Initiatives for Enhancing the Capability of NDE Engineers: An Indian Perspective

Education and training in Non-destructive Evaluation (NDE) domain is very important. The NDE engineer needs to continuously update knowledge and skill set and should be aware of the latest technologies available, with the concurrent advances in allied fields of sensors, electronics, computers, digital signal & image processing, numerical modeling etc. Towards this professional bodies and governmental organisations in India have taken several initiatives, starting from graduation through bridge courses, quiz, and training programs. These initiatives aim effective involvement of young engineers at various stages through their participation in team-building activities, workshops, taskforces, training & certification programs, train-thetrainer programs etc. This paper outlines these initiatives taken in India and elucidates how these initiatives are enhancing the skill set of the NDE engineers. The presentation also highlights how these initiatives are helping them to gain all necessary knowledge in the area of advanced NDE, to be able to take up any NDE assignment effectively, be it in research or industry or academics

A Novel Method for Ultrasonic Imaging of Flaws in Coarse Grain Austenitic Stainless Steels

Ultrasonic detection and imaging of flaws in thick coarse grained austenitic stainless steel components is challenging due to very high scattering. Spectral and wavelet transform based methods have been traditionally applied to reduce the noise to detect flaws. We propose a novel ensemble empirical mode decomposition based signal processing method for adaptive detection of flaws in coarse grained austenitic stainless steel. We have analyzed ultrasonic signals obtained from stainless steel specimens of different grain size (30-200 µm) with and without flaws. The ultrasonic signals lie in two different scattering regimes with wavelength to grain size ratio of 1.8 (near stochastic scattering) to 3 (far Rayleigh scattering). The analysis gave an idea to use particular numbers of intrinsic mode functions (IMFs) in conjunction with minimization approach for the reconstruction of ultrasonic signal. We have verified the usefulness of this method by analyzing the signals obtained from 200 µm grain size specimen with artificial defects. The proposed method has been successfully employed for adaptive detection of flaws in a 50 mm thick coarse grain austenitic stainless steel specimen and for imaging of flaws

A Novel Approach for Rapid Eddy Current Imaging of Flaws

Traditionally raster scan plan is employed in eddy current testing for imaging flaws in components. Several parallel scans using a single probe are made and the acquired data is represented in the form an image to obtain, e.g. a comprehensive picture of a flaw in the imaged region. For imaging on large surfaces time for imaging is a constraint. We present a novel probe scan plan for rapid eddy current imaging of flaws. We demonstrate the performance of this scan plan in austenitic stainless steel plates for detection of flaws using a pancake type eddy current probe. We then compare its performance with the traditional raster scan plan and other types of scan plans based on rapidness, area coverage, POD, and step size for detection of 1000 randomly located notches in a stainless steel plate. Studies reveal that the proposed scan plan outperforms the other scan plans with single probe for rapid and reliable inspection of large surfaces of electrically conducting materials