Study of the submerged arc welding of titanium

Results are presented of a study of halides as candidate materials for submerged arc welding of titanium alloys. Criteria are defined for optimum performance and tests are performed to screen candidate fluxes. CaF2-base fused fluxes are found to offer preferred welding characteristics. Four promising compositions are identified: CaF2, CaF2-(5 percent) BaCl2, CaF2-(5 percent) SrF2.SrCl2 and CaF2-(5 percent) BaCl2-(2 percent) LiF. Groove welds made with CaF2 flux and Ti--6Al--2Nb--1Ta--1Mo electrodes produce strength-toughness combinations of 1082 MPa, 47 MN√m/m2 (157 ksi--41 ks√in.) with no auxiliary shielding and 999 MPa, 69 MN√m/m2 (145 ksi--60 ksi√in.) with auxiliary argon shielding. Heat treating the welds at 5350C for 1 h resulted in small decreases in strength and corresponding small increases in toughness