Knowledge and understanding of residual stresses has been and remains a complex area of study, the determination of these stresses crucial in appreciating the state of the component both prior to and during operation. In the case of dissimilar joints, the interaction of materials increases the complexity of the residual stress state resulting due to the applied joining process. A fatigue-resistant cladding technology is presented in this thesis, with the aim of inducing compressive residual stresses in the clad layer. Through the generation of these beneficial compressive residual stresses an improvement in fatigue performance can be achieved in an erosive-corrosive environment. Characterisation of clad and substrate materials allows an understanding of the interaction of materials and the resulting residual stress distribution due to a weld cladding process, both experimentally and through finite element modelling. Finite element modelling of the weld cladding process utilised an elastic-perfectly plastic material model throughout the investigation of the modelling process. Good correlation between experimental and simulation residual stresses is presented, with factors influencing residual stress distributions discussed. The accurate capturing of residual stresses due to weld cladding is a complex process due to, for example, material metallurgy and properties. Laser cladding provides an alternative method of generating residual stresses indicating that the fatigue-resistant cladding technology is not limited to weld cladding. Furthermore, weld cladding is not a process that must be applied exclusively, with the application of autofrettage post-cladding providing a means of favourably modifying tensile residual stresses obtained through the weld cladding process. The fatigue-resistant weld cladding technology has been successfully developed and validated, with recommendations provided for further development and the implementation of this concept.Although this research was primarily focussed on the weld cladding of a hydraulic fracturing pump, the application of this technology is not limited to this component therefore presenting the potential to improve the fatigue performance of any component operating under cyclic loading conditions in an erosive-corrosive environment.
|Date of Award||31 Jul 2015|
- University Of Strathclyde
|Sponsors||EPSRC (Engineering and Physical Sciences Research Council)|
|Supervisor||James Wood (Supervisor) & Alexander Galloway (Supervisor)|