CN113423518A - Method and system for using air gaps in hot stamping tools to create custom temper properties - Google Patents

Abstract

The metal sheet blank is hot stamped between a first tool surface of a first die tool and a second tool surface of a second die tool, respectively, to form a hot stamped product. The product is then heat treated between the first tool surface and the second tool surface. The actively cooled portion of the tool surface quenches a portion of the hot stamped product to form a hardened zone. The active heating of the tool surface slows down the transfer of heat from the hot stamped product to the heated portion, which results in a hot stamped product with soft zones. A matrix of insulating gaps is formed in the heated portion to further slow the rate of heat transfer from the hot stamped product to the heated portion. The insulation gap may facilitate the use of a lower temperature heating portion, which may save energy and result in a heating portion with greater wear resistance and longer life.

Description

Method and system for using air gaps in hot stamping tools to create custom temper properties

Cross Reference to Related Applications

This application claims priority to U.S. provisional patent application No.62/805,232, filed on 13.2.2019, the entire contents of which are expressly incorporated herein by reference.

Background

Technical Field

Various embodiments relate generally to thermoforming systems and methods for producing vehicle components.

Introduction to related Art

Vehicle manufacturers strive to provide increasingly sturdy, lightweight, and inexpensive vehicles. One process for forming vehicle body parts is a hot forming process in which a heated steel blank is hot stamped and quenched (for rapid cooling and hardening) in a hot forming die. The preheated sheet material may generally be introduced into a hot forming die, formed into a desired shape, and simultaneously quenched in the die after the forming operation, thereby producing a heat treated product. Known hot forming dies for performing the stamping and quenching steps typically employ water cooling channels (for circulating cooling water through the hot forming die) formed in a conventional manner. In some applications, it may be desirable to cool certain portions of the stamped metal piece at a slower rate than other portions. These portions of the stamped component are heated by the stamping die such that the rate of cooling is slowed relative to the portions of the component exposed to the portion of the die receiving the cooling fluid. The slower cooling portions of the component will be softer (more ductile) than the portions of the component that are subjected to the rapid cooling (quenching). To heat portions of the mold, cartridge heaters may be provided within the forming block of the mold to apply heat to areas of the product being stamped.

Disclosure of Invention

One or more non-limiting embodiments provide a hot stamping apparatus and a hot stamping method by which a metal sheet blank is hot stamped between a first tool surface of a first die tool and a second tool surface of a second die tool, respectively, to form a hot stamped product. The hot stamped product is then heat treated between the first tool surface and the second tool surface. The actively cooled portion of the tool surface quenches a portion of the hot stamped product to form a hardened zone. The active heating of the tool surface slows down the transfer of heat from the hot stamped product to the heated portion, which results in a hot stamped product with soft zones. A matrix of insulating gaps is formed in the heated portion to further slow the rate of heat transfer from the hot stamped product to the heated portion. The insulation gap may facilitate the use of a lower temperature heating portion, which may save energy and result in a heating portion with greater wear resistance and longer life.

The claims set forth below disclose additional non-limiting embodiments.

One or more of these and/or other aspects of the various embodiments, as well as methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. In one embodiment, the structural components illustrated herein are drawn to scale. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. Furthermore, it should be understood that structural features shown or described in any of the embodiments herein may also be used in other embodiments. As used in the specification and in the claims, the singular form of "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

All closed (e.g., between a and B) and open (greater than C) value ranges disclosed herein expressly include all ranges falling within or nested within such ranges. For example, the disclosed ranges of 1 to 10 are understood to also disclose other ranges of 2 to 10, 1 to 9, 3 to 9, and so on. Similarly, where multiple parameters (e.g., parameter C, parameter D) are disclosed individually as having ranges, embodiments disclosed herein expressly include embodiments that combine any value within the disclosed range for one parameter (e.g., parameter C) with any value within the disclosed range for any other parameter (e.g., parameter D).

