## 3 Results and Discussion  
### CCT and DCCT Diagrams  
Figure 3 shows CCT and DCCT diagrams constructed on the basis of the results of dilatation curves, microstructures, and macrohardness values. Increasing the Cr content from 2.5 wt.% to 4 wt.% led to an increase in A\({}_{\text{cl}}\) by about 35 \({}^{\circ}\)C, otherwise it has no effect on the critical transformation temperatures. LSCM and SEM micrographs of the final transformation products formed from non-deformed and deformed austenite after cooling at 2 and 80 \({}^{\circ}\)C/s are shown in Figures 4-7.  
Figure 3: CCT (**a**,**c**,**e**) and DCCT (**b**,**d**,**f**) diagrams for Steels I (**a**,**b**), II (**c**,**d**), and III (**e**,**f**). Abbreviations: BF = bainitic ferrite, GB = granular bainite, and PF = polygonal ferrite.  
Figure 4: Laser scanning confocal microscopy (LSCM) micrographs of Steel I (**a**,**d**), II (**b**,**e**), and III (**c**,**f**) without austenite deformation after cooling at 80 and 2 \({}^{\circ}\)C/s, respectively. Abbreviations: BF = bainitic ferrite, GB = granular bainite, and PF = polygonal ferrite.  
Figure 5: Scanning electron microscopy (SEM) micrographs of Steel I (**a**,**d**), II (**b**,**e**), and III (**c**,**f**) without austenite deformation after cooling at 80 and 2 \({}^{\circ}\)C/s, respectively. Abbreviations: BF = bainitic ferrite, GB = granular bainite, and PF = polygonal ferrite.  
Figure 6: Laser scanning confocal microscopy (LSCM) micrographs of Steel I (**a**,**d**), II (**b**,**e**), and III (**c**,**f**) with austenite deformation after cooling at 80 and 2 \({}^{\circ}\)C/s, respectively. Abbreviations: BF = bainitic ferrite, GB = granular bainite, PF = polygonal ferrite, and P = pearlite.  
For Steel I, with the lowest Cr content, the preceding hot deformation had a great effect on the microstructural constituents (see Figure 3a,b and Figure 4a,d, Figure 5a,d, Figure 6a,d and Figure 7a,d). In the case of the non-deformed condition, the microstructure was a mixture of bainitic ferrite (BF) and granular bainitic (GB) over a wide range of CRs. Deforming the austenite changed the microstructure to fully polygonal ferrite (PF) at all the investigated CRs, apart from the appearance of a very small fraction of pearlite at CRs in the range of 2-20 \({}^{\circ}\)C/s (Figure 6d) which could not be detected from the dilatation curves. These changes had a clear impact in the hardness of the specimens.  
For Steel II (Figure 3c,d, Figure 4b,e, Figure 5b,e, Figure 6b,e and Figure 7b,e), depending on the CR, BF, GB, and PF were observed in the non-deformed and deformed conditions. Again, a small fraction of pearlite which could not be detected in the dilatation curve was found for CRs in the range of 2-10 \({}^{\circ}\)C/s. Here too, preceeding hot deformation caused a drop in hardness.  
For Steel III (Figure 3e,f, Figure 4c,f, Figure 5c,f, Figure 6c,f and Figure 7c,f), increasing the CR refined the microstructure, promoted the formation of BF and suppressed the formation of the high-temperature transformation products, i.e., GB and PF, in the case of both the non-deformed and deformed conditions. However, in the case of deformed austenite, the formation of BF requires a higher CR than is needed for undeformed austenite. For both non-deformed and deformed austenite, irrespective of the microstructural constituents, CR has little effect on the transformation temperatures and hardness.