Two types of 61-blade turbines are used. Originally both blades and disks were solid, later hollow blades and lighter disks were introduced at a saving of approximately 40 lb. The 12¼-oz. solid blades are forged from an austenitic steel containing 30% nickel, 14% chrome,1.75% titanium, and .12% carbon, corresponding closely to "Tinidur,"a Krupp alloy known before the war,and are attached by three machined lugs drilled to take two 11-mm.rivets each. Maximum centrifugal blade stresses have been estimated at 18,000 psi., and gas bending stressesat 2-4,000 psi. Study of the solid blades indicates that the roots didn't get much above 450 deg. C., due to the cooling air flow up from the disk, but near the center it appearsthe temperatures got up to about 750 deg. C. This applies to service models, not those previouslymentioned as having given the longer flight and test-stand life. Disks for hollow blade turbines are of lighter material than the solid types and have attached, across the front face, a thin sheet flared outnear the center. This picks up the cooling air and, via ridges on the disk, whirls it out toward the blade roots where it goes through two small holes drilled in the disk rim up through the blade and out the tip. Made of the same material as the solid blades, the hollow type are formed by deep drawing a disc through a total of 15 operations. In assembling the turbine, the blade roots are fitted over grooved stubs on the disk rim. Two small holes on each side take locating pins to hold the blades in place during assembly, but they take no stresses.
Taken from Design Analysis of Me-262 Jet Fighter by John Foster Jr. Part II- The Power Plant