Drawings

For a better understanding of the various embodiments, together with other objects and further features thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a lower die of a hot stamping system;

FIG. 2 is a perspective view of a hot stamped product made by the hot stamping system of FIG. 1;

FIG. 3 is a perspective view of a heated portion of the lower mold of FIG. 1;

FIG. 4 is a top view of the heating section shown in FIG. 3;

FIG. 5 is an enlarged top view of portion 5-5 of FIG. 4;

FIG. 6 is a cross-sectional view of a heated portion of the lower die of FIG. 5 taken along line 6-6 in FIG. 5;

FIG. 7 is a cross-sectional view of a heating portion of the hot stamping system of FIG. 1;

FIG. 8 is an enlarged cross-sectional view of portion 8-8 shown in FIG. 7; and

fig. 9 is a further enlarged cross-sectional view of fig. 8.

Detailed Description

The present disclosure relates to a hot stamping system 10 and method for producing a hot stamped product 20 having tailored properties. Such hot stamped products 20 may include vehicle body members or panels or pillars of an automobile. The "tailored" nature of forming a product or part using the system 10 and method described herein provides a formed part having regions of high strength and hardness, as well as other regions of reduced strength, ductility, and hardness. When the forming system 10 described herein is used as part of a method of forming such a customized product or component, such as a vehicle pillar (a-pillar or B-pillar), the resulting vehicle structure has a complex configuration that includes regions that are designed to deform in a predetermined manner, for example, upon receiving forces from a vehicle collision.

As shown in fig. 1 and 7, the system 10 includes an upper mold 40 and a lower mold 30 having an upper mold tool surface 40a and a lower mold tool surface 30a, respectively. Fig. 1 illustrates a lower die 30 and a lower tool surface 30 a. It should be understood that upper mold 40 and upper tool surface 40 generally have mating structures and surfaces. The upper and lower dies 40, 30 are shaped and configured to cooperate with each other to form a die cavity therebetween. The dies 30, 40 receive a workpiece/metal blank therebetween and hot stamp the workpiece/metal blank (e.g., a hot sheet metal member such as a steel plate, steel such as Press Hardened Steel (PHS), boron steel with or without a coating (e.g., an aluminum coating)).

As shown in fig. 1, the lower tool surface 30a is divided into a heating portion 50a and a cooling portion 60 a. As shown in fig. 1, the cooling portion 60a and the heating portion 50a may be formed by discrete mold portions 60, 50, respectively, of the lower mold 30 that fit together to define the entire mold 30. Fig. 3 and 4 illustrate a lower mold heating section 50 defining a heating section 50a of a lower tool surface 50 a.

As shown in fig. 7, the mold heating section 50 of the lower mold 30 (and the corresponding upper mold heating section shown in fig. 7) includes one or more heaters 70, the heaters 70 being positioned and configured to heat the tool surface heating section 50 a. In the illustrated embodiment, the heater 70 comprises a cartridge heater, but may alternatively comprise any other type of suitable heater (e.g., a channel through which a heating fluid passes). The mold cooling portion 60 of the lower mold 30 (and the corresponding upper mold cooling portion of the upper mold 40) includes one or more coolers (e.g., coolant channels through which coolant actively cools (e.g., via a refrigeration system)).

In the illustrated embodiment, both the upper mold surface 40a and the lower mold surface 30a in the heating portion 50a of the molds 30, 40 are heated. However, according to alternative embodiments, only the upper mold 40 or only the lower mold 30 may be heated. Similarly, in the illustrated embodiment, both the upper tool surface 60a and the lower tool surface 60a in the cooling portion 60 of the mold 30, 40 are cooled. However, according to alternative embodiments, only the upper mold 40 or only the lower mold 30 may be cooled.

In the illustrated embodiment, the dies 30, 40 form one continuous cooling section and one continuous heating section. However, according to various alternative embodiments, additional and/or fewer heating and/or cooling portions may be provided to accommodate the particular hardness and ductility requirements of any desired product (e.g., alternating hard and soft portions of the workpiece to provide accordion-like crumple zones; multiple soft portions surrounded by large hardened portions, etc.).

