Experimental Study On Anti-sediment Abrasion Performance Of Hydraulic Mechanical Over-current Parts And Protective Technology

Abrasion is a widespread phenomenon in the field of water conservancy.How to solve the problem of sediment wear of water turbine or water pump has become a key technical problem in the design and manufacture of fluid machinery.In this paper,three commonly used materials in the field of hydraulic machinery were tested under different sand particle sizes based on the rotary jet abrasion test bench,and the abrasion resistance performance of the materials under different sand particle sizes and the surface microstructure characteristics of metal materials under the combined action of erosion and cavitation were analyzed.In addition,single particle size tests were carried out for different heat treatment process specimens and different coatings under different substrates.The results show that:(1)The law of weight loss of abrasive damage of different metal materials is basically the same,and the relationship between the weight loss rate of the material and the particle size of the sand and the abrasion time can be expressed by the empirical formula;(2)In the case of small particle size conditions,the damage caused by the sandy water to the surface of the metal material is mainly caused by the forging extrusion of the sand in the vertical direction of the material and the cavitation of the material by the bubble collapse,which is not parallel with the material surface.The ploughing effect;as the grain size of the sand increases,the ploughing damage of the sediment becomes more apparent;(3)Under the same concentration,the small particle size working condition is more likely to cavitation than the large particle size working condition.The size of each cavitation pinhole is about 1～3μm.The formation of cavitation pinhole is related to the collapse of a single bubble.Rather than the result of a large amount of bubble accumulation damage.(4)The results show that there is a strong correlation between the abrasion resistance and the strength and hardness of the material WC-10Co4Cr coating is lower than that of 0Crl3Ni5Mo matrix by about 53.4%;the friction loss of 2Cr13 matrix is about 55.6%;The weight loss of KMTBCr26 substrate was reduced by about 60.3%;(6)The anti-wear effect of the coating is related to the choice of the matrix material,and the coating material with good anti-wear effect is not necessarily applied to all substrates.(7)The failure mode of WC-10Co4Cr coating is mainly based on the spalling of WC hard phase material,while the Ni60/WC-10Co4Cr composite coating material is mainly damaged by micro-cutting and plowing.Good fracture toughness can effectively prevent the formation and development of cavitation cracks.