Duplex stainless steel material and duplex stainless steel tube

2:

• The duplex stainless steel material according to claim 1, wherein the duplex stainless steel material comprises 0.01 to 0.50 mass % of Ta as the metal component composition, and the outer shell comprises Ta in an amount satisfying formula (1) below:
• ([Ta]/[M]total)×100≥5 formula (1)
• where [Ta] represents a number of Ta atoms contained in the outer shell, and [M]total represents a total number of atoms of metal elements contained in the outer shell.

3:

• The duplex stainless steel material according to claim 1, wherein the duplex stainless steel material comprises 0.01 to 0.50 mass % of Ta and 0.0001 to 0.0500 mass % of Ti as the metal component composition, and a (Ta mass %/Ti mass %) ratio satisfies formula (2) below:
• Ta mass %/Ti mass %≥25 formula (2).

4:

• The duplex stainless steel material according to claim 1, wherein the duplex stainless steel material comprises 0.0001 to 0.0200 mass % of Mg and 0.001 to 0.050 mass % of Al as the metal component composition, and the nucleus in each of the composite inclusions comprises an oxide of Mg and Al.

7:

• The duplex stainless steel material according to claim 5, wherein the metal component composition further comprises:
• 0.0001 to 0.0200 mass % of Ca.

8:

• The duplex stainless steel material according to claim 5, wherein the metal component composition further comprises:
• at least one selected from the group consisting of 0.1 to 2.0 mass % of Co and 0.1 to 2.0 mass % of Cu.

9:

• The duplex stainless steel material according to claim 5, wherein the metal component composition further comprises:
• 0.0005 to 0.0100 mass % of B.

10:

• A duplex stainless steel tube, comprising the duplex stainless steel material according to claim 1.

11:

• The duplex stainless steel material according to claim 6, wherein the metal component composition further comprises:
• 0.0001 to 0.0200 mass % of Ca.

12:

• The duplex stainless steel material according to claim 6, wherein the metal component composition further comprises:
• at least one selected from the group consisting of 0.1 to 2.0 mass % of Co and 0.1 to 2.0 mass % of Cu.

13:

• The duplex stainless steel material according to claim 6, wherein the metal component composition further comprises:
• 0.0005 to 0.0100 mass % of B.