A Study On The Critical Technology Research Of Online Pressure Vessel Ultrasonic Test In High Temperature

The ultrosonic wave test technology is a kind of NDT technology what is used most and researched most at present, tests material property and the structure change by way of being influenced level and condition of the ultrosonic wave. The ultrosonic wave test technology what can accurately definite the dimension,seat, tropism,degree of depth and quality of internal defect etc. is extensively used to test internal defect in various engineering materials, parts and structural member. But these are tested mostly under normal temperature, and the ultrasonic test under the high temperature environment is used seldomly, and the ultrasonic wave test theoretical research along with temperature change is seldom seen. Firstly,the measurement method of ultrosonic shear wave speed are analysised andstudied, the shear wave translational velocity value in pressure vessel steel 16MnR's steel is gotten in 20℃～450℃'s scopes change, the speed law is drawn up.according to its trend.the influence to the velocity measurement error because of the change of heated expands and the elastic modelling quantity and change of poisson ratio and density owing to the temperature is discussed and corrected.Secondly,The principle and the method of the ultrosonic wave oblique detecter K's value,near field length and beam directs angle is studied,the ultrosonic wave velocity value in the plexiglass the law of temperature in 0℃～60℃'s scopes change is gotten, the speed law is drawn upaccording to its trend. Combining the change law of shear wave speed, and the ultrosonic wave oblique detecter K's value,near field length and beam directs angle are reached,and the experiment is carried on at scene.At last,The principle and the method of the double sideband modulation, demodulation principle and related detect principle and LabVIEW graph software is studied, the simulation of the vitual ultrosonic wave test system based on sound card and LabVIEW is reached. This simulation can count out the seat of defectby way of synchronizing information and the return object phase difference and high temperature ultrosonic wave speed formula,And the seat of defect, return wave amplitude, distance-amplitude curve can be showed out by way of LabVIEW's oscillogram.