Aqueous heat treatment liquid composition, method for producing metal material, and device for producing metal material

Abstract

An aqueous heat treatment liquid composition according to one aspect of the present disclosure contains: (A) water; (B) a condensed phosphate; and (C) a glycol.

Description

Aqueous heat treatment liquid composition, method for manufacturing metal materials, and apparatus for manufacturing metal materials

[0001] This disclosure relates to an aqueous heat treatment liquid composition, a method for producing a metal material using the aqueous heat treatment liquid composition, and an apparatus for producing a metal material.

[0002] Coolants used for quenching metal materials include, for example, (i) gas or salt solution, (ii) oil-based or water-based (water-soluble) quenching fluid, (iii) water, and (iv) salt water. Cooling properties differ depending on the type of coolant, with a tendency for the cooling properties to increase in the order of (i), (ii), (iii), and (iv). Using a coolant with high cooling properties can produce harder metal materials, but on the other hand, it increases the risk of distortion and quench cracking. For this reason, the type of coolant is selected according to the desired hardness and allowable amount of distortion of the metal material after quenching.

[0003] Among these coolants, water-based quenching fluids are widely used because they have many advantages, including: higher cooling performance than oil-based quenching fluids; the ability to adjust cooling performance by dilution concentration; less risk of fire because they do not burn like oil; reduced oil usage because they can be diluted; and a reduced risk of distortion and cracking compared to water.

[0004] For example, Patent Document 1 discloses an aqueous coolant comprising one or more inorganic salts selected from carbonates, bicarbonates, sesquicarbonates, phosphates, borates, molybdates, and tungstates, and a metal corrosion inhibitor.

[0005] Japanese Patent Application Publication No. 2014-125680

[0006] The hardening process can reduce the surface gloss of metal materials, resulting in appearance defects. In such cases, post-hardening processes, such as polishing, are performed to improve the appearance defects.

[0007] When using an inert gas as a coolant, the luster after quenching is improved, allowing for the reduction of post-processing steps such as polishing. Furthermore, in the case of oil-based quenching solutions, the luster after quenching can be improved by adding alkenyl succinic acid. On the other hand, water-based quenching solutions generally tend to exhibit reduced luster, but no studies have been conducted on luster performance to date. Therefore, there is room for improvement regarding the luster when using water-based quenching solutions as a coolant. Additionally, since a fast cooling rate increases the risk of distortion and cracking, there is also room for improvement regarding the cooling rate of water-based quenching solutions.

[0008] One aspect of this disclosure aims to provide an aqueous heat treatment solution composition that exhibits good luster in a metal material after heat treatment and can suppress the cooling rate.

[0009] As a result of diligent research to solve the above problems, the inventors have discovered for the first time that by blending a condensed phosphate and glycols into an aqueous heat treatment solution composition, it is possible to realize an aqueous heat treatment solution composition that exhibits good luster of metal materials after heat treatment and suppresses the cooling rate, thus completing the present invention. That is, in order to solve the above problems, an aqueous heat treatment solution composition according to one aspect of the present disclosure contains water (A), a condensed phosphate (B), and glycols (C).

[0010] According to one aspect of this disclosure, it is possible to provide an aqueous heat treatment solution composition that exhibits good luster in a metal material after heat treatment and can suppress the cooling rate.

[0011] This figure shows the results of the examples, specifically the appearance of test specimens after quenching using each aqueous heat treatment solution composition (diluent) from Examples 1 to 3 and Comparative Example 1. This figure also shows the results of the examples, specifically the appearance of test specimens after quenching using each aqueous heat treatment solution composition (diluent) from Reference Examples 1 to 7 and Comparative Examples 14 to 23, as well as water from Comparative Example 24.

[0012] One aspect of the present invention will be described in detail below. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or greater, and B or less."

[0013] [1. Aqueous Heat Treatment Solution Composition] An aqueous heat treatment solution composition according to one aspect of the present disclosure contains water (A), condensed phosphate (B), and glycols (C). The above composition provides the following effects.

[0014] (1) Improvement of the luster of the surface of metal materials after heat treatment By using the aqueous heat treatment liquid composition according to one aspect of this disclosure as a quenching liquid or tempering liquid, the decrease in the luster of the surface of metal materials due to heat treatment can be reduced, and thus the occurrence of appearance defects in metal materials after heat treatment can be reduced. By using the aqueous heat treatment liquid composition according to one aspect of this disclosure as a quenching liquid or tempering liquid, the luster of the surface of metal materials after heat treatment is improved, and in subsequent processes after heat treatment, treatments such as polishing to improve appearance defects can be omitted. In this specification, "heat treatment" means a process of cooling a heated metal material with a coolant, and examples of such heat treatments include quenching and tempering.

[0015] (2) Suppression of Cooling Rate When a heated metal material is placed in an aqueous quenching solution, the cooling rate is not constant and usually proceeds through the following three stages: Stage 1 (Vapor Film Stage): The metal material is covered with vapor from the aqueous quenching solution and cooled through the vapor film. Stage 2 (Boiling Stage): The vapor film breaks and foamy heat treatment oil comes into contact with the metal surface. Stage 3 (Convection Stage): The temperature of the metal material falls below the boiling point of the aqueous quenching solution and cooling proceeds through convection of the aqueous quenching solution.

[0016] In conventional aqueous quenching solutions, since the boiling point of water is 100°C, the metal material cools rapidly to around 100°C after the vapor film breaks. In other words, when using conventional aqueous quenching solutions, the cooling rate in the temperature range where martensite is formed in the second stage (boiling stage) is fast, which can cause localized temperature differences in the metal material, making it prone to distortion and quench cracking.

[0017] In contrast, the aqueous heat treatment fluid composition according to one aspect of this disclosure has a suppressed cooling rate during heat treatment, and therefore, by using the aqueous heat treatment fluid composition according to one aspect of this disclosure as a quenching fluid or tempering fluid, cooling can be mitigated. For example, cooling can be mitigated by suppressing the 350-150°C cooling rate, which is one of the indicators of the coolability of aqueous quenching fluids. Herein, in this specification, the "350-150°C cooling rate" means the cooling rate (°C / s) calculated from the cooling time in the temperature range from 350°C to 150°C, measured in accordance with the cooling performance test method (Method B: core temperature measurement method) for water-soluble quenching fluids specified in JIS K2242:2012.

[0018] According to one aspect of the present disclosure, the aqueous heat treatment fluid composition can suppress the cooling rate during heat treatment and mitigate cooling, thereby reducing the risk of distortion and quench cracking occurring in metal materials during heat treatment.

[0019] The components contained in the aqueous heat treatment liquid composition according to one aspect of this disclosure are described below.

[0020] <Water (A)> The aqueous heat treatment fluid composition according to one aspect of the present disclosure is an aqueous heat treatment fluid composition containing water (A) (hereinafter sometimes referred to as "component (A)"), and therefore has the following advantages compared to oil-based quenching fluids: high cooling performance; cooling performance can be adjusted by dilution concentration; it does not burn like oil, so there is less risk of fire and it is safer; and it can be used diluted, so the amount of oil used can be reduced.

[0021] In an aqueous heat treatment fluid composition according to one aspect of this disclosure, the type of component (A) is not particularly limited. For example, distilled water, deionized water, tap water, industrial water, etc., can be used as component (A).

[0022] <Condensed Phosphate (B)> The aqueous heat treatment solution composition according to one aspect of this disclosure contains a condensed phosphate (B) (hereinafter sometimes referred to as "component (B)"), which results in good luster of the metal material surface after heat treatment.

