KR102422579B1 - Method of manufacturing tailor weleded blanks for hot stamping - Google Patents

Abstract

A method of manufacturing a tailor welded blank for hot stamping obtained by welding blanks of different thicknesses or materials to each other is introduced. The manufacturing method includes the steps of removing 45-55% of the plating layer by irradiating a laser on the surface along the edge welded portion of the plated steel sheet; and butting the plated steel sheets obtained in the previous step to each other and welding the plated steel sheets along the edge welds with a laser.

Description

Taylor welded blank manufacturing method

The present invention relates to a blank manufacturing method, in particular to a manufacturing method of a Taylor welded blank for hot stamping obtained by welding blanks of different thicknesses or materials to each other.

With the global trend of strengthening environmental and safety regulations, there is a high demand for light weight and high strength in the vehicle industry. Light weight is essential for so-called eco-friendly vehicles such as electric vehicles and hydrogen vehicles as well as traditional internal combustion engine vehicles, and high strength of parts is required to ensure safety as well as light weight.

Although ultra-high tensile steel is used for manufacturing high-strength vehicle parts, the ultra-high tensile strength steel sheet has poor formability, so there is a limit to its application range. For simultaneous realization of high strength and high formability, hot stamping technology has been developed and its application is widely expanding.

Hot stamping is a technique to obtain high-strength parts of 1400Mpa or higher by heating a steel sheet to a high austenite transformation temperature (AC ₃ ) or higher, for example, 900°C or higher, and then rapidly cooling it while forming in a press mold. As a hot stamping material, so-called boron steel containing about 0.2 wt% of carbon and a small amount of manganese (Mn) and boron (B) to improve heat treatment performance is used.

Hot stamping not only has excellent productivity because forming and heat treatment are performed at the same time, but also has excellent formability and dimensional accuracy because the steel sheet is formed at a high temperature. In addition, hot stamping has an advantage in that it can reduce springback or delayed fracture, which is a problem especially when cold forming of ultra-high strength steel sheet.

Since the hot stamping process is performed at a high temperature of 900° C. or higher, scale occurs on the surface of the steel sheet during the forming process when an uncoated steel sheet is used. This scale should be removed in a post-process, and a steel sheet having Al and Zn plating layers is proposed to omit this cumbersome descaling process. Regarding the Al-coated steel sheet, reference may be made to US Patent No. 6296805.

TWB (Tailor Welded Blank) technology is being applied in the manufacturing field of vehicle body parts. TWB technology is a technology that makes one blank (Taylor welded blank) by butt-welding blanks of different thicknesses or strengths to meet the characteristics required by the part to be manufactured. By using TWB and hot stamping together, it is possible to reduce the weight of body parts and improve collision performance.

TWB is difficult to apply to a steel sheet for hot stamping having a plating layer, for example, an Al-coated steel sheet. This is because, during the welding process, Al-Si components of the Al plating layer are mixed in the welded part to lower the weld strength.

An object of the present invention is to provide a method for manufacturing a tailor welded blank for hot stamping in order to solve the problems of the prior art.

Another object of the present invention is to provide a method for manufacturing a tailor welded blank for hot stamping, which can have excellent welding quality and strength of the welded part.

The problems to be solved in the present invention are not necessarily limited to the above-mentioned matters, and other problems not mentioned will be understood by the matters described below.

A method for manufacturing a Taylor welded blank for hot stamping according to the present invention for achieving the above object includes: removing 45 to 55% of the plating layer by irradiating a laser on the surface along the edge welded portion of a plated steel sheet; and butting the plated steel sheets obtained in the previous step to each other and welding the plated steel sheets along the edge welds with a laser.

According to the present invention, the plated steel sheet is plated by immersing the base steel sheet in an Al plating bath and then heat-treated at a temperature of 670 to 900 ° C. The plating layer is an Fe-Al-based intermetallic compound layer and an aluminum layer formed on the intermetallic compound layer and, the thickness of the plating layer is 5 to 20 μm, and the thickness of the Fe-Al-based intermetallic compound layer is 5 to 18 μm.

