Rotor blade arrangement and gas turbine

1. A rotor blade arrangement which can be fastened on a blade carrier, the rotor blade arrangement comprising:

a blade aerofoil element; and

a platform element, wherein the platform element is configured and arranged to form a part of a blade row continuous inner shroud;

wherein the blade aerofoil element and the platform element are separate elements and are each configured and arranged to be separately fastened on the blade carrier; and

wherein the blade aerofoil element and the platform element are configured and arranged to be mechanically decoupled during operation of the rotor blade arrangement;

wherein the blade aerofoil element comprises:

an aerodynamically shaped blade aerofoil having a bottom;

a shank which adjoins the blade aerofoil at the blade aerofoil bottom and is shrouded by the platform element, the shank having a bottom; and

a blade root which adjoins the shank at the shank bottom, the blade root being configured and arranged to fasten the blade aerofoil element on the blade carrier;

wherein the blade aerofoil element is formed in one piece and the platform element is formed in one piece;

wherein the blade carrier includes an axial slot for fastening the blade aerofoil element on the blade carrier;

a platform element fastener configured and arranged to fasten the platform element on the blade carrier separate from the blade aerofoil element, and the fastener being configured and arranged to engage in the blade carrier axial slot;

wherein the blade aerofoil element comprises the blade root with a firtree profile, and the platform element fastener comprises legs configured and arranged to be hooked into the blade carrier slot above the blade root;

a horizontal shoulder over which the platform element fits, is formed on the blade aerofoil; and

seals configured and arranged to seal gaps between the blade aerofoil element and the platform element, the seals positioned between the horizontal shoulder of the blade aerofoil element and the platform element, wherein the seals transmit substantially no forces between the blade aerofoil element and the platform element.

2. The rotor blade arrangement as claimed in claim 1 , wherein the blade aerofoil element is formed of materials which are different in different areas of the blade aerofoil element.

3. The rotor blade arrangement as claimed in claim 2 , wherein the blade aerofoil element comprises a leading edge and a trailing edge, and the blade aerofoil element in the regions of the leading edge and of the trailing edge is formed of a material which is different from that in remaining regions of the blade aerofoil element.

4. The rotor blade arrangement as claimed in claim 2 , wherein the blade aerofoil element comprises a leading edge, a trailing edge, or both, and an insert in the region of the leading edge or of the trailing edge, the insert formed of a material which is different from that of remaining regions of the blade aerofoil element.

5. The rotor blade arrangement as claimed in claim 2 , wherein the blade aerofoil element comprises a suction side, a pressure side, or both, and an insert in the region of the suction side or of the pressure side, the insert formed of a material which is different from that of remaining regions of the blade aerofoil element.

6. The rotor blade arrangement as claimed in claim 2 , wherein the regions of a different material extend downwardly into a region of the blade aerofoil element which is shrouded by the platform element.

7. The rotor blade arrangement as claimed in claim 1 , wherein said blade aerofoil element and said platform element are assembled together.