As shown in fig. 3 to 9, a matrix 90 of insulation gaps 100 is formed in the surface heating portions 50a of the tool surfaces 30a, 40a of the upper and lower dies 40, 30. The matrix 90 divides the surface heating portion 50a into (1) a non-contact surface area formed by the insulating gap 100 and (2) a contact surface area 110 where the gap 100 is not provided. The contact region 110 is shaped and configured to contact the blank during hot forming and to contact the resulting hot stamped product during heat treatment. In contrast, the non-contact areas formed by the gaps 100 are shaped and configured to not contact the blank during hot forming and not contact the hot stamped product during heat treatment.

As used herein, the area of any surface is its actual surface area. Thus, the depth and shape of the recess forming the gap 100 will slightly affect the area of the gap 100.

As shown in fig. 6 and 9, the gap 100 is recessed relative to the contact region 110 surrounding the gap 100. As shown in fig. 6, the gap 100 has a maximum depth d with respect to the surface of the contact region 110. According to various embodiments, the maximum depth D of at least D of the air gaps 100 is (a) at least 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and/or 5.0mm, (b) less than 20, 15, 10, 7.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3.0, and/or 2.0 mm, between any lower limit (e.0 to 0mm, 0.5mm, 0mm, and/5 mm, and/or the like) between any upper and/or lower limit (e.0 mm to 20mm, between 0mm, 1.5 mm, and/or 5mm, and/5 mm, between any value between 0mm, and/or 1mm, and/5 mm, and/or between any other, between such as between 0 mm). According to various embodiments, the depth d is about 0.25mm for at least 10 of the gaps 100. According to various embodiments, D is (a) at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, and/or 100, (b) less than 1000, 500, 400, 300, 200, 150, 100, 90, 80, 70, 60, 50, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, and/or 6, and/or (c) between any two such values (e.g., between 2 and 1000, between 5 and 500, etc.). The depth d of different air gaps 100 may be different even in a single embodiment.

According to various embodiments, the gaps 100 each have an area a when viewed in a direction perpendicular to the contact region 110 surrounding the gap 100. According to various embodiments, the area a of the gaps 100 is (a) at least 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1250, 1500, 2000, 2500, 3000, 3500, 4000, 5000, 7500, and/or 10000mm²Less than 10000, 7500, 5000, 4000, 3000, 2500, 2000, 1500, 1250, 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 90, 80, 70, 60, 50, 40, 35. 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7 and/or 6mm²And/or (c) between any two of such upper to lower values (e.g., at 5 mm)²To 10000mm²Between 10mm²To 1000mm²Between 15mm²To 200mm²Between 200mm²To 1000mm²In between). According to various embodiments, a is (a) at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, and/or 100, (b) less than 1000, 500, 400, 300, 200, 150, 100, 90, 80, 70, 60, 50, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, and/or 6, and/or (c) between any two such values (e.g., between 2 and 1000, between 5 and 500, etc.).

As shown in fig. 4 to 5, the area a of the gaps 100 is substantially rectangular, wherein the rectangular gaps 100 are arranged in a rectilinear grid of the gaps 100. In accordance with one or more embodiments and as shown in fig. 5, the gaps 100 may comprise 20mm x 20mm squares on a 25mm pitch, which results in adjacent gaps 100 being separated by 5mm wide contact surfaces 110. As shown in fig. 3 to 4, the other ones of the gaps 100 have areas formed of different shapes. According to yet another embodiment, the areas a of the gaps 100 may have any other suitable shape (e.g., triangular or hexagonal) and be laid out in any suitable matrix (e.g., a hexagonal or triangular grid, a matrix of mixed polygonal gaps 100, a matrix of irregular gaps 100 having a plurality of different shapes and areas).

