JP7126735B1 - Water-soluble temper rolling fluid composition for non-degreased and annealed steel sheet - Google Patents

Abstract

A water for a non-degreased annealed steel sheet is characterized in that a discoloration pattern phenomenon due to migration concentration of ultra-fine non-degreased annealing residues (also simply referred to as annealing residues) is unlikely to occur after skin pass rolling of a non-degreased annealed steel plate. To provide a soluble refining rolling fluid. The water-soluble temper rolling fluid used for the non-degreased and annealed steel sheet includes (A) a nitrogen-containing complex containing 1 to 3 atoms of nitrogen in a generally and appropriately known water-soluble temper rolling fluid composition; One or two or more types of cyclic compounds and one or two or more types of (B) amphoteric surfactants are contained in combination, and the mass blending amount thereof is based on the total amount of the composition for both components (A) and (B). characterized by being 0.5 to 5.0 wt%. [Selection figure] None

Description

The present invention is characterized in that after skin pass rolling of a non-degreased annealed steel sheet, a discoloration pattern phenomenon due to local concentration and uneven distribution of extremely fine non-degreased annealing residues (simply referred to as annealing residues) is unlikely to occur. The present invention relates to a water-soluble temper rolling fluid composition for degreasing and annealing steel sheets.

The processes after cold rolling in the manufacture of steel sheets are roughly divided into two process methods. First, as a general process, after cold rolling, residual rolling oil, iron powder, etc., on the steel sheet are removed by a degreasing process such as alkaline electrolytic degreasing, followed by annealing, followed by temper rolling. be.

The second is a somewhat special process in which the degreasing process such as alkaline electrolytic degreasing after cold rolling is omitted due to lack of equipment capacity or labor saving, and annealing is performed, followed by temper rolling. There is A steel sheet annealed by omitting the degreasing process after cold rolling in this process is called a non-degreased annealed steel sheet (material). In addition, it is also called milk-clean steel sheet (material) and direct-annealed steel sheet (material).

In the annealing process described above, the steel sheet after cold rolling deforms crystal grains, entangles dislocations, and accumulates strain inside while being stretched. This process removes internal strain, adjusts the grain size, eliminates entangled dislocations, and imparts the necessary mechanical and physical properties to the steel sheet. There are two types of annealing processes: continuous annealing and batch (box) annealing. General cold-rolled steel sheets are subjected to continuous annealing, and non-degreased and annealed steel sheets are subjected to batch annealing. In batch (box) annealing, the coil is annealed together, and a mixed gas of hydrogen and nitrogen is used as the atmospheric gas. It takes time.

Since the rolling oil is not degreased in the second step, the rolling oil components are thermally decomposed by the annealing. Since the main component of the rolling oil component is mineral oil (hydrocarbon compound), if it is completely decomposed, the carbon (C) in the mineral oil and the hydrogen (H ₂ ) in the atmosphere react to produce CH ₄ and the like. It becomes a hydrocarbon gas form and removes the mineral oil from the steel plate.

However, in the case of incomplete decomposition (not completely decomposed), the mineral oil does not become gaseous and remains in the form of carbides such as soot on the steel sheet, and this residue is called annealing residue.

In the first process, a high-quality steel sheet can be produced, but in the second process, the cleanliness of the steel sheet is inferior, and in the case of the surface of the steel sheet, especially the dull steel sheet, the concave part of the dull mesh is so-called An undegreased annealing residue is generated in the deep part of the dull groove due to incomplete decomposition of the remaining rolling oil. When a non-degreased annealed steel sheet with residual annealing residue is subjected to skin pass rolling, the annealing residue adhering to the surface of the steel sheet is washed away by the skin pass rolling fluid during the skin pass rolling. When the steel sheet is plastically deformed, it floats and is wound up in a coil while remaining on the surface of the steel sheet on the exit side of the mill. Organic acid amine salts, etc., which are the main components of the hot rolling fluid, are adsorbed (adhered) on the steel sheet wound into a coil, but moisture and free amines in the hot rolling fluid also remain. Volatile moisture and high vapor pressure amine evaporate and volatilize over time.

As the residual moisture and free amines in the remaining water-soluble rolling fluid evaporate and evaporate, ultra-fine annealing residues are unevenly distributed on the steel sheet due to migration and thickening. Ions are eluted. Here, migration concentration means that the annealing residue is extremely fine particulate matter, and the particles migrate (electrophoresis) and aggregate (concentrate).

The eluted iron ions react with the oxygen contained in the gap between the coils and the residual moisture in the water-soluble refining rolling fluid to form an oxide film, but the amount of oxygen and moisture is limited. Therefore, the oxide film does not progress to stable ferric oxide (red rust), and in some cases the progress stops at the previous stage. A (black to blue to yellow to brown, etc.) oxide film, a so-called low-grade oxide film, is formed and appears as a discolored pattern. A discoloration pattern usually appears in about half a day to about one day after temper rolling.

