阅读说明：本技术 用于生产压制硬化的激光焊接钢部件的方法和压制硬化的激光焊接钢部件 (Method for producing a press-hardened laser-welded steel component and press-hardened laser-welded steel component ) 是由 弗朗西斯·施米特 玛丽亚·普瓦里耶 萨多克·加伊德 于 2019-02-26 设计创作，主要内容包括：用于生产部件的方法,包括：提供第一预涂覆板(1)和第二预涂覆板(2),对第一预涂覆板(1)和第二预涂覆板进行对接焊以获得坯件(15),将坯件(15)加热至比焊接接头(22)的完全奥氏体化温度低至少10℃并且比最低温度T<Sub>min</Sub>高至少15℃的热处理温度,式(I),其中Ac3(WJ)为焊接接头(22)的完全奥氏体化温度,式(II),其中Ts<Sub>1</Sub>和Ts<Sub>2</Sub>为压制硬化之后的最强基体和最弱基体的极限抗拉强度,C<Sup>FW</Sup>为填充材料的碳含量,β为填充材料的比例,ρ为最弱基体和最强基体的厚度之比,并将坯件(15)在该热处理温度下保持2分钟至10分钟的时间；将坯件(15)压制成型为部件并冷却。<Image he="199" wi="700" file="DDA0002652122370000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(A method for producing a component, comprising: providing a first pre-coated panel (1) and a second pre-coated panel (2), butt welding the first pre-coated panel (1) and the second pre-coated panel to obtain a blank (15), heating the blank (15) to at least 10 ℃ below the full austenitizing temperature of the weld joint (22) and to a minimum temperature T min A heat treatment temperature at least 15 ℃ higher, formula (I), wherein Ac3(WJ) is the complete austenitization temperature of the welded joint (22), formula (II), wherein Ts 1 And Ts 2 Ultimate tensile strength of the strongest and weakest matrices after press hardening, C FW β is the proportion of the filler material, p is the ratio of the thicknesses of the weakest and strongest substrates, and the blank (15) is held at the heat treatment temperature for a period of 2 to 10 minutes, the blank (15) is press formed into a part and cooled.)

1. A method for producing a press hardened laser welded steel part comprising the following successive steps:

-providing a first pre-coated steel sheet (1) and a second pre-coated steel sheet (2), the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2) each comprising a steel substrate (3, 4), at least one of the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2) having an aluminium-containing pre-coating (7, 8) comprising at least 50 wt.% of aluminium on at least one of its main faces,

the first pre-coated steel sheet (1) has a first thickness (t)₁) And the second pre-coated steel sheet (2) has a second thickness (t)₂)，

The ultimate tensile strength (Ts) of the substrate (3, 4) of the first pre-coated steel sheet (1) after press hardening₁) The ultimate tensile strength (Ts) of the substrate (4) after press hardening, which is strictly greater than the second pre-coated steel sheet (2)₂) And is and

the first thickness (t) of the first pre-coated steel sheet (1) after press hardening₁) And the ultimate tensile strength (Ts)₁) Is strictly greater than the second thickness (t) of the second pre-coated steel sheet (1)₂) And the ultimate tensile strength (Ts)₂) Product of then

-theory in at least a welded joint (22) obtained by butt welding the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2) provided in the providing step, possibly using a filler material comprising at most 0.05 wt.% of aluminiumAverage aluminum content

-butt welding the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2) using laser welding to obtain a welded joint (22) between the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2), thereby obtaining a welded blank (15), this welding step possibly comprising using a filler material (20),

-heating the welding blank (15) to a heat treatment temperature (T)_t) The temperature (T) of the heat treatment_t) At least 10 ℃ below the full austenitizing temperature (Ac3(WJ)) of the weld joint (22) and above the minimum temperature T_minAt least 15 ℃ higher, wherein

Wherein

Ac3(WJ) is the complete austenitizing temperature of the welded joint (22) in DEG C, and Al is the aluminum content in the welded joint (22) in weight%

Andis the maximum sub of the weld joint (22) calculated using the formulaContent of warm ferrite