According to various embodiments, the shape and dimensions of the one or more gaps 100 and the one or more contact surfaces 110 are selected such that the one or more contact surfaces 110 are sufficiently interspersed on the heating portion 50a that support the blank during the hot stamping and substantially prevent the blank from moving into the volume of the air gap 100 during the hot stamping. According to various embodiments, overlaying a circle having a diameter c anywhere within the heating portion 50a results in the circle overlaying at least a portion of the contact surface 110. According to various embodiments, the diameter c is (a) less than 10000, 7500, 5000, 4000, 3000, 2000, 1000, 900, 800, 700, 600, 500, 400, 300, 250, 200, 150, 100, 90, 80, 70, 60, 50, 40, 30, 20, and/or 10mm and (b) greater than 0, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, and/or 100 mm.

According to various embodiments, the area of the cumulative contact surface 110 within the heating portion 50 may include (a) at least 20%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% of the area of the heating portion 50, (b) less than 20%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% of the area of the heating portion 50, and/or (c) between any two such upper to lower values (e.g., between 25% and 80%, between 26% and 50%, etc.). According to one or more embodiments, the contact surface comprises about 36% of the area of the heating portion 50.

According to various embodiments, the surface area of the heating portion 50a (including both the surface area of the contact surface area 110 and the gap 100) is (1) at least 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1250, 1500, 2000, 2500, 3000, 4000, 5000, 7500, 10000, 15000, 20000, 30000, 40000, 50000, 75000 and/or 100000mm²(2) less than 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1250, 1500, 2000, 2500, 3000, 4000, 5000, 7500, 10000, 15000, 20000, 40000, 50000, 60000, 75000mm²And/or (3) between any two of such upper to lower values (e.g., at 100 mm)²To 100000mm²In 200mm²Up to 20000mm²In between). According to various embodiments, the surface area of the heating portion 50a is the same as the surface area of the corresponding soft zone 20 a.

In the illustrated embodiment, each air gap 100 is isolated from each other gap 100 by a contact surface 110. According to various embodiments, each gap 100 is completely surrounded by the contact surface 110. However, according to alternative embodiments, some or all of the gaps 100 may be interconnected (e.g., by a break in the contact surface 110 separating two adjacent gaps 100). According to some embodiments, such an interconnection may result in isolated islands of contact surface 110 being completely surrounded by one or more gaps 100 (e.g., a matrix/grid of contact surfaces 110 separated by gaps 100, e.g., formed by reversing the relative positions of gaps 100 and contact surfaces 110 in fig. 5).

According to various embodiments, the matrix extends over a plurality of gaps 100 in orthogonal directions. For example, for a matrix comprising a rectilinear grid as shown in fig. 5, the matrix creates a rectilinear grid having x rows and y columns, where x and y are each at least 2.

According to various embodiments, the gaps 100 each have a volume v. According to various embodiments, the volume V of the interspaces 100 is (a) at least 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1250, 1500, 2000, 2500, 3000, 3500, 4000, 5000, 7500, 10000, 12500, 15000, 17500 and/or 20000mm³(b) less than 20000, 17500, 15000, 12500, 10000, 7500, 5000, 4000, 3000, 2500, 2000, 1500, 1250, 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 90, 80, 70, 60 and/or 50mm³And/or (c) between any two of such upper to lower values (e.g., at 20 mm)³Up to 20000mm³Between 100mm³To 10000mm³Etc.). According to various embodiments, V is (a) at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, and/or 100, (b) less than 1000, 500, 400, 300, 200, 150, 100, 90, 80, 70, 60, 50, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, and/or 6, and/or (c) between any two such values (e.g., between 2 and 1000, between 5 and 500, etc.).

A, D and V may be the same or different from each other, according to various embodiments.

According to various embodiments, the gap 100 may be formed by any suitable manufacturing method, including but not limited to material removal methods (e.g., machining/drilling/grinding the gap 100 into a surface of a mold), additive manufacturing (e.g., establishing a contact surface adjacent to the gap 100 (e.g., via 3D printing) to form the gap 100), casting or forging the gap 100 into a surface of a mold (e.g., simultaneously or subsequent to the formation of the contact surface), and so forth.

Although the matrix of gaps 100 has been described in detail with respect to the lower mold 30, it should be understood that a mirrored (or non-mirrored) matrix of gaps 100 may also be formed on the upper mold 40, as shown in fig. 7-9. The corresponding portion of the upper mold 40 may also be heated via a heater. Similarly, the portion of the upper mold 40 that mates with the cooling portion 60 may also be cooled.