According to the present invention, since the plating layer of the Taylor welded blank is pre-alloyed, not only the Fe-Al-based intermetallic compound layer is a major component of the plating layer, but also 45-55% of the plating layer including the Fe-Al-based intermetallic compound layer is removed, Since the thickness of the plating layer is thin and there is a hard Fe-Al-based intermetallic compound layer in the welding part, welding is easy, and the welding quality and strength in the welding part can be excellent.

In addition, since the plated layer is removed by irradiating a laser on the surface along the edge welded portion of the plated steel sheet, the laser processing speed can be fast.

Hereinafter, examples will be given in more detail so that various characteristic aspects of the present invention can be understood. In the drawings, the same or equivalent elements may be denoted by the same reference numerals, and the drawings may be exaggerated or schematically illustrated for an intuitive understanding of the features of the present invention.

A method for manufacturing a tailor welded blank according to an embodiment is described.

Aluminum-based plated steel sheets having different thicknesses or strengths are prepared. The plated steel sheets have a plating layer on one side or both sides, and the plating layer includes an Fe-Al-based intermetallic compound layer and an aluminum layer formed on the intermetallic compound layer. The plated steel sheet is plated by immersing the base steel sheet in an Al plating bath and then heat-treated at a temperature of 670 to 900 ° C.

45-55% of the plated layer is removed from the welds of the prepared plated steel sheets. The welded portion of the plated steel sheet is provided along the edge of the plated steel sheet to be butt welded. A laser is irradiated along the edge welds of the plated steel sheets for partial peeling of the plated layer. The laser may be irradiated in an inclined direction to the edge weld. It is a direction from the center side of the plated steel sheet toward the edge in the inclined direction. Since the plating layer is removed by irradiating a laser to the surface along the edge welded portion, laser processing can be performed quickly.

The aluminum layer of the plated steel sheet is less than 10%. Since 45-55% of the plating layer is removed, about 40% of the intermetallic compound layer is removed. Although the intermetallic compound is a major component of the intermetallic compound layer, it cannot be said that it is completely composed of 100% intermetallic compound. Through the alloying process of the surface plating layer, inter-diffusion between the steel sheet and Al plating, which is the base material, is obtained, and the upper portion of the plating layer may be rich in aluminum, and the lower portion of the plating layer may be rich in iron. By removing the intermetallic compound layer as well as the aluminum layer that interferes with the welding and deteriorates the quality of the weld, the quality of the weld in the weld can be improved.

The plated steel sheets from which the plated layer of the weld has been partially removed are placed face to face and welded to obtain a tailor welded blank. Welding is performed with a laser.

The Taylor welded blank obtained as above is put into a heating furnace and heated to an austenitizing temperature or higher, followed by forming and rapid cooling using a press mold. A high-strength component having a martensitic phase is obtained by quenching.

The aluminum-based plated steel sheet according to an embodiment of the present invention includes a base steel sheet and a plating layer formed on the surface of the base steel sheet, the plating layer is formed on the surface of the base steel sheet and Fe ₃ Al, FeAl(Si), Fe ₂ Al ₅ and FeAl an intermetallic compound layer comprising at least one of ₃ , and an aluminum layer formed on the intermetallic compound layer and having a thickness of less than 10% of the plating layer thickness, the plating layer having a thickness of 5 to 20 µm, and 0.1 µm deep from the surface of the plating layer Oxygen as measured by GDS is 10% by weight or less.

An aluminum-based plated steel sheet according to an embodiment of the present invention includes a base steel sheet and a plating layer formed on the surface of the base steel sheet. In addition, the plating layer is formed on the surface of the base steel sheet and includes an intermetallic compound layer including at least one of Fe ₃ Al, FeAl(Si), Fe ₂ Al ₅ and FeAl ₃ , and an aluminum layer formed on the intermetallic compound layer.

