Liquid Penetrant Testing Research Articles

Peculiarities of the Certification of Reference Specimens for Liquid-Penetrant Testing

The characteristics of reference specimens are described, as well as the specific features of their application for checking the serviceability of flaw-detecting materials and evaluating the sensitivity of liquid-penetrant testing. Features of the certification of reference specimens used for this purpose are presented.

Peculiarities of the certification of reference specimens for liquid-penetrant testing

Peculiarities of the certification of reference specimens for liquid-penetrant testing

The problem of calibration of specimens for liquid-penetrant testing

The problem of calibration of specimens for liquid-penetrant testing

Metallurgical failure analysis of a BWR recirculation pump shaft

This paper presents the metallurgical analysis of a Recirculation Pump from a Nuclear Power Plant. The damaged component was the austenitic stainless steel shaft. As a result of a preliminary visual examination, some axial cracks were found in the threaded area of the shaft in the thermal barrier area. The analyses performed include liquid penetrant testing, metallography and deposits analysis. Based on the obtained results, it was concluded that the origin of the axial cracks was thermal fatigue caused by mixing of cold seal injection water and hot reactor coolant in the thermal barrier area.

FEASIBILITY STUDY ON NON-DESTRUCTIVE TESTING FOR FATIGUE CRACK DETECTION OF CORNER WELD

This study reviews the non-destructive testing methods and evaluates their reliability and adaptability for the detection of fatigue cracks which develop from a blowhole at the root of the corner weld. X-ray, ultrasonic, magnetic particle, liquid penetrant, and eddy current testing methods are provided. For the internal crack, ultrasonic testing appears to be desirable. Minimum crack sizes detectable are about 8mm∅ with a high accuracy. For the crack opened to the surface, eddy current and magnetic particle testing give a fair estimation. But it must be understood that fatigue cracks will be missed by liquid penetrant testing.

錠剤における吸液速度の測定

A simple method for measuring the volume of liquid absorbed by tablets was devised and applied to the liquid penetration test with commercialized tablets. In case of the penetration of ethyl acetoacetate, the swelling of tablets was not observed, and the V2 vs. t plots showed good linearity where V is the volume of liquid taken up. expressed in μl. and t is the time in second. In case of the water penetration, tablets swelled remarkably and the V 2 vs. t plots showed the concave lines, but the log V vs. log t plots showed a good linearity. The slopes of the regression lines obtained from the log V vs. log t plots were in the range of 0.5 to 1.0.

A Preliminary Study of the Fluid Mechanics of Liquid Penetrant Testing.

Some aspects of the fluid mechanics of liquid penetrant testing are considered. Penetration is represented by surface tension driven flow into defects of small defect width to depth ratio. Defect width is chosen so that both gravitational and non-continuum effects may be ignored. Penetration time is found to follow a Rideal-Washburn relation, in which where t is time, l defect depth, μ the dynamic viscosity, γ the surface tension, R the defect width and θ the contact angle. The proportionality constant, however, is shown to be strongly dependent on defect geometry and penetrant application procedure. The effect of slight fluid elasticity is shown to be negligible.