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

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

Part -2 Most commonly asked Mechanical Interview Questions

Most commonly asked Mechanical Interview Questions 1. What is the difference between Critical Speed and Whirling Speed? Ans. In Solid mechanics, in the field of rotor dynamics, the critical speed is the theoretical angular velocity which excites the natural frequency of a rotating object, such as a shaft, propeller or gear. As the speed of rotation approaches the objects natural frequency, the object begins to resonate which dramatically increases system vibration. The resulting resonance occurs regardless of orientation.Whirling Speed is due to the unbalanced forces acting on a rotating shaft. 2. How a Diesel Engine Works as Generator? Ans. Diesel engine is a prime mover, for a generator, pump,and for vehicles etc. generator is connected to engine by shaft. mostly in thermal power plat ,there is an engine is used to drive generator to generate power. 3. Explain Second Law of Thermodynamics? Ans. The entropy of the universe increases over tim...
Read more

The Brinell Hardness Test

The Brinell Hardness Test The Brinell hardness test method consists of indenting the test material with a 10 mm diameter hardened steel or carbide ball subjected to a load of 3000 kg. For softer materials the load can be reduced to 1500 kg or 500 kg to avoid excessive indentation. The full load is normally applied for 10 to 15 seconds in the case of iron and steel and for at least 30 seconds in the case of other metals. The diameter of the indentation left in the test material is measured with a low powered microscope. The Brinell harness number is calculated by dividing the load applied by the surface area of the indentation. The diameter of the impression is the average of two readings at right angles and the use of a Brinell hardness number table can simplify the determination of the Brinell hardness. A well structured Brinell hardness number reveals the test conditions, and looks like this, "75 HB 10/500/30" which means that a Brinell Hardness of 75 was obtained us...
Read more