Alloy x N _ Element |% wt.] . 
EC Cr Ni Mo Ti Mn Si Fe Co 
316L | 0.022 | 16.9 206 | - | 150 bal. - 
MP35N 
(ISO 5832/6-80) 0.02 | 20.14 | 3367 9.7 0.01 0.20 - bal. 
Table 1: Melt chemical composition of experimental alloys 
Results and discussion 
The 316L alloy was a one-phase with fcc structure. The grain size in the samples before heat 
treatment was on average a=0.99x10” mm? (it was contained in the pattern range G=7 by ASTM). 
Numerous twins could be seen and occasionally primary precipitates occur (Fig.2a). Stacking faults 
dominated in the substructure (Fig.2b). Numerous slip bands were present in the structure after cold 
work. The substructure of deformed alloys was consisted of tangles and pile-ups of dislocations 
with the density growing together with the strain degree (Fig.3). 
The MP35N alloy after solution treatment was a single-phase alloy with fcc structure. It was 
characterised by the grain size a=1,81x10 mm? (it was contained in the pattern range G=6 by 
ASTM). Structure of this alloy was similar as for 316L (Fig.4 and 5). Cellular structure of 
dislocations after cold work was not observed. 
Ju aM 
CEPR TL 
Fig.2: Microstructure of 316L: a) before heat treatment; b) after solution treatment ( I EM) 
Fig.3: Microstructure of 316L after cold work: a)e = 0.1; b) € = 0.3; TEM 
200)