Steam turbine steels, e.g. 3.5NiCrMoV steel, are susceptible to stress-corrosion cracking (SCC). To evaluate the role of the different alloying elements and the presence of a hydrogen-assisted SCC mechanism, generic Fe-C-X (X=Ni/Cr/Mo/V) steels are mechanically tested with in-situ cathodic polarization in an acidic, aqueous environment at an elevated temperature. Crack formation, ductility loss and corrosion product formation are evaluated.