Abstract
State of hydrogen in V containing steel for spring (known as 9254V) was analyzed by peak separation of TDS desorption curves through Gaussian distribution. Then it was correlated to the results of hydrogen susceptibility test results, together with those of ordinary spring steel (SAE9254) . The state of hydrogen was different between them:V-containing steel was composed of two kinds of hydrogen traps originated by vanadium carbides, along with lattice, dislocation and grain boundary traps. In contrast, ordinary spring steel (SAE9254) was featured by hydrogen trapped by vacancy and vacancy cluster along with lattice, dislocation and grain boundary hydrogen. The amount of grain boundary hydrogen was found smaller in V containing steel, notwithstanding large amount of hydrogen absorption. This was claimed to be the major reason for the improved resistance hydrogen embrittlement.
