Clad welded pipe or tube and method of producing same

A clad welded pipe or tube having a two-layer structure composed of a first layer made of base metal and a second layer placed on one surface of the first layer and made of first cladding metal that is a material different from the base metal,

• wherein a pipe or tube circumferential length of weld metal in a weld at each of an inner surface and an outer surface of the clad welded pipe or tube is 0.0010 mm or more and 1.0 mm or less,
• wherein the base metal is not exposed at a first cladding metal-side surface of the clad welded pipe or tube in the weld, and
• wherein a thickness of the first cladding metal in the weld metal is 20% or more and 300% or less of a thickness of the first cladding metal in parts other than the weld metal.

A clad welded pipe or tube having a three-layer structure composed of a middle layer that is a first layer made of base metal, an inner layer that is a second layer placed on one surface of the first layer and made of first cladding metal that is a material different from the base metal, and an outer layer that is a third layer placed on the other surface of the first layer and made of second cladding metal that is a material different from the base metal,

• wherein a pipe or tube circumferential length of weld metal in a weld at each of an inner surface and an outer surface of the clad welded pipe or tube is 0.0010 mm or more and 1.0 mm or less,
• wherein the base metal is not exposed at the inner surface and the outer surface of the clad welded pipe or tube in the weld, and
• wherein a pipe or tube circumferential length of the weld metal at a thickness center of the clad welded pipe or tube is 0.0010 mm or more and 0.3 mm or less.

A clad welded pipe or tube having a three-layer structure composed of a middle layer that is a first layer made of base metal, an inner layer that is a second layer placed on one surface of the first layer and made of first cladding metal that is a material different from the base metal, and an outer layer that is a third layer placed on the other surface of the first layer and made of second cladding metal that is a material different from the base metal,

• wherein a pipe or tube circumferential length of weld metal in a weld at each of an inner surface and an outer surface of the clad welded pipe or tube is 0.0010 mm or more and 1.0 mm or less,
• wherein the base metal is not exposed at the inner surface and the outer surface of the clad welded pipe or tube in the weld, and
• wherein a thickness of the first cladding metal and a thickness of the second cladding metal in the weld metal are respectively 20% or more and 300% or less of a thickness of the first cladding metal and a thickness of the second cladding metal in parts other than the weld metal, and are each 35% or less of a thickness of the clad welded pipe or tube.