Stainless steel joint plate for automobile door trim strip and manufacturing method of stainless steel joint plate

Abstract

The stainless steel joining sheet material for an automobile door trim strip according to the present invention comprises: a surface material formed from a 300-series stainless steel sheet material having a predetermined thickness; the base material is attached to the back surface of the surface material in a flat plate form and is formed by a 400-series stainless steel plate with magnetism; and an adhesive layer located between the surface material and the base material to bond the surface material and the base material to each other, the surface material having a property of relatively greater elongation than the base material.

Description

TECHNICAL FIELD

[0001] The present invention relates to a stainless steel joint plate for a car door trim and a manufacturing method thereof, and more particularly, to a stainless steel joint plate for a car door trim and a manufacturing method thereof, which realizes excellent corrosion resistance and workability by joining stainless steels having different properties. BACKGROUND

[0002] Generally, a stainless steel car door trim is manufactured by cutting a stainless steel material according to a specification and by forming, bending, and pressing it into a door frame, a door belt, a small triangular side window, etc.

[0003] The finishing material as described above has a great influence on durability, corrosion resistance, or aesthetic sense of glossiness, color, etc. in addition to the purpose of using the material properties unique thereto, as a part directly exposed to the human vision.

[0004] Also, recently, for a car door trim, a mirror-finished product in which a surface of a stainless steel is mirror finished, a semi-mirror finished product in which a surface of a stainless steel is embossed, a colored product in which a surface of a stainless steel is coated by a plurality of coating processes, etc. are applied.

[0005] According to a manufacturing process, stainless steels have a plurality of types, and among them, a 300 series stainless steel in which chromium and nickel contents are high and which is a non-magnetic austenite type (hereinafter, referred to as 300 series stainless steel) and a 400 series stainless steel in which chromium content is high and which is a magnetic ferrite type (hereinafter, referred to as 400 series stainless steel) are mainly used.

[0006] Specifically, the 300 series stainless steel has excellent corrosion resistance and workability, but needs to be separately subjected to a mirror finishing process for surface glossiness, and has a disadvantage in that it cannot be used when it is bonded to a door frame, a door belt, PVC, TPC, etc. as a subsequent process, or when it is injection-molded into a small triangular side window.

[0007] The 400 series stainless steel can obtain a desired surface glossiness by an additional finishing process, and has a magnetic property, and thus has an advantage in that it is advantageous for subsequent processing, but has a problem in that it has weak workability because of low tensile strength and elongation, and thus cracks occur when it is formed or bent.

[0008] Furthermore, the 400 series stainless steel has weak corrosion resistance, and thus has a problem in that a surface is discolored, etc. Therefore, a method for solving the problems is required. SUMMARY

[0009] The present invention is a stainless steel joint plate for a car door trim strip, which is formed by joining a 300 series stainless steel plate having relatively high tensile strength and elongation to the upper surface of a base material formed of a predetermined 400 series stainless steel plate, and using the advantages of both the 300 series and 400 series stainless steels to ensure corrosion resistance and workability, and has magnetic properties, thereby improving productivity during post-processing.

[0010] The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

[0011] The stainless steel joint plate for a car door trim strip according to the present invention includes a surface material formed of a 300 series stainless steel plate having a predetermined thickness, a base material formed of a 400 series stainless steel plate having magnetic properties and attached to the back surface of the surface material in a flat plate form, and a bonding layer between the surface material and the base material to join them to each other, the surface material having a characteristic of having relatively greater elongation than the base material.

[0012] Also, the surface material can be expanded when the base material is formed or bent in a direction toward the inside, and the surface state is maintained without damage such as cracking.

[0013] Also, the surface material can be formed of an Austenite type stainless steel, and the base material can be formed of a Ferrite type stainless steel.

[0014] Also, the present invention is characterized in that the bonding agent can be applied to one surface of at least one of the base material or the surface material or attached to the one surface in a film form.

[0015] Also, the surface material can be formed of a material having an elongation of 50% or more and relatively strong resistance to processing impact than the base material.

[0016] Also, the present invention is characterized in that the surface material can adjust the gloss and color through a separate surface treatment.

[0017] Also, the surface material can be formed of one of STS304, STS304L, STS304J1, STS316, or STS316L, and the base material can be formed of one of STS409, STS411, STS430, STS436, or STS441.

[0018] Also, the surface material can have a thickness of 0.1 to 0.3 mm, and the base material can have a thickness of 0.3 to 0.7 mm.

[0019] In another aspect, a method of manufacturing a joined plate material for solving the above problem includes: step (a) manufacturing a base material using a 400 series stainless steel plate material; step (b) preparing a surface material using a 300 series stainless steel plate material; step (c) applying an adhesive to one of a back surface of the surface material or an upper surface of the base material to form an adhesive layer; step (d) forming the adhesive layer between the surface material and the base material and joining them to each other to manufacture a joined plate material; and step (e) processing the joined plate material into a predetermined size and shape.

[0020] Also, the method of manufacturing a joined plate material for solving the above problem can further include: step (f) performing at least one of a gloss adjustment process for adjusting a gloss of the surface material and a coloring process for adjusting a color of the surface material in the step (b).

[0021] Also, the method of manufacturing a joined plate material for solving the above problem can further include: step (f) performing at least one of a gloss adjustment process for adjusting a gloss of the surface material and a coloring process for adjusting a color of the surface material in the step (b).

