| 摘要 |
The present invention provides a titanium material having high-temperature oxidation resistance at high temperatures above 800° C. and an exhaust pipe made of this titanium material for an engine. A titanium alloy contains 0.15 to 2% by mass Si, has an Al content below 0.30% by mass, and has equiaxial structure having a mean grain size of 15 mum or above. The high-temperature oxidation resistance of the titanium alloy at high temperatures above 800° C., such as 850° C., is improved by means including adding Nb, Mo and Cr in combination with Si to the titanium alloy, forming equiaxial structure of coarse grains, creating acicular structure, Si-enrichment of a surface layer of the titanium alloy, and reducing impurities including copper, oxygen and carbon contained in the titanium alloy. |