Wherein

Ts₁The ultimate tensile strength in MPa of the strongest matrix (3) after press hardening

Ts₂The ultimate tensile strength of the weakest matrix (4) after press hardening is measured in MPa

C^FWIs the carbon content of the filler material in weight%

Beta is the proportion of the filler material added to the weld pool and is 0 to 1

ρ is the ratio of the thickness of the pre-coated steel sheet (2) including the weakest matrix to the thickness of the pre-coated steel sheet (1) including the strongest matrix (ρ ═ t)₂/t₁)

And holding the welded blank (15) at the heat treatment temperature (Tt) for a time ranging from 2 minutes to 10 minutes;

-press-forming the welded blank (15) into a steel component; and

-cooling the thus formed steel part at a cooling rate greater than or equal to the critical martensite or bainite cooling rate of the most hardenable of the matrices (3, 4) of the first and second pre-coated steel plates (1, 2) to obtain a press hardened welded steel part.

2. The method according to claim 1, wherein the ultimate tensile strength (Ts) of the substrate (3) of the first pre-coated steel sheet (1) after press hardening₁) The ultimate tensile strength (Ts) with the substrate (4) of the second pre-coated steel sheet (2)₂) The ratio of (A) to (B) is greater than or equal to 1.2.

3. Method according to any of the preceding claims, wherein the carbon content of the substrate (3) of the first pre-coated steel sheet (1) is at least 0.05 wt% higher than the carbon content of the substrate (4) of the second pre-coated steel sheet (2).

4. The method according to any one of the preceding claims, wherein the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2) provided in the providing step each comprise on at least one main face (5, 6) thereof an aluminium-containing pre-coating (7, 8) comprising at least 50 wt.% of aluminium.

5. The method according to any one of the preceding claims, wherein the first (1) and second (2) pre-coated steel sheets provided in the providing step comprise an aluminium-containing pre-coating (7, 8) comprising at least 50 wt.% of aluminium on both main faces (5, 6) thereof.

6. Method according to any of the preceding claims, wherein the aluminium-containing precoat (7, 8) remains intact on both main faces (5, 6) of at least one of the first and second precoated steel sheets (1, 2) and for example each of the first and second precoated steel sheets (1, 2) in butt welding.

7. The method according to any of the preceding claims, further comprising, before the butt welding, the steps of: even a theoretical average aluminum content in the weld joint (22) obtained by butt-welding the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2) provided in the providing step, possibly using a filler material containing at most 0.05 wt.% of aluminum

8. Method according to any one of the preceding claims, wherein, for at least one of the first (1) and second (2) pre-coated steel sheets, the steel of the substrate (3, 4) comprises by weight:

0.10％≤C≤0.5％

0.5％≤Mn≤3％

0.1％≤Si≤1％

0.01％≤Cr≤1％

Ti≤0.2％

Al≤0.1％

S≤0.05％

P≤0.1％

B≤0.010％

the remainder being iron and impurities resulting from manufacture.

9. Method according to claim 8, wherein, for at least one of the first (1) and second (2) pre-coated steel sheets, the steel of the substrate (3, 4) comprises by weight:

0.15％≤C≤0.25％

0.8％≤Mn≤1.8％

0.1％≤Si≤0.35％

0.01％≤Cr≤0.5％

Ti≤0.1％

Al≤0.1％

S≤0.05％

P≤0.1％

B≤0.005％

the remainder being iron and impurities resulting from manufacture.

10. The method according to any one of claims 1 to 9, wherein, for at least one of the first and second pre-coated steel sheets (1, 2), the steel of the substrate (3, 4) comprises by weight:

0.040％≤C≤0.100％

0.70％≤Mn≤2.00％

Si≤0.50％

S≤0.009％

P≤0.030％

0.010％≤Al≤0.070％

0.015％≤Nb≤0.100％

Ti≤0.080％

N≤0.009％

Cu≤0.100％

Ni≤0.100％

Cr≤0.2％

Mo≤0.100％

Ca≤0.006％，

the remainder being iron and impurities resulting from manufacture.

