In the Power boiler of ASME Sec.I, it does not describe the impact test and the concept because the applicable service condition is above 250 deg.F. So it is not easy to find the impact test data of SA-192. Even if the limitation is depending on the applicable code, a metallurgical point of view, SA-192 is expected the using temperature is above -20 to 10 deg.F through the impact test.
As a result, I believe SA-192 can not be sustained at -40 deg.F (-40 deg.C) even though it is impact tested unless otherwise treated besides material code rerequirements.
Thomas