[0023] In an aqueous heat treatment liquid composition according to one aspect of the present disclosure, component (B) can be a condensed phosphate with a degree of polymerization of 2 to 200. From the viewpoint of solubility in water, component (B) is preferably a condensed phosphate with a degree of polymerization of 2 to 10, more preferably a polyphosphate or metaphosphate with a degree of polymerization of 2 to 10, even more preferably a pyrophosphate (degree of polymerization 2), tripolyphosphate (degree of polymerization 3), trimetaphosphate (degree of polymerization 3), tetrapolyphosphate (degree of polymerization 4), or hexametaphosphate (degree of polymerization 6), and most preferably a pyrophosphate.

[0024] Examples of salts include alkali metal salts and ammonium salts. Examples of alkali metal salts include lithium salts, sodium salts, and potassium salts, with sodium salts or potassium salts being preferred.

[0025] Specific examples of condensed phosphates include, for example, sodium pyrophosphate, potassium pyrophosphate, sodium tripolyphosphate, potassium tripolyphosphate, sodium tetrapolyphosphate, potassium tetrapolyphosphate, sodium trimetaphosphate, potassium trimetaphosphate, sodium hexametaphosphate, potassium hexametaphosphate, ammonium pyrophosphate, ammonium tripolyphosphate, ammonium tetrapolyphosphate, ammonium trimetaphosphate, and ammonium hexametaphosphate.

[0026] Of these, the condensed phosphate (B) is preferably at least one of sodium pyrophosphate and potassium pyrophosphate. Component (B) may be used alone or in combination of two or more.

[0027] <Glycols (C)> The aqueous heat treatment liquid composition according to one aspect of the present disclosure contains glycols (C) (hereinafter sometimes referred to as "component (C)"), which can suppress the cooling rate of 350-150°C and mitigate the cooling process.

[0028] Furthermore, as will be described later, an aqueous heat treatment liquid composition according to one aspect of this disclosure may optionally contain polyalkylene glycols (D) (hereinafter sometimes referred to as "component (D)") which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide. When an aqueous heat treatment liquid composition according to one aspect of this disclosure contains component (D), component (C) can suppress layer separation of the composition and improve the storage stability of the composition.

[0029] In an aqueous heat treatment liquid composition according to one aspect of this disclosure, component (C) is preferably a glycol having water solubility, for example, with a number average molecular weight of 1,000 or less, and more preferably a glycol having water solubility at room temperature (25°C) (for example, a glycol with a number average molecular weight of 600 or less). In this specification, the number average molecular weight of glycols is calculated based on the hydroxyl value (mgKOH / g). The hydroxyl value (mgKOH / g) is measured in accordance with JIS K 0070.

[0030] Examples of glycols having a number average molecular weight of 1,000 or less include, for example, polypropylene glycols such as propylene glycol, dipropylene glycol, tripropylene glycol, and derivatives thereof; polyethylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and derivatives thereof; glycol ethers such as ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, 3-methoxybutanol, 1,3-butylene glycol, n-propyl alcohol, propylene glycol n-propyl ether, dipropylene glycol methyl ether, diethylene glycol monoethyl ether, tripropylene glycol methyl ether, methyl glycol, methyl diglycol, methyl triglycol, methyl polyglycol, isopropyl glycol, isopropyl diglycol, butyl glycol, butyl diglycol, butyl triglycol, isobutyl glycol, isobutyl diglycol, benzyl diglycol, methylpropylene triglycol, dimethyl glycol, dimethyl diglycol, dimethyl triglycol, methyl ethyl diglycol, diethyl diglycol, and derivatives thereof; polyglycerols; and the like.

[0031] Further, the glycols having a number average molecular weight of 1,000 or less may be diol-type or triol-type glycols. The preferred degree of polymerization of glycols that can be preferably used as component (C) is a degree of polymerization that results in a number average molecular weight of 1,000 or less.

[0032] From the viewpoints of the solubility of component (C) itself in water and the solubility of component (B), component (C) is preferably at least one selected from the group consisting of polypropylene glycol, propylene glycol, polyethylene glycol, ethylene glycol, and derivatives thereof, and more preferably propylene glycol. Component (C) may be used alone, or two or more kinds may be used in combination.

[0033] In the present specification, the term "glycols" is meant to encompass both glycols having hydrogen at both ends, and glycol derivatives having a group other than hydrogen at at least one end.

[0034] From the viewpoint of solubility in water, examples of the "groups other than hydrogen" include alkyl groups having 1 to 5 carbon atoms, acyl groups having 1 to 6 carbon atoms, saturated alicyclic hydrocarbon groups having 5 to 12 carbon atoms, unsaturated alicyclic hydrocarbon groups having 5 to 12 carbon atoms, and aromatic hydrocarbon groups having 5 to 12 carbon atoms.

[0035] Examples of the "alkyl group having 1 to 5 carbon atoms" include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

[0036] Examples of the "acyl group having 1 to 6 carbon atoms" include groups having an alkyl group with 1 to 5 carbon atoms and a carbonyl group.

[0037] Examples of the "saturated alicyclic hydrocarbon group having 5 to 12 carbon atoms" include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group.

[0038] Examples of the "unsaturated alicyclic hydrocarbon group having 5 to 12 carbon atoms" include a cyclopentenyl group and a cyclohexenyl group.

[0039] Examples of the "aromatic hydrocarbon group having 5 to 12 carbon atoms" include aryl groups such as a phenyl group and a naphthyl group.

[0040] The saturated alicyclic hydrocarbon group having 5 to 12 carbon atoms, the unsaturated alicyclic hydrocarbon group having 5 to 12 carbon atoms, and the aromatic hydrocarbon group having 5 to 12 carbon atoms may optionally have a substituent. Examples of such substituents include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an aryl group having 6 to 14 carbon atoms.

[0041] <Polyalkylene glycols (D) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide> The aqueous heat treatment liquid composition according to one aspect of this disclosure may not contain component (D), but it is preferable that it further contains component (D). By containing component (D) in the aqueous heat treatment liquid composition according to one aspect of this disclosure, the cooling rate between 350 and 150°C can be further suppressed, and the cooling can be further mitigated. In addition, the cooling performance can be adjusted by the content of component (D) in the aqueous heat treatment liquid composition according to one aspect of this disclosure.

[0042] In an aqueous heat treatment liquid composition according to one aspect of this disclosure, component (D) has a larger molecular weight than component (C). For example, if the aqueous heat treatment liquid composition according to one aspect of this disclosure contains two types of polyalkylene glycols containing EO units and AO units other than EO with different molecular weights, the one with the larger molecular weight is designated as component (D), and the one with the smaller molecular weight is designated as component (C). Also, for example, if the aqueous heat treatment liquid composition according to one aspect of this disclosure contains three or more types of polyalkylene glycols containing EO units and AO units other than EO with different molecular weights, the PAG with the largest molecular weight corresponds to component (D), and the PAG with the smallest molecular weight corresponds to component (C). A PAG with an intermediate molecular weight may correspond to component (D) or to component (C).

[0043] Component (D) in an aqueous heat treatment liquid composition according to one aspect of the present disclosure includes, for example, linear polyalkylene glycols containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide; and branched polyhydric alcohol adducts of ethylene oxide and alkylene oxides other than ethylene oxide.

[0044] (Linear polyalkylene glycols including repeating units derived from ethylene oxide (EO units) and repeating units derived from alkylene oxides other than ethylene oxide (AO units other than EO)) Examples of linear polyalkylene glycols including EO units and AO units other than EO include compounds represented by the following general formula (I). R １ O-(R Ａ O) ｎ -R ２ ... (I) In the above formula (I), R Ａ represents an alkylene group having 2 to 6 carbon atoms. R １ and R ２ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an acyl group having 1 to 6 carbon atoms, an optionally substituted saturated alicyclic hydrocarbon group having 5 to 12 carbon atoms, an optionally substituted unsaturated alicyclic hydrocarbon group having 5 to 12 carbon atoms, or an optionally substituted aromatic hydrocarbon group having 5 to 12 carbon atoms. n is an integer of 2 or greater such that the weight average molecular weight (Mw) of the compound falls within the numerical range described below (for example, 8,000 or more). The preferred numerical range for the weight average molecular weight of the compound will be described later.