11. The method according to any one of claims 1 to 10, wherein, for at least one of the first and second pre-coated steel sheets (1, 2), the steel of the substrate (3, 4) comprises by weight:

0.06％≤C≤0.100％

1.4％≤Mn≤1.9％

0.2％≤Si≤0.5％

0.010％≤Al≤0.070％

0.04％≤Nb≤0.06％

3.4xN≤Ti≤8xN

0.02％≤Cr≤0.1％

0.0005％≤B≤0.004％

0.001％≤S≤0.009％

the remainder being iron and impurities resulting from manufacture.

12. The method according to any one of claims 1 to 11, wherein, for at least one of the first and second pre-coated steel sheets (1, 2), the steel of the substrate (3, 4) comprises by weight:

0.24％≤C≤0.38％

0.40％≤Mn≤3％

0.10％≤Si≤0.70％

0.015％≤Al≤0.070％

0％≤Cr≤2％

0.25％≤Ni≤2％

0.015％≤Ti≤0.10％

0％≤Nb≤0.060％

0.0005％≤B≤0.0040％

0.003％≤N≤0.010％

0.0001％≤S≤0.005％

0.0001％≤P≤0.025％

wherein the contents of titanium and nitrogen satisfy the following relationship:

Ti/N＞3.42，

and the contents of carbon, manganese, chromium and silicon satisfy the following relationship:

the steel optionally comprises one or more of the following elements:

0.05％≤Mo≤0.65％

0.001％≤W≤0.30％

0.0005％≤Ca≤0.005％

the remainder being iron and impurities inevitably produced by manufacture.

13. The method according to any of the preceding claims, wherein the laser welding is performed using a protective gas, in particular helium and/or argon.

14. The method according to any of the preceding claims, wherein the first pre-coated steel sheet (1) and the second pre-coated steel sheet (2) have different thicknesses.

15. The method of any of the preceding claims, wherein the welding is performed without using a filler material.

16. The method according to any one of claims 1 to 14, wherein the welding is performed using a filler material, preferably having the following composition by weight:

0.1％≤C≤1.2％

0.01％≤Mn≤10％

0.02％≤Ni≤7％

0.02％≤Cr≤5％

0.01％≤Si≤2％

optionally:

trace amount is less than or equal to Mo and less than or equal to 1 percent

Trace amount is less than or equal to Ti and less than or equal to 0.1 percent

Trace amount is less than or equal to V and less than or equal to 0.1 percent

Trace amount is less than or equal to B and less than or equal to 0.01 percent

Trace amount is less than or equal to Nb and less than or equal to 0.1 percent

Trace amount of Al is less than or equal to 0.05 percent

The remainder being iron and impurities inevitably produced by manufacture.

17. A press hardened laser welded steel component comprising a first coated steel component part and a second coated steel component part,

each coated steel component part comprising a steel substrate, at least one of the first coated steel component part and the second coated steel sheet having on at least one major face thereof an aluminum-containing coating comprising at least 30 wt.% aluminum,

the first coated steel component part having a first thickness (t)₁) And the second coated steel sheet has a second thickness (t)₂) Ultimate tensile strength (Ts) of said matrix of said first coated steel component part₁) The ultimate tensile strength (Ts) of said substrate (4) being strictly greater than said second coated steel component part₂) And said first thickness (t) of said first coated steel component part₁) And the ultimate tensile strength (Ts)₁) Is strictly greater than the second thickness (t) of the second coated steel component part₂) And the ultimate tensile strength (Ts)₂) The product of (a);

the first and second coated steel component parts are joined by a weld joint (22), the weld joint (22) having an aluminum content of 0.5 to 1.25 wt.%, and the weld joint: (22) Contains martensite and/or bainite, and a fraction of sub-temperature ferrite (α)_IC) Is 15% to the maximum sub-temperature ferrite fractionThe maximum sub-temperature ferrite fractionIs defined using the following formula:

wherein

Ts₁The ultimate tensile strength in MPa of the strongest matrix (3) after press hardening