[0022] Also, the method of manufacturing a joined plate material for solving the above problem can further include: step (f) performing at least one of a gloss adjustment process for adjusting a gloss of the surface material and a coloring process for adjusting a color of the surface material in the step (b).

[0023] The joined plate material for a car door trim strip and a method of manufacturing the same according to the present application for solving the above problem have the following advantages. A base material formed of a 400 series stainless steel plate material having magnetism is joined with a surface material formed of a 300 series stainless steel plate material having no magnetism to manufacture a joined plate material, whereby when forming, bending, and press processing of a car door trim strip are performed, cracks on a processed surface are prevented by the characteristics of the surface material having a large tensile strength and elongation, and at the same time, the manufacturing process of the trim strip can be simply performed by the base material having magnetism.

[0024] The effects of the present application are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 FIG. 1 is a view showing the structure of a joined plate material for a car door trim strip according to an embodiment of the present application.

[0026] Figure 2 FIG. 2 is a view showing the state in which a surface material and a base material of the joined plate material for a car door trim strip according to an embodiment of the present application are joined by an adhesive.

[0027] Figure 3 FIG. 1 is a view showing a state in which a 300 series stainless steel sheet is bent in a stainless steel joining sheet for an automobile door trim according to an embodiment of the present application.

[0028] Figure 4 FIG. 2 is a view showing a state in which a 400 series stainless steel sheet is bent in a stainless steel joining sheet for an automobile door trim according to an embodiment of the present application.

[0029] Figure 5 FIG. 3 is a view showing a difference after a product formed of a stainless steel joining sheet for an automobile door trim according to an embodiment of the present application and a product formed of a single sheet of a conventional 400 series stainless steel are bent, respectively.

[0030] Figure 6 FIG. 4 is a view showing a detailed state in which deformation occurs when a stainless steel joining sheet for an automobile door trim according to an embodiment of the present application is formed or bent.

[0031] Figure 7 FIG. 5 is a view showing experimental results of a joining sheet according to an embodiment of the present application.

[0032] Figure 8 FIG. 6 is a view sequentially showing an overall manufacturing process of a stainless steel joining sheet for an automobile door trim according to an embodiment of the present application.

[0033] Figure 9 FIG. 7 is a view showing a detailed process of manufacturing a surface material in the manufacturing process of Figure 8 FIG. 8 is a view showing a detailed process of manufacturing a surface material in the manufacturing process of

[0034] Figure 10 FIG. 9 is a view briefly showing an apparatus for manufacturing a stainless steel joining sheet for an automobile door trim according to an embodiment of the present application. Figure 9

[0035] Explanation of Reference Numerals

[0036] 100: joining sheet

[0037] 110: stainless steel sheet

[0038] 120: base material

[0039] 130: adhesive layer

[0040] 12: transfer roller

[0041] 14: joining roller

[0042] 16: press roller DETAILED DESCRIPTION

[0043] ​In the present specification, when it is referred to that one structural element (or region, layer, part, etc.) is present "on" or "connected" or "combined" with other structural element, it means that it can be directly disposed / connected / combined on the other structural element, or a third structural element can be further disposed between them.

[0044] The same reference numerals are used to designate the same elements throughout the specification. Also, in the drawings, the thickness, proportions, and dimensions of structural elements are exaggerated for the sake of effective explanation of the technology.

[0045] "AND / OR" includes at least one combination that can be defined by the relevant structural elements.

[0046] The first, second, and the like terms can be used to explain various structural elements, and the structural elements are not limited to the terms. The terms are used only to distinguish one structural element from other structural elements. For example, the first structural element can be named as the second structural element, and similarly, the second structural element can be named as the first structural element without departing from the scope of the present invention. Unless explicitly indicated in the context, the singular expression includes the plural expression.

[0047] Also, the terms such as "below", "under", "above", "over", and the like are used to explain the relative relationship of the structures shown in the drawings. The terms are relative concepts, and are explained based on the direction shown in the drawings.

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains. Also, the meanings of terms commonly used in dictionaries are the same as those in the context of related technology, unless they are interpreted in an ideal or excessively formal sense, otherwise defined herein.

[0049] It should be understood that the terms such as "include" or "have" are intended to indicate that there can be additional one or more other features, numbers, steps, actions, structural elements, components, or combinations thereof, in addition to those described in the specification, and do not preclude the existence or possibility of additional one or more other features, numbers, steps, actions, structural elements, components, or combinations thereof.

[0050] The plate material for the automobile door trim can be processed into a desired form by surface treating a single stainless steel plate material of 0.4 to 0.7T, and generally, a 400 series stainless steel formed of a ferrite type is mainly used.

[0051] A plate material for a door trim of an automobile using a 400 series stainless steel has an advantage of adding a finishing process after cold rolling to increase gloss, but when forming and bending processes required for the manufacturing process of a door trim of a vehicle are performed, a problem of causing severe bending due to formation of a minute crack on a processed surface occurs due to low tensile strength and elongation. Furthermore, a problem of surface discoloration occurs due to low corrosion resistance.

[0052] Therefore, to solve such a problem, a joint plate material for a door trim of an automobile according to the present application can joint stainless steel plate materials having different characteristics to produce a joint plate material exhibiting advantages of two steel types.

[0053] Hereinafter, an embodiment of the present application will be described in detail with reference to the accompanying drawings.

