Effect of Crack on Bending Process for S55c Carbon Steel with Ultrasonic Testing on Zero Degree Probes

Abstract

Abstract Bending force and fatigue-induced crack is a generally assured trouble in industrial pipe line achieving their original design life. An amount of high-profile accidents has been covered in the past that involved bending and fatigue harm in structures. Such that incidences frequently encounter without prior warnings ascribable deficiency of proper crack monitoring method. Called for to discover and monitor the bending and fatigue crack, ultrasonic (UT) and acoustic emission (AE) technique, has been encountering growing concerns recently. This paper presenting the measurement and effect of bending test at carbon steel plate with different length and defect’s depth by using ultrasonic testing with considering the defect size at failure point. The zero-degree probe and 4MHz excitation frequency is used in UT measuring for condition of S55C carbon steel plate within before bending process and after bending process. From the result show that effect of bending force will increase the velocity (m/s), gain (dB), beam path (mm) and thickness plate (mm) based on the defect sizes. The increasing of four parameters can be explained namely 0.19% - 0.3% velocity, 17% - 20% gain, 10% - 12% beam path and 5.0% - 7.5% thickness of plate.