MINIATURE SPECIMEN TECHNIQUE AS AN NDT TOOL FOR ESTIMATION OF SERVICE LIFE OF OPERATING PRESSURE EQUIPMENT

摘要

Measurement of mechanical properties of the material of an equipment is required, to estimate its safe operating life. The Bhabha Atomic Research Centre has developed 'Boat Sampling Technique' to obtain a boat-shaped sample from the surface of the equipment without affecting its integrity. The samples removed can be used for preparation of miniature specimens for various types of tests like tensile, bend, fatigue, impact etc. Surface sampling technique, using specimens derived from boat sample can be considered as non-destructive, as the removal of sample does not affect the integrity of the equipment. It may serve as a useful tool for assessing the component integrity, for instance the weldment, HAZ and high stressed regions, which requires adequate strength, toughness and ductility properties. This paper highlights development of Boat Sampling Technique, layout of miniature test specimens in boat sample, testing procedures and co-relationship with conventional tests. It also highlights the methodology to obtain samples from Core Shroud of Boiling Water Reactors under irradiation environment.