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Production Method For Hot Press Molded Articles, Press Molded Article, Die Mold, And Mold Set

Abstract: A production method for hot press molded articles, whereby a die mold 11 is used to perform hot press molding on an Al-plated steel plate 10 having a zinc compound layer or a metal zinc layer as the outermost layer upon an Al plating layer. The die mold 11 has a hard layer 11C having a skewness (Rsk) of no more than 1.3 and a hardness Hv_Die of at least 2000 HV, as measured in a direction from the outside of a die hole 11D towards the inside, said hard layer 11C being the entire area adjacent to a die shoulder 11B out of a metal plate contact surface 11A that is a surface on the outside of the die hole 11D and in contact with the Al-plated steel plate 10 prior to hot press molding.

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Patent Information

Application #
Filing Date
20 October 2020
Publication Number
06/2021
Publication Type
INA
Invention Field
MECHANICAL ENGINEERING
Status
Email
patents@remfry.com
Parent Application
Patent Number
Legal Status
Grant Date
2024-06-13
Renewal Date

Applicants

NIPPON STEEL CORPORATION
6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Inventors

1. KUBO, Masahiro
c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071
2. FUJITA, Soshi
c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071
3. NAKAZAWA, Yoshiaki
c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071
4. IRIKAWA, Hideaki
c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071
5. FUDA, Masahiro
c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Specification

Title of the invention: Manufacturing method of hot press molded product, press molded product, die mold, and mold set Technical field [0001]  The present disclosure relates to a method for producing a hot press molded product, a press molded product, a die mold, and a mold set. Background technology [0002]  In recent years, there has been an increasing demand to curb the consumption of chemical fuels in order to protect the environment and prevent global warming. This request has an impact on various manufacturing industries. Automobiles are no exception, and there is a demand for improved fuel efficiency by reducing the weight of the vehicle body. However, in automobiles, it is necessary to achieve both weight reduction and safety. [0003]  Most automobile body structures are made of iron, especially steel plates. Reducing the weight while maintaining the strength of the structural material made of this steel plate is required for weight reduction of the vehicle body. Requests for such steel sheets are made not only in the automobile manufacturing industry but also in various manufacturing industries. Therefore, by increasing the mechanical strength of the steel sheet, it is possible to maintain or increase the mechanical strength of the structural material even if it is thinner than the conventionally used steel sheet. [0004]  Generally, a material having high mechanical strength tends to have a reduced shape freezing property in a molding process such as a bending process. That is, when processing into a complicated shape, the processing itself becomes difficult. As one of the means for solving this problem of moldability, so-called "hot press molding (hot press method, high temperature press method, die quenching method)" can be mentioned. In this hot press forming, the steel sheet to be formed is once heated to a high temperature, and the steel sheet softened by heating is press-processed to form the steel sheet, and then cooled. [0005]  According to this hot press forming, the steel sheet is once heated to a high temperature to be softened, so that the steel sheet can be easily pressed. Further, the mechanical strength of the steel sheet can be increased by the quenching effect of cooling after molding. Therefore, by this hot press molding, a molded product having both good shape freezing property and high mechanical strength can be obtained. [0006]  However, for example, when the steel sheet is heated to a high temperature of 800 ° C. or higher, the surface of the steel sheet is oxidized to generate scale (oxide). The scale is an obstacle when painting or plating to ensure corrosion resistance. Therefore, after performing hot press molding, a step of removing this scale (descaling step) is required. That is, productivity is poor. [0007]  As a method of avoiding such scale formation, there is a method of coating a steel sheet before hot press forming. A zinc (Zn) -based plated steel sheet obtained by plating a steel sheet with zinc having a sacrificial anticorrosive effect is widely used for automobile steel sheets and the like from the viewpoint of its anticorrosion performance and steel sheet production technology. However, the heating temperature (700 to 1000 ° C.) in hot press molding is higher than the boiling point of zinc, and when heated for hot press molding, the plating layer on the surface evaporates, causing significant deterioration of the surface texture. May be. [0008]  Therefore, it is preferable to use an Al-based metal-coated steel sheet, which has a higher boiling point than a Zn-based metal-coated steel sheet, that is, a so-called aluminum (Al) plated steel sheet, for the steel sheet to be hot press-formed by heating to a high temperature. .. [0009]  By applying an Al-based metal coating, it is possible to prevent scale from adhering to the surface of the steel sheet, and steps such as a descaling step are not required, so that productivity is improved. Further, since the Al-based metal coating also has a rust preventive effect, the corrosion resistance after painting is also improved. [0010]  When an Al-based metal coating is applied, the Al coating first melts and then changes to an aluminum-iron alloy layer by Fe diffusion from the steel sheet, depending on the preheating conditions before press molding. Further, the aluminum-iron alloy layer may grow to become an aluminum-iron alloy layer up to the surface of the steel sheet. Hereinafter, the aluminum-iron alloy will also be referred to as an "Al-Fe alloy" or an "alloy". Since this alloy layer is extremely hard, processing flaws are formed by contact with the die during press working. Suppression of this processing defect is an issue when hot press forming an Al-plated steel sheet. [0011]  On the other hand, Patent Document 1 describes a zinc oxide film (hereinafter, also referred to as “ZnO film”) or the like for the purpose