NDT Methods Chart Flashcards
5 basic ndt methods used to examine finished welds are :
vt, pt, mt, ut, and rt,
_____ is most cost-effective method, but must take place prior to, during and after welding.
vt
Weld subjects to nondestructive examination shall have been found _____ by visual inspection
acceptable
materials should be examined to see if they meet specs for _______.
quality, type , size, cleanliness, and freedom from defects
____ and _____ should be examined before welding
fitup and joint preparation
the _____ of a multipass weld is the most critical to welding, and is especially susceptible to cracking because it solidifies quickly.
root pass
____ should not be done before examination be cause the peening action may seal fine cracks.
shotblasting
____ is not allowed on the root or surface layer of the weld or the base metal at the edges of the weld.
peening
NDT may be used to determine the presence of a flaw but they cannot do what?
measure its influence on the serviceability of the product unless they are based on a correlation between the flaw and some characteristic that affects service.
______ tests are the only sure way to determine weld serviceability
destructive
Thicker areas of a specimen being x-rayed or higher density mater absorbs more radiation. The corresponding areas on the radiograph with be _____.
lighter
____ is used to determine the internal soundness of welds.
x-ray
To be sure that radiographic exposure produces acceptable results, a guage known as an ____ (IQI) is placed on the part so that its image will be produced on the radiograph.
image quality indicator
IQI’s are also called ______.
penetrameters
What weld is impossible to evaluate with radiograph?
fillet welds
Because it compresses all the defects that occur throughout the thickness of the weld into one plane, giving it an exaggerated impression of scattered-type defects such as porosity or inclusions.
the process of digitizing an image taken from the fluorescent screen-having that image computer enhanced and transferred to a viewing monitor is called _____.
radioscopy imager
a magnetic flux is produced at what angle to the flow of current?
90
Discontinuity in MT must be angled against _________.
magnetic lines of force
When current is passed longitudinally through a work piece, only ____ flaws will show.
longitudinal
Putting the work piece inside a solenoid coil will create longitudinal lines of force that cause ______ and _____ cracks to become visible when the magnetic power is applied.
transverse and angular cracks
MT cannot be used with _______ steels.
austenitic
A joint between a base metal and a weld metal of _____ magnetic characteristics will create __________ that may be falsely interpreted as unsound.
different, magnetic discontinuities
Sensitivity ___ with the size of the defect and is also ____ with round forms such as a gas pockets.
decreases, less
___ may have an advantage over ___ and ___ in detecting tight cracks and surface discontinuities.
MT, RT and UT
Ut should not be used for porosity in welds, why?
round gas pores respond to ut as a series of single point reflectors. confusion with base line noise with testing parameters.
______ defects parallel to the magnetic field may not give pattern.
elongated
What are the 5 P’s of weld quality to help reduce subsequent inspection to a routine checking activity?
- process selection
- preparation
- procedures
- pretesting
- personnel
