A decanter centrifuge has a hollow, rotatable drum with a screw conveyor comprising a core body (1), in which an inlet opening for material into the drum from an inlet chamber (3) is provided, the inlet opening having a delimitation surface (7) which is rear relative to the direction of rotation and extending substantially axially, said delimitation surface being provided with a wear reinforcement member (8). The wear reinforcement member extends along the rear delimitation surface (7) into the inlet chamber (3). The wear reinforcement member (8) is provided with abutment surfaces (11; 19) in abutment against abutment surfaces associated with the core body, which during operation prevents the wear reinforcement member (8) from moving tangentially forwards in the in the direction of rotation and radially out of the core body (1). At least one of said abutment surfaces associated with the core body (1) is constituted by a removable blocking member (17). The wear reinforcement member (8) and the inlet opening (5) are designed in such a manner that the wear reinforcement member (8) can be introduced to its operating position from the exterior side of the core body (1)