of improving chemical conversion treatment property and corrosion resistance as well as hot lubricity in order to prevent the occurrence of processing defects. A method of forming a film of a wurtzite type compound on the surface of an Al-plated steel sheet is disclosed. [0012]  On the other hand, Patent Document 2 describes a film of one or more Zn compounds selected from the group consisting of Zn hydroxide, Zn phosphate, and Zn organic acid for the purpose of enhancing the adhesion of the ZnO film during press molding. Is disclosed on the surface of an Al-plated steel sheet. In the method of Patent Document 2, a ZnO film is formed by hot press molding of an Al-plated steel sheet on which a Zn compound film is formed, a ZnO film having excellent adhesion is formed, and hot lubrication is performed. It is possible to improve the property, film adhesion, spot weldability, and corrosion resistance after painting. [0013]  In addition, Patent Document 3 discloses a mold having a coating layer by a physical vapor deposition method on its surface. The coating layer has a layer a on the outermost layer, a layer c directly above the base metal, and at least three layers b between the a layer and the c layer, and the hardness symbol HV0.025 of the three layers is provided. There is disclosed a plastic working die in which the hardness and layer thickness are adjusted to a specific relationship. [0014]   [Patent Document 1] International Publication No. 2009/131233   [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-139350   [Patent Document 3] Japanese Patent No. 4771223 Outline of the invention Problems to be solved by the invention [0015]  Here, the plated steel sheets of Patent Documents 1 and 2 are all excellent in hot lubricity and can suppress the occurrence of processing flaws.  By the way, in general, when hot press molding is performed using a non-plated material or a plated steel plate, the sliding of a hot press molding die on which the plated steel plate slides, such as a vertical wall portion and a flange portion of a press-formed product. Wear occurs on the moving surface. For this reason, in the high surface pressure portion of hot press molding, it is necessary to maintain the die as a measure against wear that occurs on the sliding surface of the die. It was expected that the plated steel sheets of Patent Documents 1 and 2 would reduce the mold wear, but even with Patent Documents 1 and 2, the mold wear could not be solved like other non-plated materials and plated steel sheets. It was.  Further, even if a plastic working die having a coating layer on the surface is used as described in Patent Document 3, wear generated on the sliding surface of the die is solved in the high surface pressure portion of hot press molding. could not. [0016]  An object of the present disclosure is to suppress the occurrence of wear on the sliding surface of the die mold during hot press molding on an Al-plated steel sheet having a zinc compound layer or a metallic zinc layer as the outermost layer on the Al-plated layer. The purpose of the present invention is to provide a method for producing a hot press molded product.  Further, the subject of the present disclosure is a die die that suppresses the occurrence of wear on the sliding surface, a die set of the die die and the punch die, and a die set of the die die and the steel plate holding die. Is to provide.  Another object of the present disclosure is to provide a press-molded product having excellent surface quality and suppressed occurrence of delayed fracture. Means to solve problems [0017]  The gist of this disclosure is as follows. <1>  A hot method for producing a press-molded article to hot press molding using a die tool to Al-plated steel sheet having a zinc compound layer or a metallic zinc layer as the outermost layer on the Al plating layer,  said die The mold is formed on the outer surface of the die hole and in the entire region of the steel sheet contact surface that is in contact with the Al-plated steel sheet before hot press molding, from the outside of the die hole. A method for producing a hot press-formed product having a hard layer having a skewness (Rsk) of 1.3 or less and a hardness Hv_Die of HV2000 or more measured in the inward direction. <2> The  method for producing a hot press-molded product according to <1>, wherein the skewness (Rsk) of the hard layer is −5.0 or more. <3> The  method for producing a hot press-formed product according to <1> or <2>, wherein the hard layer is a layer including a nitride layer and a hard coating layer on the surface of the nitride layer. <4> The  method for producing a hot press-molded product according to <3>, wherein the hard coating layer has a hardness Hv_Die of HV3200 or less. <5> The  method for producing a hot press-molded product according to <4>, wherein the hard coating layer is a layer containing Cr. <6> The  method for producing a hot press-molded product according to <3>, wherein the hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. <7> The  method for producing a hot press-molded product according to any one of <3> to <6>, wherein the hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less. [0018] <8>  A steel base material having a hardness Hv_Parts of HV400 or more, an Al plating layer on the steel base material, and a zinc oxide layer as the outermost layer on the Al plating layer, and a  top plate portion. It has a vertical wall portion connected to the top plate portion via the first ridge line portion and a flange portion connected to the vertical wall portion via  the second ridge line portion, and the radius of curvature of the second ridge line portion has a radius of curvature. In  the cross section where the radius of curvature [R min ] at the minimum point is 3 mm or more and less than 10 mm and the radius of curvature of the second ridgeline portion is minimized when observing the cross section of the press-formed product, the heaven Difference between the smoothness [SaA1] at the central portion PA1 min in the cross-sectional width direction of the plate portion and the smoothness [SaA2] at the central portion PA2 min in the cross-sectional height direction of the vertical wall portion [ [SaA1-SaA2] is 0.20 μm or more, and the aspect ratio [StrA1] of the surface texture at the  portion PA1 min on the top plate portion and the aspect ratio of the surface texture at the portion PA2 min on the vertical wall portion [ A press-molded product in which the difference [StrA1-StrA2] from [StrA2] is 0.50 or less. <9>  A steel base material having a hardness Hv_Parts of HV400 or more, an Al plating layer on the steel base material, and a zinc oxide layer as the outermost layer on the Al plating layer.  