Abstract: This study reports the development of a new microwave probe for the nondestructive testing of a pipe. Three-dimensional finite element simulations are carried out to optimize the profile of a microwave probe, whose results show that a probe with elliptic profile enables smaller reflection at the probes as well as much better single-mode propagation inside the pipe than conventional ones. Experimental validations are carried out using a straight brass pipe with an inner diameter of 39 mm and...
英字タイトル:
Enhancement of microwave nondestructive testing method for the inspection of pipes by optimizing the microwave probe profile

Some damages were found at the forks of low pressure turbine blades caused by random vibration and steam-flashback vibration. In this study, for the aim of fatigue property improvement, laser peening technology for 12Cr stainless steel was developed and material properties were examined. Laser peening is a process to induce compressive residual stress to the material surface. Fatigue specimens which simulate the stress concentration zone of forks were fabricated and laser peening was applied to the su...
英字タイトル:
Development of laser peening technology for low pressure turbine blades to improve fatigue properties

Austenitic stainless steel SUS304 is typically classified as a paramagnetic material, but it forms ferromagnetic martensite phase due to plastic deformation, stress or fatigue. This martensitic transformation can be applied to magnetic Non-Destructive Evaluation (NDE) technics. In this paper, we attempt to detect and estimate the artificially introduced notch, fatigue crack and fatigued part in SUS304 steel by measuring the Magnetic Flux Leakage (MFL) near the specimen surface. It is fo und that the notch ...
英字タイトル:
Evaluation of Fatigue and Damage in SUS304 using Magnetic Flux Leakage