Evaluation of erosion and fatigue resistance of ion plated chromium nitride applied to turbine blades

Oka, Y.; Yoshida, T.; Yamada, Y.; Yasui, Toyoaki; Hata, Satoshi

doi:10.1016/j.wear.2007.01.047

Cited by 12 publications

(7 citation statements)

References 10 publications

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“…Increasing main steam temperature is one of the most effective methods for improving the efficiency of a steam turbine. However, high-temperature oxidation in a boiler and a pipeline system is intensified with increased temperature, and the exfoliated iron oxide scales will enter the turbine with steam and produce serious erosion damage to the surface of the flow path [1][2][3]. The erosion on the control-stage nozzle is the most severe and leads to decreased unit efficiency and increased maintenance cost.…”

Section: Introductionmentioning

confidence: 99%

Reduction of Solid-Particle Erosion on the Control-Stage Nozzle of a Steam Turbine through Improved End-Wall Contouring

Mao

Liu

et al. 2010

Proceedings of the Institution of Mechanical Engineers, Part C:

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The iron oxide scales exfoliated from the inner wall of a boiler tube and a main steam pipe is known to cause solid-particle erosion on the control-stage nozzle. A combined experimental and numerical investigation was conducted to explore the optimization method of end-wall contouring for reducing the nozzle's erosion damage most effectively. The results indicate that increasing the end-wall contraction ratio and (or) decreasing the distance between the starting point of end-wall contouring and the trailing edge can significantly reduce the erosion-induced weight-loss of the nozzle, and can slightly improve the nozzle efficiency, irrespective of the variation in the particles size distribution and the aerodynamic parameters of a steam turbine. A main reason of erosion reduction is that the movement of loading towards the rear of the nozzle cascade caused by these contoured end walls has reduced the incident velocity of particles. In this study, the weight-loss of the nozzle was reduced by 40—50 per cent, and the nozzle efficiency was improved by 0.4—0.5 per cent by improving the end-wall contouring of the nozzle according to the methods mentioned above.

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Section: Introductionmentioning

confidence: 99%

Reduction of Solid-Particle Erosion on the Control-Stage Nozzle of a Steam Turbine through Improved End-Wall Contouring

Mao

Liu

et al. 2010

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…Solid particle erosion has been a serious concern for numerous industrial components such as gas and steam turbines, 1,2 separators, 3 pumps, 4 and boiler tubes, 5,6 as can be seen in Figure 1. Many researchers proposed various models of material removal and attempted to predict their erosion behavior in the past half century, for instance, Finnie’s erosive cutting model, 7 Bitter’s deformation and cutting model, 8 Levy’s forging and extrusion model, 9 and Tilly’s twice erosion model.…”

Section: Introductionmentioning

confidence: 99%

Surface ripple and erosion rate of stainless steel under elevated temperature erosion by angular solid particles

Wang

Cai

Mao

et al. 2013

Proceedings of the Institution of Mechanical Engineers, Part J:

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The actual industrial erosion caused by the impingement of particles swarming from different perspectives is often different from the single-angle impingement of solid particle in the erosion test. In order to predict the erosion problems in practical engineering more reasonably, a series of elevated temperature erosion tests were conducted to study the surface ripple and enduring erosion behavior of heat-resistance stainless steel suffering from the single-angle impingement or multiangle alternative impingement of angular particles. The test results indicated that the surface of target materials with good ductility produced large-scaled transverse ripples and small-scaled longitudinal ripples after experienced a long-time single-angle impingement of angular solid particles under a 773-873-K high-temperature environment. The longitudinal ripples could accelerate the emergence and development of large-scaled transverse ripples. Initial erosion scars caused the differentiation of material deformability and plastic flow in the different locations of concave-convex scars, which further drove the evolution of the surface morphology from disordered scars to coherent ripples under the sustained attack of high-velocity particles. The more dimples the eroded surface of target material produced, it was easier for the target materials to produce coherent ripple. However, the interactions among the erosion behaviors with different attack angles made initial concave-convex scars difficult to evolve to coherent ripples under the multiangle alternative erosion. Further statistical results of erosion tests indicated that it can basically satisfy the practical engineering need by taking the erosion rate of initial surface layer as the erosion rate of the target material within the whole life cycle.

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“…A practical high-temperature environment is required for testing, because of the different properties of the surfaces as the temperature environment changes. Few studies have focused on these properties at high temperature [7], although some research papers have focused on the mechanical properties of oxide films at room temperature [8,9]. It is also very important to investigate the dynamic mechanical and adhesive properties of these materials in high-temperature environments.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Mechanical Properties of Oxide Films Formed on Metallic Surfaces as Measured Using a Tribological Approach at High Temperature

Oka

Tsumura

2011

Advances in Tribology

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The surface degradation of metals in boiler tubes and turbines in high-temperature corrosive environments causes severe problems in fuel combustion power plant systems. High-temperature resistant materials have been recently developed using a thermal barrier coating (TBC) and high-chromium alloys. Oxide films or coatings formed on metal surfaces at high temperatures can sometimes decrease the corrosion rate. However, the damage to the material is often accelerated by the mechanical removal of corrosion products from the material surface. It is therefore very important to investigate the mechanical and adhesive properties of the oxide films or coatings on metal surfaces used in high-temperature environments. This paper introduces a tribological method that uses a single spherical projectile impact at high temperature to measure the mechanical and adhesive properties of oxide films formed on various metal surfaces. Impact tests were performed on the surfaces of oxide films after their growth in a hightemperature furnace, and the deformed or fractured surfaces were observed in order to measure the mechanical and adhesive properties. The mechanical and adhesive properties of an elastic modulus, fracture, and exfoliation stresses were measured using the impact method, and the results depended on the type of metal oxide films and on the high-temperature environment.

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Evaluation of erosion and fatigue resistance of ion plated chromium nitride applied to turbine blades

Cited by 12 publications

References 10 publications

Reduction of Solid-Particle Erosion on the Control-Stage Nozzle of a Steam Turbine through Improved End-Wall Contouring

Reduction of Solid-Particle Erosion on the Control-Stage Nozzle of a Steam Turbine through Improved End-Wall Contouring

Surface ripple and erosion rate of stainless steel under elevated temperature erosion by angular solid particles

Dynamic Mechanical Properties of Oxide Films Formed on Metallic Surfaces as Measured Using a Tribological Approach at High Temperature

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