The NDT ( nondestructive test )

Background information
Nondestructive testing is the floorboard of the technology of all the technical state .by the using of sound , light, magnetic and electrical characteristics, Nondestructive testing can test whether there is a defect or irregularity in object or parts and give the information of position, performance , quantity and  the size of the defect without prejudice to or does not affect the function of the tested performance , then judge the detected object .

          

 The  tested  items


Ray test
 we can detect the discontinuity (defects) in tested goods by using the attenuation characteristics in rays penetrating material and record the method and the implementation of the image.according to the different X-ray source (or radiation),Ray detection can be divided into  X-ray detection, γ ray detection, neutron  ray detection, proton beam and electron radiation detection etc.


Ultrasonic test
It is the method that the defect of tested goods can be judged and determined by Using the propagation, reflection,attenuation and other features of high frequency sound waves (> 20000 hz)that  people can’t feel. 


Magnetic particle test
After the tested goods  being magnetized in the magnetic field ,the defect parts will flux the magnetic  from the magnetic field . After the surface has been sprinkled with magnetic powder , the defect will be appeared ,as the magnetic particles are attached to the defect.Magnetic particle testing is only applicable to ferromagnetic materials.when the magnetic coating thickness on Ferromagnetic materials  are less than 50 um, the impact on magnetic powder detection sensitivity will be less.It is the important condition in magnetic particle testing that the length and the direction of the defect is perpendicular to the direction of magnetic field .


Penetration test
The penetrant agent applied to the tested goods will be permeated to the defects on the surface by capillary action . after  the cleaning of the tested goods, we will sucked out  the penetrant agent that residued in the defect by using the imaging agent , so that the shape and position of the defects will be displayed through the fluorescence or colouring image .and the Penetrant agent is connected with the penetration of defects , the surface tension of penetrant agent, the effect of Penetrating agent on solid, the  size and shape of the defect  and the viscosity of penetrating agent  etc. 


Testing equipment
Ray flaw detection machine, ultrasonic flaw detector, magnetic particle inspection machine, etc.

 

Testing standard 

Tested item

Testing standard

 radiographic                                                                                                                      tes    testing

 

GB/T 3323,JB/T 4730.2,JB/T 6440,EN 1435,ASTM E 446,ASTM E186,ISO 5817

ultrasonic

testing 

GB/T2970,GB/T6402,GB/T7233,GB/T11345,EN 12680-1,ASTM A388/A388M,JB/T 4730.3

       magnetic 

       particle

       testing

 

GB/T15822,JB/T6061,BS EN1290,JB/T 4730.4

       penetrant 

       testing

 

JB/T 9218,JB/T6062,EN 571-1,JB/T 4730.5