Influence of Alloy Elements on Machinability, Weldability and Hot Deformation Resistance in Alpha-beta Titanium Alloys Containing Cr,Fe and C

摘要

Alpha-beta titanium alloys represented as Ti-6A1-4V have been applied to parts of aircrafts,automotives and motorcycles because of their excellent specific strength,heat resistance and corrosion resistance. But the popular alloy Ti-6A1-4V is inferior in forgeability and machinability,accordingly the cost of processing is so expensive in addition to the raw materials. In the interest of forgeability,KS EL-F (Ti-4. 5A1-4CH). 5Fe-0. 2C) has been developed with excellent hot workability, whereas there was the issue that the tool-tip wear on machining was increased in proportion to the volume fraction of TiC precipitates in KS EL-F. Therefore in this study the influence of alloy elements Al,Cr,Fe and C on machinability and weldability was investigated in addition to hot workability, and the new alloy KS ELF 531C (Ti-4. 5A1-2. 5Cr-l. 2Fe-0. 1C) has been developed which is a well-balanced chemical composition on machinability, weldability and hot deformation resistance.