Patent Description:
Lightweight and high-strength automotive steel plates have become a target pursued by the automotive industry in recent years. In addition, the energy-saving and emission-reducing policy is strongly implemented across the nation. As a result, there is an increasing demand for high-strength thinned automotive plates in the automotive industry. Compared with the cold stamping technology, the hot stamping technology has the advantages of obvious weight reduction, good formability, and high dimensional precision, and thus plays an important role in imparting high strength to automotive steel plates. As consumers' requirements for safety, reliability and comfortness of automobiles increase, many automotive enterprises seek to enhance product quality by improving design of automobile structures, modifying and utilizing novel manufacturing processes. Tailor welded blanks are obtained by welding two or more steel plates having different materials, different thicknesses or different coatings to meet different requirements of components for material properties. The laser tailor-welded blank hot stamping process can reduce vehicle body weight, improve assembly accuracy and simplify assembly process. At the same time, it can also take the advantages of hot stamping to further improve the formability of steel plates.

Hot stamped products produced by laser tailor welding are characterized by high strength, complex shape, good formability, high dimensional precision, and small rebound resilience. Steel plates for hot stamping may be classified into bare steel plates and plated steel plates according to surface state. In a practical hot stamping process, the surface of bare steel is prone to oxidation at high temperatures to form oxide scale. In the course of stamping, the oxide scale is pressed into the steel to form surface defects which greatly affect its performance in use. Compared with bare plates, hot-stamped plated steel plates avoid oxidation of the steel plates, and need no shot blasting after the hot stamping. Therefore, the hot-stamped plated steel plates have attracted more and more attention. At present, hot-stamped steel with an aluminum or aluminum alloy clad layer is commonly used. With respect to the welding of a steel plate with a clad layer such as an aluminum or aluminum alloy clad layer, one process involves removal of the clad layer. Chinese Patent Publication No. <CIT> discloses a process for manufacturing a welded blank from a steel plate with an aluminum-silicon clad layer, wherein the welded blank only comprises a pre-coating of an intermetallic compound. Another process involves direct welding in the presence of a clad layer. The problem with this process is that, in the process of welding a steel plate with an aluminum or aluminum alloy clad layer, the clad layer melts into a molten pool under the influence of welding heat, forming brittle and rigid intermetallic compounds (Fe<NUM>Al, Fe<NUM>Al<NUM>, FeAl<NUM>). The intermetallic compounds aggregate into band or block distribution, resulting in notable decrease in the strength and ductility of the welded joint.

Moreover, the patent applications <CIT>, <CIT> and <CIT> disclose laser welding methods and welding wires according to prior art.

One object of the present disclosure is to provide a method for manufacturing an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer. This method can solve a problem of an existing equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, namely the performance of a welding joint becoming poor after thermal forming of the welding joint, because the method guarantees the tensile strength, elongation and corrosion resistance of the welding joint after hot stamping. After the hot stamping, the welding joint has a tensile strength greater than the tensile strength of the base material (a steel plate to be welded), and an elongation of greater than <NUM>%, so that the application requirements of a tailor welded blank in the field of hot stamping are satisfied.

To achieve the above object, the technical solution of the present disclosure is as follows:
A method for manufacturing an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, comprising the following steps:.

Conducting welding by a laser filler wire welding process, a laser composite filler wire welding process or a gas shielded welding process (such as a gas metal arc welding process) to obtain a final equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, wherein a welding joint (welding line) of the equal-strength welded component has a tensile strength greater than a tensile strength of the substrate after hot stamping, wherein the laser filler wire welding process uses a laser spot having a diameter of from <NUM> to <NUM> (e.g., from <NUM> to <NUM>), a defocus distance of from -<NUM> to <NUM> (e.g., from <NUM> to <NUM>), a laser power controlled at from <NUM> to <NUM> kW, a welding speed controlled at from <NUM> to <NUM>/s (e.g., from <NUM>/s to <NUM>/s), a welding wire having a diameter of from <NUM> to <NUM>, and a wire feeding speed of from <NUM> to <NUM>/min (e.g., from <NUM>/min to <NUM>/min). wherein the welding wire used for the welding in step <NUM>) has a composition based on weight percentage of C <NUM>-<NUM>%, Si <NUM>-<NUM>%, Mn <NUM>-<NUM>%, P≤<NUM>%, S≤<NUM>%, <NUM>%≤Al<<NUM>%, Ni <NUM>-<NUM>%, Cr <NUM>-<NUM>%, Mo <NUM>-<NUM>%, and a balance Fe and other unavoidable impurities.

