An article published on the JOURNAL OF THE EGYPTIAN SOCIETY OF TRIBOLOGY (VOLUME 14, No. 2, April 2017).
Sand erosion of epoxy resin reinforced by randomly distributed glass fibres and filled by synthetic, paraffin and glycerine oils is studied. The effect of inclination of impact angle and oil content contained in the matrix of epoxy resin is investigated. In addition, the electrostatic charge generated on the eroded surface is measured. Reinforced epoxy demonstrates low erosion resistance compared to unreinforced epoxy. SEM surface examination reveals the effect of inclination angle on wear. Specimens filled by oil lose the electrostatic charge generated from sand erosion in earlier time compared to the unfilled test specimen.
This paper deals with the failure investigations of the first stage gas turbine blade of 30MW gas turbine. This blade is manufacture with of nickel based super alloy IN738. The main focus of the paper is to found the causes of failure of the blade. By the investigations, it is found that the blade failure takes place due to the combined effect of erosion, oxidation, overheating, and hot corrosion.
An oil pipeline embedded in an underground trench had failed. Through the accident investigation they found that there was a perforation at the leak point of the pipeline. After careful analysis it is concluded that the leakage of the pipeline was mainly caused by the liquid impingement erosion.
Valve had failed as a result of particles of material becoming trapped between the valve seat recess and the valve seat ball, leading to erosion of the valve seat recess, valve seat ball and the valve operating pin; this allowed hydraulic fluid to flow when the valve was nominally in the de-energised position.The material of construction of the valve seats was not compliant with engineering drawings.The investigation demonstrated the importance of maintaining the cleanliness of hydraulic systems and of the need to control the materials of manufacture in safety critical applications.
The damage of the inelastic coating was more serious than the elastic coating. The failure causes of the antistatic coating on the radome were analyzed. The results show that the failure of inelastic and elastic antistatic coatings was caused by particles erosion, and the aging of the coatings accelerated the failure of coatings. The elastic coating had better anti-erosion ability than the inelastic coating because of its high fracture elongation and good elastic deformation, so its damage was lighter than the inelastic coating.
Il s’agit de l’étude d’un cas concret de perforation de tube en acier revêtu de goudron servant au transport de gaz naturel. Les perforations multiples ont été provoquées par des fuites d’eau sous pression d’une autre canalisation passant à proximité.
Basé sur des tests de laboratoire et le retour d’expérience du fonctionnement de la chaudière, ce document présente le phénomène d’exfoliation d’oxydes de la surface des tubes de surchauffeurs en acier austénitique et le modèle de calcul développé pour déterminer la vitesse d’érosion de la chaudière et des composants de la turbine par les particules solides transportées par la vapeur.