[0001]The present invention is a high strength cold rolled steel sheet, high-strength hot-dip galvanized steel sheet, and a high strength galvannealed steel sheet. Background technique [0002] 　Recently, in view of greenhouse gas emissions regulations due to global warming, for the purpose of improving fuel economy of automobiles, weight reduction of the vehicle body is required. In addition, it is necessary to ensure a collision safety, the application of high-strength steel sheets is growing. In particular, recently, the tensile strength of 980MPa or more, preferably there is a growing need for more of the ultra-high-strength steel 1180MPa. Furthermore, ultra-high-strength galvanized steel sheet galvanized on the surface is required to the site that requires rust prevention among the vehicle body. [0003] 　As a method of using such a high-strength steel sheet to form a motor vehicle or members include the bending such as press working. Usually, the bendability tends to deteriorate the higher the strength of the steel sheet. Therefore, when subjected to bending a high-strength steel sheet, cracks (cracks) there has been a problem that occurs on the steel sheet inside the deformable portion. [0004] 　Factors governing the bending of a high strength steel sheet, it is known that (a) occurs difficulty of necking, (b) generating the difficulty of the steel sheet inside cracks (voids), are important. This is because a low elongation steel sheet occur necking during bending, deformation by localized believed bendability is to degrade. [0005] 　In bending a steel plate, a large tensile strain in the circumferential direction on the outer peripheral surface portion bending, also large compressive strain in the circumferential surface portion bending occurs. Therefore, the bending of the ultra-high-strength steel sheet, the steel structure of the steel sheet surface layer portion not steel inside the steel structure but also greatly affected. Specifically, by making the steel sheet surface layer portion and the soft layer, is relaxed localization of deformation caused on the surface of the steel sheet during bending, it has been found that the bending is improved. Applying this technique, the invention has improved bendability of ultrahigh-strength steel sheet is disclosed in Patent Documents 1 to 4 below. [0006] 　Patent Document 1, causes solid solution of Zn to the steel sheet surface layer portion, the steel sheet surface layer portion is softened, further improving the metal structure to bending by the main and tissue martensite and bainite of constituting the steel sheet the tensile strength is technology related hot-dip galvanized steel sheet or galvannealed steel sheet described above 1180MPa is disclosed. [0007] 　Mainly in the Patent Documents 2 and 3, by controlling the atmosphere in the continuous annealing in an oxidizing atmosphere, by forming a decarburized layer on the steel sheet surface layer, a soft layer composed mainly of ferrite in the surface layer, the martensite and bainite in the inner layer improved the bending properties to separately form the hard layer and a technique related to an ultra high strength cold-rolled steel sheet is disclosed. [0008] 　Patent Document 4, after heating the steel sheet, the surface layer portion to cool water jet on the surface, then the steel sheet surface layer to the interior by uniformly cooled, changing the surface portion and the steel plate inside the cooling pattern, the surface layer soft layer mainly composed of ferrite, inner layer has improved bendability by separately forming a hard layer consisting mainly of low-temperature transformation phase, technology relating to high-strength cold-rolled steel sheet is disclosed in. CITATION Patent Literature [0009] Patent Document 1: JP 2014-237887 Patent Publication Patent Document 2: JP-A 10-130782 JP- Patent Document 3: JP-A 5-195149 Patent Publication Patent Document 4: JP 2005-273002 JP Non-Patent Document [0010] Non-Patent Document 1: Iron and Steel, vol. 74 (1988), p. 2353 Summary of the Invention Problems that the Invention is to Solve [0011] 　As described above, heretofore, in order to improve the bendability, efforts to control the steel sheet surface layer and the steel plate lining each hardness and tissues have been made. [0012] 　However, in the technique described in Patent Document 1, in order to form a solid solution of Zn to the steel sheet surface layer portion, the heating temperature during annealing Ac 3 needs to be a high temperature that point + 50 ℃ or higher. Since this speed the furnace body damage continuous annealing furnace, which is not preferable. [0013] 　In the technique described in Patent Documents 2 and 3, the atmosphere during annealing for decarburization and an oxidizing atmosphere, the steel sheet surface layer Mn, internal oxidation layer of alloying elements such as Si is formed. The presence of the inner oxide layer, may fatigue strength is greatly reduced, there is room for improvement. [0014] 　Furthermore, the technique described in Patent Document 4, since the essential water injection into the steel strip surface, there is a problem that it is difficult to apply to the heat treatment in the galvanizing line. [0015] 　Thus, for the high-strength steel sheet, which is made to consider and development for the purpose of improving bendability by various techniques. However, techniques to maintain the strength while improving the bendability has not been established yet, and further, in consideration to bending of the high-strength galvanized steel sheet, considered insufficient in the prior art . [0016] 　The present invention is to solve the above problems, and an object thereof is to provide high-strength cold-rolled steel sheet excellent in bendability, high-strength hot-dip galvanized steel sheet, and a high strength galvannealed steel sheet. Means for Solving the Problems [0017] 　The present invention has been made to solve the above problems, a high strength cold rolled steel sheet described below, a high-strength galvanized steel sheet, and a high strength galvannealed steel sheet as gist. [0018] 　(1) chemical composition, in 　mass%, 　C: 0.050 ~ 　0.40%, Si: 0.01 ~ 3.0%, Mn: 1.0 ~ 　5.0%, sol. Al: 　0.001 ~ 　1.0%, Ti: 0.005 ~ 0.20%, B: 0.0005 ~ 　0.010%, P: 0.1% or 　less, S: 0.01% or 　less, O 0.1% or less, 　N: 0.01% or 　less, 　Cr: 0 ~ 　1.0%, Mo: 0 ~ 1.0%, Ni: 　0 ~ 1.0%, Cu: 0 ~ 1.0% , 　Sn: 　　0 ～ 0.50 Pasento, 　Nb: 0 ～ 0.20 Pasento, V: 0 ～ 0.50 　Pasento, W: 0 ～ 0.50 Pasento, Ca: 0 ～ 0.01 　Pasento, Mg: 0 ～　% 0.01,　　Bi: 0 ~ 0.01%, Sb: 0 ~ 0.10%, 　Zr: 0 ~ 0.01%, REM: 0 ~ 0.01%, 　the balance is Fe and impurities, 　the following (i) satisfies the formula and (ii) expression, high-strength cold-rolled steel sheet. 　