Thermodynamic behaviour of nitrogen in the carbon saturated Fe-Mn-Si alloy during casting

Figures & data

Figure 1. Temperature dependence of N solubility in Fe-1.9 wt%Mn-2 wt%Si-C_sat melt under 1 atm N₂ pressure along with thermodynamic calculation by Wagner’s formalism (dashed line) and MQM (solid line)

Table 1. Chemical composition of C saturated Fe alloy containing Si and Mn. (wt%)

Sample number	Si	Mn	C	Fe
#1	2.92	0	4.53	balance
#2	2.69	1.46	4.54
#3	2.79	2.98	4.63
#4	2.69	4.50	4.67

Figure 2. Temperature profile programmed for the thermal analysis (dashed line) and corresponding TG analysis under the deoxidised Ar atmosphere (solid line)

Figure 3. Calculated phase diagram of the Fe-Mn-Si-C system under the unit activity of C along with the present experimental results

Figure 4. Thermal analysis results during heating for (a) Fe-Si-C_sat, (b) Fe-1.46 wt%Mn-Si-C_sat, (c) Fe-2.98 wt%Mn-Si-C_sat and (d) Fe-4.50 wt%Mn-Si-C_sat.

Figure 5. Thermal analysis results during cooling for (a) Fe-Si-C_sat, (b) Fe-1.46 wt%Mn-Si-C_sat, (c) Fe-2.98 wt%Mn-Si-C_sat and (d) Fe-4.50 wt%Mn-Si-C_sat.

Figure 6. Calculated phase diagram of Fe-1.46 wt%Mn-2.69 wt%Si-C_sat-N alloy under the unit activity of C

Figure 7. SEM micrograph of Fe-1.46 wt%Mn-2.69 wt%Si-C_sat-N alloy quenched in (a) water, (b) air and (c) furnace

Figure 8. SEM micrograph of Fe-1.46 wt%Mn-2.69 wt%Si-C_sat-N alloy at (a) 900, (b) 700 and (c) 500°C