As shown in fig. 9, the matrix of insulation gaps 100 is shaped and configured to create a gap between the hot stamped product 20 and the heating portion 50a in the area of each of the insulation gaps 100 during the hot stamping and heat treatment. According to various embodiments, the gap 100 may be filled with air or another insulator (e.g., a ceramic having a low thermal conductivity). Therefore, the gap 100 slows down the transfer of heat from the hot stamped product 20 to the heating portion 50 a.

During heat treatment, the cooling portion 60 causes rapid flow of heat from the corresponding zone 20b of the product 20 to the cooling portion 60, which results in quenching and formation of a hardened zone 20b in the product 20 (as shown in fig. 2).

When the heating portion 50 is heated, the temperature of the heating portion 50 is still lower than the temperature of the blank/product 20 at the start of the hot stamping process, which causes heat to flow from the product 20 to the heating portion 50 during hot stamping and to a greater extent during heat treatment. As a result, heating the heating portion 50 causes heat to be more slowly transferred from the hot stamped product 20 to the heating portion 50. In addition, the insulating gap 100 mitigates the transfer of heat from the hot stamped product 20 to the heating portion 50 via the gap 100. Heating the heating portions 50 and providing the matrix of insulating gaps 100 causes the corresponding zones 20a of the hot stamped product 20 pressed between the heating portions 50 of the die to cool relatively slowly, which produces soft zones 20a of the hot stamped product 20, the soft zones 20a being relatively softer and more ductile than the hardened zones 20b of the product 20 and containing less martensite than the hardened zones 20 b.

The rate of heat transfer from the hot stamped product 20 to the heated section 50 depends on the temperature gradient between the hot stamped product 20 and the heated section 50. Heating the heating portion 50 reduces the temperature gradient, which slows heat transfer and results in softer, more ductile zones 20a in the product 20. However, due to energy costs, increasing the temperature of the heated portion 50 to reduce the gradient may be expensive and may disadvantageously increase wear on the dies 30, 40, as hotter tools wear more readily than lower temperature tools.

The rate of heat transfer from the hot stamped product 20 to the heated portion 50 also depends on the heat transfer coefficient of the gap 100. The air gap 100 provides insulation that slows the transfer of heat from the hot stamped product to the heated portion 50. This slowing of the heat transfer rate helps to balance the large temperature gradient between using the hot stamped product 20 and the heated portion 50 while still providing the soft zones 20 a. The larger temperature gradient means that the temperature of the heated portion 50 can be lower, which reduces energy costs and increases the working life of the heated portion 50 of the mould 30, 40. According to various embodiments, the working life of the heating portion 50a may be extended by at least 5000, 10000, 15000, and/or 20000 cycles of hot stamping between repair/rework of the surface.

According to various embodiments, during hot stamping and heat treatment, the maximum temperature of one or more of the heated portions 50a of the tool surface (and/or the maximum temperature within the core of one or more of the heated portions 50 of the die): (a) at least 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 ℃ lower than the red hardness temperature of the tool material forming heating portion 50a and/or 50; (b) less than 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300 ℃ lower than the red hardness temperature of the tool material forming the heating portion 50a or 50; and/or (c) between 1 ℃ and 300 ℃ below the red hardness temperature of the tool material forming the heating portion 50a and/or 50, between 5 ℃ and 150 ℃ below the red hardness temperature of the tool material forming the heating portion 50a and/or 50, and/or between 10 ℃ and 100 ℃ below the red hardness temperature of the tool material forming the heating portion 50a and/or 50. According to various embodiments, keeping the heated portion 50a of the surface of the mold 50 below (and preferably well below) its red hard temperature will reduce wear and tear on the mold portions 50, 50 a. According to various embodiments, keeping the core of the heated portion 50 of the die below (and preferably well below) its red-hard temperature tends to reduce the deformation caused by thermal expansion of the die (and the shape errors that arise in the stamped part). Although the maximum temperature of the tool material forming the heated portion 50a is relatively low, the air gap 100 sufficiently slows the cooling rate of the hot stamped product such that the hardness of the entire resulting soft zone 20a of the heat treated product (i.e., after completion of the heat treatment) is advantageously less than, for example, y, where y is (a) less than 400, 350, 300, 250, 240, 230, 220, 210, 200, and/or 190Hv, (b) at least 100, 120, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 300, 350, and/or 400Hv, and/or (c) between any two such values (e.g., between 100Hv and 400Hv, between 140Hv and 300Hv, between 150Hv and 250Hv, between 180Hv and 220 Hv).