[0054] Figure 1 FIG. 1 is a view showing a structure of a stainless steel joint plate material 100 for a door trim of an automobile according to an embodiment of the present application, Figure 2 FIG. 2 is a view showing a state in which a surface material 110 and a base material 120 of the stainless steel joint plate material 100 for a door trim of an automobile according to an embodiment of the present application are jointed by an adhesive.

[0055] As shown in the drawing, the stainless steel joint plate material 100 for a door trim of an automobile according to an embodiment of the present application includes the surface material 110, the base material 120, and an adhesive layer 130.

[0056] The surface material 110 has a predetermined thickness and area, and is formed of a stainless steel plate material having non-magnetism. Specifically, the surface material 110 is formed of a 300 series stainless steel of an austenitic type, and has an elongation of a predetermined level or more, and corrosion resistance is relatively stronger than that of the base material 120 to be described later.

[0057] Further, the base material 120 is auxiliary to a back surface of the surface material 110, and has relatively smaller corrosion resistance or elongation than the surface material 110, and is formed of a stainless steel plate material having magnetism.

[0058] Specifically, unlike the surface material 110, the base material 120 is formed of a 400 series stainless steel of a ferritic type, and has a relatively thicker thickness than the surface material 110.

[0059] That is, the surface material 110 is jointed based on the base material 120, thereby forming a relatively thin surface and forming the stainless steel joint plate material 100 for a door trim of an automobile.

[0060] On the other hand, the adhesive layer 130 is located between the surface material 110 and the base material 120, and functions to joint the base material 120 to the surface material 110.

[0061] In the present embodiment, the adhesive layer 130 can be directly bonded to one side of one of the substrate 120 or the surface material 110 or attached in a thin film form to the one side and bond them to each other, and in a state where the substrate 120 and the surface material 110 are laminated, bonding can be stably achieved by pressure and heat.

[0062] Generally, in the case of the surface material 110, when bonding is performed by a general adhesive, peeling will occur after a prescribed time elapses, and thus there is a problem that stable bonding is difficult to maintain.

[0063] However, in the present invention, preferably, the adhesive layer 130 uses an adhesive having a bonding force of 200 N or more in a bonding strength test (Peel Test), and thus peeling and the like can be suppressed from occurring at the time of molding or bending, and additionally, a bonding force of 300 N or more can be maintained in a manner that can also withstand more severe processing such as reverse bending.

[0064] The entire process of bonding the surface material 110 and the substrate 120 by the adhesive layer 130 will be described later.

[0065] As described above, the stainless steel bonded sheet material 100 for a car door trim of the present invention as described above changes the shape by additional processing in a bonded state, and the surface material is bent in a manner of forming an outer surface, and thus stable processing can be performed.

[0066] In particular, in the stainless steel bonded sheet material 100 for a car door trim of the present invention, the surface material 110 has a characteristic that the elongation is relatively larger than that of the substrate 120, and when the substrate 120 is bent in a direction toward the inside, it can be expanded together without being damaged and maintaining the surface state.

[0067] Unlike a sheet material formed of a 400 series stainless steel that is a single material as a form that has been mainly used in the past, the bonded sheet material of the present invention as described above is formed in a state where the substrate 120 and the surface material 110 are bonded, and thus can have characteristics of a 300 series stainless steel and characteristics of a 400 series stainless steel.

[0068] In particular, in the bonded sheet material 100 of the present invention, the substrate 120 is formed of a 400 series stainless steel sheet material, and thus characteristics of a single 400 series stainless steel sheet material that has been used in the past are maintained, and at the same time, the surface material 110 is formed of a 300 series stainless steel sheet material, and thus has a relatively high elongation, tensile strength, and yield strength.

[0069] That is, the present invention has characteristics of a 300 series stainless steel and characteristics of a 400 series stainless steel.

[0070] As described above, the joined plate material of the present application is not simply formed of one plate material, but a 300 series stainless steel plate material and a 400 series stainless steel plate material are joined to form one plate material, whereby, compared with the 400 series stainless steel plate material for automobiles which has been used in the past and which has undergone several finishing processes, the following advantages are obtained, the processing cost is relatively low, and at the same time, when processed into a desired form, stable processing is possible due to the high elongation, tensile strength and yield strength, and the corrosion resistance is excellent.

[0071] Next, referring to Figure 3 and Figure 4 , the characteristics of the 300 series stainless steel plate material and the 400 series stainless steel plate material of the present application will be described separately.

[0072] Figure 3 FIG. 1 is a view showing the state of bending the 300 series stainless steel plate material in the stainless steel joined plate material 100 for automobile door trim strips according to an embodiment of the present application, Figure 4 FIG. 2 is a view showing the state of bending the 400 series stainless steel plate material in the stainless steel joined plate material 100 for automobile door trim strips according to an embodiment of the present application.

[0073] First, referring to Figure 3 , Figure 3 is the state of bending the 300 series stainless steel plate material, and corresponds to the surface material 110 in the present application.

[0074] The surface material 110 has an elongation of approximately 50%, and has a relatively higher elongation, tensile strength than the base material 120, and has a characteristic of being strong against processing impact. In particular, in the case of the 300 series stainless steel, since the durability is strong, the characteristics against damage or corrosion from the outside are relatively strong, and it is a material suitable as an external material.

[0075] Thus, as shown in the drawing, in the case of the 300 series stainless steel plate material, even if it is processed to zero bend to bend it into a completely folded form, swelling occurs in the corresponding position, so that the surface state is maintained and damage does not occur.

