ALUMINUM ALLOY SEAMLESS EXTRUDED TUBE EXCELLENT IN HIGH TEMPERATURE TUBE EXPANSION FORMABILITY AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an aluminum alloy seamless extruded tube excellent in high temperature tube expansion formability, and also to provide its manufacturing method.;SOLUTION: The aluminum alloy seamless extruded tube is a material for high temperature tube expansion forming process which is carried out at a temperature not less than 300°C with a gas as a pressure medium. When a value obtained by dividing the difference between a maximum thickness and a minimum thickness by an average thickness at a part for tube expansion of the aluminum alloy seamless extruded tube is not more than 0.067 and a deviation ratio of thickness exceeds 0.067, cold working is executed so that a surface reduction working ratio is made to be not less than 15%.;COPYRIGHT: (C)2010,JPO&INPIT