According to various embodiments, the blank and the cooling portion 60 produce a hardened zone 20b having a hardness h, where h is (a) greater than or equal to 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, and/or 700Hv, (b) less than or equal to 700, 675, 650, 635, 600, 575, 550, 525, 500, 475, and/or about 450Hv, and/or (c) between any two of such upper to lower values (e.g., between 225Hv and 600Hv, between 250Hv and 550Hv, between 350Hv and 600Hv, between 400Hv and 550Hv, etc.).

According to various embodiments, the tool material forming the heating portion 50a may include any suitable material: w360 steel having a red hardness temperature of 580 ℃; s600 having a red hardness temperature of 610 ℃; revolma, which has a red hardness temperature of 630 ℃. There is a tradeoff between the advantageously higher red hardness temperature of tool materials such as S600 or Revolma and their corresponding increased brittleness.

The foregoing description of the embodiments has been provided to illustrate the structural and functional principles of various embodiments and is not intended to be limiting. On the contrary, the principles of the invention are intended to cover any and all variations, modifications and/or alterations thereof (e.g., any modifications within the spirit and scope of the appended claims).

Claims (29)

1. A hot stamping method, comprising:

hot stamping a metal blank between a first tool surface of a first die tool and a second tool surface of a second die tool, respectively, to form a hot stamped product; and

heat treating the hot stamped product between the first tool surface and the second tool surface, the heat treating comprising:

using an actively cooled portion of at least one of the first and second tool surfaces to form a first zone in the hot stamped product, and

using an active heating portion of at least one of the first and second tool surfaces to form a second zone in the hot stamped product, wherein the heating portion is heated by a heater thermally connected to the heating portion,

wherein the heating portion comprises a combination of: (1) one or more insulation gaps cumulatively defining a non-contact surface area of the heating portion, wherein the non-contact surface area does not contact the hot stamped product during the heat treatment; and (2) one or more contact surfaces defining a contact surface area of the heating portion and contacting the hot stamped product during the heat treatment,

wherein the one or more insulation gaps slow down the transfer of heat from the hot stamped product to the heating portion during the heat treatment, and

wherein the heat treatment results in a hardness of less than y Hv throughout the second region, wherein y is 350 Hv.

2. The method of claim 1, wherein a maximum temperature of the heated portion during the hot stamping and the heat treatment is at least x ℃ lower than a red hardness temperature of a tool material forming the heated portion, wherein x is 1.

3. The method of claim 2, wherein x is 25 and y is 220.

4. The method of claim 3, wherein the heat treatment results in a hardness of the first region of at least 350 Hv.

5. The method of claim 3, wherein the heat treatment results in a hardness of the first region of at least 400 Hv.

6. The method of claim 3, wherein:

the tool material comprises W360; and is

The maximum temperature of the heating portion during the hot stamping is less than 600 ℃.

7. The method of claim 1, wherein the heat treatment results in a hardness of the second region of less than 220Hv and a hardness of the first region of at least 400 Hv.

8. The method according to claim 1, wherein the maximum temperature of the core of the first and second die tools during the hot stamping and the heat treatment is at least x ℃ lower than the red hardness temperature of the tool material forming the first and second die tools, wherein x is 1.

