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

BEND TESTS

BEND TESTS Object:   To determine the soundness of weld metal, heat affected zone and weld zone.These tests may also be used to give some measure of the ductility of the weld zone. It is not usual to use transverse and longitudinal bend tests for the same application. Method:   All specimens to be removed and prepared without causing significant distortion or heating. The cap and root are ground flush. The specimen is bent by the movement of a former of prescribed diameter, the relevant side of the specimen to be placed in tension. Angle of bend and diameter of former should be as specified in the appropriate standard. Reporting Results: Thickness of specimen Direction of bend (root or face) Angle of bend Diameter of former Appearance of joint after bending e.g. type and location of flaws
Read more

NDT ( NON DESTRUCTIVE TESTING )

NDT (NON DESTRUCTIVE   TESTING) :-  Non Destructive Testing in great variety are in world   wide used to detect variations in structure, minute changes in surface finish, the presence of cracks or other physical discontinuities, measure   the thickness   of materials   and   coatings   and   to   determine  other characteristics of industrial products. REASON'S FOR THE USE OF NDT: "NDT" is used by the manufacturers for the following reasons:  1. To ensure product reliability. 2. To make profit for the user. a)    To ensure customer satisfaction b)   To aid in better product reliability. c)    To control the manufacturing processes. d)   To lower the manufacturing costs. e)    To maintain uniform quality level. SOME OF THE MOST COMMON NDT METHODS ARE : 1.VISUAL ...
Read more

RADIOGRAPHY TEST

RADIOGRAPHY TEST INTRODUCTION : Industrial radiography is a nondestructive test method that uses X-rays or Gamma rays to show the presence and certain characteristics of internal discontinuities in solid materials. The method is based on the ability of X-ray or Gamma-ray radiation to penetrate solids, to a degree that varies with such factors as wave length of the radiation, and type and thickness of the material part of the radiation penetrates the material and part is absorbed. The amount absorbed and the amount transmitted are a function of the thickness of the material. Where a void or discontinuity exists, there is essentially less material to absorb the radiation. This creates a different in absorption, a difference that registers on photographic emulsions. The result is a shadow picture called a radiography Radio-graphic Sources : The common gamma ray radio-graphic sources : Cobalt - 60 Cesium - 137 Iridium - 192 Thulium - 170 Gamma Ray Radiography : Gamma rays ar...
Read more