[0045] The "alkylene group having 2 to 6 carbon atoms" in the above formula (I) includes ethylene group, propylene group, ethylmethylene group, 1,1-dimethylethylene group, 1,2-dimethylethylene group, n-butylethylene group, isobutylethylene group, 1-ethyl-2-methylethylene group, 1-ethyl-1-methylethylene group, trimethylene group, tetramethylene group, pentamethylene group and the like.

[0046] R in the above formula (I) １ and R ２ The "alkyl group having 1 to 5 carbon atoms" represented by includes, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like.

[0047] R in the above formula (I) １ and R ２Examples of the "acyl group having 1 to 6 carbon atoms" shown include a group having an alkyl group having 1 to 5 carbon atoms and a carbonyl group.

[0048] In formula (I) above, R １ and R ２ Examples of the "saturated alicyclic hydrocarbon group having 5 to 12 carbon atoms" shown include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, and cyclodecyl group.

[0049] In formula (I) above, R １ and R ２ Examples of the "unsaturated alicyclic hydrocarbon group having 5 to 12 carbon atoms" shown include the cyclopentenyl group and the cyclohexenyl group.

[0050] In formula (I) above, R １ and R ２ Examples of the "aromatic hydrocarbon group having 5 to 12 carbon atoms" shown include aryl groups such as phenyl groups and naphthyl groups.

[0051] The saturated alicyclic hydrocarbon groups, unsaturated alicyclic hydrocarbon groups, and aromatic hydrocarbon groups having 5 to 12 carbon atoms mentioned above may have substituents. Examples of such substituents include alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, and aryl groups having 6 to 14 carbon atoms.

[0052] Straight-chain polyalkylene glycols containing EO units and AO units other than EO are defined as (R) in formula (I). ＡThe O) unit includes ethylene oxide and alkylene oxides other than ethylene oxide. The alkylene oxide other than ethylene oxide is not particularly limited and can be arbitrarily selected from alkylene oxides having 3 to 6 carbon atoms, for example, propylene oxide and butylene oxide. The AO unit other than EO may be one type or a combination of two or more types. For example, the AO unit other than EO may be a propylene oxide unit, a butylene oxide unit, or a combination of a propylene oxide unit and a butylene oxide unit. Furthermore, the mixture may further contain alkylene oxide units other than propylene oxide units and butylene oxide units.

[0053] (R) in (I) of the above formula Ａ The bonding mode of the O) units is not particularly limited and includes, for example, random bonding (random copolymer), block bonding (block copolymer), graft bonding (graft copolymer), and alternating bonding (alternating copolymer). The block copolymer may be a reverse pluronic type block copolymer or a reverse stetronic type block copolymer. The bonding mode in linear polyalkylene glycols containing EO units and AO units other than EO may be any of these bonding modes, but from the viewpoint of the manufacturing cost of the copolymer, a random bonding mode is preferred.

[0054] Linear polyalkylene glycols containing EO units and AO units other than EO are preferably water-soluble. In this specification, among the compounds of general formula (I) above, R １ and R ２ When both are hydrogen, it is called a polyalkylene glycol, R １ and R ２ Polyalkylene glycol derivatives are defined as those in which at least one of the groups is a group other than hydrogen. Therefore, in this specification, the term "polyalkylene glycols" encompasses both polyalkylene glycols and polyalkylene glycol derivatives.

[0055] In linear polyalkylene glycols containing EO units and non-EO AO units, the ratio (Q / P) of the number of moles of EO units added (Q) to the number of moles of non-EO AO units added (P) is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2 or more, from the viewpoint of improving solubility in water. Furthermore, from the viewpoint of cloud point, the ratio (Q / P) is preferably 19 or less, more preferably 9 or less, and even more preferably 6 or less. The upper and lower limits of these numerical ranges may be arbitrarily combined; for example, the ratio (Q / P) is preferably 1 to 19, more preferably 1.5 to 9, and even more preferably 2 to 6.

[0056] The mass-average molecular weight (Mw) of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 8,000 or more, more preferably 10,000 or more, and even more preferably 12,000 or more, from the viewpoint of sufficiently obtaining the effect of suppressing the cooling rate at 350-150°C. Furthermore, from the viewpoint of viscosity, the mass-average molecular weight of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 50,000 or less, more preferably 40,000 or less, more preferably 30,000 or less, even more preferably 28,000 or less, and even more preferably 25,000 or less. The upper and lower limits of these numerical ranges may be combined in any way. For example, the mass-average molecular weight of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 8,000 to 50,000, more preferably 8,000 to 40,000, more preferably 8,000 to 30,000, even more preferably 10,000 to 28,000, and even more preferably 12,000 to 25,000.

[0057] The ratio (Mw / Mn) of the mass-average molecular weight (Mw) to the number-average molecular weight (Mn) of linear polyalkylene glycols containing EO units and AO units other than EO is preferably 1.5 to 10, more preferably 2.8 to 9, and even more preferably 2.5 to 5. In this specification, the mass-average molecular weight and number-average molecular weight of polyalkylene glycols refer to values ​​obtained by gel permeation chromatography (GPC) under the following measurement conditions and converted to standard polystyrene. <Measurement conditions> Column: TSKgel GMPWXL x 2, manufactured by Tosoh Corporation Guard column: LF-G, manufactured by Shodex Flow rate: 1.0 mL / min Mobile phase: 0.2 M NaNO ３ aq. Sample injection volume: 100 μL Column oven temperature: 40°C Detector: RI-1530, manufactured by JASCO Corporation

[0058] Preferred examples of linear polyalkylene glycols containing EO units and AO units other than EO include polyoxyethylene polyoxypropylene glycols No. 1 to 11 shown in Table 1 below.

[0059]

[0060] (Adducts of branched polyhydric alcohols with ethylene oxide and alkylene oxides other than ethylene oxide) Adducts of branched polyhydric alcohols with ethylene oxide and alkylene oxides other than ethylene oxide (hereinafter referred to as "EO and AO adducts of branched polyhydric alcohols") are obtained by adding ethylene oxide and alkylene oxides other than ethylene oxide to branched polyhydric alcohols.

[0061] The alkylene oxide other than ethylene oxide is not particularly limited and can be arbitrarily selected from alkylene oxides having 3 to 6 carbon atoms, for example, propylene oxide and butylene oxide. The AO other than EO may be one type or a combination of two or more types. For example, the AO other than EO may be propylene oxide, butylene oxide, or a combination of propylene oxide and butylene oxide. Furthermore, the mixture may further contain alkylene oxides other than propylene oxide and butylene oxide.

[0062] In branched polyhydric alcohol EO / non-EO AO adducts, the ratio (Q / P) of the number of moles of EO units added (Q) to the number of moles of non-EO AO units added (P) in the molecule is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2 or more, from the viewpoint of improving solubility in water. Furthermore, from the viewpoint of cloud point, the ratio (Q / P) is preferably 19 or less, more preferably 9 or less, and even more preferably 6 or less. The upper and lower limits of these numerical ranges may be arbitrarily combined; for example, the ratio (Q / P) is preferably 1 to 19, more preferably 1.5 to 9, and even more preferably 2 to 6.

[0063] The polyhydric alcohol used as a raw material for branched polyhydric alcohol EO and AO adducts other than EO is not particularly limited as long as it has three or more hydroxyl groups, but the number of hydroxyl groups is preferably 3 to 8, more preferably 3 to 6, and even more preferably 3 to 4. Furthermore, from the viewpoint of solubility in water, the polyhydric alcohol used as a raw material for branched polyhydric alcohol EO and AO adducts other than EO has 3 to 10 carbon atoms, more preferably 3 to 6, and even more preferably 3 to 4 carbon atoms. Specific examples of the polyhydric alcohol include glycerin, diglycerin, polyglycerin, trimethylolpropane, and pentaerythritol, among which glycerin is preferred.

[0064] The bonding modes of EO and non-EO AO in branched polyhydric alcohol EO / non-EO AO adducts are not particularly limited, and examples include random bonding (random copolymer), block bonding (block copolymer), graft bonding (graft copolymer), and alternating bonding (alternating copolymer). The block copolymer may be a reverse pluronic block copolymer or a reverse stetronic block copolymer. The bonding modes in branched polyhydric alcohol EO / non-EO AO adducts may be any of these bonding modes, but from the viewpoint of copolymer manufacturing cost, the random bonding mode is preferred.

[0065] Branched polyhydric alcohol adducts other than EO and EO are preferably water-soluble.

[0066] The mass-average molecular weight (Mw) of branched polyhydric alcohol AO adducts other than EO is preferably 8,000 or more, more preferably 10,000 or more, and even more preferably 12,000 or more, from the viewpoint of sufficiently obtaining the effect of suppressing the cooling rate at 350-150°C. Furthermore, from the viewpoint of viscosity, the mass-average molecular weight of branched polyhydric alcohol AO adducts other than EO is preferably 50,000 or less, more preferably 40,000 or less, more preferably 30,000 or less, even more preferably 28,000 or less, and even more preferably 25,000 or less. The upper and lower limits of these numerical ranges may be combined arbitrarily. For example, the mass-average molecular weight of branched polyhydric alcohol AO adducts other than EO is preferably 8,000 to 50,000, more preferably 8,000 to 40,000, more preferably 8,000 to 30,000, even more preferably 10,000 to 28,000, and even more preferably 12,000 to 25,000.

[0067] The ratio (Mw / Mn) of the mass-average molecular weight (Mw) to the number-average molecular weight (Mn) of branched polyhydric alcohol EO / AO adducts other than EO is preferably 1.5 to 10, more preferably 2.8 to 9, and even more preferably 2.5 to 5.

[0068] Preferred examples of branched polyhydric alcohol AO adducts other than EO / EO include the EO / PO adduct of glycerin No. 12 and the EO / PO adducts of pentaerythritol Nos. 13-14 (CAS number: 58205-99-5), as shown in Table 2 below.

[0069]

[0070] Component (D) may be used alone or in combination of two or more types. Component (D) may be a combination of linear polyalkylene glycols containing EO units and AO units other than EO units, and branched polyhydric alcohol EO / AO adducts other than EO units.

[0071] <Additives (E)> In addition to the components described above, an aqueous heat treatment liquid composition according to one aspect of the present disclosure may contain additives (E) to the extent that they do not impede the effects of this embodiment. Examples of additives (E) include metal deactivators, defoamers, disinfectants, rust inhibitors, and antioxidants, and one or more of these may be used.

[0072] (Metal deactivators) Examples of metal deactivators include benzotriazole, imidazoline, pyrimidine derivatives, and thiadiazole, sodium phosphate salts, and phosphate ester derivatives.

[0073] (Antioxidant) Examples of antioxidants include 2,6-ditert-butyl-p-cresol.

[0074] (Preservatives, defoamers, rust inhibitors) Examples of preservatives include diglycolamine, N-methyldicyclohexylamine, 2-amino-2-methyl-1-propanol, N-methyldiethanolamine, cyclohexyldiethanolamine, triethanolamine, 2-(methylamino)ethanol, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, and monobutylethanolamine.

[0075] Examples of defoaming agents include silicone compounds and polyether compounds.

[0076] Examples of rust inhibitors include dotecandioic acid and neodecanoic acid.

[0077] Additive (E) may be used alone or in combination of two or more types.

[0078] <Content of each component> (Content of component (A)) The content of component (A) relative to the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is not particularly limited. Since the aqueous heat treatment liquid composition according to one aspect of this disclosure is sold in a form with a low water content (in the form of a concentrated liquid) and can be used by the user after diluting it to the desired concentration, the content of component (A) in the aqueous heat treatment liquid composition may change during the distribution and use process.

[0079] The case in which the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a diluent will be described. In this case, the content of component (A) in the aqueous heat treatment liquid composition is set appropriately from the viewpoint of sufficiently obtaining the gloss improvement effect of component (B); from the viewpoint of sufficiently obtaining the cooling rate suppression effect of component (C), or component (C) and component (D) in combination; and so on.

[0080] For example, the content of component (A) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more. Also, for example, from the viewpoint of good luster and suppression of the cooling rate, the content of component (A) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 96% by mass or less, more preferably 92% by mass or less, and even more preferably 88% by mass or less. The upper and lower limits of these numerical ranges may be arbitrarily combined. For example, when the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a diluted solution, the content of component (A) per 100% by mass is preferably 30% by mass to 96% by mass, more preferably 35% by mass to 92% by mass, and even more preferably 40% by mass to 88% by mass.

[0081] Next, we will describe the case in which the aqueous heat treatment fluid composition according to one aspect of this disclosure is in the form of a concentrated liquid. In this case, the content of component (A) in the aqueous heat treatment fluid composition according to one aspect of this disclosure is set appropriately from the viewpoint of reducing fire risk and enhancing safety; from the viewpoint of transportation costs; from the viewpoint of concentration handling at the site of use (high degree of freedom to change the concentration range); and from the viewpoint of ensuring sufficient content of components (B), (C), and (D).

[0082] While a lower water content is preferable from the viewpoint of ease of concentration handling at the site of use (higher degree of freedom to change the concentration range), from the viewpoint of reducing fire risk, for example, the content of component (A) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one embodiment of this disclosure is preferably 10% by mass or more, and more preferably 15% by mass or more, 20% by mass or more, or 30% by mass or more. Furthermore, for example, from the viewpoint of active ingredient concentration, the content of component (A) per 100% by mass of the aqueous heat treatment liquid composition according to one embodiment of this disclosure is preferably 65% ​​by mass or less, and more preferably 60% by mass or less, 55% by mass or less, 50% by mass or less, or 45% by mass or less. The upper and lower limits of these numerical ranges may be combined arbitrarily. For example, the content of component (A) in relation to the total amount of the aqueous heat treatment liquid composition according to one embodiment of the present disclosure in the form of a concentrated liquid is preferably 10% to 65% by mass, more preferably 15% to 60% by mass, 20% to 55% by mass, 30% to 50% by mass, and even more preferably 30% to 45% by mass.

[0083] (Content of component (B)) From the viewpoint of enhancing the gloss-improving effect, the content of component (B) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more. Furthermore, from the viewpoint of the solubility of component (B), the content of component (B) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 15% by mass or less, more preferably 12% by mass or less, even more preferably 9% by mass or less, and even more preferably 8% by mass or less. The upper and lower limits of these numerical ranges may be arbitrarily combined. For example, in the case of a diluted solution, the content of component (B) per 100% by mass of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 0.5% by mass to 15% by mass, more preferably 1% by mass to 12% by mass, even more preferably 1.5% by mass to 9% by mass, and even more preferably 1.5% by mass to 8% by mass.

[0084] (Content of component (C)) The content of component (C) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 3% by mass or more, more preferably 4% by mass or more, even more preferably 5% by mass or more, and even more preferably 6% by mass or more, from the viewpoint of enhancing the effect of suppressing the cooling rate and enhancing the solubility of component (B). Furthermore, the content of component (C) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, from the viewpoint of the manufacturing cost of the composition. The upper and lower limits of these numerical ranges may be arbitrarily combined. For example, in the case of a diluted solution, the content of component (C) per 100% by mass of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 3% by mass to 40% by mass, more preferably 4% by mass to 30% by mass, even more preferably 5% by mass to 25% by mass, and even more preferably 6% by mass to 25% by mass.

