OBSERVATION OF CARBIDE STRUCTUREAND HYDROGEN EMBRITTLEMENT IN LOW CARBON Cr-Mo-V STEEL

The quantitative metallographic observation of altered carbide microstructuresin the matrix and test of hydrogen embrittlement for a low carbon Cr-Mo-Vsteel undergone different regimes of heat treatment were conducted. The experi-mental results are believed to support the authors' previous prediction that thedistribution and shape of the catbides affect obviously the susceptibility of HSLAsteel to hydrogen embrittlement. The measurement of apparent diffusion coeffi-cients of Q+T and N+T specimens revealed that the values of D increased withthe increase of tempering time, suggesting that the density of traps was reduced.