Hydrogen absorption and desorption of steel in the high strength bolt manufacturing

Abstract

It is needless to say by now that delayed fracture is an intrinsic issue in high strength bolt steels. Since hydrogen absorption of bolt steels in galvanizing must be taken into account besides the absorption from the environment of bolt usage, baking is integrated within the manufacturing process of galvanized bolts in order to decrease the absorbed hydrogen. But there are processes in bolt manufacturing other than galvanizing in which the hydrogen absorption is assumed to take place. The authors investigated the effect of each manufacturing process on the amount of the absorbed hydrogen in bolt steels. © 2012 ISIJ.