Depends on how bad you need it, because you might have to pay for it. Check with ASM International below in there book store. The IT diagram would most probably be located in the Atlas of Time Temperature Diagrams. If this is the case, you might want to visit an engineering library at a nearby college or university to access the Atlas.
The older volume, Atlas of Isothermal Transformation and Cooling Transformation Diagrams (1977) from ASM, has IT curves for 440A & 440B on p. 328-329. The data are only for 1250 [sup]o[/sup]F and above.
Original source: 'The Annealing of Steel,' by Peter Payson, Iron Age, Vol. 152 (1943).