It has a top plate portion, a vertical wall portion connected to the top plate portion via a first ridge line portion, and a flange portion connected to the vertical wall portion via a second ridge line portion, and has  the second ridge line. The radius of curvature [R min ] at the portion where the radius of curvature is the minimum is 3 mm or more and less than 10 mm, and the  portion corresponding to the portion PB 0 min where the radius of curvature of the flange portion is the minimum when observed from the side surface side. central position PB1 in the width direction of the top plate min smoothness in the [SAB1], ibid PB0 when viewed from the side min central position PB2 in the height direction of the vertical wall portion corresponding to min in The difference [SaB1-SaB2] from the smoothness [SaB2] of is 0.30 μm or more, and the aspect ratio [StrB1] of the surface texture at the  portion PB1 min on the top plate portion and the above-mentioned vertical wall portion. A press-molded product in which the difference [StrB1-StrB2] from the surface texture aspect ratio [StrB2] at the location PB2 min is 0.50 or less. [0019] <10> Of  the outer surface of the die hole and the surface adjacent to the die shoulder adjacent to the die shoulder, the entire region adjacent to the die shoulder is skewed (Rsk) measured in the direction from the outside to the inside of the die hole. A die mold having a hard layer having a hardness of 1.3 or less and a hardness of Hv_Die of HV2000 or more. <11>  The die mold according to <10>, wherein the skewness (Rsk) of the hard layer is −5.0 or more. <12>  The die mold according to <10> or <11>, wherein the hard layer is a layer including a nitride layer and a hard coating layer on the surface of the nitride layer. <13>  The die mold according to <12>, wherein the hard coating layer has a hardness Hv_Die of 3200 or less. <14>  The die mold according to <13>, wherein the hard coating layer is a layer containing Cr. <15>  The die mold according to <12>, wherein the hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. <16>  The die mold according to any one of <12> to <15>, wherein the hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less. [0020] <17>  The die die according to any one of <10> to <16> and a punch die are provided, and the  punch die faces the die shoulder adjacent surface of the die die. The skewness (Rsk) measured in the direction from the outside to the inside of the punch portion is 1.3 or less, and the hardness Hv_Die is HV2000 in the entire region of the surface facing the portion where the die die has the hard layer. A mold set having the above-mentioned second hard layer. <18>  The mold set according to <17>, wherein the skewness (Rsk) of the second hard layer is −5.0 or more. <19>  The mold set according to <17> or <18>, wherein the second hard layer is a layer including a second nitride layer and a second hard coating layer on the surface of the second nitride layer. .. <20>  The mold set according to <19>, wherein the second hard coating layer has a hardness Hv_Die of HV3200 or less. <21>  The mold set according to <20>, wherein the second hard coating layer is a layer containing Cr. <22>  The mold set according to <19>, wherein the second hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. <23>  The mold set according to any one of <19> to <22>, wherein the second hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less. [0021] <24>  The die mold according to any one of <10> to <16> and a steel plate holding mold are provided, and the  steel plate holding mold faces the die shoulder adjacent surface of the die mold. The skewness (Rsk) measured in the direction from the outside to the inside of the punch insertion portion is 1.3 or less and the hardness is in the entire region of the facing surfaces facing the portion where the die die has the hard layer. A mold set having a second hard layer having Hv_Die of HV2000 or higher. <25>  The mold set according to <24>, wherein the skewness (Rsk) of the second hard layer is −5.0 or more. <26>  The mold set according to <24> or <25>, wherein the second hard layer is a layer including a second nitride layer and a second hard coating layer on the surface of the second nitride layer. .. <27>  The mold set according to <26>, wherein the second hard coating layer has a hardness Hv_Die of HV3200 or less. <28>  The mold set according to <27>, wherein the second hard coating layer is a layer containing Cr. <29>  The mold set according to <26>, wherein the second hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. <30>  The mold set according to any one of <26> to <29>, wherein the second hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less. Effect of the invention [0022]  According to the present disclosure, when hot press molding is performed on an Al-plated steel sheet having a zinc compound layer or a metallic zinc layer as the outermost layer on the Al-plated layer, wear of the sliding surface of the die die is suppressed. A method for producing a hot press molded product can be provided.  Further, according to the present disclosure, a die die that suppresses the occurrence of wear on the sliding surface, a die set of a die die and a punch die, and a die set of a die die and a steel plate holding die are provided. Can be provided.  Further, according to the present disclosure, it is possible to provide a press-molded product having excellent surface quality and suppressed occurrence of delayed fracture. A brief description of the drawing [0023] FIG. 1 is a schematic view showing an example of a plated steel sheet hot-press formed by a die mold, a holder (steel plate holding mold), and a punch. FIG. 2A is a perspective view schematically showing an example of a press-molded product obtained by hot press molding shown in FIG. 1. FIG. 2B is a side view of the press-molded product shown in FIG. 2A. FIG. 3A is a side view schematically showing another example of a press-molded product obtained by hot press molding according to the present embodiment. FIG. 3B is a cross-sectional view of the press-molded product shown in FIG. 3A. FIG. 4A is a top view schematically showing another example of a press-molded product obtained by hot press molding according to the present embodiment. FIG. 4B is a cross-sectional view of the press-molded product shown in FIG. 4A. 5 is a schematic view showing an example of a molded product obtained by the hot press molding shown in FIG. 1. FIG. FIG. 6 is a schematic view showing an example of a plated steel sheet hot-press formed by a die die and a punch die. FIG. 7 is a schematic cross-sectional view showing an example of an Al-plated steel sheet used in the present embodiment. FIG. 8 is a schematic configuration diagram showing a hot lubricity evaluation device. Mode for carrying out the invention [0024]  Next, the present disclosure will be described in detail. [0025]  Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration may be designated by the same reference numerals to omit duplicate description. [0026]  A method for manufacturing a hot press molded product according to an embodiment of the present disclosure will be described.  