Influence of Ti on the Microstructure and Mechanical Properties of Weld Metal Deposited with Rutile-type Flux Cored Wires

The influence of Ti on microstructure and mechanical properties of deposited metal were studied by adding different amount of ferrotitanium in the rutile-type flux cored wires. The results show that with the increase of Ti content in core wires, the deoxidation manner from titanium-united deoxidation combined with Si and Mn gradually turns to titanium-based deoxidation, and the Ti content in inclusions of the deposited metal increases. In addition, the alloying elements in the deposited metal increases and the yield strength gradually approaches to the tensile strength, which indicates a weakness plasticity. Differences between the microstructure of the deposited metals are discussed and the titanium existing in compound oxides can promote the nucleation of acicular ferrite, while the titanium soluted as alloying element has an opposite effect.