NDE 2

Learning Activities 1.View Slides; 2.Read Notes, 3.Listen to lecture 4.View Demo 5.Do on-line workbook 6.Do homework Keywords Eddy Current Testing, Ultrasonic Testing, Acoustic Emission Inspection and NDE 2 Lesson Objectives When you finish this lesson you will understand: Several Other Non-destructive Testing Techniques Advantages and Disadvantages of each

AWS Welding Handbook, Vol 1, 1987 I=E/Z Z=Impedence Defects disturb magnetic field which changes Z, and is picked up by change in Coil current Defect must by oriented normal to induced current

AWS Welding Handbook, Vol 1, 1987

AWS Welding Handbook, Vol 1, 1987

Turn to the person sitting next to you and discuss (1 min.): In what circumstances might Eddy Current Testing not work well?

Ultrasonic Testing Transducer emits a beam of ultrasound which is transmitted through the sample; free surfaces or defects reflect the beam The reflected beam is monitored on an oscilloscope Water, grease, glycerin couple together the transducer with the metal There is a certain skill/art involved in positioning the transducer Nondestructive Evaluation T

Advantages of UT Can detect discontinuities in thick sections Has relatively high sensitivity to small discontinuities Able to determine depth or internal discontinuity and to estimate size and shape Can adequately inspect from one surface Equipment can be moved to the job site Is nonhazardous to personnel or other equipment

Limitations Setup and operation require trained and experienced technicians Weldments that are rough, irregular, very small or thin are difficult to inspect Discontinuities at the surface are difficult to detect A couplant is needed Reference standards are necessary to calibrate

Nondestructive Evaluation transducer defect ultrasonic wave Ultrasonic signal over flaw A - top surface B - flaw C - bottom surface A B C Welding Code

High Velocity, Short wavelength Can be focused Propagated Through water Only used for inclusions and laminations Approx. 1/2 Velocity of Longitudinal Easier Electronic timing Greater Sensitivity to small defects Can get 3D info More easily dispersed Not propagated through water

Defect Size Determination Defect Length Determination

Estimating location

Discontinuity Orientation Discontinuity Type & Shape

Estimating Height

Acoustic Emission Signals Produced by: Plastic Deformation, Clamping/Unclamping Loading Thermal Stressing Crack Propagation Picked Up by Transducer Monitor during welding Arc Welding Resistance Welding Monitor In-Service

Please Click on the Non-Destructive Testing Demonstration on the Demonstration Web page on the WE300 Website.