Patent Documents 1 and 2 are prior art documents that mention that it can be used as a temper rolling fluid that can be used for the above-described non-degreased and annealed steel sheet. Patent document 3 is disclosed as a prior art document mentioned.

Among the above-mentioned prior art documents, Patent Documents 1 and 2 are related to the anti-buildup phenomenon of temper rolling fluid that can also be used for non-degreased annealed steel sheets. There is no description about Further, Patent Document 3 is a prior art containing an amphoteric surfactant in a rolling fluid composition for refining, and there is a description of stain. , there is no description of the discoloration patterns caused by the presence of annealing residues peculiar to non-degreased and annealed steel sheets.

Patent No. 5994075 Patent No. 6087255 JP 2016-94526 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a temper rolling fluid for a non-degreased annealed steel sheet that can solve the above-mentioned discoloration pattern phenomenon caused by fine annealing residues.

In order to solve the above-mentioned problems, the inventors have made intensive research as a means to solve the problems of the prior art, and as a result, have found that (A) nitrogen-containing general water-soluble temper rolling fluid composition The present inventors have found that the above problems can be solved by containing a heterocyclic compound and (B) an amphoteric surfactant in combination, and have completed the present invention described below.

1. A water-soluble temper rolling fluid composition for a non-degreased annealed steel sheet containing (A) a nitrogen-containing heterocyclic compound and (B) an amphoteric surfactant,
The component (A) is one or two or more heterocyclic compounds containing 1 to 3 atoms of nitrogen, and its mass blending amount is 0.5 wt% (mass%) to 5.0 wt% based on the total amount of the composition. %, and the component (B) is one or more amphoteric surfactants, and the mass blending amount thereof is 0.5 wt % to 5.0 wt % based on the total amount of the composition. A water-soluble temper rolling fluid composition for non-degreased and annealed steel sheets.
2. The component (A) is indole, isoxazole, 2-ethyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-benzothiazolethiol, pyrazole, benzindazole, 4-methylbenzimidazole, 4-methylimidazole, 2 methylimidazole, imidazole, benzotriazole, tolyltriazole, methylbenzotriazole, dimethylbenzotriazole, ethylbenzotriazole, ethylmethylbenzotriazole, diethylbenzotriazole, nitrobenzotriazole, 1-hydroxybenzotriazole, 3-mercapto-1,2, Item 1. The water-soluble temper rolling fluid composition for a non-degreased annealed steel sheet according to item 1, which is one or more selected from the group consisting of 4-triazole.
3. The component (B) is laurylaminopropionic acid, sodium laurylaminopropionate, sodium laurylaminodipropionate, sodium β-laurylaminodipropionate, sodium lauroylmethylalanine, sodium cocamidepropionate, and lauryliminodipropionic acid. Item 1 or two or more selected from the group consisting of sodium, coconut amidopropyl betaine, lauramidopropyl betaine, lauryldimethylaminoacetic acid betaine, sodium cocoamphodiacetate, and lauryl amino oxide 2. The water-soluble temper rolling fluid composition for a non-degreased and annealed steel sheet according to 2 above.

Advantageous Effects of Invention The present invention has an effect that discoloration pattern phenomenon due to local concentrated uneven distribution of extremely fine non-degreased annealing residues is less likely to occur after skin pass rolling of non-degreased annealed steel sheets.

The mechanism by which the water-soluble refining rolling fluid to which (A) the nitrogen-containing heterocyclic compound and (B) the amphoteric surfactant of the present invention are added suppresses the discoloration pattern is not clear, but is presumed as follows. be done.

The discoloration pattern phenomenon can be suppressed by using (A) a nitrogen-containing heterocyclic compound and (B) an amphoteric surfactant in combination to remove fine annealing residues from the deep part of the dulled steel sheet into a three-dimensional structure. This is believed to be due to the dispersion and immobilization by the adsorption film, and the suppression of electrophoretic thickening caused by evaporation of water and free amines.

The water-soluble temper rolling fluid used for the non-degreased and annealed steel sheet of the present invention is composed of (A) a nitrogen-containing heterocyclic compound and (B) an amphoteric surfactant in a general and appropriately known water-soluble temper rolling fluid composition. Contains both.

Commonly known water-soluble refining rolling fluid components include several kinds of organic acids (aliphatic fatty acids, aromatic fatty acids, dibasic acids, etc., hereinafter simply referred to as fatty acids or carboxylic acids), alkanolamine, and water. It is the main component and contains a small amount of surfactant. In addition, depending on the process and equipment configuration of the steelworks, it may contain chelating agents, inorganic alkalis, water-soluble polymers, and trace amounts of bactericidal preservatives and antifoaming agents.

