Spot welded member

1. A spot welded member, comprising a spot weld formed by holding a sheet stack of multiple steel sheets between a pair of electrodes and spot-welding the sheet stack,

wherein the spot welded member comprises a region A and a region B the region B being a heat shock region of the spot weld outwardly extending from an edge of a corona bond area to adjacent region A,

wherein at least one of the multiple steel sheets is a high-strength zinc-based coated steel sheet having a tensile strength of 780 MPa or more, the high-strength zinc-based coated steel sheet having a first zinc-based coating with an Al content of 0.5% or more by mass, in the region A, on a base steel sheet, and

wherein the region B includes a coated layer B including an FeAl alloy layer disposed on a surface of the base steel sheet, and a second zinc-based coated layer, disposed on the FeAL alloy laver,

wherein the FeAL alloy layer has an average thickness of 0.3 μm or more and the second zinc-based coated layer has an average thickness of 2.0 μm or more.

2. The spot welded member according to claim 1 , the Al content of the first zinc-based coating satisfies formula (1):

[Average thickness of FeAl alloy layer]≥0.8×In[Al content]+0.2  (1)

where In is a natural logarithm, [average thickness of FeAl alloy layer] is the average thickness (μm) of the FeAl alloy layer, and [Al content] is the Al content (% by mass) of the first zinc-based coating.

3. The spot welded member according to claim 1 , wherein the coated layer B further includes a Zn-rich phase (n) having an Fe content of 5% or less by mass.

4. The spot welded member according to claim 2 , wherein the coated layer B further includes a Zn-rich phase (n) having an Fe content of 5% or less by mass.

5. The spot welded member according to claim 1 , wherein the Zn-rich phase (n) has (001) orientation with respect to a basal surface.

6. The spot welded member according to claim 2 , wherein the Zn-rich phase (n) has (001) orientation with respect to a basal surface.

7. The spot welded member according to claim 3 , wherein the Zn-rich phase (n) has (001) orientation with respect to a basal surface.

8. The spot welded member according to claim 4 , wherein the Zn-rich phase (n) has (001) orientation with respect to a basal surface.

9. The spot welded member according to claim 1 , wherein the base steel sheet of the zinc-based coated steel sheet has a component composition containing, by mass %:

C: 0.01% to 0.22%,

Si: 0.02% to 2.00%,

Mn: 1.0% to 4.0%,

P: 0.060% or less, and

S: 0.01% or less.

10. The spot welded member according to claim 2 , wherein the base steel sheet of the zinc-based coated steel sheet has a component composition containing, by mass %:

C: 0.01% to 0.22%,

Si: 0.02% to 2.00%,

Mn: 1.0% to 4.0%,

P: 0.060% or less, and

S: 0.01% or less.

11. The spot welded member according to claim 3 , wherein the base steel sheet of the zinc-based coated steel sheet has a component composition containing, by mass %:

C: 0.01% to 0.22%,

Si: 0.02% to 2.00%,

Mn: 1.0% to 4.0%,

P: 0.060% or less, and

S: 0.01% or less.

12. The spot welded member according to claim 4 , wherein the base steel sheet of the zinc-based coated steel sheet has a component composition containing, by mass %:

C: 0.01% to 0.22%,

Si: 0.02% to 2.00%,

Mn: 1.0% to 4.0%,

P: 0.060% or less, and

S: 0.01% or less.

13. The spot welded member according to claim 7 , wherein the base steel sheet of the zinc-based coated steel sheet has a component composition containing, by mass %:

C: 0.01% to 0.22%,

Si: 0.02% to 2.00%,

Mn: 1.0% to 4.0%,

P: 0.060% or less, and

S: 0.01% or less.

14. The spot welded member according to claim 8 , wherein the base steel sheet of the zinc-based coated steel sheet has a component composition containing, by mass %:

C: 0.01% to 0.22%,

Si: 0.02% to 2.00%,

Mn: 1.0% to 4.0%,

P: 0.060% or less, and

S: 0.01% or less.

15. The spot welded member according to claim 9 , wherein the component composition of the base steel sheet of the zinc-based coated steel sheet further contains, by mass %, one or two or more selected from the group consisting of:

Nb: 0.002% to 0.100%,

Ti: 0.002% to 0.100%, and

B: 0.0002% to 0.0050%.

16. The spot welded member according to claim 10 , wherein the component composition of the base steel sheet of the zinc-based coated steel sheet further contains, by mass %, one or two or more selected from the group consisting of:

Nb: 0.002% to 0.100%,

Ti: 0.002% to 0.100%, and

B: 0.0002% to 0.0050%.

17. The spot welded member according to claim 11 , wherein the component composition of the base steel sheet of the zinc-based coated steel sheet further contains, by mass %, one or two or more selected from the group consisting of:

Nb: 0.002% to 0.100%,

Ti: 0.002% to 0.100%, and

B: 0.0002% to 0.0050%.

18. The spot welded member according to claim 12 , wherein the component composition of the base steel sheet of the zinc-based coated steel sheet further contains, by mass %, one or two or more selected from the group consisting of:

Nb: 0.002% to 0.100%,

Ti: 0.002% to 0.100%, and

B: 0.0002% to 0.0050%.

19. The spot welded member according to claim 13 , wherein the component composition of the base steel sheet of the zinc-based coated steel sheet further contains, by mass %, one or two or more selected from the group consisting of:

Nb: 0.002% to 0.100%,

Ti: 0.002% to 0.100%, and

B: 0.0002% to 0.0050%.

20. The spot welded member according to claim 14 , wherein the component composition of the base steel sheet of the zinc-based coated steel sheet further contains, by mass %, one or two or more selected from the group consisting of:

Nb: 0.002% to 0.100%,

Ti: 0.002% to 0.100%, and

B: 0.0002% to 0.0050%.