MANUFACTURE OF TITANIUM ALLOY ROLLING MATERIAL HAVING SATISFACTORY TEXTURE

摘要

PURPOSE:To manufacture a titanium alloy rolling material having a satisfactory texture, by cogging an (alpha)+(beta) type titanium alloy ingot in a (beta) area, cooling it once, and after that, repeating it, cogging it in an (alpha)+(beta) area, and also executing an equi-axed crystal forming treatment as necessary. CONSTITUTION:An (alpha)+(beta) type titanium alloy ingot is heated to 1,000-1,150 deg.C, and after that, (beta) area cogging whose forging ratio is =1.5 is executed at =950 deg.C, and a casting structure is fined. Subsequently, the obtained cogging material is cooled to =800 deg.C, and transformation to an (alpha)+(beta) type from a (beta) type is finished completely enough. Subsequently, in a temperature range which generates no crack due to working and does not approach the (beta) area, the cogging material is reheated to 850-950 deg.C, (alpha)+(beta) area cogging whose forging ratio is =2 is executed, and the crystal is made finer. Also, a rolling material immediately after it has been hot-rolled is slowly cooled to about 700 deg.C at 15 deg.C/hr, and after that, is radiated, and an equi-axed crystal forming treatment is executed, by which the crystal grain can be made fined.