sol. Bs / B ≦ 0.50 · · · 　(I) Sol. Bq / B> 0.50 ··· (ii ) 　where the meaning of each symbol in the formula is as follows. 　B: B content in the steel (mass%) 　sol. Bs: B content present as solid solution in a range from the surface of 30μm depth of the steel sheet 　(mass%) sol. Bq: B content present as a solid solution state in the quarter-thickness position of the steel sheet (wt%) [0019] 　(2) the chemical composition, in 　mass%, 　Cr: 0.001 　~ 1.0%, Mo: 0.001 ~ 1.0%, Ni: 0.001 　~ 1.0%, Cu: 0.001 to 1.0% 　and, Sn: 0.001 ~ 0.50% 　containing at least one member selected from, 　high-strength cold-rolled steel sheet according to (1). [0020] 　(3) the chemical composition, by 　mass%, Nb: 　0.001 ~ 0.20%, V: 0.001 ~ 0.50%, 　and, W: 0.001 ~ 0.50%, 　are selected from containing one or more that, 　high-strength cold-rolled steel sheet according to (1) or (2). [0021] 　(4) the chemical composition, by 　mass%, 　Ca: 0.0001 　~ 0.01%, Mg: 0.0001 ~ 0.01%, Bi: 0.0001 　~ 0.01%, Sb: 0.0001 　0.10% ~, Zr: 0.0001 ~ 0.01%, 　and, REM: 0.0001 ~ 0.01%, 　containing one or more selected from, 　the above (1) to (3) high-strength cold-rolled steel sheet according to any one of. [0022] 　(5) the steel structure in a range from the surface of 30μm depth of the steel sheet, in area%, 　polygonal ferrite 10 to 95%, 　the balance is in the martensite, one or more selected from bainite and residual austenite, and, 　the proportion of tempered martensite in the whole martensite is 50% or more, 　the steel structure in the quarter-thickness position of the steel sheet, in area%, 　polygonal ferrite: 60% or less, 　the balance being martensite , bainite, is at least one selected from retained austenite, and 　the proportion of tempered martensite in the whole martensite is 50% or more, 　according to any one of (1) to (4) high-strength cold-rolled steel sheet. [0023] 　(6) the steel structure in a range from the surface of 30μm depth of the steel sheet, in area%, 　polygonal ferrite: 30 to 95%, 　the steel structure in the quarter-thickness position of the steel sheet, in area% , 　polygonal ferrite: 10 to 60%, 　high-strength cold-rolled steel sheet according to (5). [0024] 　(7) the steel structure in a range from the surface of 30μm depth of the steel sheet, in area%, 　polygonal ferrite: 10 to 80%, 　the steel structure in the quarter-thickness position of the steel sheet, in area% , 　polygonal ferrite: 20% or less, 　martensite: 50% or more, 　bainite: 40% or less, 　residual austenite: is 20% or less, 　high-strength cold-rolled steel sheet according to (5). [0025] 　(8) Tensile strength of not less than 980 MPa, and the ratio R / t of the thickness t and the minimum bending radius R is 2.5 or less, 　high-strength cold-rolled steel sheet according to (6). [0026] 　(9) Tensile strength is at least 1180 MPa, and the ratio R / t of the thickness t and the minimum bending radius R is 3.5 or less, 　high-strength cold-rolled steel sheet according to (7). [0027] 　(10) having a hot-dip galvanizing layer on the surface of the high strength cold rolled steel sheet according to any one of (1) to (9), a high-strength galvanized steel sheet. [0028] 　(11) on the surface of the high strength cold rolled steel sheet according to any one of (1) to (9) having a galvannealed layer, a high strength galvannealed steel sheet. Effect of the invention [0029] 　According to the present invention, it is possible to obtain high strength cold rolled steel sheet excellent in bendability, high strength galvanized steel sheet, a high strength galvannealed steel sheet. BRIEF DESCRIPTION OF THE DRAWINGS [0030] It is a diagram for explaining the positional relationship between the nozzle and the steel sheet in FIG. 1 descaling process. DESCRIPTION OF THE INVENTION [0031] 　The present inventors have conducted extensive studies in order to obtain a high-strength cold-rolled steel sheet excellent in bendability. As a result, the state of existence of a hardenability element B, and mainly precipitated state in the steel surface layer portion, by mainly a solid solution state in the one of the steel sheet inside, can improve the bending properties without reducing the strength of the steel sheet It was heading. [0032] 　Specifically, the proportion of existing B amount and the steel in the total amount of B as a solid solution state, (in the description below, referred to as "surface layer portion".) From the surface of the steel sheet 30μm depth ranging in 0.50 and, and, (in the following description, also referred to as "internal".) 1/4 thickness position of the steel sheet in by the ratio of 0.50 than, it can be improved in deterioration suppressing and bending of the intensity It was found that there. [0033] 　Furthermore, in order to control the state of presence of B so as to satisfy the above conditions, as well as the scale thickness immediately after the hot-rolled coil winding in a predetermined range, the cooling conditions after hot rolling coil winding It found that adjusting is enabled. [0034] 　The present invention has been made based on the above findings. It will be described in detail below each requirement of the present invention. [0035] 　(A) Chemical composition 　reasons for limiting each element are as follows. Incidentally, "%" for the content in the following description means "mass%". [0036] 　C: 0.050 ~ 　0.40% C (carbon) is an essential element for increasing the strength of the steel sheet. On the other hand, of bending is excessively contained, to degrade the press formability and weldability. Therefore, C content is 0.050 to 0.40 percent. From the viewpoint of enhancing the strength, C content is preferably 0.080% or more. Further, in view of suppressing the press formability and weldability occurs, C content is preferably not more than 0.25%. [0037] 　Si: 0.01 ～ 3.0 　Pasento Si (silicon) is a solid solution strengthening element, which is an effective element for high strength of the steel plate. On the other hand, not only significantly degrade the wettability of excessively The inclusion chemical convertibility and