According to one embodiment of the present invention, the intermetallic compound layer may include at least one of Fe ₃ Al, FeAl(Si), Fe ₂ Al ₅ and FeAl ₃ . In addition, the intermetallic compound layer may mainly include one or more of Fe ₃ Al, FeAl(Si), Fe ₂ Al ₅ and FeAl ₃ .

According to one embodiment of the present invention, the intermetallic compound layer may include 50% or more of at least one of Fe3Al, FeAl(Si), Fe2Al5 and FeAl3, preferably 80% or more, more preferably It may contain 90% or more, and most preferably 95% or more.

According to an embodiment of the present invention, the intermetallic compound layer mainly includes one or more alloy phases of Fe3Al, FeAl(Si), Fe2Al5, and FeAl3, but impurities and other elements that may be included in the plating bath are also unavoidably included. It may contain small amounts.

In the present invention, when Mg is added as an example, Mg may be partially included in the Al-Fe-based alloy phase in the alloying layer, and the intermetallic compound layer is another alloy phase including the Al-Fe-Mg-based alloy phase. may also include

When an alloying heat treatment is performed after aluminum plating on the base steel sheet, Fe of the base steel sheet is diffused into the aluminum plating layer having a high Al content. As a result, an intermetallic compound layer mainly composed of an intermetallic compound of Al and Fe formed as a result of diffusion may be formed on the base steel sheet. Although not limited thereto, the alloy phase of the Al-Fe-based intermetallic compound mainly constituting the intermetallic compound layer may include Fe3Al, FeAl(Si), Fe2Al5, FeAl3, and the like. On the above-described alloying layer, an aluminum layer may be present that is the same as the original plating layer component or contains Fe diffused in a small amount from the base steel sheet, and in some cases, the aluminum layer may not exist due to complete alloying.

The thickness of the plating layer may be 5 to 20 μm. If the thickness of the plating layer is less than 5㎛, corrosion resistance is inferior, whereas if the thickness of the plating layer exceeds 20㎛, there is a problem that the weldability is lowered. Therefore, in the present invention, it is preferable to limit the thickness of the alloy plating layer to a thickness of 5 to 20 μm. On the other hand, the thickness of the plating layer may be preferably 6.2 ~ 19.5㎛, more preferably 5 ~ 15㎛ thickness.

Oxygen measured by GDS (Glow Discharge Spectrometer) at a depth of 0.1 μm from the surface of the plating layer may be 10 wt% or less, and more preferably 7.4 wt%. That is, in the present invention, the lower the oxygen measured by GDS at a depth of 0.1 μm from the surface of the plating layer, the better, so the lower limit may not be separately limited.

However, according to one embodiment of the present invention, oxygen measured by GDS at a depth of 0.1 μm from the surface of the plating layer including the error range may be greater than 0% and less than or equal to 10% by weight, or greater than 0% and less than or equal to 7.4%.

In the present invention, when the aluminum plating layer is alloyed, it is possible to effectively suppress an increase in the oxygen content on the surface of the plating layer because the alloying heat treatment is performed in a short time by increasing the temperature without cooling after the hot-dip aluminum plating. If the oxygen content of the surface of the plating layer exceeds 10% by weight, the surface quality of the coated steel sheet may be inferior. On the other hand, since it is advantageous as the oxygen content on the surface of the plating layer is small, the lower limit thereof may not be separately limited.

Meanwhile, an aluminum layer mainly made of aluminum may be formed on the surface side of the plating layer and on the intermetallic compound layer. In the present invention, the thickness of the aluminum layer may be controlled to be less than 10% of the thickness of the plating layer, and in some cases, the aluminum layer may not exist due to sufficient alloying. Since the interface between the aluminum layer and the intermetallic compound layer in the aluminum-based plated steel sheet is unstable, if the thickness of the aluminum layer is 10% or more of the thickness of the plating layer, peeling of the aluminum layer may occur when winding after alloying heat treatment. On the other hand, the smaller the thickness of the aluminum layer, the more preferable. The thickness of the aluminum layer may be less than 5%, more preferably less than 1%, and may be 0%.