[0076] Preferably, the surface material 110 is formed of one of STS304, STS304L or STS316L, and in the present embodiment, STS304L which is relatively inexpensive and contains Ti (titanium) is used.

[0077] Further, the thickness of the surface material 110 can be 0.1 mm to 0.3 mm. This is thinner than the base material 120 described later, and can minimize the weight of the stainless steel joined plate material 100 for automobile door trim strips of the present application, and thereafter, when processing is performed, the surface material 110 is formed at a position where deformation occurs more.

[0078] Additionally, a hairline texture can be processed on the surface of the surface material 110, or various surface decoration treatments such as vibration, beadblasting, and embossing can be performed.

[0079] As mentioned above, for Figure 3 The surface material 110 shown is relatively simple to process due to its properties, and can be further surface-processed.

[0080] On the other hand, refer to Figure 4 , Figure 4 The state of the 400 series stainless steel sheet is bent, which corresponds to substrate 120 in this invention.

[0081] The substrate 120 is attached to the back side of the surface material 110, has a relatively low elongation of about 20-30% compared to the surface material 110, and is less resistant to processing impacts, but is magnetic and can be manufactured at a low cost. In particular, for 400 series stainless steel, due to the low elongation, it is more advantageous to form a skeleton internally than to place it on the surface.

[0082] However, 400 series stainless steel sheets are magnetic materials. When additional processing is performed, they have the advantage of being magnetically positioned and have the advantage of having strength above a specified level. However, due to their low gloss, additional finishing processes are required, which has the disadvantage of needing to perform a polishing operation.

[0083] For the substrate 120 as described above, when deformation of a specified level or above occurs, breakage occurs due to the low elongation rate. In particular, as shown in the figure, when it is processed into a completely folded shape with zero bending, cracks will appear on the surface.

[0084] Preferably, the substrate 120 is formed of one of the steel grades STS409, STS430, STS436 or STS441, and STS409 is used in this embodiment.

[0085] Furthermore, the thickness of the substrate 120 can be from 0.3 mm to 0.7 mm. This is a thicker thickness compared to the surface material 110, maintaining a specified level of rigidity. At the same time, the surface material 110 is used to form locations where more deformation occurs when the stainless steel joining sheet 100 of the joined automotive door trim strip is processed.

[0086] As described above, the 300 series stainless steel sheet and the 400 series stainless steel sheet have different properties from each other, and are joined together as the surface material 110 and the substrate 120, thereby constituting the joined sheet 100 of the present invention.

[0087] In the present embodiment, as described above, the surface material 110 uses STS 304L and the base material 120 uses STS 409, as shown in Table 1 below, which can be considered and selected based on the table derived from the Posco Mill Test Certificate, in terms of yield strength, tensile strength, and elongation.

[0088] Table 1

[0089]

[0090] Based on Table 1, the surface material 110 and the base material 120 of the present application can be formed of stainless steel having different thicknesses and characteristics, respectively.

[0091] Next, referring to Figure 5 and Figure 6 , the joined sheet material 100 for a car door trim strip of the present application, in which the base material 120 is joined with the surface material 110, is described as follows.

[0092] Figure 5 To show the difference after bending the product formed of the joined sheet material for a car door trim strip of the present application and the product formed of a single sheet of the existing 400 series stainless steel, Figure 6 To show the detailed state of deformation occurring when bending the joined sheet material 100 for a car door trim strip of the present application.

[0093] Referring to the photographs shown in the drawings, which are the joined sheet material 100 for a car door trim strip of stainless steel bending a single sheet formed of a 400 series stainless steel sheet and the joined sheet material of the present application, respectively, in the case of the single sheet, when bending above a prescribed level, the surface will be cracked.

[0094] Specifically, Figure 5 (a) of FIG. 1 is a photograph of a car door trim strip of stainless steel formed of a 400 series stainless steel sheet, in which, when deformation above the elongation occurs, the surface will be cracked or damaged.

[0095] In this case, in the case of the 400 series stainless steel sheet, since it has magnetism and has a hardness above a prescribed level, it is relatively suitable as a material for positioning or maintaining a form when processing is performed, but when additional processing is performed, since the elongation is low, there is a problem in that it is difficult to process.

[0096] Furthermore, generally, for a car door trim strip formed of only a 400 series stainless steel sheet, mainly STS 430J1L is used, although the cost itself is lower than that of a 300 series stainless steel sheet, in essence, in order to use it as a car door trim strip, it is necessary to additionally perform a finishing process of adjusting the surface glossiness 3 to 5 times, thereby there is a problem that the cost is substantially increased.

[0097] In contrast, as shown in (b) of FIG. 1, in the stainless steel joint sheet 100 for a car door trim strip of the present application, in a case where the surface material 110 and the base material 120 are formed as joint materials, each material has a characteristic. Figure 5

[0098] Especially, when the base material 120 is bent in the inward direction, the surface material 110 will be expanded and will not be damaged but can maintain the surface state.

[0099] In detail, as shown in (b) of FIG. 1, the surface material 110 is jointed to the upper portion of the base material 120, and the base material 120 forms a relatively thick thickness, and thus the center line of the joint sheet is located in the base material 120. Figure 6

[0100] Furthermore, the separation distance d of the surface material 110 in the center line is adjusted due to the thickness difference between the surface material 110 and the base material 120, and the surface material 110 is formed at a position where relatively more expansion occurs.

