Hydrogen dissolving capacity in slag and diffusible hydrogen in deposited metal

Effects of composition of the slag on the diffusible hydrogen content in deposited metals were studied by means of changing the content of CaO andMgO in the basic electrode slag and changing the content of Al₂O₃ and MgO in the CO₂ gas-shielded FCAW slag.The results show that the same weight CaO replacing MgO has an obvious improvement on the hydrogen dissolving capacity in slag.It's because the radius of the Ca²⁺ is bigger than the radius of the Mg²⁺ which has 12 match places, and easy to form the peroxide CaO, which can improve the oxygen content in slag.Some Al₂O₃ replacing MgO in FCAW slag will improve the hydrogen dissolving capacity in slag;the reason is the hydrogen has better solubility and diffusion coefficient in Al₂O₃.