According to an embodiment of the present invention, the plating layer is 100% by weight except for the Fe content diffused from the base steel sheet, Si: more than 4% and 15% or less, the remainder Al and other unavoidable impurities. can Si serves to uniformly alloy with Fe in the plating layer, and must be contained in an amount exceeding at least 4% in order to obtain such an effect. On the other hand, since Si also serves to suppress the diffusion of Fe, when contained in an amount exceeding 15%, Fe diffusion is excessively suppressed, and thus a desired plating layer structure may not be obtained in the present invention. The Si content may be preferably 4.5 to 14.1%, more preferably 6 to 13%, and most preferably 8 to 11%.

In addition, as an embodiment, the plating layer may optionally further include 1.1% or less of Mg by weight. When Mg is added, it serves to improve the corrosion resistance of the plated steel sheet, and an effect of increasing the alloying rate can also be obtained. However, when the Mg content exceeds 1.1%, a large amount of Mg oxide is generated on the surface after alloying and/or after hot press forming, which may cause a problem in that weldability is deteriorated. Therefore, in the present invention, the Mg content is limited to 1.1% or less. can do. In addition, more preferably, Mg may be limited to 0.9% or less, and in some cases, Mg may be limited to 0.1% or less. Also, in some cases, the plating layer may not include Mg.

According to an embodiment of the present invention, the base steel sheet is a steel sheet for hot press forming, and may not be particularly limited as long as it is used for hot press forming. However, if one non-limiting example is given, the base steel sheet is, by weight, C: 0.04 to 0.5%, Si: 0.01 to 2%, Mn: 0.01 to 10%, Al: 0.001 to 1.0%, P: 0.05% or less, It may have a composition including S: 0.02% or less and N: 0.02% or less.

C is an essential element in order to increase the strength of the heat treatment member, and may be added in an appropriate amount. That is, in order to sufficiently secure the strength of the heat treatment member, C may be added in an amount of 0.04% or more. Preferably, the lower limit of the C content may be 0.1% or more. However, if the content is too high, in the case of producing cold-rolled materials, the strength of the hot-rolled material is too high when cold-rolling the hot-rolled material, so that not only the cold-rollability is greatly inferior, but also the spot weldability is greatly reduced. In order to secure weldability, 0.5% or less may be added. In addition, the C content may be 0.45% or less, and more preferably, the content may be limited to 0.4% or less.

Si not only has to be added as a deoxidizer in steelmaking, but also serves to suppress the formation of carbides, which have the greatest influence on the strength of a hot press-formed member. In the present invention, it may be added in an amount of 0.01% or more in order to secure retained austenite by concentrating carbon at the martensite lath grain boundary after the formation of martensite in hot press forming. In addition, the upper limit of the Si content may be set to 2% in order to secure sufficient plating properties when aluminum plating is performed on the steel sheet after rolling. Preferably, the Si content may be limited to 1.5% or less.

Mn may be added in an amount of 0.01% or more in order to not only secure a solid solution strengthening effect, but also lower a critical cooling rate for securing martensite in a hot press-formed member. In addition, the Mn content can be limited to 10% or less in terms of securing the workability of the hot press forming process by properly maintaining the strength of the steel sheet, reducing the manufacturing cost, and improving the spot weldability. Preferably, the Mn content may be 9% or less, and in some cases may be 8% or less.

Al can increase the cleanliness of steel by deoxidizing in steel making along with Si, and may be added in an amount of 0.001% or more to obtain an effect. In addition, the content of Al may be limited to 1.0% or less in order to prevent the Ac3 temperature from becoming too high so that heating required for hot press molding can be performed in an appropriate temperature range.

P exists as an impurity in the steel, and it is advantageous as its content is as small as possible. Therefore, in the present invention, the P content may be limited to 0.05% or less, preferably limited to 0.03% or less. Since P is an impurity element which is advantageous as it is small, it is not necessary to specifically set an upper limit of its content. However, in order to excessively lower the P content, there is a concern that the manufacturing cost may increase, and in this case, the lower limit may be set to 0.001%.

