Hastelloy mesh for service at the elevated temperature media

Hastelloy X is a high performance nickel-chromium-iron-molybdenum alloy made for service at the elevated temperatures. It attains a combination of supreme oxidation resistance, fabrication and strength at the high temperature. Hastelloy X describes supreme ductility after prolong service to elevated temperatures about 870oC and has supreme forming and welding properties. The alloy has a significant service in gas turbine engines for burning component zones for example transition ducts, combustor cans and flame holders and heaters. It is also preferred for service in the industrial furnace applications as it has extremely great resistance to oxidation in the reducing and neutral atmospheres.

The initial step was to select the development process for the mesh, it included wire cutting, weaving and eradication from the jig. The mesh, as a reinforcement structure was developed by initial cutting and inserting wires in the jig. To develop the reinforcement structure, the Hastelloy wire mesh is developed to offer strength by weaving the warp and weft wires.

Resistance welding is a traditional electric welding process utilized by the industries. The resistance weld is attained by heat and pressure combination. The electrical resistance of the material is welded causing the localized heating in the compartment. The essential magnitude of welding period is found by material type and thickness, current and cross-sectional area of the welding tip contact surfaces. The benefits of spot welding include spot welding includes energy consumption, part deformation, development rates, automation, no need of filler materials, nominal heat supply to weld metal and expert welder.

Hastelloy X mesh maintains a uniform aperture size during spot welding; feeler wire tool was utilized to estimate the clearance among two adjacent wires when meshes were developed. For adequate stability and firmness during plasma spray, meshes were connected on the stainless steel frame.

For mesh coating with bond and ceramic coatings, a rough surface was needed. The coated Hastelloy mesh was heated for two hours at 200oC in an electric furnace to discard the soaked moisture from coating. The Hastelloy mesh offers larger aperture size than molybdenum mesh. The heat processed samples undergo isothermal and cyclic oxidation analyses, the areas of external and internal components were exposed to air. The internal parts were also developed by cutting the specimens in longitudinal and transverse directions. This test analysis is utilized for strengthening and non-strengthening materials that do not crack or failure for the external surface in the limits of a loading analysis.

An effect of static heat exposure on the cracking and damage of the material. To avoid the heat shock to the composites the heating rate of the furnace in the isothermal analyses from room temperature to 1050oC was selected as 1.8 oC per minute. At temperature of 1050oC, the shade of the specimen got orange color and subsequent to each interval two samples, sprayed and one hea processed, were eradicated for metallographic test.

With heat cycling and isothermal tests, the processed ceramic samples were tested to find changes in their appearance. The Hastelloy mesh offered good performance throughout the tests.