditions such as heat treatment>

Heat treatment conditions: carburization step 930 ° C × 150 minutes, CP (carbon potential energy) = 1.1% by mass

Diffusion step: 930 ° C × 60 minutes, CP (carbon energy) = 0.8% by mass

Soaking step: 850 ° C × 20 minutes, CP (carbon energy) = 0.8% by mass

Oil cooling conditions: oil temperature 120 ° C, oil cooling time 10 minutes, stirring 20 Hz

Tempering conditions: 180 ° C × 60 minutes

Placement method: knife holder (8 quenching frames, 4 x 2 segments)

<evaluation project>

‧ average ellipticity (mm)

‧Ellipticity rate 3 σ(mm)

‧ average taper strain (mm)

‧ taper strain 3 σ (mm)

‧ Average internal hardness (1.5mm internal quenching material, HV)

‧ average effective hardened layer depth (mm)

A-2. Initial cooling performance

According to the cooling performance test method specified in JIS K2242:2012, the silver sample heated to 810 ° C is put into the heat treatment oil composition, and the cooling curve of the silver sample is obtained, and the following "characteristic seconds" and "300 ° C seconds are calculated. "." The oil temperature of the oil composition before the injection of the silver sample was carried out, and Examples 1-1 to 1-9, Comparative Example 1, Example 2, and Comparative Examples 2-1 to 2-2 were each set to 120 °C.

<characteristic seconds>

In the above cooling curve, the temperature (characteristic temperature) at which the vapor film stage is completed is calculated in accordance with JIS K2242:2012, and the number of seconds until the temperature is reached is the characteristic second.

<300°C seconds>

In the above cooling curve, the cooling time from 800 ° C to 300 ° C is 300 ° C.

A-3. Stability over time of cooling performance

The result of the above A-2 is the result before the repeated quenching deterioration test. Next, the repeated quenching deterioration test was performed under the conditions shown below. After the deterioration test, the same test and evaluation as A-2 above is repeated again, with the emphasis on The result after the quenching deterioration test. The rate of change before and after the test was calculated according to the following formula (2).

[(value after test - value before test) / value before test] × 100 (2)

<test conditions>

Test piece: SUS316

Quenching temperature: 850 ° C

Oil quantity: 400ml

Oil temperature: 170 ° C

Quenching times: 400 times

A-4. Dynamic viscosity

The 100 ° C dynamic viscosity of the heat-treated oil composition was measured before and after the repeated quenching deterioration test of A-3 in accordance with JIS K2283:2000.

B. Modulation and evaluation of heat treatment oil composition

(Examples 1-1 to 1-9, Comparative Example 1)

The heat-treated oil composition of the composition of Table 1 was prepared, and the evaluation and measurement of the above A-2 and A-4 were carried out. The results are shown in Table 1.

The materials in Table 1 are as follows.

Base oil 1:40 ° C dynamic viscosity 90mm ² / s mineral oil

Petroleum 1-1: partially hydrogenated aliphatic-aromatic copolymerized petroleum resin, softening point 110 ° C, number average molecular weight 760

Oil 1-2: aliphatic petroleum resin, softening point 99 ° C, number average molecular weight 1300

Petroleum 1-3: aliphatic-aromatic copolymerized 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 of Table 1, the heat-treated oil compositions of Examples 1-1 to 1-9 had a short cycle time of 300 ° C and had the same degree of cooling performance as the two types of No. 1 oil of JIS K2242:2012.

Further, in the heat-treated oil compositions of Examples 1-1 to 1-9, it was confirmed that the characteristic number of seconds was short. Therefore, it is understood that when the heat-treating oil compositions of Examples 1-1 to 1-9 are used, it is possible to suppress unevenness in cooling performance of each part during quenching of the group and to suppress strain of each part.

(Example 2, Comparative Example 2-1 to 2-2)

The heat treatment oil composition of the composition of Table 2 was prepared, and the measurement and evaluation of the above A-1 to A-4 were carried out.

Further, the dynamic viscosity at 100 ° C of the above A-4 was measured before and after the above-mentioned A-3 repeated quenching deterioration test. The results are shown in Table 2.

The materials in Table 2 are as follows.

Base oil 2-1: 40 ° C dynamic viscosity 120mm ² / s mineral oil

Base oil 2-2: 40 ° C dynamic viscosity 60 mm ² / s mineral oil

Base oil 2-3:40 °C dynamic viscosity 200mm ² / s mineral oil

Petroleum Resin 2: partially hydrogenated aliphatic-aromatic copolymerized petroleum resin, softening point 110 ° C, number average molecular weight 760

Alpha olefin copolymer: α-olefin copolymer with dynamic viscosity of 2000 mm ² /s at 100 ° C

As is clear from the results of Table 2, the heat-treated oil composition of Example 2 had a short cycle time of 300 ° C and had the same degree of cooling performance as the two types of No. 1 oil of JIS K2242:2012. Further, in the heat-treated oil composition of Example 2, the values of the ellipticity 3 σ and the taper strain 3 σ were small, and it was confirmed that the strain unevenness during group quenching can be suppressed. Further, it was confirmed that the heat-treated oil composition of Example 2 can suppress deterioration of the temporal property at the time of performing the repeated heat treatment (increased number of characteristics, increased number of seconds at 300 ° C, and reduced dynamic viscosity).

Further, it was confirmed that the heat-treated oil composition of Example 2 exhibited an excellent value in the number of seconds of the initial stage and the number of seconds at 300 ° C, and maintained good performance from the initial stage to the long period after repeated use.

Industrial availability

The heat-treated oil composition of the present embodiment can maintain the same degree of cooling performance as the two types of No. 1 oil of JIS K2242:2012, but can also reduce the unevenness of cooling performance of each part during group quenching, and can suppress occurrence of repeated heat treatment of the metal material. The cooling performance changes over time. Therefore, the heat-treated oil composition of the present embodiment can be suitably used as a heat-treated oil for heat treatment such as quenching, annealing, tempering, or the like on alloy steels such as carbon-containing steel, nickel-manganese steel, chromium-molybdenum steel, and manganese steel. In particular, it is suitable to use it as a heat treatment oil at the time of quenching.

Claims (6)

A heat treatment oil composition characterized by comprising: (A) a base oil; (B) one or more selected from the group consisting of petroleum resins and/or petroleum resin derivatives; and the characteristic number of seconds of the heat treatment oil composition obtained from a cooling curve 1.00 seconds or less, and the cooling time of the cooling curve from 800 ° C to 300 ° C, that is, 300 ° C seconds is less than 6.00 seconds and less than 14.50 seconds, wherein the cooling curve is in accordance with the Japanese JIS K2242: 2012 cooling performance test method And ask for it. The heat treatment oil composition of claim 1, which has a softening point of 40 ° C or more as measured by a petroleum resin and/or a petroleum resin derivative of the component (B) according to the Japanese JIS K2207:2006 method. The heat treatment oil composition according to claim 2, wherein the petroleum resin and/or petroleum resin derivative of the component (B) has a softening point of 60 ° C or more and 150 ° C or less according to the Japanese JIS K2207:2006 method. The heat-treated oil composition according to any one of claims 1 to 3, wherein the base oil of the component (A) has a dynamic viscosity at 40 ° C of 40 to 500 mm ² /s. The heat-treated oil composition according to any one of claims 1 to 4, which contains 10 to 99.9% by mass of the base oil of the component (A), and 0.1 to 90% by mass (B) based on the total amount of the heat-treated oil composition. a petroleum resin and/or petroleum resin derivative of the composition. The heat treatment oil composition according to any one of claims 1 to 5, wherein the heat treatment oil composition has a dynamic viscosity at 100 ° C of 10 to 30 mm 2 /s.