Preferably, in step <NUM>), prior to the welding, the steel plate to be welded is subjected to surface cleaning to ensure that the steel plate is straight, clean, and free of oil and water.

Preferably, during the welding in step <NUM>), the shielding gas is one containing an active gas, wherein the active gas has a volume percentage of from <NUM>% to <NUM>%. Preferably, the active gas is carbon dioxide. Preferably, the shielding gas is carbon dioxide or a mixture of carbon dioxide and argon. Preferably, carbon dioxide in the mixture has a volume percentage of from <NUM> to <NUM>%, such as <NUM> to <NUM>% or <NUM> to <NUM>%. Preferably, in the present disclosure, the shielding gas has a flow rate of from <NUM> to <NUM>/min, such as from <NUM> to <NUM>/min.

Preferably, the laser composite filler wire welding process uses a laser spot having a diameter of from <NUM> to <NUM> (e.g., from <NUM> to <NUM>), a defocus distance of from -<NUM> to <NUM> (e.g., from <NUM> to <NUM>), a laser power controlled at from <NUM> to <NUM> kW (e.g., from <NUM> to <NUM> kW), a welding speed controlled at from <NUM> to <NUM>/s (e.g., from <NUM>/s to <NUM>/s); a welding wire having a diameter of from <NUM> to <NUM>, a wire feeding speed of from <NUM> to <NUM>/min (e.g., from <NUM>/min to <NUM>/min), a welding current of from <NUM> to <NUM> A, and a voltage of from <NUM> to <NUM> V.

Preferably, the gas shielded welding process uses a welding current of from <NUM> to <NUM> A, a welding voltage of from <NUM> to <NUM> V, a welding speed of from <NUM> to <NUM>/min (e.g., <NUM>-<NUM>/min), and a welding wire having a diameter of from <NUM> to <NUM>.

Preferably, the substrate of the steel plate to be welded has a composition based on weight percentage of C: <NUM>-<NUM>%, Si: <NUM>-<NUM>%, Mn: <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, Al<<NUM>%, Ti<<NUM>%, B: <NUM>-<NUM>%, Cr: <NUM>-<NUM>%, and a balance of Fe and other unavoidable impurities.

Preferably, the substrate of the steel plate to be welded comprises Al: <NUM>-<NUM>%, more preferably <NUM>-<NUM>%; Ti: <NUM>-<NUM>%, more preferably <NUM>-<NUM>%; B: <NUM>-<NUM>%, more preferably <NUM>- <NUM>%; Cr: <NUM>-<NUM>%, more preferably <NUM>-<NUM>%.

Preferably, the substrate of the steel plate to be welded has a thickness of from <NUM> to <NUM>.

Preferably, the clad layer of the steel plate to be welded is pure aluminum or aluminum alloy, wherein the aluminum alloy has a composition based on weight percentage of Si: <NUM>-<NUM>%, Fe: <NUM>-<NUM>%, and a balance of Al and other unavoidable impurities.

The welding wire used for the welding in step <NUM>) has a composition based on weight percentage of C <NUM>-<NUM>%, Si <NUM>-<NUM>%, Mn <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, <NUM>%≤Al<<NUM>%, Ni <NUM> -<NUM>%, Cr <NUM>-<NUM>%, Mo <NUM>-<NUM>%, and a balance Fe and other unavoidable impurities.

In some embodiments of the present disclosure, the present disclosure provides a method for manufacturing an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, characterized in that the method comprises the following steps:.

