Fatigue Properties and Residual Stresses of Laser-Welded Heat-Resistant Pressure Vessel Steel, Verification on Vessel Model

Most power plants use the Rankine cycle, where the heat supplied to water and steam is converted into mechanical work; therefore, most components have to be made of heat-resistant steel. Sufficient mechanical properties must be ensured for welded pipes to meet stringent requirements. Therefore, laser-welded 5 mm thick heat-resistant pressure vessel steel plates were subjected to various mechanical tests, including high-cycle fatigue tests. The microstructural notches were determined using X-ray diffraction too to determine critical areas that are susceptible to crack initialization and affect the service life. Finally, a functional model of the pressure vessel subsequently verified the results and assumptions. The presented results ensure the transferability of the results to real-life applications and outline the promising application potential of laser welding for producing vessels and pipes from heat-resistant steel in the industry.