GKSS-Forschungszentrum, Institut für Werkstofftechnologie, Geesthacht,
Fa. INTERATOM, Kernwerkstoffe, Bergisch Gladbach 1,
Kernforschungszentrum Karlsruhe, Institut für Material- und Festkörperforschung, Karlsruhe,
Pages: 17 Published: Jan 1982
The present investigations were undertaken with the aim to understand, to what extent variations of the tube fabrication parameters and slight modifications in the chemical composition might influence the swelling behaviour of Type 1.4970 stainless steel.
The parameters varied were: Variations in the manufacturing parameters for cold-worked tubes (type and degree of drawing, solution-annealing temperature and thermomechanical treatments), and variations in minor elements (C, Ti, Mo) within the specified range of chemical composition. In addition, the Si-content and the Ti/C ratio — the so-called stabilization — were changed within a broader range.
The samples were irradiated with 46 MeV-Ni-ions to 64 dpa at 575 °C and swelling as well as austenite stability, formation of precipitates and other microstructural changes were investigated by TEM. Though the austenite was stable under irradiation with respect to ferrite/martensite-transformation, the cold-drawn alloys showed a tendency to recrystallize during irradiation and exhibited lean precipitation. With respect to swelling, the only parameter that substantially reduced it, was the high Si addition; otherwise the alloys were practically insensitive to changes in the investigated parameters. These results are discussed in terms of the radiation-induced recrystallization and the high Si-effect, both of which are found to be beneficial in reducing swelling.
austenitic alloy, alloy modification, carbide, cold working, gamma prime, G-phase, heavy ion irradiation, TEM, microstructure, minor elements, phase stability, precipitates, recrystallization, silicon, DIN 1.4970, swelling
Paper ID: STP34382S