Using a laser filler wire welding process or a gas shielded welding process, wherein a laser spot diameter is from <NUM> to <NUM>; a defocus distance is from <NUM> to <NUM>; a laser power is controlled in a range of from <NUM> kW to 6kW; a welding speed is controlled in a range of from <NUM>/s to <NUM>/s; a welding wire diameter is from <NUM> to <NUM>; a wire feeding speed is from <NUM>/min to <NUM>/min; and a shielding gas is a mixture of argon and carbon dioxide.

Preferably, the shielding gas is a mixture of argon + carbon dioxide, wherein carbon dioxide has a volume percentage of from <NUM>% to <NUM>%.

In some embodiments of the present disclosure, the present disclosure also provides an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer manufactured by the method for manufacturing an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer according to any embodiment of the present disclosure.

In some embodiments of the present disclosure, the present disclosure also provides an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, characterized in that the equal-strength component comprises a steel plate comprising a substrate and at least one clad layer on a surface thereof, wherein the clad layer comprises an intermetallic compound alloy layer in contact with the substrate and a metal alloy layer thereon, wherein the substrate has a composition based weight percentage of C: <NUM>-<NUM>%, Si: <NUM>-<NUM>%, Mn: <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, Al<<NUM>%, Ti<<NUM>%, B: <NUM>-<NUM>%, Cr: <NUM>-<NUM>%, and a balance of Fe and unavoidable impurities. Preferably, the substrate has a composition based on weight percentage of C: <NUM>-<NUM>%, Si: <NUM>-<NUM>%, Mn: <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, Al<<NUM>%, Ti<<NUM>%, B: <NUM>-<NUM>%, Cr: <NUM>-<NUM>%, and a balance of Fe and unavoidable impurities. More preferably, the substrate has a composition based on weight percentage of C: <NUM>-<NUM>%, Si: <NUM>-<NUM>%, Mn: <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, Al<<NUM>%, Ti<<NUM>%, B: <NUM>-<NUM>%, Cr: <NUM>-<NUM>%, and a balance of Fe and unavoidable impurities. Preferably, the substrate of the steel plate to be welded comprises Al: <NUM>-<NUM>%, more preferably <NUM>-<NUM>%; Ti: <NUM>-<NUM>%, more preferably <NUM>-<NUM>%; B: <NUM>-<NUM>%, more preferably <NUM>- <NUM>%; Cr: <NUM>-<NUM>%, more preferably <NUM>-<NUM>%.

Preferably, the clad layer of the equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer is pure aluminum or aluminum alloy, wherein the aluminum alloy has a composition based on weight percentage of Si: <NUM>-<NUM>%, Fe: <NUM>-<NUM>%, and a balance of Al.

Preferably, the substrate of the equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer has a thickness of from <NUM> to <NUM>.

The welding wire used between the steel plates of the equal-strength component has a composition based on weight percentage of C <NUM>-<NUM>%, Si <NUM>-<NUM>%, Mn <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, <NUM>%≤Al<<NUM>%, Ni <NUM>-<NUM>%, Cr <NUM>-<NUM>%, Mo <NUM>-<NUM>%, and a balance Fe and other unavoidable impurities.

Preferably, the welding line of the equal-strength steel thin-wall welded component according to any embodiment of the present disclosure has a tensile strength of not less than <NUM> MPa, more preferably not less than <NUM> MPa, more preferably not less than <NUM> MPa. Preferably, the tensile strength is not higher than 1700MPa. The welding joint has an elongation of greater than <NUM>%. If the welding joint is fractured under a tensile load, the fracture occurs in the substrate. More preferably, the tensile strength of the welding line is higher than the tensile strength of the substrate. Preferably, the welding joint of the equal-strength steel thin-wall welded component according to any embodiment of the present disclosure has a hardness of ≥<NUM> HV, more preferably ≥<NUM> HV.

A welding wire is used in the welding according to the method for manufacturing an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, wherein the welding wire has a composition based on weight percentage of C <NUM>-<NUM>%, Si <NUM>-<NUM>%, Mn <NUM> -<NUM>%, P≤<NUM>%, S≤<NUM>%, <NUM>%≤Al<<NUM>%, Ni <NUM>-<NUM>%, Cr <NUM>-<NUM>%, Mo <NUM>-<NUM>%, and a balance of Fe and other unavoidable impurities. The welding wire has a diameter of from <NUM> to <NUM>.