In the method for producing a hot press-molded product according to the present embodiment, hot press molding is performed on an Al-plated steel sheet having a zinc compound layer or a metallic zinc layer as the outermost layer on the Al-plated layer using a die mold. This is a method for manufacturing a press-molded product.  Then, the die mold covers the entire region adjacent to the die shoulder portion of the steel plate contact surface which is the outer surface of the die hole and is in contact with the Al-plated steel sheet before hot press molding. It has a hard layer having a skewness (Rsk) of 1.3 or less and a hardness Hv_Die of HV2000 or more measured in the direction from the outside to the inside of the hole. [0027]  The method for manufacturing a hot press-molded product according to the present embodiment suppresses the occurrence of wear on the sliding surface of the die die that occurs in the high surface pressure portion during hot press molding by the above configuration. Then, the method for producing the hot press molded product according to the present embodiment was found based on the following findings. [0028]  When a conventional Al-plated steel sheet for hot press forming (a plated steel sheet in which Al-plated layers are provided on both sides of the steel sheet) is hot-press-formed, the aluminum in the Al-plated layer reacts with the material (iron) of the die mold. Seizure occurs. A large amount of intermetallic compound (aluminum adhesion) produced by this seizure may adhere to the surface of the die mold. [0029]  In Patent Documents 1 and 2, for the purpose of suppressing the adhesion of aluminum adhesions to the die mold, plated steel sheets (hereinafter, "with ZnO film") in which a ZnO film is formed on the surfaces of the Al plating layers provided on both sides of the steel sheet Al-plated steel sheet ") has been proposed.  Since the surface of the Al-plated steel sheet with a ZnO film is covered with the ZnO film, adhesion of aluminum deposits to the surface of the die mold due to seizure can be suppressed even when hot press molding is performed. As a result, the coefficient of friction with the surface of the die mold is reduced. [0030]  However, even if there is a ZnO film, the mold will wear. A high surface pressure is applied to the region of the outer surface of the die hole adjacent to the die shoulder portion of the surface that slides on the plated steel sheet during hot press forming. Therefore, when the Al-plated steel sheet is used regardless of the presence or absence of the ZnO film, wear may occur on the sliding surface of the die mold. [0031]  On the other hand, in the present embodiment, the outer surface of the die hole of the die die and the contact surface of the steel sheet in contact with the Al-plated steel sheet before hot press molding is adjacent to the shoulder portion of the die. It has a hard layer in all areas. The skewness (Rsk) of this hard layer measured in the direction from the outside to the inside of the die hole is 1.3 or less.  Here, the skewness Rsk is defined in JIS B 0601 (2001) and is an index showing the symmetry of the peaks and valleys with respect to the average line. When this Rsk is positive (0 >  Cold-rolled steel sheet with a thickness of 1.6 mm (in mass%, C: 0.21%, Si: 0.12%, Mn: 1.21%, P : 0.02%, S: 0.012%, Ti: 0.02%, B: 0.03%, Al: 0.04%, and the balance: Fe and impurities) on both sides by Al plating by Zenzimer method A layer was formed. The annealing temperature was about 800 ° C., and the Al plating bath contained 9% by mass of Si and also Fe eluted from the cold-rolled steel sheet. The adhesion amount (basis weight) of the Al plating layer after plating is adjusted by the gas wiping method, and the adhesion amount (basis weight) of the Al plating layer formed on both sides (upper surface and lower surface) of the cold-rolled steel sheet is 40 g / After making m 2 , it was cooled. After that, a chemical solution (nanotek slurry manufactured by C.I. Kasei Co., Ltd., zinc oxide grain size = 70 nm) was applied on both sides of the Al plating layer with a roll coater, and baked at about 80 ° C. A ZnO film having a (Zn equivalent amount) of 0.8 g / m 2 was formed on both sides.  In this way, a test material of an Al-plated steel sheet (A1) was obtained. [0116]  Adhesion amount (graining amount) on the upper and lower surfaces of the Al-plated layer, presence or absence of film, film material, adhesion amount on upper and lower surfaces of film (Zn A test material of an Al-plated steel sheet was obtained in the same manner as the Al-plated steel sheet (A1) except that the conversion amount) was changed as shown in Table 1 below. [0117] [table 1] [0118] -Example A- << Preparation of die mold >>  ・  Prepare the steel of the material shown in Table 1 of the base material, and roughen it into a shape similar to the upper mold 102A and lower mold 102B shown in FIG. 8 in the annealed state. Then, after quenching by cooling with nitrogen gas from heating and holding at 1180 ° C. in vacuum, tempering at 540 to 580 ° C. was performed to adjust the quality to 64 HRC. Then, finishing processing was performed to obtain a base material for a die mold. [0119]  -Formation of Nitride Layer  Next, a nitride layer was formed on the steel plate contact surface in contact (sliding) with the plated steel sheet 10 in the upper die 102A and the lower die 102B.  