S is an impurity in steel, and since it is an element that impairs ductility, impact properties and weldability of members, the maximum content is limited to 0.02%, and preferably 0.01% or less. In addition, if the minimum content is less than 0.0001%, the manufacturing cost may increase, so the lower limit of the content may be 0.0001%.

N is an element included as an impurity in steel, and in order to reduce the sensitivity to cracking during continuous casting of slabs and to secure impact properties, the lower the content, the more advantageous, so it can be included in 0.02% or less. There is no need to set the lower limit in particular, but considering the increase in manufacturing cost, the N content may be set to 0.001% or more.

In the present invention, optionally, in addition to the above-described steel composition, the sum of at least one selected from the group consisting of Cr, Mo and W: 0.01 to 4.0%, Ti, Nb, Zr and the sum of at least one from the group consisting of V One or more of: 0.001 to 0.4%, Cu + Ni: 0.005 to 2.0%, Sb + Sn: 0.001 to 1.0%, and B: 0.0001 to 0.01% may be additionally added.

The sum of one or more selected from the group consisting of Cr, Mo and W: 0.01 to 4.0%

Cr, Mo, and W can improve hardenability and secure strength and grain refinement through the precipitation strengthening effect, so that at least one of these may be added in an amount of 0.01% or more based on the total content. In addition, in order to secure the weldability of the member, the content may be limited to 4.0% or less. In addition, if the content of these elements exceeds 4.0%, the effect may be saturated, so the content may be limited to 4.0% or less.

The sum of one or more selected from the group consisting of Ti, Nb, Zr and V: 0.001 to 0.4%

Ti, Nb and V are effective in improving the steel sheet of heat-treated members by forming fine precipitates and stabilizing retained austenite and improving impact toughness by refining grains. . However, if the added amount exceeds 0.4%, the effect is not only saturated, but also may cause cost increase due to excessive addition of ferroalloy.

Cu and Ni are elements that improve strength by forming fine precipitates. In order to obtain the above-described effect, the sum of one or more of these components may be 0.005% or more. However, if the value exceeds 2.0%, the upper limit may be set to 2.0% because excessive cost increases.

Sb and Sn are concentrated on the surface during annealing heat treatment for Al-Si plating to suppress the formation of Si or Mn oxide on the surface, thereby improving plating properties. In order to obtain such an effect, 0.001% or more may be added. However, if the addition amount exceeds 1.0%, the upper limit is set to 1.0% because not only excessive ferroalloy cost is required, but also it is dissolved in the slab grain boundary and may cause coil edge cracks during hot rolling.

B is an element capable of not only improving hardenability even with a small amount of addition, but also segregating at prior austenite grain boundaries to suppress brittleness of hot press-formed members due to grain boundary segregation of P and/or S. Therefore, B may be added in an amount of 0.0001% or more. However, if it exceeds 0.01%, the effect is not only saturated, but also causes brittleness in hot rolling, so the upper limit may be 0.01%, and in one embodiment, the B content may be 0.005% or less.

The remainder other than the above-mentioned components may include iron (Fe) and unavoidable impurities, and additional addition is not particularly limited as long as the components may be included in the steel sheet for hot press forming.

When an aluminum-based plated steel sheet having the plated layer having the above configuration is heat-treated in a temperature range of 880 to 950° C. for 3 to 10 minutes and then hot press-formed to manufacture a hot press-formed member, more than 90% of the plated layer is one of FeAlSi and Fe Al Since it can be formed as a diffusion layer made of the above, hydrogen that has penetrated into the steel during hot press forming can easily escape, so that the diffusible hydrogen content in the steel satisfies 0.1 ppm or less, thereby improving hydrogen resistance. In addition, the spot welding current range satisfies 1 kA or more, so that the spot weldability can be improved.

