A=for anneal by heating to a temperature above the AC3 and cool in the furnace
N=for normalize by heating to a temperature above the AC3 and cool in still air
OQ=for quench into oil from a temperature above the AC3
WQ=for quench into water from a temperature above the AC3
AH=for air harden by heating to a temperature above the AC3 and cool in air at a rate fast enough to produce a hardened microstructure
T=for temper by heating to a temperature below AC1
ST=for solution treat by heating to temperature high enough to dissolve and any intermetallic phases followed by a rapid cool.
①AH或OQ(from 950°C to 1050°C)+T(590°C to 650°C)或AH或OQ(from 950°C to 1050°C), T(660°C to 700°C) and cool in air to below 95°C and T(590°C to 620°C)