Formation And Thermodynamic Analyses Of Inclusions In Ti-Containing Steel Weld Metals With Different Al Contents

The Ti-containing steel weld metals with Al contents of 0.01-0.085% were prepared. The effects of AI contents in weld metals on the inclusions evolution were in detail investigated by means of thermodynamic calculations coupled with electron probe micro-analyses. The results show that the inclusions in the 0.01% Al weld metal are mainly composed of ilmenite with more amounts of (Mn-Si-Al)-oxide and titanial-spinel. When Al content is increased up to 0.035%, a more amount of corundum and a small amount of pseudobrookite are formed. In 0.085% Al weld metal, the (Mn-Si-Al)-oxide phase disappears completely, and the inclusions contain a substantial amount of corundum, in addition to a minimal amount of pseudobrookite. Ti3O5, MnTi2O4 and MnTiO3 are the primary constituents of pseudobrookite, titanial_spinel and ilmenite solid solutions, respectively. Titanial_spinel and ilmenite have higher amounts of Mn, but lower Ti levels compared with pseudobrookite.