抄録
Beta-titanium alloy bolts were developed with cold forging process. It was formerly difficult to manufacture beta-titanium bolts by cold forging, because beta-titanium alloy is easy to wear with dies. Now the lubricant coating of beta-titanium material and new cold forging processes are developed, resulting in manufacturing cold-forged beta-titanium bolts. It is confirmed to be able to mass-produce beta-titanium bolts. The beta-titanium bolts could be strengthened up to 800∼1200 MPa by heat treatments. It is, however, essential to control both the tensile strength and ductility, depending on uses.
