254 Prakt. Met. Sonderband 46 (2014) 
ever more relevance as deformation proceeds; grains shape macroscopically changes and SAF 210 
an increased number of defects is introduced within crystal lattices. were wel 
The aim of the present work is to study the effects of plastic deformation in various DSS 
grades in terms of strain-induced phase transformation, by discussing the associated 
changes in properties. Unfortunately, a suitable technique for SIM detection in DSS is not 
available and the use of several methods is mandatory. 
Ferri 
2. EXPERIMANTAL Auste 
The investigated DSS were SAF grades 2101, 2304, 2205, 2507 (chemical compositions 
in Table 1), received as different final products and, therefore, possessing different starting Cold roll 
microstructures. All the samples were cold rolled at various deformation degrees by using phases. 
a manual reversing mill and involving thickness reductions from 15% to 85%. the orthc 
oriented 
Table 1 — Chemical composition of the investigated Duplex Stainless Steels [wt.%]. consider: 
on, © si Mn cr Ni Mo Cu pP s N 
2101 0.028 0.69 3.82 21.72 1.13 0.10 0.34 0.028 0.0025 0.16 
2304 0.030 0.56 1.43 23.17 4.29 0.18 0.16 0.027 0.0010 0.13 
2205 0.030 0.56 1.46 22.75 5.04 3.19 - 0.025 0.0020 0.16 
2507 0.015 0.24 0.83 24.80 6.89 3.83 0.23 0.023 0.0010 0.27 
For the metallographic investigation, the As-Received (AR) and the Cold Rolled (%CR) 
materials were mechanically polished and etched using the Beraha's reagent. The etched 
samples were observed using a Leica Cambridge Stereoscan 440 Scanning Electron 
Microscope operating in backscattered-electron mode, and the micrographs were edited 
on an image-analysis software for an estimation of the percentage of the phases. 
Hardness tests (HV10) were performed on AR and %CR samples, in order to measure the 
effect of the deformation on the materials in terms of overall hardening. The AR, 50%CR Plastic d 
and 85%CR materials were also analysed by X-Ray Diffraction (XRD) on a Siemens D500 detectab 
diffractometer, using CrKa radiation in the angular range 20 = 60-140° (step size of 0.05° may prox 
and 3 seconds of counting time for each step). etched s 
Since SIM is ferromagnetic, magnetic measurements can reveal its presence in the %CR 
samples. For the present work, specials AC and DC magnetometers were developed and 
emploved for testing the samples, reaching the magnetic saturation from hysteresis loop. 
3. RESULTS AND DISCUSSION 
3.1. MICROSTRUCTURES 
The observations on the AR-materials revealed different types of starting microstructures 
(Fig. 1), related to the particular manufacturing processes. Samples were free from 
secondary phases and the estimated phases fractions are reported in Table 2. Except in