[0085] (Content of component (D)) The content of component (D) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more, from the viewpoint of enhancing the effect of suppressing the cooling rate. Furthermore, the content of component (D) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and even more preferably 8% by mass or less, from the viewpoint of the solubility of component (B). The upper and lower limits of these numerical ranges may be arbitrarily combined. For example, in the case of a diluted solution, the content of component (C) per 100% by mass of the total amount of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, even more preferably 1.5% by mass to 10% by mass, and even more preferably 1.5% by mass to 8% by mass.

[0086] (C / D ratio) Furthermore, the content of component (D) is preferably determined considering the content of component (C). The preferred numerical range for the C / D ratio can be set to a range that yields the desired effect depending on the molecular weight of component (D) used, the ratio of the number of moles of AO units added in the molecule (Q / P) (e.g., EO / PO ratio), the molecular structure (linear or branched), etc. However, a larger C / D ratio tends to increase storage stability, and a smaller C / D ratio tends to increase the cooling suppression effect. For example, from the viewpoint of increasing the storage stability of the aqueous heat treatment liquid composition, the ratio of the content of component (C) to the content of component (D) (C / D) is preferably 2 or more by mass ratio, more preferably 2.3 or more, even more preferably 3 or more, and even more preferably 3.5 or more. Furthermore, from the viewpoint of increasing the cooling rate suppression effect, the ratio of the content of component (C) to the content of component (D) (C / D) is preferably 10 or less by mass ratio, more preferably 8 or less, and even more preferably 6 or less. The upper and lower limits of these numerical ranges may be combined in any way. For example, the ratio of the content of component (C) to the content of component (D) (C / D) is preferably 2 to 10 by mass, more preferably 2.3 to 10, even more preferably 3 to 8, and even more preferably 3.5 to 6.

[0087] (Content of components (B), (C), and (D) in the concentrated solution) The content of components (B), (C), and (D) in the concentrated solution is set appropriately, taking into consideration the concentration ratio of the concentrated solution and the balance of the content of the three components (B) to (D), so that the content of each component when diluted falls within the range described above.

[0088] When the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a concentrated liquid, for example, from the viewpoint of enhancing the luster-improving effect, the content of component (B) is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more, when the total amount of components (B), components (C), and components (D) is 100% by mass. Furthermore, from the viewpoint of solubility, the content of component (B) is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 15% by mass or less, when the total amount of components (B), components (C), and components (D) is 100% by mass. The upper and lower limits of these numerical ranges may be combined arbitrarily. For example, in the case of a concentrated liquid, the content of component (B) is preferably 2% to 30% by mass, more preferably 2% to 25% by mass, even more preferably 3% to 20% by mass, and even more preferably 4% to 15% by mass, when the total amount of components (B), (C), and (D) is 100% by mass.

[0089] Furthermore, for example, from the viewpoint of the solubility of component (B), the content of component (C) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and even more preferably 20% by mass or more, when the total amount of components (B), components (C), and components (D) is 100% by mass. Furthermore, from the viewpoint of the manufacturing cost of the composition, the content of component (C) is preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, when the total amount of components (B), components (C), and components (D) is 100% by mass. The upper and lower limits of these numerical ranges may be combined arbitrarily. For example, in the case of a concentrated liquid, the content of component (C) is preferably 5% to 80% by mass, more preferably 10% to 70% by mass, even more preferably 15% to 65% by mass, and even more preferably 20% to 60% by mass, when the total amount of components (B), (C), and (D) is 100% by mass.

[0090] Furthermore, for example, from the viewpoint of suppressing the cooling rate during dilution, the content of component (D) is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 6% by mass or more, even more preferably 7% by mass or more, and even more preferably 8% by mass or more, when the total amount of components (B), components (C), and components (D) is 100% by mass. Furthermore, from the viewpoint of the solubility of component (B), the content of component (D) is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, when the total amount of components (B), components (C), and components (D) is 100% by mass. The upper and lower limits of these numerical ranges may be combined arbitrarily. For example, in the case of a concentrated liquid, the content of component (D) is preferably 2% to 35% by mass, more preferably 5% to 35% by mass, even more preferably 6% to 30% by mass, even more preferably 7% to 25% by mass, and even more preferably 8% to 25% by mass, when the total amount of components (B), (C), and (D) is 100% by mass.

[0091] (Content of component (E)) The content of component (E) in the aqueous heat treatment liquid composition according to one aspect of this disclosure can be appropriately determined within a range that does not impede the effects of this embodiment and within a range that allows the effects of component (E) to be exerted.

[0092] When the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a diluent, the content of component (E) is not particularly limited, but is preferably 0.01 to 10% by mass, more preferably 0.05 to 7.5% by mass, and even more preferably 0.1 to 5% by mass, based on 100% by mass of the total amount of the aqueous heat treatment liquid composition.

[0093] Furthermore, the content of component (E) when the aqueous heat treatment liquid composition according to one aspect of this disclosure is in the form of a concentrated liquid is not particularly limited. The content of component (E) relative to 100% by mass of the total amount of the aqueous heat treatment liquid composition can be determined according to the concentration ratio of the concentrated liquid so that the content of component (E) when diluted falls within the range described above. For example, the content of component (E) is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 5% by mass, relative to 100% by mass of the total amount of the aqueous heat treatment liquid composition. If the aqueous heat treatment liquid composition according to one aspect of this disclosure contains multiple components as component (E), each component shall be contained independently within the above range.

[0094] <Preferred Formulation Example> An aqueous heat treatment liquid composition according to one embodiment of the present disclosure contains component (A), component (B), and component (C), and optionally contains component (D), and when the total amount of the aqueous heat treatment liquid composition is 100% by mass, it is preferable that it contains: Component (B) 0.5% by mass or more and 15% by mass or less Component (C) 3% by mass or more and 40% by mass or less Component (D) 0.5% by mass or more and 20% by mass or less.

[0095] Furthermore, an aqueous heat treatment fluid composition according to another embodiment of the present disclosure contains component (A), component (B), and component (C), and optionally contains component (D), and preferably contains, when the total amount of the aqueous heat treatment fluid composition is 100% by mass, component (B) is 1.5% by mass or more and 8% by mass or less, component (C) is 3% by mass or more and 25% by mass or less, and component (D) is 0.5% by mass or more and 10% by mass or less.

[0096] <Properties of the Aqueous Heat Treatment Solution Composition> (Brightness) The aqueous heat treatment solution composition according to one aspect of the present disclosure preferably exhibits improved surface brightness of a metal material hardened or tempered using the composition, compared to an aqueous heat treatment solution composition that does not contain component (B), and more preferably exhibits good surface brightness of a metal material hardened or tempered using the composition. For example, it is preferable that the brightness evaluation result, as evaluated by the evaluation method described in the examples below, is "somewhat good" or "good," and more preferably "good."

[0097] (Cooling Rate) The aqueous heat treatment fluid composition according to one aspect of this disclosure preferably has a suppressed (slower) cooling rate compared to an aqueous heat treatment fluid composition that does not contain components (C) and (D). The degree to which the cooling rate of the aqueous heat treatment fluid composition according to one aspect of this disclosure is suppressed is not particularly limited.

[0098] The cooling rate of the aqueous heat treatment liquid composition according to one aspect of this disclosure is preferably less than 400°C / s, more preferably 300°C / s or less, and even more preferably 250°C / s or less, when cooling from 350 to 150°C. An aqueous heat treatment liquid composition with a cooling rate of less than 400°C / s when cooling from 350 to 150°C can be said to have a suppressed (slow) cooling rate. Furthermore, there is no particular lower limit to the cooling rate of the aqueous heat treatment liquid composition according to one aspect of this disclosure when cooling from 350 to 150°C, but for example, it is 30°C / s or more. The upper and lower limits of these numerical ranges may be arbitrarily combined. For example, the cooling rate of the aqueous heat treatment liquid composition according to one aspect of this disclosure when cooling from 350 to 150°C is preferably 30°C / s or more and less than 400°C / s, more preferably 30°C / s to 300°C / s, and even more preferably 30°C / s to 250°C / s.

