Effect of Charging Temperature on Hydrogen Damage Behavior of TA15 Alloy

In this research, the effect of charging temperature on the hydrogen damage behavior of TA15 alloy was studied. The results show that the strength of the alloy increases first and then decreases with the increase in charging temperature under the condition of 800–900 K, 10 MPa, and hydrogen charging for 1 h, but the elongation decreases continuously. When the charging temperature is 800 K, the tensile strength of the alloy increases by 9% compared with the as-received samples, while the elongation decreases by 12%. When the charging temperature is 900 K, the tensile strength of the alloy decreases by 85%, and the alloy is completely brittle fracture (the embrittlement index reaches 100%). The microanalysis demonstrates that as the hydrogen charging temperature increases from 800 K to 900 K, the hydrides in the alloy undergo a transformation, shifting from precipitating predominantly along the α/β phase boundary to precipitating within the α and β phases. The sizes and quantities of these hydrides increase significantly, resulting in a change in the way of the hydrogen cracking of the alloy. Rather than occurring along the α/β phase boundary, as previously observed, the cracking now propagates along the hydrides within the α and β phases or along the hydride/matrix interfaces.