Organic acids used in water-soluble temper rolling fluids have around 5 to 21 carbon atoms, mainly around 5 to 12 carbon atoms, from the viewpoint of rust prevention, solubility, lubricity, odor, etc. is widely used. However, since an organic acid having 5 or more carbon atoms is hardly soluble in water as it is, it is neutralized with alkanolamine, which is a main component, to form an aqueous solution in the form of an organic acid amine salt, and the pH of the water-soluble tempered rolling mill is adjusted. It contains an excess of free alkanolamine to keep it above neutral. From the above, it can be concluded that the water-soluble rolling mill with a basic composition consists of several types of organic acid amine salts and free alkanolamine dissolved in water. Salt will account for the majority of the dissolved components.

Examples of the organic acid and alkanolamine, which are the main components of the water-soluble temper rolling fluid, include the following.

Aliphatic saturated and unsaturated monocarboxylic acids are not particularly limited, but caproic acid, heptanoic acid, octanoic acid, 2-butyloctanoic acid, nonanoic acid, isononanoic acid, decanoic acid, neodecanoic acid, undecanoic acid, dodecanoic acid, myristine acid, palmitic acid, isopalmitic acid, stearic acid, isostearic acid, arachidic acid, isoarachidic acid, oleic acid, elaidic acid, erucic acid, linoleic acid and the like. Aliphatic saturated and unsaturated dicarboxylic acids include adipic acid, pimelic acid, octanedioic acid (suberic acid), nonanedioic acid (azelaic acid), decanedioic acid (sebacic acid), undecanedioic acid, dodecanedioic acid, fumaric acid acids, mesaconic acid, itaconic acid, C21 dibasic fatty acids, and the like. Other aliphatic carboxylic acids include glycolic acid, lactic acid, glyceric acid and citric acid.

Aromatic mono- and aromatic polycarboxylic acids include, but are not limited to, benzoic acid, o-, m- and p-methylbenzoic acid, o-, m- and p-nitrobenzoic acid, pn-, p- sec- and p-tert-butylbenzoic acid, o-, m- and p-benzenedicarboxylic acid, 2-benzothiazolylthiopropionic acid, 2-benzothiazolylthioacetic acid and the like.

Alkanolamine is not particularly limited, but monoisopropanolamine [=1-amino-2-propanol], monoethanolamine [=2-aminoethanol], dimethylaminoethanol [=N,N-dimethyl], which have a relatively high vapor pressure -2-aminoethanol], N-methylethanolamine, 2-amino-2-methylpropanol, etc., and diisopropanolamine [=1,1'-iminodi-2-propanol], triisopropanol, which has a lower vapor pressure than the above. Amine [=tris(2-hydroxypropyl)amine], diethanolamine [=2,2'-iminodiethanol], triethanolamine and the like are used alone or in combination.

Others are not particularly limited, but examples of chelating agents include nitrilotriacetic acid, ethylenediaminetetraacetic acid, sodium salts and ammonium salts thereof, and the like. Examples of inorganic alkalis include sodium hydroxide and potassium hydroxide; examples of antiseptic agents include triazine-based and thiazoline-based antiseptic agents; examples of water-soluble polymers include polyethers such as polyethylene glycol and polypropylene glycol; can include nonionic surfactants as surfactants, such as silicone antifoaming agents.

The nitrogen-containing heterocyclic compound (A) constituting the present invention is a heterocyclic compound containing 1 to 3 atoms of nitrogen, and the heterocyclic compound containing 1 atom of nitrogen is indole, isoxazole, 2 -ethyl-2-oxazoline, 2-ethyl-2-oxazoline, and other heterocyclic compounds containing two nitrogen atoms, 2-benzothiazolethiol, pyrazole, benzindazole, 4-methylbenzimidazole, 4-methylimidazole, 2 Heterocyclic compounds containing three nitrogen atoms, such as methylimidazole and imidazole, include benzotriazole, tolyltriazole, methylbenzotriazole, dimethylbenzotriazole, ethylbenzotriazole, ethylmethylbenzotriazole, diethylbenzotriazole, nitrobenzotriazole, 1 -Hydroxybenzotriazole, 3-mercapto-1, 2, 4 triazole, etc., one or more selected from the group consisting of 0.5 wt% (mass%) to 5.0 wt% Added. In the case of addition of 0.5 wt% or less based on the total amount of the composition, the effect of dispersing and fixing the fine annealing residue is insufficient, while addition of 5.0 wt% or more does not improve the effect, so it is economical. inferior in terms of