Ts₂The ultimate tensile strength of the weakest matrix (4) after press hardening is measured in MPa

Beta is the proportion of the filler material added to the weld pool and is 0 to 1

C^FWIs the carbon content of the filler material in weight%

ρ is the ratio of the thickness of the part of the coated steel component comprising the weakest matrix to the thickness of the part of the coated steel component comprising the strongest matrix (ρ ═ t-₂/t₁)

And

the matrix (3, 4) of at least one of the first and second coated steel component parts has a microstructure that is predominantly martensitic and/or bainitic.

18. The press hardened laser welded steel part according to claim 17, wherein the ultimate tensile strength (Ts) of the matrix of the first coated steel part₁) The ultimate tensile strength (Ts) with the matrix of the second coated steel component part₂) The ratio of (A) to (B) is greater than or equal to 1.2.

19. The press hardened laser welded steel part according to any one of claims 17 or 18 wherein the steel of the base body comprises by weight for at least one of the first coated steel part and the second coated steel part:

0.10％≤C≤0.5％

0.5％≤Mn≤3％

0.1％≤Si≤1％

0.01％≤Cr≤1％

Ti≤0.2％

Al≤0.1％

S≤0.05％

P≤0.1％

B≤0.010％

the remainder being iron and impurities resulting from manufacture.

20. The press hardened laser welded steel part according to claim 19 wherein the steel of the base body comprises, for at least one of the first coated steel part portion and the second coated steel part portion by weight:

0.15％≤C≤0.25％

0.8％≤Mn≤1.8％

0.1％≤Si≤0.35％

0.01％≤Cr≤0.5％

Ti≤0.1％

Al≤0.1％

S≤0.05％

P≤0.1％

B≤0.005％

the remainder being iron and impurities resulting from manufacture.

21. The press hardened laser welded steel part according to any one of claims 17 to 20 wherein the steel of the base body comprises by weight for at least one of the first coated steel part and the second coated steel part:

0.040％≤C≤0.100％

0.70％≤Mn≤2.00％

Si≤0.50％

S≤0.005％

P≤0.030％

0.010％≤Al≤0.070％

0.015％≤Nb≤0.100％

Ti≤0.080％

N≤0.009％

Cu≤0.100％

Ni≤0.100％

Cr≤0.2％

Mo≤0.100％

Ca≤0.006％，

the remainder being iron and impurities resulting from manufacture.

22. The press hardened laser welded steel part according to any one of claims 17 to 21 wherein the steel of the base body comprises by weight for at least one of the first coated steel part and the second coated steel part:

0.24％≤C≤0.38％

0.40％≤Mn≤3％

0.10％≤Si≤0.70％

0.015％≤Al≤0.070％

0％≤Cr≤2％

0.25％≤Ni≤2％

0.015％≤Ti≤0.10％

0％≤Nb≤0.060％

0.0005％≤B≤0.0040％

0.003％≤N≤0.010％

0.0001％≤S≤0.005％

0.0001％≤P≤0.025％

wherein the contents of titanium and nitrogen satisfy the following relationship:

Ti/N＞3.42，

and the contents of carbon, manganese, chromium and silicon satisfy the following relationship:

the steel optionally comprises one or more of the following elements:

0.05％≤Mo≤0.65％

0.001％≤W≤0.30％

0.0005％≤Ca≤0.005％

the remainder being iron and impurities inevitably produced by manufacture.

23. The press hardened laser welded steel part according to any one of claims 17 to 22 wherein the steel of the base body comprises by weight for at least one of the first coated steel part and the second coated steel part:

0.06％≤C≤0.100％

1.4％≤Mn≤1.9％

0.2％≤Si≤0.5％

0.010％≤Al≤0.070％

0.04％≤Nb≤0.06％

3.4xN≤Ti≤8xN

0.02％≤Cr≤0.1％

0.0005％≤B≤0.004％

0.001％≤S≤0.009％

the remainder being iron and impurities resulting from manufacture.