Abstract: Disclosed is 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, in which the base steel plate comprises a predetermined chemical composition such that Nb/N is 3.0 or more and Ceq is 0.35 to 0.45, and the duplex stainless steel plate comprises: a predetermined chemical composition such that PI is 34.0 to 43.0; 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 2.00% or less and an amount of precipitated Mo is 0.50% or less.

Abstract: A rail has excellent fatigue crack propagation resistance characteristics, wherein the rail has a component composition including C: 0.80 to 1.30 mass %, Si: 0.10 to 1.20 mass %, Mn: 0.20 to 1.80 mass %, P: not more than 0.035 mass %, S: 0.0005 to 0.012 mass %, Cr: 0.20 to 2.50 mass % and the remainder being Fe and inevitable impurities and satisfying CP represented by equation (1) being not more than 2500: CP=X/RA??(1) and X={(10×[% C])+([% Si]/12)+([% Mn]/24)+([% Cr]/21)}5??(2), where [% Y] is content of an element Y (mass %), and RA is a prior austenite grain size (?m).

Abstract: Disclosed is 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, in which the base steel plate comprises a predetermined chemical composition such that Nb/N is 3.0 or more and Ceq is 0.35 to 0.45, and the duplex stainless steel plate comprises: a predetermined chemical composition such that PI is 33.0 to 38.0; 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% or less and an amount of precipitated Mo is 0.50% or less.

Abstract: Disclosed is 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, in which the base steel plate comprises a predetermined chemical composition such that Nb/N is 3.0 or more and Ceq is 0.35 to 0.45, and the duplex stainless steel plate comprises: a predetermined chemical composition such that PI is 33.0 to 38.0; 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% or less and an amount of precipitated Mo is 0.50% or less.

Abstract: Disclosed is 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, in which the base steel plate comprises a predetermined chemical composition such that Nb/N is 3.0 or more and Ceq is 0.35 to 0.45, and the duplex stainless steel plate comprises: a predetermined chemical composition such that PI is 34.0 to 43.0; 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 2.00% or less and an amount of precipitated Mo is 0.50% or less.

Abstract: A thick steel plate is provided by heating a continuously-cast slab, hot forging the continuously-cast slab using opposing dies having respective short sides differing such that when a short side length of a die having a shorter one of the short sides is taken to be 1, a short side length of a die having a longer one of the short sides is 1.1 to 3.0, allowing cooling to obtain a steel raw material, reheating the steel raw material, performing hot rolling of the steel raw material including at least two passes carried out, allowing cooling to obtain a thick steel plate, reheating the thick steel plate to at least the Ac3 temperature and no higher than 1050° C., rapidly cooling the thick steel plate to 350° C. or lower, and tempering the thick steel plate at at least 550° C. and no higher than 700° C.

Abstract: A thick steel plate is provided by heating a continuously-cast slab, hot forging the continuously-cast slab using opposing dies having respective short sides differing such that when a short side length of a die having a shorter one of the short sides is taken to be 1, a short side length of a die having a longer one of the short sides is 1.1 to 3.0, allowing cooling to obtain a steel raw material, reheating the steel raw material, performing hot rolling of the steel raw material including at least two passes carried out, allowing cooling to obtain a thick steel plate, reheating the thick steel plate to at least the Ac3 temperature and no higher than 1050° C., rapidly cooling the thick steel plate to 350° C. or lower, and tempering the thick steel plate at at least 550° C. and no higher than 700° C.