galvanized steel plate, bendability also degrade. Therefore, Si content is 0.01% to 3.0%. From the viewpoint of enhancing the strength, Si content is preferably to 0.10% or more, more preferably 0.20% or more. Further, in view of suppressing the wettability of degradation of the chemical conversion treatability and galvanizing it is preferably Si content is 2.0% or less and more preferably 1.50% or less. [0038] 　Mn: 1.0 ~ 　5.0% Mn (Manganese) is a powerful austenite stabilizing element, is an element effective for hardenability improvement of the steel sheet. On the other hand, of bending is excessively contained, to degrade the weldability and low temperature toughness. Therefore, Mn content is 1.0 to 5.0%. From the viewpoint of hardenability improvement, Mn content is preferably 1.5% or more. From the viewpoint of suppressing the weldability and low temperature toughness deterioration, Mn content is preferably not more than 3.0%. [0039] 　sol. Al: 0.001 ~ 　1.0% Al (aluminum) is to contain at least 0.001% for deoxidation of steel. However, excessive effect be contained is saturated and not only the cost is increased, thereby increasing the load of the hot rolling to increase the transformation temperature of the steel. Therefore, sol. Al content is 1.0% or less. sol. Al content is preferably to 0.005% or more, preferably 0.5% or less. [0040] 　Ti: 0.005 ~ 　0.20% Ti (titanium) is by fixing N as TiN in the steel, inhibits the formation of BN as a hardenability decrease factor. Further, to refine the austenite grain size at the time of heating to improve the toughness. On the other hand, when the excessive content ductility of the steel sheet is lowered. Therefore, Ti content is from 0.005 to 0.20%. Ti content is preferably to 0.010% or more, preferably 0.050% or less. [0041] 　B: 0.0005 ~ 0.010% B 　(boron) segregates in austenite grain boundaries, or ferrite / austenite grain boundaries at the time of heating of the steel sheet, for increasing the hardenability of the steel by stabilizing the grain boundaries, in the present invention is an essential element. On the other hand, when the excessive content by forming a boride, resulting in impairing the hardenability of the steel. Therefore, B content is from 0.0005 to 0.010%. B content is preferably to 0.0010% or more, preferably 0.0050% or less. [0042] 　P: 0.1% or less 　P (phosphorus) is a solid solution strengthening element, but is an effective element for high strength of a steel sheet, deteriorating the weldability and toughness and is excessively contained. Accordingly, P content is 0.1% or less. P content is more preferably 0.05% or less. However, to extremely reduce the P content, since the de-P cost increases, it is preferable to 0.001% the lower limit from the viewpoint of economy. [0043] 　S: 0.01% or less 　S (Sulfur) is an element contained as an impurity, and forms MnS deteriorates the toughness and hole expansion in the steel. Accordingly, as a range toughness and hole expansion deterioration is not noticeable, the S content is 0.01% or less. S content is preferably not more than 0.005%, and more preferably 0.002% or less. However, to extremely reduce the S content, since the desulfurization cost is high, it is preferable to 0.0005% the lower limit from the viewpoint of economy. [0044] 　O: 0.1% or less 　O (oxygen) is an element contained as an impurity, the content thereof makes spread beyond the forms coarse oxides bendability and hole in the steel of 0.1%. Therefore, O content is 0.1% or less. O content is preferably 0.01% or less, more preferably 0.005% or less. However, it is preferable to 0.0001% the lower limit in terms of manufacturing cost. [0045] 　N: 0.01% or less 　N (nitrogen) is an element contained as an impurity, a by forming a coarse nitrides bendability and Anahiroge properties in the steel a content exceeding 0.01% degrade. Therefore, N content is 0.01% or less. N content is preferably 0.005% or less. However, to extremely reduce the N content, for de-N cost increases, it is preferable to 0.0005% the lower limit from the viewpoint of economy. [0046] 　The high-strength steel sheet of the present invention, in addition to the above elements, Cr in an amount shown below, Mo, Ni, Cu, Sn, Nb, V, W, Ca, Mg, Bi, Sb, of Zr and REM one or more elements selected may be contained. [0047] 　Cr:　 　0 ~ 1.0% 　Mo: 0 ~ 1.0% Ni: 0 ~ 　1.0% Cu: 0 ~ 1.0% Sn: 0 ~ 　0.50% Cr (chromium), Mo (molybdenum), Ni (nickel), Cu (copper), Sn (tin) may be contained as required for an effective element for high strength of any steel sheet. However, excessive inclusion of these elements effect is saturated, leading to an increase in cost. Therefore, Cr, Mo, and the content of Ni and Cu both 1.0% or less, of Sn content is 0.50% or less. Cr, Mo, Ni content and Cu are preferably also 0.60% or less one, Sn content is preferably not more than 0.30%. [0048] 　To obtain the above effect, Cr, Mo, Ni, one or more selected from Cu and Sn, preferably contained more than 0.001%, it is more preferable to contain 0.05% or more. [0049] 　Nb: 　0 ~ 0.20% 　V: 0 ~ 0.50% W: 0 ~ 　0.50% Nb (niobium), V (vanadium) and W (tungsten) is a carbide forming element, strength of a steel sheet it may be contained if necessary because it is an element effective for. However, even if excessively be contained effect is saturated, thereby increasing the cost. Therefore, the Nb content is set to 0.20% or less, both the content of V and W to 0.50% or less. Nb content is preferably not more than 0.10%, the content of V and W are both preferably set to 0.30% or less. [0050] 　To obtain the above effect, Nb, one or more selected from V and W, preferably contained more than 0.001%, it is more preferable to contain at least 0.005%. [0051] 　Ca:　 　0 　~ 0.01% Mg: 0 ~ 0.01% 　Bi: 0 ~ 0.01% Sb: 0 ~ 　0.10% Zr: 0 ~ 0.01% REM: 0 ~ 　0.01% Ca ( calcium), Mg (magnesium), Sb (antimony), Zr (zirconium), REM (rare earth element) is an element contributing to the fine dispersion of inclusions in steel, Bi (bismuth) is Mn in steel, Si it is an element to reduce micro-segregation of substitutional alloying elements and the like. These elements, since it contributes to the bending resistance improving steel plates, may be contained as needed. However, when the excessive content causes deterioration of ductility. Therefore, Ca, and Mg, Bi, both the content of Zr and REM and 0.01% or less, the Sb content is set to 0.10% or