caa a22 4500 467981590 CHVBK 20180323112520.0 cr unu---uuuuu 170328e19900701xx s 000 0 eng 10.1007/BF00700316 doi (NATIONALLICENCE)springer-10.1007/BF00700316 Microstructural features of plastic deformation under superplasticity conditions for steel Kh18AGN [Elektronische Daten] [G. Zlateva, N. Petkov] Conclusions: 1. Dispersed nitride phase precipitated in steel Kh18AGN as a result of the treatment suggested is a main condition for both obtaining a superfine grain size and also for limiting its growth during superplastic deformation. 2. In the second optimum rate range for superplastic deformation the main deformation mechanism is grain boundary sliding accomplished by movement of grain boundary dislocations. Intragranular sliding only occurs in narrow boundary areas under conditions of increased diffusion mass transfer. 3. With deformation rate above or below the optimum value relative participation of grain boundary sliding as the main mechanism of superplastic deformation decreases as a result of intragranular sliding. With low deformation rates it is combined with active diffusion creep as a result of which an equiaxed grain shape is retained. With high deformation rates diffusion is difficult and grain boundary processes do not manage to remove internal stresses arising with an increase in grain boundary sliding. This brings the condition of superplastic deformation towards normal hot ductile, with which ductility is lower than with deformation in the second rate range. Plenum Publishing Corporation, 1991 Zlateva G. aut Petkov N. aut Metal Science and Heat Treatment Kluwer Academic Publishers-Plenum Publishers 32/7(1990-07-01), 490-493 0026-0673 32:7<490 1990 32 11041 https://doi.org/10.1007/BF00700316 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00700316 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zlateva G. aut NATIONALLICENCE 700 1- Petkov N. aut NATIONALLICENCE 773 0- Metal Science and Heat Treatment Kluwer Academic Publishers-Plenum Publishers 32/7(1990-07-01), 490-493 0026-0673 32:7<490 1990 32 11041 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer