Aluminum-based plated steel sheet, method of manufacturing aluminum-based plated steel sheet, and method of manufacturing component for vehicle

1. An aluminum-based plated steel sheet comprising:

a base material;

an aluminum-based plating layer located above the base material; and

an intermetallic compound layer that is located between the base material and the aluminum-based plating layer and contains an intermetallic compound of Al and Fe,

wherein the base material contains, by mass %,

C: 0.15% or more and 0.50% or less,

Si: 0.010% or more and 2.000% or less,

Mn: 0.3% or more and 5.0% or less,

Cr: 0.010% or more and 2.000% or less,

P: 0.1% or less,

S: 0.1% or less,

Al: 0.5% or less,

B: 0.0002% or more and 0.0100% or less,

N: 0% or more and 0.01% or less,

W: 0% or more and 3% or less,

Mo: 0% or more and 3% or less,

V: 0% or more and 2% or less,

Ti: 0% or more and 0.5% or less,

Nb: 0% or more and 1% or less,

Ni: 0% or more and 5% or less,

Cu: 0% or more and 3% or less,

Sn: 0% or more and 0.1% or less,

Sb: 0% or more and 0.1% or less, and

a remainder including Fe and impurities,

the aluminum-based plating layer contains, on average,

80 mass % or more and 97 mass % or less of Al,

3 mass % or more and 15 mass % or less of Si,

0 mass % or more and 5 mass % or less of Zn,

0 mass % or more and 5 mass % or less of Fe,

0 mass % or more and 3 mass % or less in total of one or more selected from the group consisting of Mg and Ca, and

impurities

so that a total amount thereof is 100 mass %,

an average value of a thickness of the intermetallic compound layer is 2 μm or more and 10 μm or less,

a maximum value of the thickness of the intermetallic compound layer is 11 μm or more and 25 μm or less, and

a standard deviation of the thickness of the intermetallic compound layer is 2 μm or more and 10 μm or less.

2. The aluminum-based plated steel sheet according to claim 1 comprising:

an oxide-containing region that contains one or more selected from the group consisting of a Si oxide, a Mn oxide, a Cr oxide, and a B oxide in a total amount of 1 mass % or more and 10 mass % or less, in a range of 5 μm from an interface between the base material and the intermetallic compound layer in a direction toward a center of the base material.

3. The aluminum-based plated steel sheet according to claim 2 ,

wherein the aluminum-based plating layer contains one or more selected from the group consisting of Mg and Ca in a total amount of 0.01 mass % or more and 3 mass % or less.

4. A method of manufacturing the aluminum-based plated steel sheet according to claim 3 , the method comprising:

hot rolling a steel slab to obtain a hot-rolled steel sheet;

coiling the hot-rolled steel sheet;

pickling the hot-rolled steel sheet;

cold rolling the hot-rolled steel sheet to obtain a cold rolled steel sheet; and

continuously performing an annealing treatment and a hot dip aluminum-based plating treatment on the cold rolled steel sheet,

wherein the steel slab contains, by mass %,

C: 0.15% or more and 0.50% or less,

Si: 0.010% or more and 2.000% or less,

Mn: 0.3% or more and 5.0% or less,

Cr: 0.010% or more and 2.000% or less,

P: 0.1% or less,

S: 0.1% or less,

Al: 0.5% or less,

B: 0.0002% or more and 0.0100% or less,

N: 0% or more and 0.01% or less,

W: 0% or more and 3% or less,

Mo: 0% or more and 3% or less,

V: 0% or more and 2% or less,

Ti: 0% or more and 0.5% or less,

Nb: 0% or more and 1% or less,

Ni: 0% or more and 5% or less,

Cu: 0% or more and 3% or less,

Sn: 0% or more and 0.1% or less,

Sb: 0% or more and 0.1% or less, and

a remainder including Fe and impurities,

a steel sheet coiling temperature CT during the coiling is set to 700° C. or more and 850° C. or less,

an arithmetic average roughness Ra of a surface of the cold rolled steel sheet after the cold rolling is set to 0.5 μm or more and 5 μm or less, and

a plating bath in the hot dip aluminum-based plating treatment contains

80 mass % or more and 97 mass % or less of Al,

3 mass % or more and 15 mass % or less of Si,

impurities,

0 mass % or more and 5 mass % or less of Zn,

0 mass % or more and 5 mass % or less of Fe, and

0 mass % or more and 3 mass % or less in total of one or more selected from the group consisting of Mg and Ca

so that a total amount thereof is 100 mass %.

5. A method of manufacturing a component for a vehicle, comprising:

heating the aluminum-based plated steel sheet according to claim 3 to 850° C. or more;

press forming the aluminum-based plated steel sheet with a die; and

rapidly cooling the aluminum-based plated steel sheet with the die at a cooling rate of 30° C./s or more.

6. The aluminum-based plated steel sheet according to claim 1 ,

wherein the aluminum-based plating layer contains one or more selected from the group consisting of Mg and Ca in a total amount of 0.01 mass % or more and 3 mass % or less.

7. A method of manufacturing a component for a vehicle, comprising:

heating the aluminum-based plated steel sheet according to any one of claims 1 to 6 to 850° C. or more;

press forming the aluminum-based plated steel sheet with a die; and

rapidly cooling the aluminum-based plated steel sheet with the die at a cooling rate of 30° C./s or more.

8. A method of manufacturing the aluminum-based plated steel sheet according to any one of claims 1 to 6 , the method comprising:

hot rolling a steel slab to obtain a hot-rolled steel sheet;

coiling the hot-rolled steel sheet;

pickling the hot-rolled steel sheet;

cold rolling the hot-rolled steel sheet to obtain a cold rolled steel sheet; and

continuously performing an annealing treatment and a hot dip aluminum-based plating treatment on the cold rolled steel sheet,

wherein the steel slab contains, by mass %,

C: 0.15% or more and 0.50% or less,

Si: 0.010% or more and 2.000% or less,

Mn: 0.3% or more and 5.0% or less,

Cr: 0.010% or more and 2.000% or less,

P: 0.1% or less,

S: 0.1% or less,

Al: 0.5% or less,

B: 0.0002% or more and 0.0100% or less,

N: 0% or more and 0.01% or less,

W: 0% or more and 3% or less,

Mo: 0% or more and 3% or less,

V: 0% or more and 2% or less,

Ti: 0% or more and 0.5% or less,

Nb: 0% or more and 1% or less,

Ni: 0% or more and 5% or less,

Cu: 0% or more and 3% or less,

Sn: 0% or more and 0.1% or less,

Sb: 0% or more and 0.1% or less, and

a remainder including Fe and impurities,

a steel sheet coiling temperature CT during the coiling is set to 700° C. or more and 850° C. or less,

an arithmetic average roughness Ra of a surface of the cold rolled steel sheet after the cold rolling is set to 0.5 μm or more and 5 μm or less, and

a plating bath in the hot dip aluminum-based plating treatment contains

80 mass % or more and 97 mass % or less of Al,

3 mass % or more and 15 mass % or less of Si,

impurities,

0 mass % or more and 5 mass % or less of Zn,

0 mass % or more and 5 mass % or less of Fe, and

0 mass % or more and 3 mass % or less in total of one or more selected from the group consisting of Mg and Ca

so that a total amount thereof is 100 mass %.

9. The method of manufacturing the aluminum-based plated steel sheet according to claim 8 ,

wherein, in the annealing treatment, a value of a relational expression log (P H2O /P H2 ) between a water vapor partial pressure P H2O and a hydrogen partial pressure P H2 in an annealing atmosphere in a sheet temperature range of 650° C. or more and 900° C. or less is set to −3 or more and −0.5 or less, and

an annealing time at the sheet temperature is set to 60 seconds or more and 500 seconds or less.

10. The method of manufacturing the aluminum-based plated steel sheet according to claim 8 ,

wherein the plating bath contains one or more selected from the group consisting of Mg and Ca in a total amount of 0.01 mass % or more and 3 mass % or less.

11. The method of manufacturing the aluminum-based plated steel sheet according to claim 9 ,

wherein the plating bath contains one or more selected from the group consisting of Mg and Ca in a total amount of 0.01 mass % or more and 3 mass % or less.