Effect of Baking and Stress on the Hydrogen Content of Cadmium Plated High Strength Steels

摘要

Variations in the diffusible hydrogen concentration of cadmium plated AISI 4340 and 300M steels due to baking and stress are reported. Long baking times of greater than 100 hours at 190C are needed to remove all the hydrogen from bright cadmium plated specimens, and around 40 hours for dull cadmium plated ones. Very short baking not only does not remove hydrogen, but actually pumps it in. Baking for 96 hours is insufficient to remove hydrogen embrittlement from sharp, double notched 300M tensile specimens having a notched tensile strength of 1800 MPa. It is shown that there is not difference in the hydrogen concentration does not change with time for cadmium plated specimens standing for one month at room temperature. Stressing, on the other hand, causes an increase in the hydrogen, presumably by allowing it to enter from the plate due to lattice deformation.