The application of nondestructive testing in production

NDT is based on material physical property or using property of component occur this facts due to it is defective。under the premise of no change, no damage the material and workpiece state and using performance,detect on its quality，to judge material or product is correspond to requirements or not。NDT utilizes principle that internal material organization structure abnormal causes physical quantity change,In turn with the change of physical quantity to infer material internal organization of anomalies. Is a difference in the design, material, process and use of relatively independent technology, is a door through the whole process of product design, development, production and use of comprehensive technology. At the design stage, to support the damage tolerance design; In development phase, is used to eliminate the unqualified raw materials, the bad material, nonconforming product and manufacturing process improvement。In product testing, to determine conformity of the product to the acceptance criteria; In the detection of in service, used to monitor the change of product structure and the state, ensure that the product safe and reliable operation. According to different physical principle, the nondestructive testing methods are varied. The most widely used in industrial applications of radiographic testing, ultrasonic testing, magnetic particle testing, penetrant testing and eddy current testing, known as the five conventional NDT methods; Among them, the radiographic testing and ultrasonic testing are mainly used for internal defect detection, and magnetic particle testing, penetrant inspection and eddy current testing can only detect surface and near surface defects. In addition to acoustic emission detection, laser holographic tomography, infrared detection, computing machine detection, leak detection, microwave and dislocation speckle interference detection and so on a variety of new nondestructive testing method。