Abstract: In the hydrogen resistant steel alloy carbides are formed to fix carbon so as to avoid the formation of methane at Fe₃C, that causes hydrogen damage.This Process depends not only on an appropriate design of the steel composition, but also on aproper selection of heat treatment This research was doneby using complex phase analysis method to study the precipitation of alloy carbides and their relationship with hydrogen in 12SiMoVNb steel.
By normanizatibn at lOOO℃ and tempering at 720-740tJ small carbides (most one of them is V₄C₃) distribute in the ferrite matrix and solid solution strengthening by Mo% V, Nb were obtained. They are both decisive factors in achieveing good arc mechanical properties and promoting the resistance against hydrogen attack at 400t and at P_H2-200 kg/cm².