Next, a method of manufacturing an aluminum-based plated steel sheet for hot press forming according to another aspect of the present invention will be described in detail. However, the following manufacturing method of the aluminum-based plated steel sheet for hot press forming is only an example, and the aluminum-based plated steel sheet for hot press forming of the present invention does not necessarily have to be manufactured by this manufacturing method, and any manufacturing method It should be noted that there is no problem in using the method to implement each embodiment of the present invention as long as it satisfies the claims of the present invention.

The aluminum-based plated steel sheet according to another aspect of the present invention uses an aluminum plating bath containing Si: more than 4% and 15% or less, the remainder Al and other unavoidable impurities in weight% on the surface of the hot-rolled or cold-rolled base steel sheet. It can be obtained by performing hot-dip aluminum plating with a plating amount of 10 to 40 g/m2 on a single-sided basis, initial cooling in succession to the plating process, and then performing an on-line alloying treatment in which heat treatment is performed immediately.

Hereinafter, a method for obtaining an aluminum plated steel sheet is described.

In one embodiment of the present invention, a base steel sheet is prepared, and the base steel sheet is immersed in an aluminum plating bath containing more than 4% and 15% or less of Si: more than 4% and less than 15% by weight, and the remainder Al and other unavoidable impurities are applied to the surface of the base steel sheet on a single-sided basis. An aluminum plated steel sheet can be obtained by plating aluminum with a plating amount of 10 to 40 g/m 2 . Meanwhile, more preferably, the plating amount may be 15 to 38 g/m 2 . In addition, an annealing treatment may optionally be performed on the steel sheet before plating.

Si is an element that serves to uniformly alloy with Fe in the plating layer, and may be included in an amount exceeding at least 4% in order to obtain the above effect. However, since Si serves to suppress the diffusion of Fe, when it is contained in excess of 15%, the alloying rate is lowered, so that it is difficult to obtain sufficient alloying. Therefore, in the present invention, the Si content included in the plating bath may be limited to more than 4% and 15% or less. Meanwhile, the Si content may be preferably 4.5 to 14.1%, more preferably 6 to 13%, and most preferably 8 to 11%.

As an embodiment, Mg may be selectively added to the aluminum plating bath. Mg serves to improve the corrosion resistance of the aluminum-based plated steel sheet, and also serves to increase the alloying rate. However, when Mg is contained in excess of 1.1%, a large amount of Mg oxide is generated on the surface after alloying and/or after hot press forming, which may cause a problem in that weldability is deteriorated. Therefore, the Mg content optionally included in the present invention may be limited to 1.1% or less. On the other hand, more preferably, Mg may be limited to 0.9% or less, and in some cases, Mg may be limited to 0.1% or less. Also, in some cases, the plating bath may not contain Mg.

After aluminum plating, initial cooling can be performed at a cooling rate of 0.1 to 5°C/sec to a temperature range of 640°C or higher. In addition, the initial cooling may be performed more preferably in a temperature range of 640 to 680 °C, and the cooling rate may be 1 to 4 °C/sec.

In the present invention, initial cooling after aluminum plating is important in that it is a means of forming a uniform alloy layer. If the cooling end temperature is less than 640 ° C., there is a problem that equipment load may occur because more output must be applied for alloying in the subsequent on-line alloying heat treatment.

On the other hand, if the cooling rate is less than 0.1 ℃ / sec, the solidification layer is not sufficiently generated on the plating surface, non-uniform alloying proceeds during online alloying, which may cause a problem in that the surface properties of the steel sheet are inferior. On the other hand, when the cooling rate exceeds 5° C./sec, the plating layer is excessively cooled, and the equipment load and time are lengthened to secure a predetermined temperature for alloying, thereby impairing productivity.

After the initial cooling, an on-line alloying treatment in which heat treatment is performed continuously may be performed. In addition, the heating temperature range during the alloying heat treatment may be 670 ~ 900 ℃, the holding time may be 1 ~ 20 seconds.