[0099] (Storage Stability) The aqueous heat treatment liquid composition according to one aspect of this disclosure preferably has good storage stability. For example, it is preferable that the storage stability evaluation result, as evaluated by the evaluation method described in the examples below, is "good".

[0100] <Form of the Aqueous Heat Treatment Solution Composition> The aqueous heat treatment solution composition according to one aspect of this disclosure may be prepared by blending the above-mentioned components at the desired concentration at the time of use from the beginning, or a concentrated solution (stock solution) may be prepared first and then diluted with water to the desired concentration at the time of use. The aqueous heat treatment solution composition according to one aspect of this disclosure has good storage stability even in the form of a concentrated solution. For this reason, considering the reduction of transportation costs and the ability to adjust the cooling performance by dilution concentration, the aqueous heat treatment solution composition according to one aspect of this disclosure is preferably in the form of a concentrated solution.

[0101] As a concentrated aqueous heat treatment liquid composition according to one aspect of this disclosure, from the viewpoint of ease of handling, the aqueous heat treatment liquid composition is concentrated to a volume ratio of preferably 2 to 20 times, more preferably 2.5 to 15 times, and even more preferably 3 to 10 times.

[0102] <Method for producing an aqueous heat treatment liquid composition> An aqueous heat treatment liquid composition according to one aspect of this disclosure can be produced by mixing the above-mentioned components. The mixing method is not particularly limited as long as the components can be mixed uniformly.

[0103] [2. Method for Manufacturing Metal Materials] A method for manufacturing metal materials according to one aspect of the present disclosure includes a heat treatment step for the metal material, wherein an aqueous heat treatment liquid composition according to one aspect of the present disclosure is used as a coolant for cooling the heated metal material in the heat treatment step.

[0104] According to a method for manufacturing a metal material according to one aspect of this disclosure, since an aqueous heat treatment liquid composition according to one aspect of this disclosure is used as a coolant to cool the heated metal material in the heat treatment process, it is possible to manufacture a metal material that has good luster after heat treatment and suppresses distortion and quench cracking.

[0105] In a method for manufacturing a metal material according to one aspect of the present invention, the specific type of metal material to be manufactured is not particularly limited.

[0106] The type of heat treatment step for a metal material included in a method for manufacturing a metal material according to one aspect of this disclosure is not limited. Examples of the heat treatment step include a quenching step and a tempering step. In a method for manufacturing a metal material according to one aspect of this disclosure, an aqueous heat treatment liquid composition according to one aspect of this disclosure is used in the heat treatment step. The method for manufacturing a metal material according to one aspect of this disclosure may include only a quenching step, only a tempering step, or both a quenching step and a tempering step as the heat treatment step. If the method for manufacturing a metal material according to one aspect of this disclosure includes both a quenching step and a tempering step as the heat treatment step, the tempering step may be included after the quenching step. If the method for manufacturing a metal material according to one aspect of this disclosure includes a tempering step after the quenching step, it is preferable to use the aqueous heat treatment liquid composition according to one aspect of this disclosure as a coolant to cool the metal material after tempering in the tempering step.

[0107] In the heat treatment process, the method of heating the metal material is not particularly limited, and conventionally known heating methods such as high-frequency induction hardening and carburizing can be used. Furthermore, in the quenching process, the cooling method using the aqueous heat treatment liquid composition is not particularly limited, and cooling methods employed in conventionally known quenching methods can also be employed in this embodiment. For example, an immersion method may be employed in which the heated metal material is immersed in the aqueous heat treatment liquid composition according to one aspect of this disclosure described above to cool it, or an injection method may be employed in which the aqueous heat treatment liquid composition according to one aspect of this disclosure described above is sprayed onto the heated metal material to cool it.

[0108] A method for manufacturing a metallic material according to one aspect of this disclosure may further include steps other than the heat treatment step.

[0109] [3. Apparatus for Manufacturing Metal Materials] An apparatus for manufacturing metal materials according to one aspect of the present disclosure is an apparatus for manufacturing metal materials that performs at least a heat treatment step for a metal material, wherein an aqueous heat treatment liquid composition according to one aspect of the present disclosure is used as a coolant for cooling the heated metal material in the heat treatment step.

[0110] According to a metal material manufacturing apparatus according to one aspect of the present disclosure, since an aqueous heat treatment liquid composition according to one aspect of the present disclosure is used as a coolant to cool the heated metal material in the heat treatment process, it is possible to manufacture a metal material that has good luster after heat treatment and suppresses distortion and quench cracking.

[0111] In a metal material manufacturing apparatus according to one aspect of the present invention, the specific type of metal material to be manufactured is not particularly limited.

[0112] The type of heat treatment process for a metal material carried out in a metal material manufacturing apparatus according to one aspect of this disclosure is not limited. Examples of such heat treatment processes include quenching and tempering. In the metal material manufacturing apparatus according to one aspect of this disclosure, an aqueous heat treatment liquid composition according to one aspect of this disclosure is used in the heat treatment process. The metal material manufacturing apparatus according to one aspect of this disclosure may carry out only a quenching process, only a tempering process, or both a quenching and tempering process as the heat treatment process. When the metal material manufacturing apparatus according to one aspect of this disclosure carries out both a quenching and tempering process as the heat treatment process, the tempering process may be carried out after the quenching process. When the metal material manufacturing apparatus according to one aspect of this disclosure includes a tempering process after the quenching process, it is preferable to use the aqueous heat treatment liquid composition according to one aspect of this disclosure as a coolant for cooling the metal material after tempering in the tempering process.

[0113] A manufacturing apparatus for a metallic material according to one aspect of this disclosure comprises at least a heat treatment apparatus for performing a heat treatment process on the metallic material. The specific configuration of the heat treatment apparatus is not particularly limited. Depending on the type of heating and cooling method used in the heat treatment process to be performed (e.g., quenching and tempering), the heat treatment apparatus may be equipped with a mechanism capable of performing these methods. The heating and cooling methods in the heat treatment process are as described in the manufacturing method for a metallic material according to one aspect of this disclosure.

[0114] A metal material manufacturing apparatus according to one aspect of this disclosure may further include components other than a heat treatment apparatus.

[0115] [Summary] The aqueous heat treatment liquid composition according to Embodiment 1 of the present invention has the following composition: water (A), condensed phosphate (B), and glycols (C).

[0116] The aqueous heat treatment liquid composition according to aspect 2 of the present invention may further contain polyalkylene glycols (D) having a molecular weight greater than that of glycols (C) and comprising repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide.

[0117] In the aqueous heat treatment liquid composition according to embodiment 3 of the present invention, the condensed phosphate (B) may be a pyrophosphate in the configuration described in embodiment 1 or 2 above.

[0118] The aqueous heat treatment liquid composition according to embodiment 4 of the present invention may be configured such that, in any one of embodiments 1 to 3 above, the number average molecular weight of the glycols (C) is 1,000 or less.

[0119] In the aqueous heat treatment liquid composition according to aspect 5 of the present invention, the polyalkylene glycol (D) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxide other than ethylene oxide may have a mass-average molecular weight of 8,000 or more, as described in aspect 2 above.

[0120] In any one of the above embodiments 1 to 5, the aqueous heat treatment liquid composition according to embodiment 6 of the present invention may be configured such that the glycols (C) are at least one selected from the group consisting of polypropylene glycol, propylene glycol, polyethylene glycol, ethylene glycol, and derivatives thereof.

