Abstract: HIC or HB appears in some pressure vessels in hydrogen or wet hydrogen sulfide environment. HIC or HB is not easy to be found, but HIC or HB can be found by ultrasonic phased array. Specific system settings such as system, probe, test block, sensitivity, scan depth, display delay, horizontal image center, transmit pulse width, PRF, transmit voltage, scan type, scan waveform, focus depth, angle and aperture has be introduced.