TUBE WITH SPIRAL GROOVE ON INNER SURFACE, MANUFACTURING METHOD THEREFOR, AND HEAT EXCHANGER

摘要

PROBLEM TO BE SOLVED: To provide a tube with a spiral groove on an inner surface, free from an orange peel and excellent in surface and inner surface properties, a manufacturing method therefor, and a heat exchanger.SOLUTION: The present invention provides a tube with a spiral groove on an inner surface manufactured by forming a plurality of linear grooves along a length direction on an inner surface at a distance in a circumferential direction, processing an aluminum extruded stock tube having a fin formed among these linear grooves into a coil shape, extending the stock tube to twist the tube material, and drawing the stock tube. A metal structure is either entirely a fiber structure along a length direction of the tube or entirely the fiber structure except for a surface layer that is a crystal structure.