Narrow Results

The characterization of the single crystal of type 304 stainless steels was performed by using particle induced x-ray emission and Rutherford backscattering spectroscopy with channeling technique (PIXE-C and RBS-C). They proved that the solution annealing process is absolutely necessary for production of a good single crystal of stainless steels.

They are also shown that the positions of P atoms before He irradiation were mostly substitutional sites of fcc structure and that MeV He ion irradiation induced segregation of Si and S atoms to the (110) surface.

It is very important to study and develop ultra strong maraging steel which is metal having high tensile strength and good impact toughness and which is excellent in formability, workability, corrosion resistance, high temperature strength, weldability and the like. In this study, to the basic chemical composition, Nb(Niobium) is added which is high corrosion-resistance and heat-resistant as a heat resisting alloy with sufficient malleability and ductility to produce the maraging steel. The maraging steel is taken heat treatment under the general condition of the solution annealing and age hardening. The mechanical properties according to the content of Nb are observed. The results, Equally in all conditions, strength was increased significantly for 1 hour age hardening after solution annealing and it showed the trend of the increase of strength as the aging time was increased. The fatigue life of solution-annealed specimen is decreased by the content of Nb.