The base material was subjected to ion nitriding treatment under the following conditions. That is, after performing ion nitriding treatment under the condition of holding at 500 ° C. for 5 hours in an atmosphere of a flow rate ratio of 5% N 2 (residual H 2 ), each test surface was finished by polishing to form a nitrided layer. [0120]  -Formation of PVD film A  Bias voltage of -400 V is applied to the base material in an Ar atmosphere with a pressure of 0.5 Pa using an arc ion plating device at the location where the nitrided layer of the base material is formed, and heat for 60 minutes. Plasma cleaning with filament was performed. After that, various metal targets that are evaporation sources of metal components and N 2 gas as the reaction gas are used as the base, and CH 4 gas is used as needed, and the base material temperature is 500 ° C., the reaction gas pressure is 3.0 Pa, and -50 V. A PVD film was formed at the Bias voltage. [0121] (Example 1)  According to the method described in << Preparation of Die Mold >>, the composition of the PVD film shall be as shown in Table 2 below, and the hardness of the PVD film shall be the value shown in Table 2 below. Die molds (upper mold 102A and lower mold 102B) were produced.  With respect to the steel sheet contact surface of the obtained die mold, the skewness (Rsk) in the sliding direction of the plated steel sheet 10 that contacts (slides) was measured by the above-mentioned method. Further, the hardness Hv_Die of the steel plate contact surface of the obtained die mold was measured by the above-mentioned method.  The evaluation described later was carried out using the plated steel sheets and die dies shown in Table 2. [0122] (Examples 2 to 21)  According to the method described in << Preparation of Die Mold >>, the composition of the PVD film is set in Table 2 below, and the hardness of the PVD film is the value shown in Table 2 below. Die dies (upper die 102A and lower die 102B) were produced.  The evaluation described later was carried out using the plated steel sheets and die dies shown in Table 2. [0123]  Since a sufficient film thickness could not be secured for the "DLC film" in Example 5 (Condition No. 7) by the PVD method, a hard layer having a film thickness of 2 μm was formed by using the plasma CVD method. [0124]  Further, in Example 11 (Condition No. 13) and Example 20 (Condition No. 25), an AlVN film was laminated on the AlCrN film to form a laminated film. [0125] (Comparative Example 1)  Die dies (upper mold 102A and lower mold 102B) were produced in the same manner as in Example 1 except that the nitrided layer and the PVD film were not formed in the production of the die mold.  The evaluation described later was carried out using the plated steel sheets and die dies shown in Table 2. [0126] (Comparative Example 2)  Die dies (upper mold 102A and lower mold 102B) were produced in the same manner as in Example 1 except that the PVD film was not formed in the production of the die mold.  The evaluation described later was carried out using the plated steel sheets and die dies shown in Table 2. [0127] (Comparative Example 3) In  the production of the die mold, the die molds (upper mold 102A and lower mold 102B) were formed in the same manner as in Example 1 except that a "WC film" was further formed on the PVD film of AlCrN. Made.  The evaluation described later was carried out using the plated steel sheets and die dies shown in Table 2. [0128] (Comparative Examples 4 and 5)  According to the method described in << Preparation of Die Mold >>, the composition of the PVD film is set in Table 2 below, and the hardness of the PVD film is the value shown in Table 2 below. Die dies (upper die 102A and lower die 102B) were produced by adjusting the above.  The evaluation described later was carried out using the plated steel sheets and die dies shown in Table 2. [0129]  -Mold wear  First, an evaluation device for hot lubricity was prepared. The hot lubricity evaluation device shown in FIG. 8 includes a near-infrared heating furnace 100 and a mold composed of only the upper mold 102A and the lower mold 102B. The upper die 102A and the lower die 102B have convex portions having a width of 10 mm extending in a direction orthogonal to the drawing direction of the plated steel sheet, and by sandwiching the test material between the top surfaces of the convex portions, a predetermined value is provided. Apply a pressing load. The hot lubricity evaluation device is also provided with a plated steel sheet heated in the near-infrared heating furnace 100 and a thermocouple (not shown) for measuring the temperature of the plated steel sheet when sandwiched between molds. There is. In FIG. 8, 10 shows a test material of a plated steel sheet.  Using the hot lubricity evaluation device shown in FIG. 8, the test material of 30 mm × 500 mm was heated to 920 ° C. in a nitrogen atmosphere by the near-infrared heating furnace 100, and then the test material became about 700 ° C. A mold consisting of only the upper mold 102A and the lower mold 102B was pulled out while applying a pressing load of 3 kN (that is, sliding the test material on the mold). The pull-out length was 100 mm, and the pull-out speed was 40 mm / s. The average rate of temperature rise when heating to 920 ° C. was 7.5 ° C./sec. [0130]  By analyzing the surface shape difference of the steel plate contact surface that comes into contact (sliding) with the plated steel sheet 10 of the "mold of the hot lubricity measuring device" before and after the above hot lubricity evaluation test, the mold The amount of wear was measured. Specifically, a contact-type shape measuring machine was used to measure the profile of the mold surface at the sliding portion before and after sliding, and the mold wear amount was measured. For the mold wear amount, the average wear amount was calculated from the profile of each surface of the upper mold and the lower mold, and used as the average value thereof.  The obtained mold wear amount was evaluated according to the following evaluation criteria.  A: Mold wear amount 0.5 μm or less  B: Mold wear amount 0.5 μm or more and 1 μm or less  C: Mold wear amount 1 μm or more and 2 μm or less  D: Mold wear amount exceeds 2 μm [0131]  -Adhesion  to the adhesion mold was evaluated by the following test.  By analyzing the surface shape difference of the steel plate contact surface that comes into contact (sliding) with the plated steel sheet 10 of the "mold of the hot lubricity measuring device" before and after the above hot lubricity evaluation test, the mold The amount of adhesion was measured. Specifically, a contact-type shape measuring machine is used to measure the profile of the mold surface at the sliding parts before and after sliding, and the adhesion height at the position where the height of the adhesion portion is maximized. (Hereinafter, the maximum adhesion height of the mold) was measured. The maximum adhesion height of the mold was set to the maximum value of the adhesion heights of the upper mold and the lower mold.  