[0121] The aqueous heat treatment liquid composition according to embodiment 7 of the present invention may be configured such that, in embodiment 2 or 5 above, the ratio (Q / P) of the number of moles of ethylene oxide units added (Q) to the number of moles of alkylene oxide units other than ethylene oxide added (P) in a molecule of polyalkylene glycol (D) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxide other than ethylene oxide is 1 or more and 19 or less.

[0122] In the aqueous heat treatment liquid composition according to embodiment 8 of the present invention, in embodiment 2, 5, or 7 above, the ratio (C / D) of the content of glycols (C) to the content of polyalkylene glycols (D) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide is 2.3 or more and 10 or less by mass ratio.

[0123] The aqueous heat treatment liquid composition according to aspect 9 of the present invention may contain, in any one of the above aspects 1 to 8, water (A), condensed phosphate (B), and glycols (C), and optionally contain polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, and when the total amount of condensed phosphate (B), glycols (C), and polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide is taken as 100% by mass, the composition may include 2% by mass or more and 30% by mass or less of condensed phosphate (B), 5% by mass or more and 80% by mass or less of glycols (C), and 2% by mass or more and 35% by mass or less of polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide.

[0124] The aqueous heat treatment liquid composition according to embodiment 10 of the present invention may contain, in any one of embodiments 1 to 8 above, water (A), condensed phosphate (B), and glycols (C), and optionally contain polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, and when the total amount of the aqueous heat treatment liquid composition is 100% by mass, the composition may include 0.5% by mass or more and 15% by mass or less of the condensed phosphate (B), 3% by mass or more and 40% by mass or less of the glycols (C), and 0.5% by mass or more and 20% by mass or less of the polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide.

[0125] A method for producing a metal material according to embodiment 11 of the present invention may include a heat treatment step for the metal material, wherein the aqueous heat treatment liquid composition described in any one of embodiments 1 to 10 above may be used as a coolant for cooling the heated metal material in the heat treatment step.

[0126] A metal material manufacturing apparatus according to embodiment 12 of the present invention is a metal material manufacturing apparatus that performs at least a heat treatment step for a metal material, and in the heat treatment step, the aqueous heat treatment liquid composition described in any one of embodiments 1 to 10 above may be used as a coolant to cool the heated metal material.

[0127] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in each embodiment are also included in the technical scope of this disclosure.

[0128] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0129] [Test Example 1] 1. The following materials were used for the aqueous heat treatment liquid compositions of the material examples and comparative examples. <Water (A): Component (A)> ・Tap water <Condensed phosphate (B): Component (B)> ・Potassium pyrophosphate (manufactured by Ohira Chemical Industry Co., Ltd., product name: potassium pyrophosphate) <Glycols (C): Component (C)> ・Propylene glycol (manufactured by AGC Inc., product name: propylene glycol, polypropylene glycol with a degree of polymerization of 1, molecular weight 76.09 g / mol) <Polyalkylene glycols containing repeating units derived from EO and repeating units derived from AO other than EO (D): Component (D)> ・Linear polyalkylene glycol 1 (linear PAG1) containing EO units and PO units (random polymerization, Mw = 17,000, Mn = 7,700, Mw / Mn = 2.2, EO / PO ratio (molar ratio) = 4.0) - Branched polyhydric alcohol EO / PO adduct 1 (branched PAG1) (mixed adduct of EO and PO of glycerin, Mw = 21,000, Mn = 11,000, Mw / Mn = 1.9, EO / PO ratio (molar ratio) = 2.6)

[0130] 2. The aqueous heat treatment solution compositions (stock solutions) for Preparation Examples 1 to 3 and Comparative Example 1 were prepared with the compositions shown in Table 3. A blank space in Table 3 indicates that the component was not added.

[0131] 3. The storage stability of the aqueous heat treatment liquid compositions (undiluted solutions) of Examples 1 to 3 and Comparative Example 1 was evaluated. In addition, the luster and cooling properties of the diluted solutions obtained by diluting the aqueous heat treatment liquid compositions (undiluted solutions) of Examples 1 to 3 and Comparative Example 1 with water to the predetermined dilution ratios shown in Table 4 were evaluated.

[0132] 3-1. Storage Stability The aqueous heat treatment liquid compositions (undiluted solutions) of Examples 1 to 3 and Comparative Example 1 were left standing at room temperature, and the separation state was visually confirmed after one week.

[0133] Products in which no layer separation was observed visually were evaluated as having good storage stability.

[0134] 3-2. Brightness The brightness of the steel material after quenching was evaluated based on the following reference: "Influence of oxygen in the heat treatment oil bath on brightness (Idemitsu Tribo Review, No. 31, pp. 1963-1966, published September 30, 2008)".

[0135] Specifically, a dumbbell-shaped steel material S45C (diameter: 16 mm, length: 30 mm, hardness HRC: 16) and a cylindrical steel material SUJ2 (diameter: 10 mm, length: 30 mm, hardness HRC: 15) were combined to form a test specimen. In detail, the dumbbell-shaped steel material S45C and the cylindrical steel material SUJ2 were tied together at the center using SUS303 wire (see Figure 1). The test specimen was then heated in a furnace with a mixed gas atmosphere of nitrogen and hydrogen, and then quenched by immersion in the aqueous heat treatment solution composition of the example or comparative example to perform a quenching test.

[0136] The following four conditions were used for the quenching test: (Quenching test conditions) Furnace temperature: 850°C Time of holding the test specimen in the furnace: 40 minutes after the furnace temperature reaches 850°C Temperature of the aqueous heat treatment solution composition: 30°C Immersion time of the test specimen in the aqueous heat treatment solution composition (quenching time): 10 minutes.

[0137] The lustrousness of the test specimens after quenching was evaluated based on the following criteria, focusing on "brightness." (Brightness) Visual samples with predetermined coloring were prepared and visually compared with the color of the test specimens after quenching. The degree of coloring of the visual samples is indicated by the following numerical values: 0: No coloring at all. 1: Slight coloring. 2: Coloring present. 3: Dark coloring.

[0138] A numerical value of 3, representing the degree of coloring of the test piece after quenching, was evaluated as poor luster; a numerical value of 2 was evaluated as slightly poor luster; a numerical value of 1 was evaluated as slightly good luster; and a numerical value of 0 was evaluated as good luster.

[0139] 3-3. Cooling Performance In accordance with the cooling performance test method (Method B: Core Temperature Measurement Method) for water-soluble quenching solutions specified in JIS K2242:2012, a silver rod heated to 810°C was immersed in an aqueous heat treatment solution composition (liquid temperature: 30°C), and the cooling curve of the silver rod was determined. Based on this cooling curve, the cooling rate (350-150°C cooling rate (°C / s)) when the silver rod cooled from 350°C to 150°C was calculated.

[0140] 4. Results: The evaluation results for storage stability are shown in Table 3, and the evaluation results for brilliance and coolability are shown in Table 4. Figure 1 shows the appearance of the test pieces after quenching using each of the aqueous heat treatment liquid compositions (diluted solutions) in Examples 1 to 3 and Comparative Example 1.

[0141]

[0142]

[0143] As shown in Table 3, the aqueous heat treatment liquid compositions of Examples 1 to 3 did not undergo layer separation over time and exhibited good storage stability.

[0144] Furthermore, the results in Table 3 show that the aqueous heat treatment fluid compositions of Examples 1 to 3 exhibited a more suppressed 350-150°C cooling rate than the aqueous heat treatment fluid composition of Comparative Example 1, which did not contain components (C) and (D). Additionally, the results in Example 3 indicate that when the aqueous heat treatment fluid composition contains component (D), the suppression effect on the 350-150°C cooling rate tended to increase as the concentrations of components (B), (C), and (D) increased.