9. The method of claim 1, wherein:

the area of the heating part is at least 10000mm²；

The contact surface area occupies less than 50% of the area of the heated portion; and is

The contact surface area and the non-contact surface area are shaped such that overlaying a circle having a diameter c onto any location within the area of the heating portion results in the circle overlaying at least a portion of the contact surface area, wherein c is less than 75 mm.

10. The method of claim 1, wherein the heat treatment results in a hardness of between 180 and 220Hv across the second region.

11. The method of claim 10, wherein the heat treatment results in a hardness of the second region of at least 350 Hv.

12. The method of claim 1, wherein the insulating gaps each comprise an air gap.

13. The method of claim 1, wherein the heating portion comprises (1) a matrix of the one or more insulation gaps or (2) a matrix of the one or more contact surfaces.

14. The method of claim 13, wherein the matrix comprises (1) a grid of the one or more insulation gaps or (2) a grid of the one or more contact surfaces.

15. The method of claim 13, wherein:

the heating sections respectively include a first heating section of the first tool surface and a second heating section of the second tool surface; and is

The matrix includes first and second matrices formed in the first and second heating portions, respectively.

16. The method of claim 1, wherein each of the at least 5 of the insulation gaps occupies at least 20mm²The area of (a).

17. The method of claim 1, wherein each of at least 5 of the insulation gaps is at least 0.1mm deep.

18. The method of claim 1, wherein each of at least 5 of the insulation gaps has at least 100mm³The volume of (a).

19. The method of claim 1, wherein the active heating of the active heating portion slows the transfer of heat from the hot stamped product to at least one of the first die and the second die during the heat treatment.

20. A hot stamping system, comprising:

a first mold having a first tool surface;

a second die having a second tool surface, the first and second dies configured to cooperate with each other such that the first and second tool surfaces form a die cavity between the first and second tool surfaces for receiving a metal blank therein and hot stamping the metal blank into a hot stamped product;

a cooler positioned and configured to cool a cooling portion of at least one of the first tool surface and the second tool surface;

a heater positioned and configured to heat a heating portion of at least one of the first tool surface and the second tool surface; and

the heating section includes (1) a matrix of insulating gaps separated by contact surfaces or (2) a matrix of contact surfaces separated by insulating gaps,

wherein the insulation gaps are shaped and configured to create a gap between the hot stamped product and the heating portion in the area of each of the insulation gaps after the metal blank is hot stamped,

wherein the contact surface is shaped and configured to contact the hot stamped product after the metal blank is hot stamped,

wherein the insulation gap is shaped and configured to slow down the transfer of heat from the hot stamped product to the heating portion.

21. The hot stamping system of claim 20, wherein the insulating gaps each comprise an air gap.

22. The hot stamping system of claim 20, wherein:

the hot stamping system is shaped and configured to heat treat the hot stamped product between the first tool surface and the second tool surface;

the hot stamping system is shaped and configured to use the cooling portion during the heat treatment to form a first zone in the hot stamped product;

the hot stamping system is shaped and configured to use the heating portion to form a second zone in the hot stamped product; and is

The first zone is harder than the second zone.

23. The hot stamping system of claim 22, wherein the heating portion is divided into: (1) a non-contact region formed by the insulating gap and configured to not contact the hot stamped product during the heat treatment; and (2) a contact region shaped and configured to contact the hot stamped product during the heat treatment.

24. The hot stamping system of claim 22, the heater being positioned and configured to slow a transfer of heat from the hot stamped product to at least one of the first and second die tools during the heat treatment.

25. The hot stamping system of claim 20, wherein the matrix comprises a grid.

26. The hot stamping system of claim 20, wherein each of the at least 5 of the insulation gaps occupies at least 20mm²The area of (a).

27. The hot stamping system of claim 20, wherein each of at least 5 of the insulation gaps occupies at least 100mm³The volume of (a).

28. The hot stamping system of claim 20, wherein each of at least 5 of the insulation gaps is at least 0.1mm deep.

29. The hot stamping system of claim 20, wherein:

the heating sections respectively include a first heating section of the first tool surface and a second heating section of the second tool surface; and is

The matrix includes first and second matrices formed in the first and second heating portions, respectively.

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