Skip to main content

VISUAL INSPECTION OF WELDING

VISUAL  INSPECTION OF WELDING

INTRODUCTION
Inspection starts with examination of the material prior to fabrication, scabs, seams, scale or other harmful surface conditions may be detected in visual inspection.

The inspector should check the following :
  • Weld preparation, dimensions and finish. 
  • Clearance dimensions of backing strips. 
  • Alignment and fit up to the pieces being welded. 
  • Verification of cleanliness. 

Visual Inspection During Welding
Visual inspection checks details of the work while welding is in progress. Among the details to be checked are :
  • Welding process. 
  • Cleaning. 
  • Preheat and inter pass temperature. 
  • Joint preparation. 
  • Filler metal. 
  • Flux or shielding gas. 
  • Chipping, grinding, or gouging. 
  • Post heating temperature and time. 
Visual Inspection After Welding
Visual inspection is useful for finished-product verification of such items as :
  • Profile irregularities of the weldment. 
  • Conformity to drawing requirements. 
  • Acceptability of welds with regard to appearance (eg: surface roughness). 
  • The presence of unfilled undercut, overlaps and cracks. 
  • Evidence of mishandling from center punch or other inspection markings or excessive grinding. 

Labels:

Popular posts from this blog

What is Annealing ?

Annealing:- Annealing  Process :- Annealing is a heat treatment process by which the properties of steel are enhanced to meet machinability requirements. In this process Hypoeutectoid steels (less than 0.83% carbon) are heated above upper critical temp., soaked and cooled slowly and  Hypereutecoid (above 0.83%) are heated above lower critical temp., soaked and allowed to cool slowly. Annealing  Process Steps: 1.Heat material into the asutenite region (i.e. above 1600F) – rule of thumb: hold   steel for one hour for each one inch of thickness 2.Slowly furnace cool the steel – DO NOT QUENCH 3.Key slow cooling allows the C to precipitate out so resulting structure is coarse  pearlite with excess ferrite 4.After annealing steel is quite soft and ductile The purpose of Annealing is : 1)Reduce hardness and brittleness 2)Alter microstructure for desired mechanical properties 3)Soften...
Read more

Part - 6 Most commonly asked Mechanical Interview Questions with answer

Most commonly asked Mechanical Interview Questions  1.           Why Entropy decreases with increase in temperature? Ans.      ds=dQ/T Entropy is inversely proportional to the temperature so, as temp. Increases, entropy decreases. 2.            Why different types of sound are produced in different bikes, though they run on SI Engines? Ans.        Engine specifications are different in different manufactures like as Bore Diameter (CC), Ignition timing. Also the exhaust passage takes more responsible for sound. 3.            How much Watt means 1Hp? Ans.       746.2 Watt 4.            Explain Bicycle Rear Wheel Sprocket working? Ans.       Rear wheel sprocket works u...
Read more

LIQUID (DYE) PENETRATION TEST (D.P.T.)

LIQUID (DYE) PENETRATION TEST INTRODUCTION A liquid penetrant test is non-destructive type of testing to detect flaws that are open to the surface. e.g. cracks, seams, laps, lack of bond, porosity, cold shuts etc. can be effectively used not only in the inspection of ferrous metals but is especially useful for non-ferrous metal products and on non-porous, non-metallic materials such as ceramics, plastics and glass. PRINCIPLE OF OPERATION The principle of liquid penetrant test is that the liquids used enter small openings such as cracks or porosities by capillary action. They are influenced by factors such as the condition of the surface of material and the interior of the discontinuity. For liquid to penetrate effectively, the surface of the material must be thoroughly cleaned of all material that would obstruct the entrance of the liquid into the defect. After cleaning, the liquid penetrant is applied evenly over the surface and allowed to remain long enough to permit penetration i...
Read more