In the compositional design of the welding wire according to the present disclosure:
Silicon is a deoxygenating element in the welding wire. It can prevent iron from combining with oxygen, and reduce iron oxide in a molten pool. However, if silicon is used alone for deoxygenation, due to the high melting point (about <NUM>) and small particle size of the resulting silicon dioxide, it's difficult for silicon dioxide particles to float and be removed from the molten pool, which leads to easy entrapment of slag in the welding line. Therefore, the weight percentage of silicon in the welding wire according to the present disclosure is controlled within the range of <NUM>-<NUM>%, preferably within the range of <NUM>-<NUM>%, more preferably in the range of <NUM>-<NUM>%.

Manganese is an important hardenability element, having a great influence on the toughness of the welding line. It is also a deoxygenating element, but its deoxygenating ability is slightly lower than that of silicon. If manganese is used alone for deoxygenation, it's difficult for the resulting manganese oxide to float and be removed from the molten pool due to its high density. Therefore, silicon and manganese are used in combination in the welding wire for deoxygenation according to the present disclosure, so that the deoxygenation product is a composite silicate salt (MnO. SiO<NUM>) which has a lower melting point (about <NUM>) and a lower density and can aggregate into large molten slag in the molten pool. Hence, its floating is favored, and good deoxygenating effect can be achieved. In addition, manganese also has a function of desulfurization. It combines with sulfur to produce manganese sulfide, which can reduce the propensity of sulfur to cause thermal cracking. With various factors taken into consideration, the weight percentage of manganese in the welding wire according to the present disclosure is controlled between <NUM>-<NUM>%, preferably <NUM>-<NUM>%, more preferably <NUM>-<NUM>%.

Sulfur tends to form iron sulfide in the molten pool, and iron sulfide is distributed in the grain boundary like a network. Thus, the toughness of the welding line is reduced notably. Therefore, sulfur in the welding wire is harmful, and its content must be strictly controlled. Generally, the S content is controlled at S≤<NUM>%.

The strengthening effect of phosphorus in steel is second only to carbon. Phosphorus increases the strength and hardness of the steel. Phosphorus can also improve the corrosion resistance of the steel, but the plasticity and toughness are reduced remarkably, especially at low temperatures. Hence, phosphorus is harmful in the welding wire, and its content must be strictly controlled. Generally, the phosphorus content is controlled at P≤<NUM>%, preferably ≤<NUM>%.

On the one hand, nickel can strongly increase the strength of steel, and on the other hand, it always keeps the toughness of iron at a very high level, thereby lowering the embrittlement temperature of the steel. The lattice constant of nickel is similar to that of austenite, leading to formation of a continuous solid solution, thereby reducing the critical Ms point, increasing the stability of austenite, and improving the hardenability of the welding zone. Therefore, the weight percentage of nickel in the welding wire according to the present disclosure is controlled at <NUM>-<NUM>%, preferably <NUM>-<NUM>%.

Chromium can increase the strength and hardness of steel without decreasing the plasticity and toughness obviously. Chromium can increase the hardenability of the steel and has a secondary hardening effect, which can increase the hardness and wear resistance of carbon steel without embrittling the steel. Chromium can expand the γ phase region, improve the hardenability and thermal strength, reduce the temperature window in which the δ phase exists at high temperatures, promote the δ→γ phase transition, and inhibit precipitation of high temperature δ ferrite. Therefore, the weight percentage of chromium in the welding wire according to the present disclosure is controlled within <NUM>-<NUM>%, preferably <NUM>-<NUM>%.

Molybdenum in the welding wire can increase the strength and hardness of steel, refine the grains, and improve the high temperature strength, creep strength and fatigue strength. When the molybdenum content is equal to or less than <NUM>%, the plasticity can be improved, and the cracking tendency can be reduced. Molybdenum can also expand the γ phase region, improve the hardenability and thermal strength, reduce the temperature window in which the δ phase exists at high temperatures, promote the δ→γ phase transition, and inhibit precipitation of high temperature δ ferrite. Therefore, the weight percentage of molybdenum in the welding wire according to the present disclosure is controlled between <NUM>-<NUM>%, preferably between <NUM>-<NUM>%, and more preferably <NUM>-<NUM>%.