[0101] That is, the surface material 110 is separated by a distance d in the center line of the joint sheet and is located on the surface, and thus even if relatively more expansion occurs, it can be deformed due to the high elongation and maintain the surface state.

[0102] As described above, compared to a single sheet formed of only the 400 series stainless steel sheet, the stainless steel joint sheet 100 for a car door trim strip of the present application is relatively simple to process, and can have excellent corrosion resistance due to the characteristics of the 300 series stainless steel sheet.

[0103] Especially, the stainless steel joint sheet 100 for a car door trim strip of the present application is processed into a desired form by an additional process in a state of being manufactured from a joint sheet.

[0104] The stainless steel joint sheet 100 for a car door trim strip of the present application can be used for a vehicle trim strip when an additional process is performed, and when a vehicle trim strip is manufactured, a variety of methods will be used, and a door belt method, a door frame method can be used.

[0105] ​​The process is as follows: in a state where the stainless steel joining sheet 100 for a car door trim is formed into a roll shape, the stainless steel joining sheet 100 for a car door trim is joined with a separate thermoplastic (polyvinyl chloride (PVC) or thermo plastic elastomer (TPE) or the like by a high-frequency induction heating method, and then processes such as shearing, bending, and cutting are performed.

[0106] Also, unlike this, a method of processing by a insert injection method of a small triangular quarter glass is used. This is a method of injecting a thermoplastic (PVC) after a mold is inserted into the stainless steel joining sheet 100 for a car door trim processed by pressing, and thus a magnet is embedded inside the mold to fix the position of the stainless steel joining sheet 100 for a car door trim.

[0107] Therefore, in the case of manufacturing a trim for a vehicle by the above-described method, manufacturing with a material having magnetism is relatively simple, but 400 series stainless steel having magnetism has a problem in that the processability is relatively reduced compared to 300 series stainless steel.

[0108] However, as shown in the present application, the surface material 110 of 300 series is joined with the base material 120 of 400 series to manufacture the stainless steel joining sheet 100 for a car door trim of the present application, and thus the metal trim material has a predetermined level of magnetism, and when an additional process is performed, the position can be fixed by a magnet.

[0109] Also, when bending or pressing is performed at a level above a predetermined level, the surface material 110 having a relatively high elongation rate is located on the outside, and thus it is possible to prevent cracks from occurring on the surface.

[0110] That is, the present application is a joining sheet 100 in which a base material 120 formed of 400 series stainless steel having magnetism is joined with a surface material 110 formed of 300 series stainless steel having no magnetism, and thus when a car door trim is manufactured, cracks are prevented from occurring on the surface by the characteristic of the surface material 110 having a large elongation rate, and at the same time, the process of the trim is simply performed by the base material 120 having magnetism.

[0111] Next, referring to Figure 7 The joining sheet of the present application has a predetermined level of adhesion.

[0112] Figure 7 A graph showing the experimental results of the adhesion of the joining sheet of the embodiment of the present application.

[0113] The bonded sheet 100 of the present application can include a separate adhesive layer 130 between the surface material 110 and the base material 120 to achieve bonding, can maintain a bonding strength above a prescribed level, and thus can have durability superior to that of a single 400 series stainless steel sheet.

[0114] Specifically, as shown in the results of a bonding strength test (Peel Test) of the bonded sheet of the present application, the peak load value of the measured value exceeds 200 N. Figure 7

[0115] Even if formed in the bonded sheet 100 in which the base material 120 and the surface material 110 of the present application are bonded by the adhesive layer 130, it can have a strength similar to that of a single material sheet, and thus it can be known that the bonded sheet has no durability problems.

[0116] As described above, the bonded sheet of the present application has excellent workability compared to a single sheet used in the past, and can stably maintain durability due to a high elongation rate and tensile strength.

[0117] Additionally, for a sheet used for a door trim of an automobile, a gloss adjustment process and a coloring process for adjusting color can be additionally performed, and in this process, the bonded sheet of the present application can be relatively inexpensive and can be quickly performed compared to a 400 series stainless steel sheet commonly used.

[0118] First, the gloss adjustment process is described. For a 400 series stainless steel single sheet used in the past, STS430J1L is used as a reference to additionally perform a finishing process to obtain a desired gloss.

[0119] In particular, for a 400 series stainless steel, although a finishing process is performed in a production process, a process is additionally performed 3 to 5 times, and thus a high-gloss surface can be obtained.

[0120] Unlike this, for the bonded sheet 100 of the present application, the surface material 110 itself is formed of STS304, which is a 300 series thin sheet stainless steel, and after being rolled, a gloss can be obtained through a simple heat treatment process. Of course, if necessary, a polishing process can be additionally performed, but a gloss above a prescribed level can be obtained only through a simple heat treatment.

[0121] That is, as shown in the present application, the bonded sheet 100 in which a 300 series stainless steel is used as the surface material 110 and a 400 series stainless steel is used as the base material 120 can obtain a gloss above a prescribed level even without a separate polishing process.

[0122] ​Next, the difference between the joint plate 100 of the present application and the conventional 400 series single plate will be described with respect to the coloring process.

[0123] In this case, when the coloring process of the surface material 110 is performed, titanium ions or chromium ions are evaporated according to the color to embody the color, and the surface material 110 uses a 300 series stainless steel plate.

