Evaluation of fatigue strength for large titanium alloy VT3-1 blanks taking account of material structure

Conclusions

• 1. Statistical treatment of the results of fatigue tests showed that different processing schedules for manufacturing article blanks made of alloy VT3-1 have a significant effect on the average number of cycles to failure and an insignificant effect on their scatter.

• 2. The average endurance of specimens cut from forgings manufactured by processing schedule III is lower by a factor of two to six than for those manufactured by processing schedule II, and this is apparently connected with a sharp decrease in reduction using processing schedule III.

• 3. The endurance of specimens cut from forgings manufactured by processing schedule III with a failure probability P≤1% is higher than with manufacture by schedules I and II, and this is connected with the presence of threshold values of endurance on their distribution curves.

• 4. In manufacturing different types of blanks by one processing schedule their fatigue strength characteristics also differ, as a result of which forging parameters within one processing schedule should be established for each type and size of blank.

• 5. For large blanks considerable micro and macrostructural inhomogeneity is typical. Macrograin size and the nature and uniformity of the microstructure depend to a considerable degree on the manufacturing process for semifinished products.