In the welding wire according to the present disclosure, the C content is preferably <NUM>-<NUM>%, more preferably <NUM>-<NUM>%.

In a preferred embodiment, the welding wire used for the welding in the method for manufacturing the equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer according to the present disclosure has a composition based on weight percentage of C <NUM>-<NUM>%, Si <NUM>-<NUM>%, Mn <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, <NUM>%≤Al<<NUM>%, Ni <NUM>-<NUM>%, Cr <NUM>-<NUM>%, Mo <NUM>-<NUM>%, and a balance Fe and other unavoidable impurities. More preferably, the welding wire has a composition based on weight percentage of C <NUM>-<NUM>%, Si <NUM>-<NUM>%, Mn <NUM>-<NUM>%, P<<NUM>%, S<<NUM>%, <NUM>%≤Al<<NUM>%, Ni <NUM>-<NUM>%, Cr <NUM>-<NUM>%, Mo <NUM>-<NUM>%, and a balance of Fe and other unavoidable impurities.

When welding a plated plate having a preset welding gap, a welding wire comprising Mo, Cr, Ni and other elements according to the present disclosure is delivered to the tailor welding area to suppress the formation of high temperature δ ferrite. Molybdenum and chromium elements can expand the γ phase region, improve the hardenability and thermal strength, reduce the temperature window in which the δ phase region exists at high temperatures, promote the δ→γ phase transition, and inhibit precipitation of high temperature δ ferrite. The lattice constant of nickel is similar to that of austenite, leading to formation of a continuous solid solution, thereby reducing the critical Ms point, increasing the stability of austenite, and improving the hardenability of the welding zone.

In addition, the coexistence of Mo, Cr, and Ni can further improve the fatigue performance of the welding joint, realize the high martensite conversion in the welding line structure, and improve the mechanical properties of the welding joint.

The carbon equivalent formula recommended by the International Institute of Welding is as follows: <MAT>.

According to the above formula, the filling of the welding wire will slightly increase the carbon equivalent of the welding joint, thereby ensuring the hardenability of the joint. In addition, the filling of the welding wire will further dilute the composition of the clad layer in the welding line, and chromium, molybdenum, nickel and other elements in the welding wire increase the stability of austenite and improve the hardenability of the welding line, thereby helping to prevent formation of iron-aluminum intermetallic compounds and granular ferrite phase in the welding line during hot stamping, so that the welding line of the equal-strength steel thin-wall welded component has a tensile strength greater than that of the base material.

In the method for manufacturing equal-strength steel thin-wall welding component with an aluminum or aluminum alloy clad layer:.

In addition, no matter what method is used to remove or thin the clad layer in the prior art, the production speed will be slowed. With the use of the clad layer pretreatment process according to the present disclosure, the production efficiency can be increased by at least <NUM>%.

The direct welding according to the filler wire welding method of the present disclosure, without removing or thinning the clad layer of the component to be welded, guarantees the tensile strength, elongation and corrosion resistance of the welding joint after hot stamping. After the hot stamping, the tensile strength of the welding joint is greater than that of the base material, and the elongation is greater than <NUM>%, satisfying the application requirements of the automotive industry.

The disclosure will be further illustrated with reference to the following Examples and accompanying drawings.

A hot formed steel plate to be welded was subjected to surface cleaning to remove contaminants such as oil and water stains from the surface to guarantee cleanliness of the surface.

The <NUM> steel plate having an aluminum alloy clad layer (see Table <NUM> for the composition of the steel plate) was subjected to laser filler wire tailor welding using the following process: a welding wire as described in the present disclosure (see Table <NUM> for the composition of the welding wire), a light beam having a spot diameter of <NUM>, a welding power of <NUM> kW, a welding speed of <NUM>/s, a preset butt gap of <NUM>, a defocus distance of <NUM>, a wire feeding speed of <NUM>/min, a welding wire diameter of <NUM>, a shielding gas of <NUM>% argon + <NUM>% carbon dioxide gas, and a gas flow of <NUM>/min were used.