The maximum adhesion height of the obtained mold was evaluated according to the following evaluation criteria.  A: Maximum mold adhesion height 0.5 μm or less  B: Maximum mold adhesion height 0.5 μm or more and 1 μm or less  C: Maximum mold adhesion height 1 μm or more and 3 μm or less  D: Maximum mold adhesion height Over 3 μm [0132] [Table 2] [0133]  From Table 2, in Examples 1 to 18, a hard layer having a skewness (Rsk) of 1.3 or less in the sliding direction and a hardness Hv_Die of HV2000 or more was formed on the steel plate contact surface of the die mold. It was confirmed that the wear of the sliding surface of the die mold can be reduced.  Further, in Examples 8 to 11 and 16 to 20, the skewness (Rsk) in the sliding direction is 0 or more and 1.3 or less, and the hardness Hv_Die is HV2500 or more and HV3000 or less on the steel plate contact surface of the die mold. It was confirmed that by forming the hard layer, it is possible to reduce the wear of the sliding surface of the die mold and to suppress the adhesion to the mold. [0134]  -Example B- << Preparation of Die Mold >> The shape of the die mold produced in the condition numbers 1, 3, 6, 10, 11, 14, 15, 17, and 19 in the above "Example A". 2A and 2B are shaped so that the press-molded products shown in FIGS. 2A and 2B can be formed, and the radius of curvature [R min ] at the portion where the radius of curvature is the minimum in the second ridge is shown in Tables 3 and 4 below. Each condition in "Example A" except that the shape is changed to the value described in 1 and the base material is changed to the one shown in Tables 3 and 4 below for the hardness Hv_Die at the vertical wall portion. A die mold was produced in the same manner as the number.  The nitrided layer and the PVD film were formed over the entire area where the mold and the material were expected to come into contact with each other during press molding. [0135] << Preparation of press-molded product >>  Using the die molds with the condition numbers shown in Tables 3 and 4, the furnace temperature setting: 920 ° C., material furnace 5 minutes (only molded product number 11 is material furnace 6 minutes), molding start temperature : Hot press molding was performed at 700 ° C.  Regarding the obtained press-molded product, the radius of curvature [R min ] at the portion where the radius of curvature is the minimum in the second ridge, and the radius of curvature of the second ridge is the smallest when the cross section of the press-molded product is observed. In the cross section , the smoothness at the center portion PA1 min in the cross-sectional width direction of the top plate portion [SaA1], the smoothness at the center portion PA2 min in the cross-sectional height direction of the vertical wall portion [SaA2], The surface aspect ratio [StrA1] at the location PA1 min on the top plate and the surface aspect ratio [StrA2] at the location PA2 min on the vertical wall were measured by the above-mentioned methods. The measurement results are shown in Table 3. [0136]  Further, regarding the obtained press-molded product, the radius of curvature [R min ] at the portion where the radius of curvature is the minimum in the second ridge line portion, and the portion where the radius of curvature of the flange portion is the minimum when observed from the side surface side PB0. Smoothness at the center point PB1 min in the width direction in the top plate corresponding to min [SaB1], and the center point PB2 min in the height direction in the vertical wall portion corresponding to the point PB0 min when observed from the side surface side. The smoothness [SaB2] at the top plate , the surface aspect ratio [StrB1] at the point P1 min on the top plate , and the surface aspect ratio [StrB2] at the point PB2 min on the vertical wall are measured by the above-mentioned method. did. The measurement results are shown in Table 4.  Furthermore, the evaluation described later was carried out using the press-molded products shown in Tables 3 and 4. [0137]  -For  the product after electrodeposition coating with a film thickness of 15 μm and top coating with a film thickness of 20 μm were applied to the press-molded product with each molded product number obtained , the surface quality of the vertical wall portion The surface quality of the above was judged according to the following criteria.  A: Excellent surface quality (gloss difference <15, no scratches on the surface)  B: Surface quality OK (15 ≤ gloss difference <30, no scratches on the surface)  C: Surface quality NG (gloss difference ≥ 30, on the surface) No scratches)  D: Surface defects NG (There are streaky scratches on the product surface) [0138]  · Glossiness difference  when viewed from the side of the top plate portion the radius of curvature of the flange portion is smallest portion PB0 min central position PB1 in the width direction of the top plate corresponding to min and, among the vertical wall position PB0 when viewed from the side min central position PB2 in the height direction of the vertical wall portion corresponding to the min gloss with, respectively measured by the following methods, the difference in gloss at the two locations Calculated.  The glossiness is measured by measuring the relative value of the reflectance based on the reflectance of black mirrored glass n = 1.567, which is defined in JIS Z 8741 (1997), at an incident angle of light of 60 °. did. [0139] [Table 3] [0140] [Table 4] [0141] -It is considered that  the minimum radius of curvature [R min ] at the second ridge line portion of the molded product number 1 is large and the surface pressure applied to the vertical wall portion is low, and the difference in smoothness [SaB1-SaB2] is small. [0142] -The  minimum radius of curvature [R min ] at the second ridges of molded product numbers 2 and 10 is smaller than that of molded product number 1, and it is considered that the surface pressure applied to the vertical wall portion is high, and the difference in smoothness [SaB1-SaB2] Is getting bigger.  In hot press molding using a die that satisfies at least one of the conditions that the hardness Hv_Die is less than HV2000 and the skewness (Rsk) is more than 1.3, plating adhesion to the die occurs and the vertical Since scratches are generated on the wall, the aspect ratios [StrA2] and [StrB2] of the surface texture of the vertical wall portion, which are parameters indicating the anisotropy of the surface state, are greatly reduced and are close to zero.  