About radiography films: Radiography films are primarily made up of two things; 1. Base 2. Emulsion Base: Base is a transparent, flexible blue tinted object, usually made from a clear and flexible plastic such as cellulose acetate. It provides physical support to emulsion and does not participate in the image-forming process. It is not sensitive to radiation, nor can it record an image. Emulsion: Emulsion consists of gelatin which consists of….
Radiography Test (RT)
Radiography testing (RT) is one of the most widely used non destructive test (NDT) method. With the help of this method we can detect hidden flaws or discontinuities present in welds such as cracks, porosity & blow holes, slag, flux or oxide inclusions, lack of fusion, incomplete penetration, Mismatch and tungsten inclusion etc. Short wavelength electromagnetic radiations such as X-rays or Gamma rays (γ) are used for Radiography testing. Both….
Preparatory Questions (Set – 7)
1. Which of the following butt weld preparations is generally most susceptible to lack of side wall fusion during MMA welding? A “U” preparation A “V” preparation A Double V preparation All of the above 2. Which of the following units is used for charpy V notch energy? Pounds per square inch Joules KSi All of the above 3. What destructive test would be required to ascertain the likelihood of….
Preparatory Questions (Set – 6)
1. Which of the following processes joins metals plastically? Friction welding Resistance welding Plasma welding None of the above 2. In submerged arc welding, excessive arc voltage may cause? Excessive penetration Change in weld metal composition Narrow weld width All of the above 3. In a tensile test, a brittle material would be indicated if the fracture surface? Shows a reduction in size Is flat and featureless Breaks in….
Preparatory Questions (Set – 5)
1. Which of the following NDT methods can only detect surface breaking defects? MPI DPI UT RT 2. Which of the following is applicable to electrode efficiency? The mass of metal deposited as a percentage of the mass core wire melted Iron powder electrodes have efficiencies above 100% Electrodes of high efficiencies tend to procedure welds of a smooth flat profile Both a and b 3. Cellulose….
Preparatory Questions (Set – 4)
1. Which of the following does not require baking; E 6010 E 7018 Both a & b None of the above 2. Gamma rays and X-rays are part of a family of waves called Acoustic waves Light waves Electromagnetic waves Transverse waves 3. Why is hot – pass so-called? Because it is applied at a high amperage Because it is applied when the root is still hot….
Preparatory Questions (Set – 3)
1. Overlap in welds could be influenced by: Welding process Welding position Poor welding technique All the above 2. In MAG/CO2 welding which parameter gives the greatest control of weld appearance during dip transfer or short-circuiting welding? Wire stick-out length Welder’s convenience Wire feed speed Inductance 3. In X-ray work the quality of the radiographic image is assessed by the: Density of the film IQI indicator KVA available Stand-off distance….
Preparatory Questions (Set – 2)
1. Stress relieving is not helpful in which of the following cases? Softening the steel Lowering the peak residual stress Improving resistance to stress corrosion cracking Improving dimensional stability after machining 2. Stray arcing may be regarded as a serious defect because: It may reduce the thickness dimension of a component It may cause liquation cracks It may cause hard zones All the above 3. Slag inclusions would occur with:….
Preparatory Questions (Set – 1)
1. The Discontinuity which results from the entrapment of gas within the weld cross-section is known as: Undercut Lack of penetration Lack of fusion Porosity 2. A discontinuity can be called as defect only when It is a Linear indication It is a rounded indication It exceeds the code limit if it is a crack 3. Due to the improper termination of the welding arc which discontinuity is likely to….
Welding Symbols (Part -1)
Welding symbols are a set of information conveyed by the design department to the welding Engineer and the welding operator. It contains all the necessary information viz. welding position, dimensions and geometry of the weld, details of groove/fillet, welding process etc. A basic weld symbol consists of three parts namely; Arrow Line Reference Line Tail These are shown in the diagram given below Arrow Line: Arrow indicates the position of….