After the welding, metallographic examination was conducted on the cross-section of the welding line. The macromorphology of the welding line was excellent, and there was no obvious spatter.

After the welding, the tailor welded blank was subjected to hot stamping and quenching, wherein the heating temperature was <NUM>, the heating time was <NUM> minutes, and the blank was pressurized in a water-passing mold for <NUM> seconds.

After the above-mentioned thermal cycle, the tailor welded blank was first completely austenitized. During the heating, atoms diffused between the clad layer and the steel, so that the original clad layer completely transformed into an intermetallic compound layer having a thickness larger than the thickness of the original clad layer. In addition, this layer had the characteristics of high melting point and high hardness, which prevented oxidation and decarburization of the substrate during the heating stage and the pressurizing stage. During the pressurizing stage in the mold, martensitic transformation occurred in the tailor welded blank. Then, evaluation was conducted on the performances of the welding joint according to Table <NUM>. See <FIG> for the tensile curve of the welding joint, <FIG> for the fracture position, <FIG> for the metallographic image of the joint (no granular ferrite was observed in the welding line structure), and <FIG> for the hardness of the joint. See Table <NUM> for the performances of the tailor welded blank after the hot stamping.

The <NUM> steel plate having an aluminum alloy clad layer (see Table <NUM> for the composition of the steel plate) was subjected to laser filler wire tailor welding using the following process: a welding wire as described in the present disclosure (see Table <NUM> for the composition of the welding wire), a light beam having a spot diameter of <NUM>, a welding power of <NUM> kW, a welding speed of <NUM>/s, a preset butt gap of <NUM>, a defocus distance of <NUM>, a wire feeding speed of <NUM>/min, a welding wire diameter of <NUM>, a shielding gas of <NUM>% argon + +<NUM>% carbon dioxide gas, and a gas flow of <NUM>/min were used.

After the welding, the same hot stamping process as that used in Example <NUM> was used for flat plate hot stamping. See Table <NUM> for the performances of the tailor welded blank after the hot stamping.

The <NUM> steel plate having an aluminum alloy clad layer (see Table <NUM> for the composition of the steel plate) was subjected to laser filler wire tailor welding using the following process: a welding wire as described in the present disclosure (see Table <NUM> for the composition of the welding wire), a light beam having a laser spot diameter of <NUM>, a welding power of <NUM> kW, a welding speed of <NUM>/s, a preset butt gap of <NUM>, a defocus distance of <NUM>, a wire feeding speed of <NUM>/min, a welding wire diameter of <NUM>, a shielding gas of <NUM>% argon + <NUM>% carbon dioxide gas, and a gas flow of <NUM>/min were used.

The <NUM> steel plate having an aluminum alloy clad layer (see Table <NUM> for the composition of the steel plate) was subjected to laser filler wire tailor welding using the following process: a welding wire as described in the present disclosure (see Table <NUM> for the composition of the welding wire), a light beam having a laser spot diameter of <NUM>, a welding power of <NUM> kW, a welding speed of <NUM>/s, a preset butt gap of <NUM>, a defocus distance of <NUM>, a wire feeding speed of <NUM>/min, a welding wire diameter of <NUM>, a shielding gas of <NUM>% carbon dioxide gas, and a gas flow of <NUM>/min were used.

After the welding, the tailor welded blank was subjected to hot stamping and quenching, wherein the heating temperature was <NUM>, the heating time was <NUM> minutes, and the blank was pressurized in a water-passing mold for <NUM> seconds. See Table <NUM> for the performances of the tailor welded blank after the hot stamping.

The <NUM> steel plate having an aluminum alloy clad layer (see Table <NUM> for the composition of the steel plate) was subjected to laser filler wire tailor welding using the following process: a welding wire as described in the present disclosure (see Table <NUM> for the composition of the welding wire), a light beam having a laser spot diameter of <NUM>, a welding power of <NUM> kW, a welding speed of <NUM>/s, a preset butt gap of <NUM>, a defocus distance of <NUM>, a wire feeding speed of <NUM>/min, a welding wire diameter of <NUM>, a shielding gas of <NUM>% argon + +<NUM>% carbon dioxide gas, and a gas flow of <NUM>/min were used.

