不锈钢相图1.docVIP

PAGE  PAGE 27 AEB-L is a conventionally ingot-cast martensitic stainless steel designed and manufactured by Uddeholm Tooling AB (Sweden). Its nominal chemical composition (in weight percent) is as follows:C = 0.65Cr = 12.8Si = 0.4Mn = 0.65Figure 1 shows the phase diagram of Uddeholm AEB-L stainless steel (in deg. Celsius) calculated with  HYPERLINK /thermo_calc.html Thermo-Calc, coupled with TCFE3 thermodynamic database.Figure 1. Phase diagram of  HYPERLINK /pdf/AEB_L_Phase_Diagram_in_deg_C.pdf Uddeholm AEB-L stainless steel (in deg. Celsius) calculated with  HYPERLINK /thermo_calc.html Thermo-Calc, coupled with TCFE3 thermodynamic database. Silicon and manganese were excluded from thermodynamic calculations.The equilibrium values for solidus and liquidus temperatures were calculated to be 1461 °C (2661 °F) and 1379 °C (2515 °F), respectively.In the temperature range of 1144-1379 °C (2091-2515 °F) the microstructure of Uddeholm AEB-L stainless steel consists of just one single phase: austenite. Thus, if AEB-L steel is hardened from an austenitization temperature that is higher than 1144 °C (2091°F) the resulting martensitic microstructure will contain no primary carbides.Below the temperature of 1144 °C (2091 °F) the chromium-rich M7C3 primary carbides start to precipitate from the austenitic matrix. At the austenitization temperature of, say, 1052 °C (1925 °F) the equilibrium amount of chromium-rich M7C3 primary carbides is 3.3 molar percent (2.6 volume percent). The equilibrium amount of carbon and chromium in the austenitic matrix at 1052 °C (1925 °F) is 0.44 wt. % and 11.4 wt. %, respectively. (The amount of carbon and chromium in the matrix is a good indicator of the steels hardenability and corrosion resistance, respectively.)The equilibrium value for A1 temperature (eutectoid temperature) was calculated to be 814 °C (1497 °F). Under equilibrium conditions the austenite in Uddeholm AEB-L stainless steel transforms into ferr