[0124] For example, when the color of the surface material 110 is gold, evaporation is performed using nitrogen gas and titanium in a sealed space, black is performed using carbon gas and chromium, and bronze is performed using a mixed gas of carbon and nitrogen and titanium.

[0125] As described above, the joint plate for a stainless steel automobile door trim 100 of the present application can embody the color of the surface material 110 through a separate coloring process.

[0126] Generally, for the coloring process, a vacuum evaporation method (PVD: Physical vapor deposition) method in which a plate is inserted into a sealed space to perform evaporation or a nano ceramic coating (NCC: Nano Ceramic Coating) method is used.

[0127] When the coloring process is performed through the vacuum evaporation method, after a target object is inserted into the inside of a vacuum chamber of a predetermined size to form a high vacuum state, coloring is performed through an evaporation process.

[0128] In this case, in the present application, when the plate is inserted into the inside of the vacuum chamber, it is inserted by being wound in a coil shape, and thus, compared to the volume, a relatively large amount of the plate can be colored.

[0129] In the present application, not the entire joint plate but only the surface material 110 is inserted by being wound, and thus, a length of 2000 m (0.15 t is a reference) or more can be colored at a time.

[0130] In contrast, in the case of a single steel plate of a 400 series stainless steel, it is difficult to insert the plate by being wound due to the thickness of the plate itself, and even if it is wound, the entire length is short, and thus, compared to the method of coloring only the surface material 110 as in the present application, a relatively short length can be colored.

[0131] In the vacuum evaporation process, the evacuation time for the vacuum inside the vacuum chamber is substantially the same, and thus, the length colored in the same time differs, and relatively, compared to the method of coloring the entire joint plate, the method of coloring only the surface material 110 can color a larger amount.

[0132] On the other hand, when the coloring process is carried out by nano-ceramic coating, the thickness of the surface material 110 is relatively thin compared with the coloring of a single sheet of 400 series stainless steel, thereby reducing energy consumption and increasing production speed.

[0133] That is, the surface materials 110 and 400 series stainless steel single sheets, which are the objects of coloring, are essentially different in thickness, thus causing a difference in productivity during the coloring process.

[0134] Furthermore, when only the surface material 110 is coated, coating can be achieved using a slit die, thus offering more than four times the productivity compared to currently used spraying, and enabling high-quality coating.

[0135] The geometric structure and physical properties of the stainless steel bonding plate 100 for automotive door trim strip according to an embodiment of the present invention have been described above. The process of manufacturing the stainless steel bonding plate 100 for automotive door trim strip as described above will be described below.

[0136] Figure 8 The diagram shows the overall manufacturing process of the stainless steel joining plate 100 for automotive door trim strips according to an embodiment of the present invention. Figure 9 To show in Figure 8 A diagram showing the detailed process of manufacturing surface material 110 during the manufacturing process. Figure 10 To briefly illustrate the manufacturing process Figure 9 A diagram of an assembly for a stainless steel joining plate 100 used for automotive door trim strips.

[0137] The overall manufacturing process of the stainless steel bonding sheet 100 for automotive door trim strips of the present invention is described. First, step (a) is performed to manufacture substrate 120 using stainless steel sheet of the 400 series as a ferritic type.

[0138] The substrate 120 is made of 400 series stainless steel sheet and is formed into a flat plate of a predetermined thickness. The thickness of the substrate 120 is 0.3 mm to 0.7 mm, and it is formed into a shape by being rolled by individual rollers in an extruded state.

[0139] That is, as described above, the substrate 120 is made into a flat plate of a predetermined thickness and wound along its length.

[0140] Moreover, such as Figure 10 As shown, the substrate 120, in a wound state, is transferred along a predetermined transfer path by a separate transfer roller 12. In this case, the transfer roller heats the substrate 120 to a predetermined level, thereby ensuring stable bonding with the surface material 110 via the adhesive layer 130.

[0141] Next, a step (b) of preparing the surface material 110 with an austenite type 300 series stainless steel sheet is performed.

[0142] Like the base material 120, the surface material 110 is formed of a sheet having a prescribed thickness, but unlike the base material 120, is made of a 300 series stainless steel sheet.

[0143] Specifically, the surface material 110 can have a thickness of 0.1 mm to 0.3 mm and an elongation of about 50%, and can be formed of one of STS304, STS304L, STS304Jl, STS316, or STS316L.

[0144] In the present embodiment, like the base material 120, the surface material 110 is manufactured in a sheet form and is stored in a rolled state, and thereafter, the rolled portion is re-rolled and transferred so as to be bonded to the base material 120.

[0145] Thereafter, a step (c) of forming a bonding layer 130 for joining the surface material 110 and the base material 120 is performed.

[0146] In the step (c), the bonding layer 130 can be formed between the surface material 110 and the base material 120 and join them to each other, and is applied to at least one of the back surface of the surface material 110 or the upper surface of the base material 120.

[0147] In the present embodiment, as shown in FIG. 1, the bonding layer 130 is formed by applying it to the lower surface of the surface material 110 and then drying it. Figure 10

[0148] In this case, the surface material 110 can pass through a separate drying furnace 13 provided on the transfer path, and can be transferred after passing through an additional drying process in which the bonding layer 130 is applied.

[0149] As described above, after the step (c) of forming the bonding layer 130 on the upper surface of the base material 120, a step (d) of joining the base material 120 and the bonding layer 130 is performed.