The <NUM> steel plate having an aluminum alloy clad layer (see Table <NUM> for the composition of the steel plate) was subjected to laser filler wire tailor welding using the following process: a welding wire as described in the present disclosure (see Table <NUM> for the composition of the welding wire), a light beam having a laser spot diameter of <NUM>, a welding power of <NUM> kW, a welding speed of <NUM>/s, a preset butt gap of <NUM>, a defocus distance of <NUM>, a wire feeding speed of <NUM>/min, a welding wire diameter of <NUM>, a shielding gas of <NUM>% argon + +<NUM>% carbon dioxide gas, a gas flow of <NUM>/min, a welding electric current of <NUM> A and an electric voltage of <NUM> V for MAG composite tailor welding were used. After the welding, metallographic examination was conducted on the cross-section of the welding line. The macromorphology of the welding line was excellent, and there was no obvious spatter.

The <NUM> steel plate having an aluminum alloy clad layer (see Table <NUM> for the composition of the steel plate) was subjected to gas metal arc tailor welding using the following process: a welding wire as described in the present disclosure (see Table <NUM> for the composition of the welding wire), a welding electric current of <NUM> A, a welding electric voltage of <NUM> V, a welding speed of <NUM>/s, a preset butt gap of <NUM>, a welding wire diameter of <NUM>, a shielding gas of <NUM>% argon + <NUM>% carbon dioxide gas, and a gas flow of <NUM>/min were used. After the welding, metallographic examination was conducted on the cross-section of the welding line. The macromorphology of the welding line was excellent, and there was no obvious spatter.

Claim 1:
A method for manufacturing an equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, comprising the following steps:
<NUM>) Preparation before steel plate welding
Taking a straight steel plate to be used as a steel plate to be welded, wherein the steel plate to be welded comprises a substrate and at least one clad layer on a surface thereof, wherein the clad layer comprises an intermetallic compound alloy layer in contact with the substrate and a metal alloy layer thereon, wherein the clad layer in a to-be-welded zone of the steel plate to be welded is not removed or hinned;
<NUM>) Presetting butt gap
Presetting a butt gap between two steel plates to be welded at <NUM> -<NUM>;
<NUM>) Welding
Conducting welding by a laser filler wire welding process, a laser composite filler wire welding process or a gas metal arc welding process to obtain a final equal-strength steel thin-wall welded component with an aluminum or aluminum alloy clad layer, wherein the laser filler wire welding process uses a laser spot having a diameter of from <NUM> to <NUM>, a defocus distance of from -<NUM> to <NUM>, a laser power controlled at from <NUM> to <NUM> kW, a welding speed controlled at from <NUM> to <NUM>/s, a welding wire having a diameter of from <NUM> to <NUM>, and a wire feeding speed of from <NUM> to <NUM>/min; wherein the laser composite filler wire welding process uses a laser spot having a diameter of from <NUM> to <NUM>, a defocus distance of from -<NUM> to <NUM>, a laser power controlled at from <NUM> to <NUM> kW, a welding speed controlled at from <NUM> to <NUM>/s, a welding wire having a diameter of from <NUM> to <NUM>, a wire feeding speed of from <NUM> to <NUM>/min, a welding electric current of <NUM>-<NUM> A, and an electric voltage of <NUM>-<NUM> V; and the gas metal arc welding process uses a welding electric current of <NUM>-<NUM> A, and a welding electric voltage of <NUM>-<NUM> V, a welding speed of from <NUM> to <NUM>/min, and a welding wire having a diameter of from <NUM> to <NUM>;
wherein the welding wire used for the welding in step <NUM>) has a composition based on weight percentage of C <NUM>-<NUM>%, Si <NUM>-<NUM>%, Mn <NUM>-<NUM>%, P≤<NUM>%, S≤<NUM>%, <NUM>%≤Al<<NUM>%, Ni <NUM>-<NUM>%, Cr <NUM>-<NUM>%, Mo <NUM>-<NUM>%, and a balance Fe and other unavoidable impurities.