Duplex stainless clad steel plate and method of producing same

A duplex stainless clad steel plate in which a duplex stainless steel plate as a cladding metal is bonded or joined to one or both surfaces of a base steel plate, wherein

• the base steel plate comprises a first chemical composition containing, in mass %, C:
• 0.06% to 0.25%, Si:
• 0.05% to 0.50%, Mn:
• 0.70% to 1.60%, P:
• 0.030% or less, S:
• 0.010% or less, Al:
• 0.005% to 0.100%, Mo:
• 0.01% to 0.15%, Nb:
• 0.010% to 0.040%, Ti:
• less than 0.005%, and N:
• 0.0010% to 0.0100%, optionally at least one selected from the group consisting of Cu:
• 0.50% or less, Ni:
• 0.50% or less, Cr:
• 0.40% or less, and V:
• 0.050% or less, with the balance being Fe and inevitable impurities, in a range such that Nb/N is 3.0 or more and Ceq represented by the following Expression (1) is 0.35 to 0.45:
• Ceq=C+Mn/6+(Cu+Ni)/15+(Cr+Mo+v)/5 (1)
• where the symbol of each element indicates the content in mass % of the element, and any element not contained is calculated as 0,
• the duplex stainless steel plate comprises:
• a second chemical composition containing, in mass %, C:
• 0.030% or less, Si:
• 1.00% or less, Mn:
• 2.00% or less, P:
• 0.0400% or less, S:
• 0.0100% or less, Ni:
• 4.50% to 7.00%, Cr:
• 21.0% to 24.0%, Mo:
• 2.5% to 3.5%, and N:
• 0.08% to 0.20%, optionally at least one selected from the group consisting of Cu:
• 1.50% or less, W:
• 1.50% or less, Co:
• 1.50% or less, Ti:
• 0.25% or less, and Nb:
• 0.25 or less, with the balance being Fe and inevitable impurities, in a range such that PI defined by the following Expression (2) is 33.0 to 38.0:
• PI=Cr+3.3Mo+16N (2)
• where the symbol of each element indicates the content in mass % of the element;
• and
• a microstructure containing a ferrite phase in an area fraction of 35% to 65%, and
• in the microstructure, an amount of precipitated Cr is 1.00 mass % or less and an amount of precipitated Mo is 0.50 mass % or less.