Further, since there is a difference in the degree of light reflection between the scratched portion of the vertical wall portion and the ZnO layer, the difference in glossiness is large. [0143] -The  minimum radius of curvature [R min ] at the second ridge line of molded product numbers 3 to 9 is smaller than that of molded product number 1, and it is considered that the surface pressure applied to the vertical wall portion is high, and the difference in smoothness [SaB1-SaB2] ] Is getting bigger.  However, in hot press molding using a die that satisfies both the condition that the skewness (Rsk) is 1.3 or less and the condition that the hardness Hv_Die is HV2000 or more and HV3200 or less, scratch scratches occur on the vertical wall portion. Is suppressed, and the decrease in the aspect ratios [StrA2] and [StrB2] of the surface texture of the vertical wall portion, which is a parameter indicating the anisotropy of the surface state, is also suppressed.  Therefore, the difference in glossiness between the vertical wall portion and the top plate portion is small. [0144] -Molded product numbers 8 to 10 This  is an example in which the strength of the base material of the press-molded product is different. [0145] -Molded product number 11 This  is an example in which the film type is different. [0146]  The "base material vertical wall portion HV_Parts (HV, 20 ° C.)" shown in Tables 3 and 4 is the hardness measured by collecting from the position of 1/4 of the plate thickness of the vertical wall portion of the press-molded product. HV_Parts. [0147]  Although the preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that anyone with ordinary knowledge in the field of technology to which this disclosure belongs can come up with various modifications or modifications within the scope of the technical ideas set forth in the claims. , These are also naturally understood to belong to the technical scope of the present disclosure. [0148]  The entire disclosure of Japanese application 2018-077794 is incorporated herein by reference in its entirety.  All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated herein by reference. Description of the sign [0149]  10  Plated steel plate  11, 111 Die mold (die) 11A, 111A Steel plate contact surface  11B, 111B Die shoulder  11C, 111C Hard layer  11D, 111D Die hole  12 Holder (steel plate holding die)  12C Second hard layer  13 Punch  100 Near infrared heating furnace  102A Upper die  102B Lower die  112  Steel plate  113 Punching die 113C Second hard layer  114A, 114B Aluminum plating layer  116A, 116B Zinc compound layer or metallic zinc layer The scope of the claims [Claim 1]  A method for producing a hot press-molded product in which an Al-plated steel sheet having a zinc compound layer or a metallic zinc layer as the outermost layer on the Al-plated layer is hot-press-molded using a  die mold. , The outer surface of the die hole and the contact surface of the steel sheet in contact with the Al-plated steel sheet before hot press forming, all of which are adjacent to the shoulder of the die, from the outside to the inside of the die hole. A method for producing a hot press-formed product having a hard layer having a skewness (Rsk) of 1.3 or less measured in a direction and a hardness Hv_Die of HV2000 or more. [Claim 2]  The method for producing a hot press molded product according to claim 1, wherein the skewness (Rsk) of the hard layer is −5.0 or more. [Claim 3]  The method for producing a hot press-molded product according to claim 1 or 2, wherein the hard layer is a layer including a nitride layer and a hard coating layer on the surface of the nitride layer. [Claim 4]  The method for producing a hot press-molded product according to claim 3, wherein the hard coating layer has a hardness Hv_Die of HV3200 or less. [Claim 5]  The method for producing a hot press-molded product according to claim 4, wherein the hard coating layer is a layer containing Cr. [Claim 6]  The method for producing a hot press-molded product according to claim 3, wherein the hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. [Claim 7]  The method for producing a hot press-molded product according to any one of claims 3 to 6, wherein the hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less. [Claim 8]  It has a steel base material having a hardness Hv_Parts of HV400 or more, an Al plating layer on the steel base material, and a zinc oxide layer as the outermost layer on the Al plating layer, and has a  top plate portion and the top plate. It has a vertical wall portion connected to the portion via the first ridge line portion and a flange portion connected to the vertical wall portion via  the second ridge line portion, and the radius of curvature of the second ridge line portion is minimized. The radius of curvature [R min ] at the location is 3 mm or more and less than 10 mm, and in  the cross section where the radius of curvature of the second ridgeline portion is minimized when observing the cross section of the press-formed product, the top plate portion The difference [SaA1-SaA2] between the smoothness [SaA1] at the center portion PA1 min in the width direction of the cross section and the smoothness [SaA2] at the center portion PA2 min in the height direction of the cross section of the vertical wall portion. ] Is 0.20 μm or more, and the aspect ratio [StrA1] of the surface texture at the  portion PA1 min on the top plate portion and the aspect ratio [StrA2] of the surface texture at the portion PA2 min on the vertical wall portion. , The difference [StrA1-StrA2] is 0.50 or less. [Claim 9]  It has a steel base material having a hardness Hv_Parts of HV400 or more, an Al plating layer on the steel base material, and a zinc oxide layer as the outermost layer on the Al plating layer, and has a  top plate portion and the top plate. It has a vertical wall portion connected to the portion via the first ridge line portion and a flange portion connected to the vertical wall portion via  the second ridge line portion, and the radius of curvature of the second ridge line portion is minimized. The radius of curvature [R min ] at the location is 3 mm or more and less than 10 mm, and the  radius of curvature of the flange portion is minimized when observed from the side surface side in the width