水素添加したTi-6Al-2Sn-4Zr-6Mo合金の衝撃靱性

抄録

The effect of various heat treatments on the behavior of the hydrogen embrittlement of Ti-6Al-2Sn-4Zr-6Mo alloy, and the relation between hydrogen embrittlement and microstructural factor was investigated.
In the case of the specimens which were air cooled after solution treatment in the (α+β) region, the width of hydrogen embrittled fracture surface, which corresponded to the hydride formation zone, and the hydrogen embrittlement ratio increased with the increase of solution treatment temperature, namely the decrease of the areal percentage of primary α. On the other hand, in the case of the specimens which were water quenched after solution treatment in the (α+β) region, the opposite tendency was observed. In the case of solution treatment temperature higher than 1 173 K, the width of hydrogen embrittled fracture surface and the hydrogen embrittlement ratio increased in the order of furnace cooled, water quenched and air cooled specimens after a solution treatment with the same treatment temperature. The hydrogen embrittlement ratio was lower and the width of hydrogen embrittled fracture surface was wider in the specimens which were solution treated in the β region than that in those which were solution treated in the (α+β) region with the same cooling condition after solution treatment.