Metallic coated steel product

1. A metallic coated steel product including a steel product and a plating layer that is provided on a surface of the steel product and comprises a Zn— Al—Mg alloy layer,

wherein, in a cross-section of the Zn—Al—Mg alloy layer, an area fraction of MgZn 2 phase is from 45 to 75%, a total area fraction of MgZn 2 and Al phases is not less than 70%, and an area fraction of Zn—Al—MgZn 2 ternary eutectic structure is from 0 to 5%, and

wherein the plating layer has a chemical composition consisting of, by mass:

Zn: from more than 44.90% to less than 79.90%;

Al: from more than 15% to less than 35%;

Mg: from more than 5% to less than 20%;

Ca: from 0.1% to less than 3.0%;

Si: from 0% to 1.0%;

B: from 0% to 0.5%;

Y: from 0% to 0.5%;

La: from 0% to 0.5%;

Ce: from 0% to 0.5%;

Cr: from 0% to 0.25%;

Ti: from 0% to 0.25%;

Ni: from 0% to 0.25%;

Co: from 0% to 0.25%;

V: from 0% to 0.25%;

Nb: from 0% to 0.25%;

Cu: from 0% to 0.25%;

Mn: from 0% to 0.25%;

Sr: from 0% to 0.5%;

Sb: from 0% to 0.5%;

Pb: from 0% to 0.5%;

Sn: from 0% to 20.00%;

Bi: from 0% to 2.0%;

In: from 0% to 2.0%;

Fe: from 0% to 5.0%; and

impurities,

wherein, provided that an element group A consists of Y, La, and Ce, an element group B consists of Cr, Ti, Ni, Co, V, Nb, Cu, and Mn, an element group C consists of Sr, Sb, and Pb, and an element group D consists of Sn, Bi, and In:

a total content of elements selected from the element group A ranges from 0% to 0.5%;

a total content of Ca and elements selected from the element group A ranges from 0.1% to less than 3.0%;

a total content of elements selected from the element group B ranges from 0% to 0.25%;

a total content of elements selected from the element group C ranges from 0% to 0.5%; and

a total content of elements selected from the element group D ranges from 0% to 20.00%.

2. The metallic coated steel product according to claim 1 , wherein the Zn—Al—Mg alloy layer contains at least one intermetallic compound phase selected from the group consisting of Mg 2 Si phase, Ca 2 Si phase, CaSi phase, Ca—Zn—Al intermetallic compound phase, and Ca—Zn—Al—Si intermetallic compound phase.

3. The metallic coated steel product according to claim 1 , wherein the contents of Al, Mg, Ca, and Si respectively range from more than 22% to less than 35%, from more than 10% to less than 20%, from 0.3% to less than 3.0%, and from 0.1% to 1.0%.

4. The metallic coated steel product according to claim 1 , wherein the content of the Al ranges from more than 15% to 22%.

5. The metallic coated steel product according to claim 1 , wherein the content of B ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains B;

the total content of elements selected from the element group A ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains elements selected from the element group A;

the total content of elements selected from the element group B ranges from 0.05% to 0.25% by mass in a case in which the plating layer contains elements selected from the element group B; and

the total content of elements selected from the element group C ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains elements selected from the element group C.

6. The metallic coated steel product according to claim 1 , wherein the Zn—Al—Mg alloy layer contains a Ca—Al—B intermetallic compound phase selected from the group consisting of Al 2 CaB 5 phase and compound phases derived from Al 2 CaB 5 phase with substitution of some atoms by Zn and Mg, and wherein the Ca—Al—B intermetallic compound phase contains B at a concentration of not less than 40% by atom.

7. The metallic coated steel product according to claim 1 , wherein the total content of elements selected from the element group D ranges from 0.05% to 20% by mass in a case in which the plating layer contains elements selected from the element group D; and

the Zn—Al—Mg alloy layer contains at least one intermetallic compound phase selected from the group consisting of Mg 2 Sn phase, Mg 3 Bi 2 phase, and Mg 3 In phase.

8. The metallic coated steel product according to claim 1 , wherein the plating layer contains an Al—Fe alloy layer between the steel product and the Zn—Al—Mg alloy layer.

9. The metallic coated steel product according to claim 2 , wherein the contents of Al, Mg, Ca, and Si respectively range from more than 22% to less than 35%, from more than 10% to less than 20%, from 0.3% to less than 3.0%, and from 0.1% to 1.0%.

10. The metallic coated steel product according to claim 2 , wherein the content of the Al ranges from more than 15% to 22%.

11. The metallic coated steel product according to claim 2 , wherein the content of B ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains B;

the total content of elements selected from the element group A ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains elements selected from the element group A;

the total content of elements selected from the element group B ranges from 0.05% to 0.25% by mass in a case in which the plating layer contains elements selected from the element group B; and

the total content of elements selected from the element group C ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains elements selected from the element group C.

12. The metallic coated steel product according to claim 3 , wherein the content of B ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains B;

the total content of elements selected from the element group A ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains elements selected from the element group A;

the total content of elements selected from the element group B ranges from 0.05% to 0.25% by mass in a case in which the plating layer contains elements selected from the element group B; and

the total content of elements selected from the element group C ranges from 0.05% to 0.5% by mass in a case in which the plating layer contains elements selected from the element group C.

13. The metallic coated steel product according to claim 2 , wherein the Zn—Al—Mg alloy layer contains a Ca—Al—B intermetallic compound phase selected from the group consisting of Al 2 CaB 5 phase and compound phases derived from Al 2 CaB 5 phase with substitution of some atoms by Zn and Mg, and wherein the Ca—Al—B intermetallic compound phase contains B at a concentration of not less than 40% by atom.

14. The metallic coated steel product according to claim 3 , wherein the Zn—Al—Mg alloy layer contains a Ca—Al—B intermetallic compound phase selected from the group consisting of Al 2 CaB 5 phase and compound phases derived from Al 2 CaB 5 phase with substitution of some atoms by Zn and Mg, and wherein the Ca—Al—B intermetallic compound phase contains B at a concentration of not less than 40% by atom.

15. The metallic coated steel product according to claim 4 , wherein the Zn—Al—Mg alloy layer contains a Ca—Al—B intermetallic compound phase selected from the group consisting of Al 2 CaB 5 phase and compound phases derived from Al 2 CaB 5 phase with substitution of some atoms by Zn and Mg, and wherein the Ca—Al—B intermetallic compound phase contains B at a concentration of not less than 40% by atom.

16. The metallic coated steel product according to claim 5 , wherein the Zn—Al—Mg alloy layer contains a Ca—Al—B intermetallic compound phase selected from the group consisting of Al 2 CaB 5 phase and compound phases derived from Al 2 CaB 5 phase with substitution of some atoms by Zn and Mg, and wherein the Ca—Al—B intermetallic compound phase contains B at a concentration of not less than 40% by atom.

17. The metallic coated steel product according to claim 2 , wherein the total content of elements selected from the element group D ranges from 0.05% to 20% by mass in a case in which the plating layer contains elements selected from the element group D; and

the Zn—Al—Mg alloy layer contains at least one intermetallic compound phase selected from the group consisting of Mg 2 Sn phase, Mg 3 Bi 2 phase, and Mg 3 In phase.

18. The metallic coated steel product according to claim 3 , wherein the total content of elements selected from the element group D ranges from 0.05% to 20% by mass in a case in which the plating layer contains elements selected from the element group D; and

the Zn—Al—Mg alloy layer contains at least one intermetallic compound phase selected from the group consisting of Mg 2 Sn phase, Mg 3 Bi 2 phase, and Mg 3 In phase.