[0145] [Test Example 2] 1. In addition to the materials used in Test Example 1, the following was used as the material for the aqueous heat treatment solution composition of the material examples and comparative examples. <Component (D)> Linear polyalkylene glycol 2 (linear PAG2) containing EO units and PO units (random polymerization, Mw = 11,000, Mn = 8,200, Mw / Mn = 1.3, EO / PO ratio (molar ratio) = 6.7)

[0146] 2. The aqueous heat treatment solution compositions (stock solutions) for Preparation Examples 4-6 and Comparative Examples 2-13 were prepared with the compositions shown in Tables 5-7. A blank space in Tables 5-7 indicates that the component was not added.

[0147] 3. The storage stability of the aqueous heat treatment liquid compositions (undiluted solutions) of Evaluation Examples 4 to 6 and Comparative Examples 2 to 13 was evaluated as described above.

[0148] 4. The results of the evaluation of storage stability are shown in Tables 5 to 7.

[0149]

[0150]

[0151]

[0152] As shown in Table 5, the aqueous heat treatment liquid compositions of Examples 4-6 did not undergo layer separation over time and exhibited good storage stability. Furthermore, a comparison of Examples 4-5 with Comparative Example 13 revealed that the presence of component (C) in the aqueous heat treatment liquid composition suppressed layer separation even when component (D) was further added. Additionally, a comparison of Examples 4-5 with Comparative Examples 2-10 revealed that a higher C / D ratio (the ratio of component (C) to component (D)) tended to result in better storage stability.

[0153] [Test Example 3] 1. Materials The following condensed phosphates were used in the preparation of the aqueous heat treatment solution composition of the reference example: • Potassium pyrophosphate (manufactured by Ohira Chemical Industry Co., Ltd., product name: potassium pyrophosphate) • Sodium pyrophosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: sodium pyrophosphate)

[0154] In addition, the following inorganic salts, which are different types of inorganic salts from condensed phosphates, were used in the preparation of the comparative example's aqueous heat treatment solution composition: • Sodium nitrite (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Sodium Nitrite) • Sodium sulfite (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Sodium Sulfite) • Ammonium nitrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Ammonium Nitrate) • Potassium carbonate (manufactured by Takasugi Pharmaceutical Co., Ltd., product name: Potassium Carbonate Takasugi Grade 1) • Ammonium sulfate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Ammonium Sulfate) • Sodium tetraborate (manufactured by Junsei Chemicals, Inc., product name: Sodium Tetraborate Decahydrate) • Potassium dihydrogen citrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Potassium dihydrogen citrate) • Anionic carboxylic acid (manufactured by Sanyo Chemical Industries, Ltd., product name: Sanhibiter No. 2-1, anionic surfactant) • Disodium hydrogen phosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: Disodium hydrogen phosphate) • Polyoxyethylene alkyl ether phosphate (CAS number: 9046-01-9) (manufactured by Toho Chemical Industry Co., Ltd., product name: Phosphanol RS-410)

[0155] 2. Aqueous heat treatment fluid compositions (diluted solutions) for Reference Examples 1 to 7 were prepared using the compositions shown in Preparation Table 8. In the aqueous heat treatment fluid compositions (diluted solutions) for Reference Examples 1 to 7, the concentration of condensed phosphate was changed in steps.

[0156] Furthermore, aqueous heat treatment fluid compositions (diluted solutions) for Comparative Examples 14 to 23 were prepared with the compositions shown in Table 9. In the aqueous heat treatment fluid compositions (diluted solutions) for Comparative Examples 14 to 23, a different type of inorganic salt was used instead of condensed phosphate. In Comparative Example 24, water was used. Note that blanks in Tables 8 and 9 indicate that the component was not added.

[0157] 3. The above-described glossiness evaluation was performed on the aqueous heat treatment liquid compositions (diluted solutions) of Reference Examples 1 to 7, the aqueous heat treatment liquid compositions (diluted solutions) of Comparative Examples 14 to 23, and water in Comparative Example 24.

[0158] 4. The results of the evaluation of glossiness are shown in Tables 8 and 9. Figure 2 shows the appearance of the test pieces after quenching using the aqueous heat treatment liquid compositions (dilutions) of Reference Examples 1 to 7 and Comparative Examples 14 to 23, as well as water in Comparative Example 24.

[0159]

[0160]

[0161] As shown in Tables 8-9, the addition of condensed phosphates to the inorganic salts improved the luster. Furthermore, from the results of Reference Examples 1-7 in Table 8, the luster-improving effect tended to weaken at lower concentrations of condensed phosphates, but the luster was improved compared to Comparative Examples 14-24, which did not contain condensed phosphates.

[0162] A water-based heat treatment fluid composition according to one aspect of this disclosure can be used as a quenching or tempering fluid for metal materials.

Claims

1. An aqueous heat treatment solution composition containing water (A), condensed phosphate (B), and glycols (C).

2. The aqueous heat treatment liquid composition according to claim 1, further comprising polyalkylene glycols (D) having a molecular weight greater than that of glycols (C), and containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide.

3. The aqueous heat treatment liquid composition according to claim 1 or 2, wherein the condensed phosphate (B) is a pyrophosphate.

4. The aqueous heat treatment liquid composition according to any one of claims 1 to 3, wherein the number average molecular weight of the glycols (C) is 1,000 or less.

5. The aqueous heat treatment liquid composition according to claim 2, wherein the polyalkylene glycol (D), which includes repeating units derived from ethylene oxide and repeating units derived from alkylene oxide other than ethylene oxide, has a mass-average molecular weight of 8,000 or more.

6. The aqueous heat treatment liquid composition according to any one of claims 1 to 5, wherein the glycols (C) are at least one selected from the group consisting of polypropylene glycol, propylene glycol, polyethylene glycol, ethylene glycol, and derivatives thereof.

7. The aqueous heat treatment liquid composition according to claim 2 or 5, wherein the ratio (Q / P) of the number of moles of ethylene oxide units added (Q) to the number of moles of alkylene oxide units other than ethylene oxide added (P) in a molecule of polyalkylene glycol (D) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxide other than ethylene oxide is 1 or more and 19 or less.

8. The aqueous heat treatment liquid composition according to claim 2, 5, or 7, wherein the ratio (C / D) of the content of glycols (C) to the content of polyalkylene glycols (D) containing repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide is 2.3 or more and 10 or less by mass ratio.

9. The aqueous heat treatment liquid composition according to any one of claims 1 to 8, comprising the water (A), the condensed phosphate (B), and the glycols (C), optionally containing polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, wherein when the total amount of the condensed phosphate (B), the glycols (C), and polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide is 100% by mass, the composition comprises: the condensed phosphate (B) 2% by mass or more and 30% by mass or less; the glycols (C) 5% by mass or more and 80% by mass or less; and the polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide 2% by mass or more and 35% by mass or less.

10. The aqueous heat treatment liquid composition according to any one of claims 1 to 8, comprising the water (A), the condensed phosphate (B), and the glycols (C), and optionally containing polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide, wherein when the total amount of the aqueous heat treatment liquid composition is 100% by mass, the composition comprises: 0.5% by mass or more and 15% by mass or less of the condensed phosphate (B); 3% by mass or more and 40% by mass or less of the glycols (C); and 0.5% by mass or more and 20% by mass or less of the polyalkylene glycols (D) which include repeating units derived from ethylene oxide and repeating units derived from alkylene oxides other than ethylene oxide.

11. A method for producing a metal material, comprising a heat treatment step for the metal material, wherein, in the heat treatment step, the aqueous heat treatment liquid composition described in any one of claims 1 to 10 is used as a coolant for cooling the heated metal material.

12. A metal material manufacturing apparatus that performs at least a heat treatment step for a metal material, wherein, in the heat treatment step, the aqueous heat treatment liquid composition described in any one of claims 1 to 10 is used as a coolant for cooling the heated metal material.

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