A turbine blade in an industrial gas turbine includes a blade surface to be cooled by a film of cooling fluid, a plurality of cooling holes on the blade surface through which cooling fluid flows, each cooling hole including an inlet portion and an outlet portion, and a trench on the blade surface surrounding at least one outlet portion of the cooling hole, the trench extending in an axial direction and a radial direction from the outlet portion of the cooling hole, wherein the outlet portion of the cooling hole has a shape configured to generate a first stage diffusion of the cooling fluid and a wall of the trench is positioned in the axial direction from the outlet portion of the cooling hole to generate a second stage diffusion of the cooling fluid, thereby forming the film of cooling fluid.

A method for thermochemically treating a part while masking a portion and corresponding mask are provided. The method includes the steps of providing a mask comprising a body with a seat, at least a deformable sealing washer located in the seat, and a tightening bushing, the body having a cavity, placing a first portion of the part in the cavity, a second portion of the part being located in a passage in the sealing washer, and a third portion of the part being located outside the mask, moving the tightening bushing to its tightened position so that the sealing washer is deformed and applied against the second portion of the part, and applying a thermochemical treatment to the third portion of the part.

A method for thermochemically treating a part while masking a portion and corresponding mask are provided. The method includes the steps of providing a mask comprising a body with a seat, at least a deformable sealing washer located in the seat, and a tightening bushing, the body having a cavity, placing a first portion of the part in the cavity, a second portion of the part being located in a passage in the sealing washer, and a third portion of the part being located outside the mask, moving the tightening bushing to its tightened position so that the sealing washer is deformed and applied against the second portion of the part, and applying a thermochemical treatment to the third portion of the part.

A stainless steel that includes chromium and other alloying element as a plurality of alloying elements including: a base material layer including chromium of a specified chromium content necessary for forming a passive film or more; and a superficial layer including chromium at a lower chromium content than the chromium content contained in the base material layer, and the superficial layer including the other alloying elements at a same content of the other alloying element as the content of the other alloying element contained in the base material layer.

A stainless steel that includes chromium and other alloying element as a plurality of alloying elements including: a base material layer including chromium of a specified chromium content necessary for forming a passive film or more; and a superficial layer including chromium at a lower chromium content than the chromium content contained in the base material layer, and the superficial layer including the other alloying elements at a same content of the other alloying element as the content of the other alloying element contained in the base material layer.

Metal components subject to wear or contact fatigue in a first area, and subject to bending, axial and/or torsional stress loading in a second area comprise a surface hardened, first surface layer in the first area; and a surface compressive-stress treated, second surface layer in the second area. The second surface layer has a material hardness different from, and typically lower than the first surface layer, and induced residual compressive stress to improve fatigue strength. Example components described include a gear, a cog, a pinion, a rack, a splined shaft, a splined coupling, a torquing tool and a nut driving tool. A hybrid manufacturing process is described, including area-selective surface hardening combined with a process to add compressive stress to fatigue failure prone areas.

Metal components subject to wear or contact fatigue in a first area, and subject to bending, axial and/or torsional stress loading in a second area comprise a surface hardened, first surface layer in the first area; and a surface compressive-stress treated, second surface layer in the second area. The second surface layer has a material hardness different from, and typically lower than the first surface layer, and induced residual compressive stress to improve fatigue strength. Example components described include a gear, a cog, a pinion, a rack, a splined shaft, a splined coupling, a torquing tool and a nut driving tool. A hybrid manufacturing process is described, including area-selective surface hardening combined with a process to add compressive stress to fatigue failure prone areas.

A ferrule and associated method characterized by an outer layer having a hardness; an intermediate layer below the outer layer, the intermediate layer having a hardness that is less than the hardness of the outer layer; and a core below the intermediate layer, the core having a hardness that is less than the hardness of the intermediate portion.

A ferrule and associated method characterized by an outer layer having a hardness; an intermediate layer below the outer layer, the intermediate layer having a hardness that is less than the hardness of the outer layer; and a core below the intermediate layer, the core having a hardness that is less than the hardness of the intermediate portion.

A turbine blade in an industrial gas turbine includes a blade surface to be cooled by a film of cooling fluid, a plurality of cooling holes on the blade surface through which cooling fluid flows, each cooling hole including an inlet portion and an outlet portion, and a trench on the blade surface surrounding at least one outlet portion of the cooling hole, the trench extending in an axial direction and a radial direction from the outlet portion of the cooling hole, wherein the outlet portion of the cooling hole has a shape configured to generate a first stage diffusion of the cooling fluid and a wall of the trench is positioned in the axial direction from the outlet portion of the cooling hole to generate a second stage diffusion of the cooling fluid, thereby forming the film of cooling fluid.