Existence State Analysis of Hydrogen Existing in Welding Process of Ferritic Steel

The existence state of hydrogen in welding process of ferritic steel was analyzed by theoretical calculation method and experiment. The results show that hydrogen exists in high temperature arc and molten pool in atomic state; that hydrogen exists in high temperature austenite octahedral interstice in atomic state; that hydrogen atoms gather in ferritic grain boundary during medium-low temperature ferritic stage, most of which form high pressure gaseous molecules and escape from open grain boundaries connected as network.