[0150] In the step (d), the bonding layer 130 is formed between the surface material 110 and the base material 120 and joins them to each other to manufacture a joined sheet 100.

[0151] ​Specifically, in the step (d), as shown in Figure 10 The substrate 120 and the surface material 110 are engaged with each other and transferred by a separate engagement roller 14 provided downstream of the transfer roller 12 on the transfer path.

[0152] In this case, the surface material 110 and the substrate 120 are independently transferred, connected to the transfer path of the substrate 120 at the downstream portion of the transfer direction, and transferred in a converging manner.

[0153] In the present embodiment, the surface material 110 is independently transferred after the adhesive layer 130 is formed on the lower surface, and is stacked on the upper portion of the back material 120.

[0154] That is, as described above, the surface material 110 and the substrate 120 are transferred by a plurality of rollers in a state of being wound in a roll type, and are merged and stacked with a portion of the transfer path. Also, the surface material 110 is passed through the engagement roller 14 in a state of being stacked on the upper portion of the substrate 120, and is simultaneously transferred and engaged.

[0155] The engagement roller 14 can be heated to a prescribed level of temperature, and can simultaneously perform heating and pressurization when the substrate 120 and the surface material 110 are engaged.

[0156] As described above, after passing through the engagement roller 14, the substrate 120 and the surface material 110 pass through the press roller 16 in a state of being stacked, and are applied with pressure, and the engaged panel material 100 in a state of being engaged with each other is transferred.

[0157] After that, the substrate 120 and the surface material 110 that have passed through the press roller 16 pass through a separate cooling zone 18 in an engaged state, are transferred in a completely engaged state, and are rewound and stored.

[0158] Next, a step (e) of processing the engaged panel material in which the substrate 120 and the surface material 110 are engaged into a predetermined shape is performed.

[0159] The step (e) is a process of tailoring the engaged panel material according to use, and cutting according to a predetermined size and rule.

[0160] The engaged panel material 100 of the present application is used as a car door trim, and thus can be cut into a form and a specification that conform to the size thereof.

[0161] In particular, the joining plate 100 of the present application is cut into an automobile door trim after which various methods are used when actually processing the trim, and a door belt method, a door frame method, or a small triangular quarter glass inlay injection method can be used.

[0162] The method proceeds as follows: the stainless steel joining plate 100 for an automobile door trim is joined to a separate thermoplastic (polyvinyl chloride (PVC) or thermo plastic elastomer (TPE), etc.) by a high frequency induction heating method, after which shearing, bending, and cutting, etc. are performed, or after pressing processing is performed, an inlay injection method, etc. is performed using a mold.

[0163] Therefore, when a vehicle trim is manufactured by the above-described method, even if deformation occurs due to the surface material 110, the surface is maintained in a stable state, and at the same time, by the magnetic properties of the base material 120, the position can be stably fixed when the trim is processed.

[0164] In the stainless steel joining plate 100 for an automobile door trim of the present application manufactured according to the above-described process, as the surface material 110 having a predetermined area and the base material 120 attached to the back of the surface material 110 are joined to each other, in addition to excellent durability and elongation and tensile strength, which are characteristics of a 300 series stainless steel material, magnetic properties, which are characteristics of a 400 series stainless steel material, are also exhibited, and relatively low production costs, etc. can be exhibited in combination.

[0165] Additionally, the step (b) of the present application can perform at least one of a gloss adjustment process of adjusting the gloss of the surface material 110 and a coloring process of adjusting the color of the surface material 110.

[0166] Reference Figure 9 The gloss adjustment process can adjust the gloss by mirror processing on the surface by an additional process when the surface material 110 is processed or by a bead blasting process, etc., and in the present embodiment, is processed to have a gloss of about 200 to 300 at an angle of 60 degrees.

[0167] Specifically, the gloss adjustment process performed on the surface material 110 is as follows.

[0168] First, a process (b-1) of preparing a 300 series stainless steel plate is performed. Also, a heat treatment process is performed on the stainless steel plate. In this case, a selection process (b-2) of selecting the degree of gloss of the stainless steel plate is performed.

[0169] In particular, the degree of gloss of the surface material 110 is selected to be a general glossy surface or a semi-glossy surface or the gloss itself is adjusted to which degree, and the subsequent process is performed.

[0170] Among them, in the case of the surface material 100, generally, in the case of a 300 series stainless steel plate, only by simple heat treatment, it can have a gloss level above the prescribed level, and according to the situation, when a higher gloss is required, a mirror surface process (process b-3) is performed.

[0171] That is, when the surface material 100 is made into a glossy surface, a heat treatment and an additional mirror surface process are performed.

[0172] On the contrary, when the surface material 110 needs to be surface-treated to a semi-glossy surface, a sandblasting process or a process using an embossing roll (process b-4) is additionally performed.

[0173] As described above, in the present application, the surface material 110 is subjected to the gloss adjustment process before being joined with the base material 120, and in the gloss adjustment process, a glossy surface or a semi-glossy surface can be adjusted.

[0174] For example, in the present application, when the surface material 110 has a glossy surface, it has a thickness of 0.1 ~ 0.2 t in STS304 or STS316, and a separate mirror surface processing is performed on one side. At the same time, in the base material 120, STS409, 411, 430, etc. have a thickness of 0.3 ~ 0.6 t, and a separate surface treatment process is not performed.