less. Ca, Mg, Bi, the content of Zr and REM is preferably also 0.006% or less one, Sb content is preferably not more than 0.080%. [0052] 　To obtain the above effect, Ca, Mg, Bi, Sb, at least one selected from Zr and REM, preferably contained 0.0001% or more, more it is contained 0.0010% or more preferable. [0053] 　In the present invention, REM refers to a total of 17 elements Sc, Y and lanthanoid, and the content of the REM means the total content of these elements. It should be noted that the lanthanide is industrially, it is added in the form of misch metal. [0054] 　In the chemical composition of the steel sheet of the present invention, the balance being Fe and impurities. [0055] 　Here, the "impurities", in manufacturing the steel sheet industrially, ores, raw material scraps, a component mixed by various factors of the manufacturing process, is allowed to the extent that the present invention does not adversely affect means shall. [0056] 　(B) the presence status of B 　as described above, in the present invention, in order to improve the bending properties without reducing the strength of the steel sheet, the state of presence of B is hardenability elements following formula (i) and ( it is necessary to control so as to satisfy the ii) expression. [0057] 　sol. Bs / B ≦ 0.50 · · · 　(I) Sol. Bq / B> 0.50 ··· (ii ) 　where the meaning of each symbol in the formula is as follows. 　B: B content in the steel 　(mass%) sol. Bs: B content present as solid solution in a range from the surface of 30μm depth of the steel sheet 　(mass%) sol. Bq: B content present as a solid solution state in the quarter-thickness position of the steel sheet (wt%) [0058] 　The steel sheet surface layer portion, it is important to present the B primarily precipitation state. sol. When the value of bs / B exceeds 0.50, since the hardenability of the surface layer portion is excessively increased, it can not be ensured bendability. sol. The value of bs / B preferably to 0.30 or less and more preferably 0.20 or less. [0059] 　On the other hand, in the steel sheet inside, it is important to present the B predominantly in a solid solution state. sol. When the value of Bq / B is 0.50 or less, since the hardenability of the internal steel sheet is reduced, it can not be ensured the necessary strength. sol. The value of Bq / B is preferably in the 0.65 or more, more preferably 0.80 or more. [0060] 　In addition, sol. Bs and sol. The value of Bq, in each predetermined position, after calculating the B amount consumed as a precipitate by measuring the mass of boron compound in the steel by electrowinning left method, B-containing included it in the steel It shall be determined by subtracting from the amount. [0061] 　Specifically, for the content of B present as boron compound in a range from the surface of the steel sheet of 30μm depth, without grinding the steel sheet surface is measured by electrowinning to 30μm depth. As for the content of B present as boron compound in 1/4 thickness position of the steel sheet, after mechanically grinding the steel sheet to a 1/4 thickness position is measured by electrowinning to 30μm depth. Note that the determination of precipitation B amount by extraction residue method using the technique disclosed in Non-Patent Document 1. [0062] 　(C) the steel structure 　will be described steel structure of the steel sheet of the present invention. Incidentally, "%" in the following description means "area%". [0063] 　Although not provided any special restriction on the steel plate of the steel structure of the present invention, in order to achieve both strength and bending property, it is preferable to adjust each of the steel structure of the surface portion and the interior of the steel sheet. Specifically, in 30μm depth in the range from the surface of the steel sheet, the area ratio of the polygonal ferrite is 10 to 95% martensite and the remainder sites, as well as one or more selected from bainite and residual austenite, the steel sheet in 1/4 thickness position of the area ratio of polygonal ferrite to 60% or less, martensite remainder, bainite, that the one or more selected from retained austenite preferred. [0064] 　The foregoing martensite include tempered martensite plus martensite and tempered remain quenching. Compared to tempered martensite, brittle martensite remains quenching, tends to become a starting point of fracture upon the addition of a plastic deformation of the bending or the like. Therefore, in order to ensure the desired bending properties, in each surface portion and the interior of the steel sheet, preferably 50% or more the proportion of tempered martensite in the total martensite, be less than 70% more preferable. [0065] 　Further, when importance is attached bendability further the surface layer portion of the steel sheet, the area ratio of polygonal ferrite with 30 to 95%, in the interior of the steel sheet, the area ratio of the polygonal ferrite 10-60% preferably with. Area percentage of polygonal ferrite is more preferably in the range 50-90% at a surface layer portion of the steel sheet, and even more preferably in the range of 70-90%. The area ratio of polygonal ferrite in the internal steel sheet is more preferably 20 to 40%. [0066] 　On the other hand, when importance is attached to strength, further, the surface layer portion of the steel sheet, with the area ratio of polygonal ferrite of 10 to 80%, in the interior of the steel sheet, 20% or less of the area ratio of polygonal ferrite, martensite the area ratio of the site at least 50%, the area ratio of bainite of 40% or less, the area ratio of residual austenite preferably 20% or less. More preferably the area ratio of polygonal ferrite is 30% or more in the surface layer of the steel sheet, further preferably 50% or more. Further, more preferably the area ratio of polygonal ferrite is less than 10% inside the steel sheet, more preferably less than 5%, the area ratio of the martensite and more preferably 70% or more. [0067] 　Steel structure of the present invention is measured by the following method. First, it cuts out the rolling direction cross-section of the steel sheet and revealing the steel structure by nital solution. Thereafter, the surface ~ 30 [mu] m depth position and the quarter thickness location, scanning electron microscope (magnification: 5000 times, 5 fields) are photographed using. Then, from the obtained structure