Amphoteric surfactants (B) constituting the present invention include amino acid double-faced surfactants such as laurylaminopropionic acid, sodium laurylaminopropionate, sodium laurylaminodipropionate, and sodium β-laurylaminodipropionate. , Sodium lauroylmethylalanine, etc., for alanine-type double-sided surfactants, such as sodium cocamide propionate, sodium lauryliminodipropionate, etc. For betaine-type double-sided surfactants, Tyne, betaine lauryldimethylaminoacetate, imidazoline type double-faced surfactants such as sodium cocoamphodiacetate, amine oxide type double-faced surfactants such as lauryl amino oxide, etc. One selected from these groups Alternatively, two or more types are selected and added at 0.5 wt % to 5.0 wt %. If the content is less than 0.5 wt%, the effect of dispersing and fixing the fine annealing residue is insufficient.

In the present invention, as a technique for reproducing the discoloration pattern in a laboratory, it is possible to reproduce the discoloration pattern by using the annealing residue collected from the non-degreased and annealed steel sheet.

Table 1 shows the blending composition (wt %) of the water-soluble temper rolling fluids of Examples 1 to 6 and Comparative Examples 1 to 6 and the discoloration pattern evaluation test results. The discoloration pattern evaluation test method and judgment were performed according to the following.

After degreasing the SPCC-SD steel plate specified in JIS G3141, Examples 1 to 6 and Comparative Examples 1 to
Two specimens (10 cm x 10 cm x 0.8 cm) were prepared by immersing the liquid 6 in a liquid diluted to 7 vol% with deionized water and removing the liquid. A test solution was prepared by adding 7.0% by weight of the annealing residue collected from the non-degreased and annealed steel sheet to the solution obtained by diluting the solutions of Examples 1 to 6 and Comparative Examples 1 to 6 with ion-exchanged water to 7 vol%, and thoroughly stirring the solution. 50 μl of the test liquid is dropped on one test piece, another test piece is placed on top of the other, and left to stand at room temperature of about 25° C. for one day. After standing still, the stacked steel sheets were released, and the surface of the steel sheets was evaluated according to the following criteria.
×: When a discoloration pattern is clearly observed △: When a discoloration pattern is slightly observed ○: When a discoloration pattern is not observed

As shown in Table 1, it was confirmed that the discoloration pattern phenomenon was suppressed by using Examples 1 to 6 compared to Comparative Examples 1 to 6, and as a result quality defects could be reduced.

While the present invention has been described in connection with embodiments currently believed to be practical and effective, the invention is not limited to the embodiments disclosed in this patent application and the claims. and within the range not contrary to the gist and idea of the invention that can be read from the entire application, and the water-soluble tempered rolling fluid with such changes is also included in the technical scope of the present invention. must be understood as

The present invention can also be used during temper rolling in which alkaline electrolytic degreasing and the like are performed after cold rolling, which is a general process.

Claims (3)

Water-soluble temper rolling for non-degreased annealed steel sheet, comprising (A) a nitrogen-containing heterocyclic compound and (B) an amphoteric surfactant in a composition of a water-soluble temper rolling fluid containing organic acid, alkanolamine and water as main components A liquid composition,
The component (A) is one or two or more heterocyclic compounds containing 1 to 3 atoms of nitrogen, and its mass blending amount is 0.5 wt% (mass%) to 5.0 wt% based on the total amount of the composition. %, and the component (B) is one or more amphoteric surfactants, and the mass blending amount thereof is 0.5 wt % to 5.0 wt % based on the total amount of the composition. A water-soluble temper rolling fluid composition for non-degreased and annealed steel sheets. The component (A) is indole, isoxazole, 2-ethyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-benzothiazolethiol, pyrazole, benzindazole, 4-methylbenzimidazole, 4-methylimidazole, 2 methylimidazole, imidazole, benzotriazole, tolyltriazole, methylbenzotriazole, dimethylbenzotriazole, ethylbenzotriazole, ethylmethylbenzotriazole, diethylbenzotriazole, nitrobenzotriazole, 1-hydroxybenzotriazole, 3-mercapto-1,2, The water-soluble temper rolling fluid composition for a non-degreased annealed steel sheet according to claim 1, which is one or more selected from the group consisting of 4-triazole. The component (B) is laurylaminopropionic acid, sodium laurylaminopropionate, sodium laurylaminodipropionate, sodium β-laurylaminodipropionate, sodium lauroylmethylalanine, sodium cocamidepropionate, and lauryliminodipropionic acid. Sodium, coconut oil fatty acid amidopropyl betaine, lauramidopropyl betaine, lauryldimethylaminoacetic acid betaine, sodium cocoamphodiacetate, lauryl amino oxide, or one or more selected from the group consisting of 3. The water-soluble temper rolling fluid composition for a non-degreased and annealed steel sheet according to 2 above.