direction of the top plate portion corresponding to PB 0 min . The smoothness at the central portion PB1 min [SaB1] and the smoothness at the central portion PB2 min in the height direction of the vertical wall portion corresponding to the portion PB0 min when observed from the side surface side . The difference [SaB1-SaB2] is 0.30 μm or more, and the aspect ratio [StrB1] of the surface texture at the  portion PB1 min on the top plate portion and the surface texture at the portion PB2 min on the vertical wall portion. A press-molded product in which the difference [StrB1-StrB2] from the aspect ratio [StrB2] is 0.50 or less. [Claim 10]  Of the outer surface of the die hole and the surface adjacent to the die shoulder adjacent to the die shoulder, the skewness (Rsk) measured in the direction from the outside to the inside of the die hole is 1. A die mold having a hard layer having a hardness of 3 or less and a hardness of Hv_Die of HV2000 or more. [Claim 11]  The die mold according to claim 10, wherein the skewness (Rsk) of the hard layer is −5.0 or more. [Claim 12]  The die mold according to claim 10 or 11, wherein the hard layer is a layer including a nitride layer and a hard coating layer on the surface of the nitride layer. [Claim 13]  The die mold according to claim 12, wherein the hard coating layer has a hardness Hv_Die of 3200 or less. [Claim 14]  The die mold according to claim 13, wherein the hard coating layer is a layer containing Cr. [Claim 15]  The die mold according to claim 12, wherein the hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. [Claim 16]  The die mold according to any one of claims 12 to 15, wherein the hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less. [Claim 17]  The die die according to any one of claims 10 to 16 and a punch die are provided, and the  punch die is a surface of the die die facing the die shoulder adjacent surface. Among them, the skewness (Rsk) measured in the direction from the outside to the inside of the punch portion is 1.3 or less, and the hardness Hv_Die is HV2000 or more in the entire region facing the portion where the die die has the hard layer. A mold set with a second hard layer. [Claim 18]  The mold set according to claim 17, wherein the skewness (Rsk) of the second hard layer is −5.0 or more. [Claim 19]  The mold set according to claim 17 or 18, wherein the second hard layer is a layer including a second nitride layer and a second hard coating layer on the surface of the second nitride layer. [Claim 20]  The mold set according to claim 19, wherein the second hard coating layer has a hardness Hv_Die of HV3200 or less. [Claim 21]  The mold set according to claim 20, wherein the second hard coating layer is a layer containing Cr. [Claim 22]  The mold set according to claim 19, wherein the second hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. [Claim 23]  The mold set according to any one of claims 19 to 22, wherein the second hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less. [Claim 24]  The die mold according to any one of claims 10 to 16 and a steel plate holding mold are provided, and the  steel plate holding mold faces the die shoulder adjacent surface of the die mold. The skewness (Rsk) measured in the direction from the outside to the inside of the punch insertion portion is 1.3 or less, and the hardness Hv_Die is in the entire region of the surface facing the portion where the die die has the hard layer. A mold set having a second hard layer having an HV of 2000 or higher. [Claim 25]  The mold set according to claim 24, wherein the skewness (Rsk) of the second hard layer is −5.0 or more. [Claim 26]  The mold set according to claim 24 or 25, wherein the second hard layer is a layer including a second nitride layer and a second hard coating layer on the surface of the second nitride layer. [Claim 27]  The mold set according to claim 26, wherein the second hard coating layer has a hardness Hv_Die of HV3200 or less. [Claim 28]  The mold set according to claim 27, wherein the second hard coating layer is a layer containing Cr. [Claim 29]  The mold set according to claim 26, wherein the second hard coating layer is a layer containing Ti and having a hardness Hv_Die of HV3160 or less. [Claim 30]  The mold set according to any one of claims 26 to 29, wherein the second hard coating layer has a hardness Hv_Die of HV2500 or more and HV3000 or less.

Documents

Application Documents

# Name Date
1 202017045638-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [20-10-2020(online)].pdf 2020-10-20
2 202017045638-STATEMENT OF UNDERTAKING (FORM 3) [20-10-2020(online)].pdf 2020-10-20
3 202017045638-REQUEST FOR EXAMINATION (FORM-18) [20-10-2020(online)].pdf 2020-10-20
4 202017045638-PROOF OF RIGHT [20-10-2020(online)].pdf 2020-10-20
5 202017045638-PRIORITY DOCUMENTS [20-10-2020(online)].pdf 2020-10-20
6 202017045638-POWER OF AUTHORITY [20-10-2020(online)].pdf 2020-10-20
7 202017045638-FORM 18 [20-10-2020(online)].pdf 2020-10-20
8 202017045638-FORM 1 [20-10-2020(online)].pdf 2020-10-20
9 202017045638-DRAWINGS [20-10-2020(online)].pdf 2020-10-20
10 202017045638-DECLARATION OF INVENTORSHIP (FORM 5) [20-10-2020(online)].pdf 2020-10-20
11 202017045638-COMPLETE SPECIFICATION [20-10-2020(online)].pdf 2020-10-20
12 202017045638-FORM 3 [20-11-2020(online)].pdf 2020-11-20
13 202017045638.pdf 2021-10-19
14 202017045638-FER.pdf 2021-10-19
15 202017045638-OTHERS [16-11-2021(online)].pdf 2021-11-16
16 202017045638-FER_SER_REPLY [16-11-2021(online)].pdf 2021-11-16
17 202017045638-DRAWING [16-11-2021(online)].pdf 2021-11-16
18 202017045638-CORRESPONDENCE [16-11-2021(online)].pdf 2021-11-16
19 202017045638-COMPLETE SPECIFICATION [16-11-2021(online)].pdf 2021-11-16
20 202017045638-CLAIMS [16-11-2021(online)].pdf 2021-11-16
21 202017045638-US(14)-HearingNotice-(HearingDate-29-04-2024).pdf 2024-04-04
22 202017045638-REQUEST FOR ADJOURNMENT OF HEARING UNDER RULE 129A [26-04-2024(online)].pdf 2024-04-26
23 202017045638-US(14)-ExtendedHearingNotice-(HearingDate-29-05-2024).pdf 2024-04-29
24 202017045638-FORM-26 [28-05-2024(online)].pdf 2024-05-28
25 202017045638-Correspondence to notify the Controller [28-05-2024(online)].pdf 2024-05-28
26 202017045638-Written submissions and relevant documents [11-06-2024(online)].pdf 2024-06-11
27 202017045638-PatentCertificate13-06-2024.pdf 2024-06-13
28 202017045638-IntimationOfGrant13-06-2024.pdf 2024-06-13

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1 202017045638E_28-07-2021.pdf

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