Semi-finished pipe, method for producing semi-finished pipe, pipe, and method for producing pipe

A semi-finished pipe used for forming a finished pipe by cutting performed by a lathe, the semi-finished pipe comprising:

• a first layer for forming the finished pipe that remains even after cutting performed by the lathe;
• and
• a second layer for a dummy use that is formed on an outer side of the first layer, and forms an object to be cut by the lathe, wherein
• the first layer is made of an alloy, and the second layer is made such that a degree of alloying in the second layer is lowered in an outward direction.

A method of manufacturing a semi-finished pipe used for forming a finished pipe by cutting performed by a lathe, the method comprising:

• a step of preparing a wire;
• a step of forming a first layer for forming the finished pipe that remains even after cutting performed by the lathe on an outer peripheral side of the wire;
• and
• a step of forming a second layer for a dummy use that becomes an object to be cut by cutting performed by the lathe on an outer peripheral side of the first layer, wherein
• in the step of forming the first layer and in the step of forming the second layer, the first layer and the second layer are formed using metals with which the first layer and a portion of the second layer close to the first layer are alloyed when the semi-finished pipe is heated.

A pipe manufacturing method for manufacturing a finished pipe from a semi-finished pipe using a lathe, the pipe manufacturing method comprising:

• a step of preparing a semi-finished pipe for forming a finished pipe by cutting performed by a lathe, the semi-finished pipe comprising:
• a first layer for forming the finished pipe that remains even after cutting performed by the lathe;
• and
• a second layer for a dummy use that is formed on an outer side of the first layer, and forms an object to be cut by the lathe, wherein
• the first layer and the second layer are made of metals of which the first layer and a portion of the second layer close to the first layer are alloyed to each other by heating the semi-finished pipe;
• a grasping step of grasping the semi-finished pipe from the outer side of the second layer;
• a cutting step of cutting the second layer from the outer side of the second layer such that a part of the second layer remains;
• and
• an alloying step of alloying the first layer and the remaining second layer by heating the semi-finished pipe.

A pipe manufacturing method for manufacturing a finished pipe from a semi-finished pipe using a lathe, the pipe manufacturing method comprising:

• a step of preparing a semi-finished pipe for forming a finished pipe by cutting performed by a lathe, the semi-finished pipe comprising:
• a first layer for forming the finished pipe that remains even after cutting performed by the lathe;
• and
• a second layer for a dummy use that is formed on an outer side of the first layer, and forms an object to be cut by the lathe, wherein
• the first layer and the second layer are made of metals of which the first layer and a portion of the second layer close to the first layer are alloyed to each other by heating the semi-finished pipe;
• an alloying step of alloying the first layer and a portion of the second layer close to the first layer by heating the semi-finished pipe;
• a grasping step of grasping the semi-finished pipe from the outer side of the second layer;
• and
• a cutting step of cutting the second layer from the outer side of the second layer down to a portion of the second layer close to the first layer.