Research And Analysis Of Ultrasonic Testing And Influential Factors Of Chemical Engineering Pressure Vessel In High-temperature Environment

The chemical industry pressure vessel majority are ruing under the harsh operating modes such as high temperature, high pressure, low temperature, fatigue and corrosiveness medium etc, and the inefficacy form in production and uses is fairly more complicated, and along with lengthening of enlistment period, the dangerous nature is also constantly increasing by what the original defect of existence inside the equipment initiated. To solve failure analysis and the prevention question of chemical industry pressure vessel, and firstly is the checkout and supervising the harmfulness defect, the ultrasonic testing technology is the checkout surface under the high temperature state and lies hidden in the earth the most serviceable method of defect, but owing to the couplant preparation difficulties such as heat tolerance ability, sound energy attenuation, sound field specific property variation and probe applicability etc , being hard to realize to the effectively checkout of defect, and the more suitable questions of existence need to be studied the settlement.This text was measured change ( inside 50 - 450℃'s scopes ) along with the temperature, the attenuation coefficient inside 16MnR's steel pressure vessel of ultrasonic shear wave by way of the trial,and according to its trend drawing up closing changes the attenuation of ultrasonic shear wave along with the temperature to change the law relation type. And to two major aspects that cause the ultrasonic to weaken, the sound pressure losses that created at material nature attenuation and the coupling interface carries on the discussion to analyze. The attenuation value is clearly enlarged when the temperature surpasses 300℃, and the couplant interface loss detecting a flaw the interface is the major factor that the sound wave is weakend.Analyses the rules of angle probe's sound field of ultrasonic wave, and measured in 50 - 450℃'s scopes the speed of sound of ultrasonic shear wave in the 16MnR, combines the change of ultrasonic wave speed of sound, reached the rules of the near field length and angle of spread in the angle probe's of ultrasonic wave .Knowable, the probe chip as forф10mm and near field head of a district's degree is at 6 - 8mm. And along with going up gradually of temperature,θ0,θ_上andθ_下all reduces gradually.Build under the high temperature environment welding seam defect ultrasonic shear wave checkout method, and combines theory having carried on the engineering applying.