photograph by point counting method to calculate polygonal ferrite, bainite, martensite, the area ratio of tempered martensite. [0068] 　Further, the area ratio of residual austenite, the EBSP-OIM (Electron Back Scatter Diffraction Pattern-Orientation Image Microscopy) method, determined by calculating the area of ​​the region having the FCC structure. [0069] 　(D) the mechanical properties 　as described above, the steel sheet according to the present invention combines a high strength and excellent bendability. Although not provided particularly limited mechanical properties, the in the case of emphasizing bendability, tensile strength not less than 980 MPa, and, at the ratio R / t of the thickness t and the minimum bending radius R is 2.5 or less It is preferred. On the other hand, when importance is attached to strength, tensile strength not less than 1180 MPa, and the ratio R / t of the thickness t and the minimum bending radius R is preferably 3.5 or less. If more emphasis on strength, tensile strength is more preferably not less than 1470 MPa. [0070] 　The minimum bending radius R, bending test: evaluated by V block method defined in JIS Z 2248. Specifically, cut strip specimens in the rolling direction and the thickness direction perpendicular to the direction (width direction), the bending radius do bend 90 ° V changed, bend radius minimize minimum bend radius cracking does not occur to. [0071] 　(E) plating layer 　The high strength cold rolled steel sheet according to the present invention which have been described above may have a galvanized layer on the surface of the steel sheet. By imparting galvanized layer on the surface of the steel sheet, thereby improving the corrosion resistance. [0072] 　Moreover, galvanized layer may be alloyed. The galvanized layer is alloyed, since Fe is incorporated into the hot-dip galvanizing layer by alloying, excellent weldability and paintability obtained. [0073] 　Further, the galvanized layer, in order to improve the paintability and weldability, may be subjected to the upper layer plating. Further, the high-strength cold-rolled steel sheet of the present invention, the galvanized layer, various processes, for example, chromate treatment, phosphate treatment, lubricity enhancing treatment, may be subjected to weldability improving treatment. [0074] 　(F) the production method 　is not particularly limited production conditions of a high strength cold rolled steel sheet according to the present invention, by using a method comprising the steps described below, can be produced. [0075] 　(A) hot-rolling process 　(a-1) Slab heating step 　First, heating the slab to a temperature of at least 1150 ° C.. In the final product sheet, sufficient sol. The value of Bq / B to a predetermined range, it is preferred that the slab heating temperature to facilitate the dissolution of the boron compound to 1150 ° C. or higher. Incidentally, the steel slab to be used, it is preferable to cast in a continuous casting method in view of productivity, Zokatamariho may be a thin slab casting process. Further, the cast slab may be once cooled to room temperature, it may be sent directly to the furnace without cooling to room temperature. [0076] 　(A-2) rough rolling process 　Next, the heated slab, the total reduction ratio in the temperature range of 1050 ~ 1150 ° C. rolling to be 50% or more. When the total rolling reduction at the above temperature range is less than 50%, recrystallization in hot rolling becomes insufficient, which may lead to insufficient homogeneity of the hot rolled sheet structure. [0077] 　(A-3) the finish rolling step 　a total rolling reduction of 1050 ° C. from the temperature to the final pass (finishing final pass) before the finish rolling step with 60 to 95%, a reduction ratio of 10 to the finishing final pass 30 %, the temperature of finishing the final pass and 850 ~ 1000 ℃. [0078] 　When the total rolling reduction of from 1050 ° C. temperature below before finishing the final pass exceeds 95%, if the reduction ratio of finishing final pass exceeds 30% or when the temperature of finishing final pass is less than 850 ° C. is , precipitation during hot rolling boron compound is promoted. As a result, sol in the final product plate. The value of Bq / B becomes difficult to a predetermined range. On the other hand, if the total rolling reduction of from 1050 ° C. temperature below before finishing the final pass is less than 60%, if the reduction ratio of finishing final pass is less than 10%, or the temperature of the finishing final pass exceeds 1000 ° C. case, lead to coarsening of the hot rolled sheet structure, which may lead to coarsening hence workability deterioration of the final product sheet organization. [0079] 　(A-4) a descaling step 　in the process from rough rolling to finish rolling is subjected to descaling more than once on the steel sheet surface. At that time, the final descaling temperature is set to 950 ~ 1100 ℃. If the final descaling temperature is less than 950 ° C., since the scale growth after descaling is suppressed, to control the average thickness tsc of the scale of the steel sheet immediately after wound hot rolled coil to be described later to the desired range it becomes difficult. On the other hand, if the final descaling temperature exceeds 1100 ° C., since the scale after the final descaling grow excessively, the scale is peeled off during rolling, poor appearance due to biting of the scale may occur. Although not specified de total number of scaling particular, in order to suppress appearance defects caused by biting of the scale was peeled during rolling, it is preferably carried out more than once. [0080] 　Other affecting operating conditions tsc, Desuke pressure, elapsed time to final descaling-winding can be mentioned, and as shown in FIG. 1, the distance from the nozzles to the steel plate (D), the nozzle and the steel sheet angle (theta) formed by the thickness direction also can be an important element. As long as the tsc is controlled within a desired range is not particularly specified for the above conditions in the present invention, for example, Desuke water pressure: 10 ~ 20 MPa, the final descaling ~ elapsed time of the take-up-up: 15 to 40 seconds, distance from the nozzle to the steel sheet D: 0.99 ~ 250 mm, the plate thickness direction and is the angle between the nozzle and the steel sheet θ: 5 ~ 10 °, with, it is possible to obtain a desired tsc. [0081] 　(A-5) a cooling step 　from the finish rolling step is completed after a lapse of one second or more, at an average cooling rate of more than 5 ° C. / sec, cooled to coiling temperature 400 ~ 700 ° C.. When the time from the finish rolling end to the cooling start is less than 1 second, the anisotropy of the recrystallization is insufficient steel sheet austenite undesirable for obvious. When the average cooling rate to coiling temperature from the finish rolling end is less than 5 ° C. / sec, is promoted ferrite transformation in a high temperature range, the hot rolled sheet structure is not preferable because coarse. [0082] 　Furthermore, when the coiling temperature exceeds 700 ° C., the precipitation of boron compound is promoted, sol in the final product sheet. The value of Bq / B becomes difficult to a predetermined range. On the other hand, when the coiling temperature is less than 400 ° C., since the hot-rolled sheet strength is increased excessively, there is a possibility of inhibiting the subsequent cold rolling property. [0083] 　The average thickness of the scale immediately after the hot-rolled coil winding tsc: 3 [mu] m or more 　sol. The value of bs / B to a predetermined range, it is necessary to promote the precipitation of only boron compound steel outermost layer. For this purpose, it is preferably not less than 3μm immediately after winding the scale as a source of oxygen to the steel sheet surface layer portion. Although not provided particular limitation on the upper limit of the scale thickness, tsc is more than 15 [mu] m, subsequent pickling workability becomes difficult to deteriorate. Therefore, tsc is preferably set to 15μm or less. [0084] 　Incidentally, it is actually difficult to measure the average thickness of the scale of the steel sheet immediately after the hot-rolled coil winding directly. Thus, after aligning the chemical composition and the winding prior hot rolling conditions of the steel sheet sufficiently scale after coiling is not growth temperature, separately prepare a hot-rolled steel sheet was subjected to coiling at 300 ° C. or less specifically and, by measuring the scale thickness, and measuring tsc. [0085] 　10 -5 SRT: slab heating temperature 　R1: 1050 ~ 1150 the total rolling reduction of at ℃ 　R2: total rolling reduction of up to ~ finishing the final pass before 1050 ℃ following 　R3: a reduction rate of finishing the final pass 　Td: final de scaling temperature 　FT: finishing the final inlet side temperature of the path 　Delta] t: finish rolling end from to start cooling time 　CR1: average cooling rate between FT ~ CT 　CT: coiling temperature 　tsc: immediately after winding the scale thickness 　Do: (iv ) below the calculated value [0116] 　 HR: 650 ° C. ~ maximum heating average heating rate in the temperature range of the temperature 　T1: maximum heating temperature 　t: heating retention time 　CR2: first cooling rate 　T2: second cooling start temperature 　CR3: second cooling rate 　T3: the second cooling stop temperature 　T4: heat treatment temperature 　t2: time required holding at the heat treatment temperature [0117] 　The resulting rolling direction and the thickness direction tensile No. JIS5 from perpendicular direction (width direction) test piece was taken in cold rolled steel sheet, subjected to tensile test in accordance with JIS Z 2241, tensile strength (TS), yield the strength (YS) and the total elongation (El) were measured. [0118] 　In addition, the test piece was cut out of 150mm × 150mm, complete the "JFS T 1001 hole expansion test method" of the Japan Iron and Steel Federation standard, to measure the hole expansion ratio (λ). Further, cut strip specimens in the rolling direction and the thickness direction perpendicular to the direction (width direction) is performed by changing the bending radius of the V bending test stipulated in JIS Z 2248, the minimum bend radius R which is free from fractures the calculated and evaluated bendability by the ratio of the thickness t and the minimum bending radius R of the cold-rolled steel sheet (R / t). [0119] 　Then, the area ratio of the steel structure, well, sol. Bs / B and sol. The value of Bq / B, was measured by the following methods. [0120] 　First, cut out the rolling direction cross-section of the steel sheet, the current out of the steel structure by nital solution, then, the surface ~ 30 [mu] m depth position and the quarter thickness location, scanning electron microscope (magnification: 5000 times, 5 fields) the It was taken using. Then, from the obtained structure photograph by point counting method to calculate polygonal ferrite, bainite, martensite, the area ratio of tempered martensite. [0121] 　Further, the area ratio of residual austenite, the EBSP-OIM (Electron Back Scatter Diffraction Pattern-Orientation Image Microscopy) method, was determined by calculating the area of ​​the region having the FCC structure. [0122] 　In addition, sol. Bs and sol. The value of Bq, in each surface portion and the interior of the steel sheet, after calculating the B amount consumed as a precipitate by measuring the mass of boron compound in the steel by electrowinning left method, it in steel It was determined by subtracting the B content in. [0123] 　Specifically, for the content of B present as boron compound in the surface layer portion of the steel sheet without grinding the steel sheet surface was measured by electrowinning to 30μm depth. As for the content of B present as boron compound in the interior of the steel sheet, after mechanically grinding the steel sheet to a 1/4 thickness position was determined by electrowinning to 30μm depth. Note that the determination of precipitation B amount by extraction residue method using a technique disclosed in Non-Patent Document 1. [0124] 　The results are shown in Tables 4 and 5. Incidentally, the bending property was emphasized in the present embodiment, the tensile strength of not less than 980 MPa, and the determination result is good when the ratio R / t of the thickness t and the minimum bending radius R is 2.5 or less I decided to. [0125] [Table 4] [0126] [table 5] [0127] 　 　Varufa: polygonal ferrite area ratio 　VB: bainite area ratio 　VM: the area ratio of the martensite 　VTM: area ratio of tempered martensite 　Vγ: area ratio of retained austenite [0128] 　 Sol. Bs: solid solute B amount in