In the present invention, the on-line alloying process refers to a process of heat treatment by increasing the temperature after molten aluminum plating, as can be seen in the schematic diagram shown in FIG. 1 . In the online alloying heat treatment method according to the present invention, since the heat treatment for alloying starts before the plating layer is cooled and hardened after hot-dip aluminum plating, alloying is possible in a short time. In the conventionally known plating layer composition system of aluminum plated steel sheet, it was difficult to apply an on-line alloying method in which heat treatment was performed immediately after plating because the alloying rate was slow and sufficient alloying could not be completed in a short time. However, in the present invention, the alloying of the aluminum plating layer can be effectively completed despite the short heat treatment time of 1 to 20 seconds by forming a thin plating bath component, in particular, the content of Si and the thickness of the plating layer that affects the alloying rate.

The heating temperature is based on the surface temperature of the steel sheet to be heat treated. If the heating temperature is less than 670 DEG C, there may be a problem that the alloying becomes insufficient. On the other hand, if the heating temperature exceeds 900 °C, it is difficult to cool after alloying, and if the cooling rate is increased, there may be a problem in that the strength of the base steel sheet is too high. Therefore, the heating temperature during the alloying heat treatment is preferably limited to 670 ~ 900 ℃, more preferably 680 ~ 880 ℃, may be most preferably 700 ~ 800 ℃.

Meanwhile, during the alloying heat treatment, the holding time may be limited to 1 to 20 seconds. In the present invention, the holding time means the time during which the heating temperature (including deviation ±10°C) is maintained in the steel sheet. If the holding time is less than 1 second, the heating time is too short to achieve sufficient alloying. On the other hand, if the holding time exceeds 20 seconds, there may be a problem in that the productivity is too reduced. Accordingly, the holding time during the alloying heat treatment is preferably limited to 1 to 20 seconds, more preferably 1.5 to 18 seconds, and most preferably 1 to 10 seconds.

After the alloying is completed as described above, it can be manufactured as a molded member by performing hot press forming. In this case, the hot press forming may use a method generally used in the art, for example, after heating the aluminum-based plated steel sheet according to the present invention in a temperature range of 880 to 950 ° C. for 3 to 10 minutes, and then heating using a press. The steel sheet may be hot formed into a desired shape, but is not limited thereto. In addition, the composition of the base steel sheet of the hot press-formed member may be the same as the composition of the base steel sheet of the above-described aluminum-based plated steel sheet.

Having described the embodiments of the present invention above, these embodiments will be helpful in understanding various aspects and features of the present invention. Elements presented in these embodiments may be selectively combined with each other, and another embodiment that has not been described in this document may be presented by such a combination.

Hereinafter, claims for defining the scope of the present invention are described. The element(s) recited in the claims may be variously changed and modified and replaced with equivalents without departing from the spirit of the invention. Reference numerals in the claims, if any, are only intended to aid an easy and intuitive understanding of the claimed inventions or elements thereof, and do not limit the scope of the claimed inventions.

Claims (1)

A step of partially removing the plated layer by irradiating a laser on the surface along the edge weld of the plated steel sheet. - The plated steel sheet is a plated steel sheet obtained by immersing a base steel sheet in an Al plating bath and then heat-treating it at a temperature of 670~900℃. A Fe-Al-based intermetallic compound layer and an aluminum layer formed on the intermetallic compound layer are provided, the plating layer thickness is 5-20 μm and the Fe-Al-based intermetallic compound layer thickness is 5-18 μm, and the Fe- 45-55% of the plating layer including the Al-based intermetallic compound layer is removed; and
It includes the step of welding the plated steel sheets obtained in the previous step to each other with a laser along the edge weld,
The base steel sheet is C: 0.04 to 0.5% by weight, Si: 0.01 to 2%, Mn: 0.01 to 10%, Al: 0.001 to 1.0%, P: 0.05% or less, S: 0.02% or less, N: 0.02 % or less, a method for manufacturing a Taylor welded blank for hot stamping, characterized in that it contains the remainder Fe and unavoidable impurities.