Effect of manganese on the martensite transformation temperature and properties of stainless steels at low temperatures

Conclusions

• 1. Stainless steels with 14%Cr, 3.8%Ni, and 0.4%Ti, depending on the manganese concentration (8–16%), can be divided into two groups according to the stability of austenite with respect to the γ→α transformation: a) Steels containing 8–10%Mn have a γ→α′ transformation (below 0°C) and also a γ→α″ transformation; b) in steels with 12–16%Mn the transformation occurs only under the combined influence of deformation and temperature with formation of the α″ phase.

• 2. Heating the steels in the temperature range of carbide precipitation (700°C) raises M_S in the steels with 8 and 10%Mn but has no effect on M_S in the steels with higher manganese concentrations. Heating to 700°C has no effect on M_D.

• 3. The presence of α_δ and α′ phases in the austenite lowers the plasticity and impact strength of the steels at low temperatures; the formation of α″ phase in the process of testing has a much smaller effect on the characteristics of plasticity and impact strength.