Plated steel sheet

1. A plated steel sheet, comprising:

a steel sheet; and

a plating layer on the steel sheet, wherein:

the plating layer is a hot-dip galvanizing layer or an alloyed hot-dip galvanizing layer;

the steel sheet comprises:

a base material; and

a decarburized ferrite layer on the base material;

the base material includes a chemical composition represented by, in mass %:

C: 0.03% to 0.70%;

Si: 0.25% to 3.00%;

Mn: 1.0% to 5.0%;

P: 0.10% or less;

S: 0.0100% or less;

sol. Al: 0.001% to 1.500%;

N: 0.02% or less;

Ti: 0.0% to 0.300%;

Nb: 0.0% to 0.300%;

V: 0.0% to 0.300%;

Cr: 0% to 2.000%;

Mo: 0% to 2.000%;

Cu: 0% to 2.000%;

Ni: 0% to 2.000%;

B: 0% to 0.0200%;

Ca: 0.00% to 0.0100%;

REM: 0.0% to 0.1000%; and

a balance: Fe and impurities;

the base material includes a structure, at a position at which a depth from a surface of the steel sheet corresponds to ¼ of a thickness of the steel sheet, represented by, in volume fraction:

tempered martensite: 3.0% or more;

ferrite: 4.0% or more; and

retained austenite: 8.3% or more;

an average hardness of the tempered martensite in the base material is 5 GPa to 10 GPa;

a part or all of the tempered martensite and the retained austenite in the base material form a Martensite-Austenite constituent;

a volume fraction of ferrite in the decarburized ferrite layer is 120% or more of the volume fraction of the ferrite in the base material at the position at which the depth from the surface of the steel sheet corresponds to ¼ of the thickness of the steel sheet;

an average grain diameter of the ferrite in the decarburized ferrite layer is 20 μm or less;

a thickness of the decarburized ferrite layer is 5 μm to 200 μm;

a volume fraction of tempered martensite in the decarburized ferrite layer is 1.0 volume % or more;

a number density of the tempered martensite in the decarburized ferrite layer is 0.01/μm 2 or more; and

an average hardness of the tempered martensite in the decarburized ferrite layer is 8 GPa or less.

2. The plated steel sheet according to claim 1 , wherein, in the chemical composition,

Ti: 0.001% to 0.300%,

Nb: 0.001% to 0.300%, or

V: 0.001% to 0.300%,

or any combination thereof is satisfied.

3. The plated steel sheet according to claim 1 , wherein, in the chemical composition,

Cr: 0.001% to 2.000%, or

Mo: 0.001% to 2.000%,

or both of them is satisfied.

4. The plated steel sheet according to claim 1 , wherein, in the chemical composition,

Cu: 0.001% to 2.000%, or

Ni: 0.001% to 2.000%,

or both of them is satisfied.

5. The plated steel sheet according to claim 1 , wherein, in the chemical composition, B: 0.0001% to 0.0200% is satisfied.

6. The plated steel sheet according to claim 1 , wherein, in the chemical composition,

Ca: 0.0001% to 0.0100%, or

REM: 0.0001% to 0.1000%,

or both of them is satisfied.