Ultrasonic test technology of cast steel for large butterfly valves used in hydropower
The embedded flaws of butterfly valve steel castings were detected by ultrasonic testing technology.In the estab-lishment of detection process,the appropriate single/double crystal longitudinal wave straight probe parameters were select-ed through comparative experiments by combining the unique acoustic characteristics of steel castings.Moreover,the key points of the detection process for single crystal and double crystal straight probes were elaborated separately.On the basis of testing experience,the waveform characteristics and mechanisms of four typical clustered internal defects commonly found in large butterfly valve steel castings were summarized.It was proven that the composite testing process using single/double crystal longitudinal wave straight probes as a practical non-destructive testing technology could ensure that the steel castings of butterfly valves entering the precision machining process meet the corresponding quality requirements.
NETL
NSTL
万方数据
