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Wear failures of components often occur and cause great economic losses in modern industry production. To obtain excellent wear resistance surface will help reduce the abrasion. Herein, a wear-resistant iron-based alloy coating was deposited on a low-carbon steel substrate by argon arc overlaying, and sequentially surface nanocrystallized through ultrasonic impact treatment (UIT). Micro-structural, mechanical property (including nanohardness and elastic modulus) and wear behavior changes of the coating before and after UIT were experimentally investigated. In addition, the wear mechanism variation owing to the application of UIT was discussed. The results show that a highly deformed nanocrystalline layer with an average grain size in the range of~100 nm was generated at a depth of approximately 34 µm from the treated coating surface, which contains a certain amount of the deformation-induced α'-martensite phase. Compared with the as-deposited coating, the coating after UIT processing exhibits considerable improvements in the ratio of nanohardness (H) to elastic modulus (E) and better wear resistance under the same wear test conditions. The wear mechanism has also changed from the adhesive type of the as-deposited coating to an abrasive type on the introduction of a nanocrystalline microstructure.have demonstrated that coatings with thicknesses on the order of millimeters produced by argon arc surfacing welding exhibit a dense microstructure, excellent strength and toughness as well as high wear resistance. Such coatings can even replace entire components and significantly improve the wear resistance [6]. Iron-based alloys known as their low cost and excellent comprehensive properties have drawn much attention and shown great potential application in different fields of industries [7,8]. Therefore, iron-based alloy coating on easy wear parts and components has positive contribution to extend their service life and improve their service performance. Unfortunately, high residual stress and deformation introduced during overlaying may change the shape and the size of components, which limits their use in certain demanding conditions. In this sense, appropriate surface treatment is crucial for the performance improvement of overlaying coating.Surface nanocrystallization owing to their unique microstructural characteristics exhibits superior physical, chemical, and mechanical properties and have attracted considerable interest as a viable alternative in protection applications [9]. Thus, surface nanocrystallization techniques such as surface mechanical attrition treatment (SMAT) [9], shot peening (SP) [10], hammer peening [11], laser shock peening (LSP) [12] and ultrasonic impact treatment (UIT) [13] are more attractive and expected to present new ideas to realize materials' nanostructured layer in various surface protection applications.Compared with the other mechanical surface treatment techniques mentioned above, it is demonstrated that the UIT is more convenient and economical and controllable to rapidly realize s...

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Wind power projects are a crucial step towards achieving the objectives of “carbon neutrality” and “carbon peak” because they can improve the energy crisis and contribute towards environmental pollution reduction. However, the risks of wind power projects cannot be ignored, and the success of the design phase can affect the risks and benefits of wind power projects throughout their life cycle. This paper first proposes causality hypotheses for four types of risk factors in wind power projects: policy, economy, technology, and construction. It constructs a structural equation model for wind power project risk factors and then tests and modifies the model. Then, based on the latent variables of policy, economy, technology, and construction, and the relevant explicit variables, the risk index evaluation system of the wind power project design phase is constructed. The risk assessment catastrophe model of wind power projects is further established, and it is used to evaluate the risk of the K wind power project in the design phase. The risk assessment can identify the overall risk and main risk sources in wind power projects in the design phase and provide countermeasures for effectively controlling risks in wind power projects in China.