the surface layer (mass 　ppm) sol. Bq: solid solute B amount in the interior (mass 　ppm) YS: yield strength 　TS: tensile strength 　El: total elongation 　lambda: hole expansion ratio 　R / t: minimum bend radius / thickness [0129] 　In the present invention example presence state of the chemical composition and B satisfy the provisions, together with the tensile strength is not less than 980 MPa, the value the values ​​of R / t is 2.5 or less, a result of having a high strength and good bendability It was. [0130] 　On the other hand, either or both of the presence state of the chemical composition and B is the comparative example out of the range defined in the present invention, resulted in more tensile strength or good bending properties 980MPa can not be obtained. Example 2 [0131] 　Of the steels having the chemical compositions shown in Table 1 was cast steel ingots and Steels A and B in the laboratory. Then subjected to hot rolling under the conditions shown in Table 6, the thickness was obtained hot rolled steel sheets of 2.5 mm. The various conditions in the descaling process are the same as in Example 1. Then, after performing the pickling, performed cold rolling reduction ratio shown in Table 7, the thickness was obtained cold-rolled steel sheet of 1.0 mm. To the resulting cold-rolled steel sheet was subjected to heat treatment that simulates a continuous galvanizing line under the conditions shown in Table 7. [0132] [Table 6] [0133] [Table 7] [0134] 　 T5: pre-plating temperature 　T6: alloying treatment temperature [0135] 　The obtained cold-rolled steel sheet, in the same manner as in Example 1, the tensile strength (TS), yield strength (YS), total elongation (El), the hole expanding ratio (lambda), the minimum and the plate thickness t bending radius R the ratio of (R / t), the area ratio of the steel structure, well, sol. Bs / B and sol. It was measured in the value of Bq / B. [0136] 　The results are shown in Tables 8 and 9. Even emphasizes bendability in this embodiment, the tensile strength of not less than 980 MPa, and the determination result is good when the ratio R / t of the thickness t and the minimum bending radius R is 2.5 or less I decided to. [0137] [Table 8] [0138] [Table 9] [0139] 　In the present invention example presence state of the chemical composition and B satisfy the provisions, together with the tensile strength is not less than 980 MPa, the value the values ​​of R / t is 2.5 or less, a result of having a high strength and good bendability It was. [0140] 　On the other hand, either or both of the presence state of the chemical composition and B is the comparative example out of the range defined in the present invention, resulted in more tensile strength or good bending properties 980MPa can not be obtained. Example 3 [0141] 　The steel having the chemical composition shown in Table 10 were cast steel ingot was melted in the laboratory. Then subjected to hot rolling under the conditions shown in Table 11, to obtain a hot rolled steel sheet having a thickness of 2.0 ~ 3.0 mm. The various conditions in the descaling process are the same as in Example 1. Subsequently, after applying pickling, subjected to cold rolling reduction ratio shown in Table 12, the thickness was obtained cold-rolled steel sheet of 1.0 mm. To the resulting cold-rolled steel sheet was subjected to annealing under the conditions shown in Table 12. [0142] [Table 10] [0143] [Table 11] [0144] [Table 12] [0145] 　The obtained cold-rolled steel sheet, in the same manner as in Example 1, the tensile strength (TS), yield strength (YS), total elongation (El), the hole expanding ratio (lambda), the minimum and the plate thickness t bending radius R the ratio of (R / t), the area ratio of the steel structure, well, sol. Bs / B and sol. It was measured in the value of Bq / B. [0146] 　The results are shown in Tables 13 and 14. Incidentally, focusing on strength in the present embodiment, the tensile strength is at least 1180 MPa, and the results when the ratio R / t of the thickness t and the minimum bending radius R is 3.5 or less is determined to be good it is assumed that. [0147] [Table 13] [0148] [Table 14] [0149] 　In the present invention example presence state of the chemical composition and B satisfy the provisions, together with the tensile strength is greater than or equal to 1180 MPa, values ​​the values ​​of R / t becomes 3.5 or less, a result of having a high strength and good bendability It was. [0150] 　On the other hand, either or both of the presence state of the chemical composition and B is the comparative example out of the range defined in the present invention, resulted in more tensile strength or good bending properties 1180MPa is not obtained. Example 4 [0151] 　Of the steels having the chemical compositions shown in Table 10, steels A, B, and cast C, D, F, the steel ingot was melted in the laboratory I and J. Then subjected to hot rolling under the conditions shown in Table 15, to obtain a hot rolled steel sheet having a thickness of 2.0 ~ 3.0 mm. The various conditions in the descaling process are the same as in Example 1. Then, after performing the pickling, performed cold rolling reduction ratio shown in Table 16, the thickness was obtained cold-rolled steel sheet of 1.0 mm. To the resulting cold-rolled steel sheet was subjected to heat treatment that simulates a continuous galvanizing line under the conditions shown in Table 16. [0152] [Table 15] [0153] [Table 16] [0154] 　The obtained cold-rolled steel sheet, in the same manner as in Example 1, the tensile strength (TS), yield strength (YS), total elongation (El), the hole expanding ratio (lambda), the minimum and the plate thickness t bending radius R the ratio of (R / t), the area ratio of the steel structure, well, sol. Bs / B and sol. It was measured in the value of Bq / B. [0155] 　These results are shown in Tables 17 and 18. Even emphasize strength in this embodiment, the tensile strength is at least 1180 MPa, and the results when the ratio R / t of the thickness t and the minimum bending radius R is 3.5 or less is determined to be good it is assumed that. [0156] [Table 17] [0157] [Table 18] [0158] 　In the present invention example presence state of the chemical composition and B satisfy the provisions, together with the tensile strength is greater than or equal to 1180 MPa, values ​​the values ​​of R / t becomes 3.5 or less, a result of