[0175] Also, in the present application, when the surface material 110 has a semi-glossy surface, it is surface-treated by a pressurization process using an additional embossing roll and by a sandblasting process, thereby having a required gloss.

[0176] As described above, in the present application, the surface material 110 can be subjected to a gloss adjustment process having a required level of gloss.

[0177] After that, the coloring process (b-5) is performed in a state in which the surface material 110 is subjected to the gloss adjustment process and made into a glossy surface or a semi-glossy surface.

[0178] In detail, the coloring process is a process of coloring the surface material 110 using at least one inorganic material, and in the present application, it is performed by vacuum evaporation in a physical vapor deposition (PVD) method.

[0179] In this case, when the coloring process of the surface material 110 is performed, titanium ions or chromium ions can be evaporated according to colors to embody colors, in which case the surface material 110 uses a 300 series stainless steel plate.

[0180] For example, when the color of the surface material 110 is gold, evaporation is performed using nitrogen gas and titanium in a sealed space, black uses carbon gas and chromium, and bronze color is embodied using a mixed gas of carbon and nitrogen and titanium.

[0181] Next, the surface material 110, which has undergone the coloring process, can additionally undergo a nano-ceramic wet coating process (b-6).

[0182] As the nano-ceramic wet coating is performed, the surface of the surface material can be inhibited from being contaminated, and durability and gloss maintenance of the surface can be greatly helped.

[0183] As described above, the automobile door trim strip use stainless steel joint plate 100 of the present application can embody colors in the surface material 110 through a separate coloring process.

[0184] As described above, the preferred embodiments of the present application have been explained, and it is obvious to those skilled in the art to which the present application pertains that the present application can be embodied in other specific forms other than the above-described embodiments without departing from the spirit or essential characteristics of the present application. Accordingly, the above-described embodiments are not limitative but illustrative, and the present application is not limited to the above-described embodiments but can be variously modified within the scope of the appended claims and their equivalents.

Claims

1. A stainless steel joint plate for a door trim of an automobile, characterized by comprising: a surface material formed of a 300 series stainless steel plate material made to a predetermined thickness; a base material attached to a back surface of the surface material in a flat plate form, formed of a 400 series stainless steel plate material having magnetism; and a bonding layer between the surface material and the base material to join them to each other, the surface material having a property that an elongation is relatively greater than that of the base material.

2. The stainless steel joint plate for a door trim of an automobile according to claim 1, characterized in that the surface material has a thickness of 0.1 to 0.3 mm, and the base material has a thickness of 0.3 to 0.7 mm.

3. The stainless steel joint plate for a door trim of an automobile according to claim 1, characterized in that the surface material is formed of one of STS304, STS304L, STS304Jl, STS316 or STS316L, the base material is formed of one of STS409, STS411, STS430, STS436 or STS441, the surface material expands when the base material is formed or bent in a direction toward an inner side, and maintains a surface state without damage including a crack.

5. The stainless steel joint plate for a door trim of an automobile according to claim 1, characterized in that the surface material is formed of an austenitic type stainless steel, the base material is formed of a ferritic type stainless steel, the adhesive is applied to one side of at least one of the base material or the surface material or is attached to the one side in a film form, the surface material is formed of a material having an elongation of substantially 50% or more and relatively strong resistance to processing impact than the base material, the surface material adjusts a gloss and a color by a separate surface treatment.

6. A method of manufacturing a stainless steel joint plate for a door trim of an automobile, characterized by comprising: a step (a) of manufacturing a base material using a 400 series stainless steel plate material; a step (b) of preparing a surface material using a 300 series stainless steel plate material; a step (c) of applying an adhesive to one of a back surface of the surface material or an upper surface of the base material to form a bonding layer; a step (d) of forming the bonding layer between the surface material and the base material and joining them to each other to manufacture a joint plate; and a step (e) of processing the joint plate to a predetermined size and shape.

7. The method of manufacturing a stainless steel joint plate for a door trim of an automobile according to claim 6, characterized in that the joint plate joined in the step (d) has a joint force of 200 N or more.

8. The method of manufacturing a stainless steel joint plate for a door trim of an automobile according to claim 6, characterized in that at least one of a gloss adjusting process of adjusting a gloss of the surface material and a coloring process of adjusting a color of the surface material is performed in the step (b).

9. The method of manufacturing a stainless steel joint plate for a door trim of an automobile according to claim 8, characterized in that the surface material is wound in a roll form to perform the gloss adjusting process or the coloring process when the gloss adjusting process or the coloring process is performed. ​ ​ ​ ​ 4. The stainless steel joining sheet for an automobile door trim according to claim 1, characterized by ​ ​ ​ ​ 6. The stainless steel joining sheet for an automobile door trim according to claim 1, characterized by ​ 7. The stainless steel joining sheet for an automobile door trim according to claim 1, characterized by ​ 8. The stainless steel joining sheet for an automobile door trim according to claim 1, characterized by ​ 9. A method of manufacturing a stainless steel joint panel for an automobile door trim strip, characterized by, ​ ​ ​ ​ ​ ​ ​ 10. The method of manufacturing a stainless steel joint panel for an automobile door trim strip according to claim 9, characterized in that, ​ 11. The method of manufacturing a stainless steel joint panel for an automobile door trim strip according to claim 9, characterized in that, ​ 12. The method of manufacturing a stainless steel joint panel for an automobile door trim strip according to claim 11, characterized in that, ​

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