having a high strength and good bendability It was. [0159] 　On the other hand, either or both of the presence state of the chemical composition and B is the comparative example out of the range defined in the present invention, resulted in more tensile strength or good bending properties 1180MPa is not obtained. Industrial Applicability [0160] 　According to the present invention, it is possible to obtain high strength cold rolled steel sheet excellent in bendability, high strength galvanized steel sheet, a high strength galvannealed steel sheet. claims [Claim 1]Chemical composition, inmass%, 　C: 0.050 ~ 　0.40%, Si: 0.01 ~ 3.0%, Mn: 1.0 ~ 　5.0%, sol. Al: 　0.001 ~ 　1.0%, Ti: 0.005 ~ 0.20%, B: 0.0005 ~ 　0.010%, P: 0.1% or 　less, S: 0.01% or 　less, O 0.1% or less, 　N: 0.01% or 　less, 　Cr: 0 ~ 　1.0%, Mo: 0 ~ 1.0%, Ni: 　0 ~ 1.0%, Cu: 0 ~ 1.0% , 　Sn: 　　0 ～ 0.50 Pasento, 　Nb: 0 ～ 0.20 Pasento, V: 0 ～ 0.50 　Pasento, W: 0 ～ 0.50 Pasento, Ca: 0 ～ 0.01 　Pasento, Mg: 0 ～　% 0.01,　　Bi: 0 ~ 0.01%, Sb: 0 ~ 0.10%, 　Zr: 0 ~ 0.01%, REM: 0 ~ 0.01%, 　the balance is Fe and impurities, 　the following (i) satisfies the formula and (ii) expression, high-strength cold-rolled steel sheet. 　sol. Bs / B ≦ 0.50 · · · 　(I) Sol. Bq / B> 0.50 ··· (ii ) 　where the meaning of each symbol in the formula is as follows. 　B: B content in the steel (mass%) 　sol. Bs: B content present as solid solution in a range from the surface of 30μm depth of the steel sheet 　(mass%) sol. Bq: B content present as a solid solution state in the quarter-thickness position of the steel sheet (wt%) [Claim 2] 　The chemical composition, in 　mass%, 　Cr: 　0.001 ~ 1.0%, Mo: 0.001 ~ 1.0%, Ni: 　0.001 ~ 1.0%, Cu: 0.001 ~ 1. 0%, 　and, Sn: 0.001 ~ 0.50% 　containing at least one member selected from, 　high strength cold rolled steel sheet according to claim 1. [Claim 3] 　The chemical composition, by 　mass%, Nb: 　0.001 ~ 0.20%, V: 0.001 ~ 0.50%, 　and, W: 0.001 ~ 0.50%, 　1 kind selected from containing more, 　high strength cold rolled steel sheet according to claim 1 or claim 2. [Claim 4] 　The chemical composition, by 　mass%, 　Ca: 　0.0001 ~ 0.01%, Mg: 0.0001 ~ 0.01%, Bi: 　0.0001 ~ 0.01%, Sb: 0.0001 ~ 0. 　% 10, Zr: 0.0001 ~ 0.01%, 　and, REM: 0.0001 ~ 0.01%, 　containing one or more selected from, 　in either of claims 1 to 3 high-strength cold-rolled steel sheet according. [Claim 5] 　Steel structure in a range from the surface of 30μm depth of the steel sheet, in area%, 　polygonal ferrite 10 to 95%, 　the balance is in the martensite, one or more selected from bainite and residual austenite, and 　the the proportion of tempered martensite in the whole martensite is 50% or more, 　the steel structure in the quarter-thickness position of the steel sheet, in area%, 　polygonal ferrite: 60% or less, 　the balance being martensite, bainite, is at least one selected from retained austenite, and 　the proportion of tempered martensite in the whole martensite is 50% or more, 　high strength cold rolled according to any one of claims 1 to 4 steel plate. [Claim 6] 　Steel structure in a range from the surface of 30μm depth of the steel sheet, in area%, 　polygonal ferrite: 30 to 95%, 　the steel structure in the quarter-thickness position of the steel sheet, in area%, 　polygonal ferrite: 10 to 60%, 　high strength cold rolled steel sheet according to claim 5. [Claim 7] 　Steel structure in a range from the surface of 30μm depth of the steel sheet, in area%, 　polygonal ferrite: 10 to 80%, 　the steel structure in the quarter-thickness position of the steel sheet, in area%, 　polygonal ferrite: 20% or less, 　martensite: 50% or more, 　bainite: 40% or less, 　residual austenite: is 20% or less, 　high-strength cold-rolled steel sheet according to claim 5. [8.] 　Tensile strength not less than 980 MPa, and the ratio R / t of the thickness t and the minimum bending radius R is 2.5 or less, 　high-strength cold-rolled steel sheet according to claim 6. [Claim 9] 　Tensile strength of not less than 1180 MPa, and the ratio R / t of the thickness t and the minimum bending radius R is 3.5 or less, 　high-strength cold-rolled steel sheet according to claim 7. [Claim 10] 　On the surface of the high strength cold rolled steel sheet according to any one of claims 1 to 9 having a galvanized layer, a high strength galvanized steel sheet. [Claim 11] 　On the surface of the high strength cold rolled steel sheet according to any one of claims 1 to 9 having a galvannealed layer, a high strength galvannealed steel sheet.

Documents

Application Documents

#	Name	Date
1	201817001803-STATEMENT OF UNDERTAKING (FORM 3) [16-01-2018(online)].pdf	2018-01-16
2	201817001803-PROOF OF RIGHT [16-01-2018(online)].pdf	2018-01-16
3	201817001803-POWER OF AUTHORITY [16-01-2018(online)].pdf	2018-01-16
4	201817001803-FORM 18 [16-01-2018(online)].pdf	2018-01-16
5	201817001803-FORM 1 [16-01-2018(online)].pdf	2018-01-16
6	201817001803-DRAWINGS [16-01-2018(online)].pdf	2018-01-16
7	201817001803-DECLARATION OF INVENTORSHIP (FORM 5) [16-01-2018(online)].pdf	2018-01-16
8	201817001803-COMPLETE SPECIFICATION [16-01-2018(online)].pdf	2018-01-16
9	201817001803-Power of Attorney-190118.pdf	2018-01-29
10	201817001803-Correspondence-190118.pdf	2018-01-29
11	201817001803-OTHERS-190118.pdf	2018-02-12
12	201817001803.pdf	2018-03-23
13	201817001803-FORM 3 [13-07-2018(online)].pdf	2018-07-13
14	201817001803-FORM 3 [02-01-2019(online)].pdf	2019-01-02
15	201817001803-RELEVANT DOCUMENTS [08-07-2019(online)].pdf	2019-07-08
16	201817001803-FORM 13 [08-07-2019(online)].pdf	2019-07-08
17	201817001803-AMENDED DOCUMENTS [08-07-2019(online)].pdf	2019-07-08
18	201817001803-OTHERS-090719.pdf	2019-07-15
19	201817001803-Correspondence-090719.pdf	2019-07-15
20	201817001803-FORM 3 [10-04-2020(online)].pdf	2020-04-10
21	201817001803-certified copy of translation [29-01-2021(online)].pdf	2021-01-29
22	201817001803-PETITION UNDER RULE 137 [04-05-2021(online)].pdf	2021-05-04
23	201817001803-Information under section 8(2) [06-05-2021(online)].pdf	2021-05-06
24	201817001803-FORM 3 [06-05-2021(online)].pdf	2021-05-06
25	201817001803-FER_SER_REPLY [07-05-2021(online)].pdf	2021-05-07
26	201817001803-CLAIMS [07-05-2021(online)].pdf	2021-05-07
27	201817001803-FER.pdf	2021-10-18
28	201817001803-PatentCertificate19-10-2023.pdf	2023-10-19
29	201817001803-IntimationOfGrant19-10-2023.pdf	2023-10-19

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1	SearchStrategy201817001803E_29-04-2020.pdf