Indian Welding Journal

K. P. Ananthagopal ¹, S. Prasannakumar ¹

Affiliations
1 Larsen and Toubro Ltd, Bangalore, IN

Abstract

Welding is a major fabrication process in various machine building, automobile and structural fabrication industries. Out of the wide range of welding processes available, CO₂ welding is finding increased applications, because of its versatality and economy. The recent development of flux-cored wires for MIG-C0sub>2 welding has increased their utility further. In this paper, results of the experiments carried out with solid as well as flux-cored wires are presented. For the first time, the surface topography of the weld beads has been quantitatively represented. It is shown that fluxcored welding process provides smoother metal transfer with less spatter and together with the slag cover available, results in a better bead topography than solid wire welding ; thereby requiring less post-weld cleaning and dressing.

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S. Balasubramaniam ¹, S. Prasannakumar ²

Affiliations
1 NCMI, Bombay, IN
2 IIT, Madras, IN

Abstract

Welding has come to stay as an important fabrication technique since the past six decades, after its economy and productivity have been established. In the early days of fabrication by welding, statements like 'Welding promotes brittle failure' were often made to focus the attention towards the influence of weld defects. It is recorded in numerous documents of the international Institute of Welding that brittle as well as fatigue failures originated from weld defects, which acted as fracture initiation sites. Over the years, detailed investigations were carried out to understand the fracture behaviour of welded joints, particularly as to the significance of weld defects.

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S. Balasubramaniam , S. Prasannakumar ¹

Affiliations
1 I.I.T., Madras, IN

Abstract

The present decade has seen an important development in the field of welding viz., the application of the principles of fracture mechanics for analysing the fracture behaviour of welded joints. This is a direct result of the long-standing efforts made in characterising the influence of the weld defects like cracks, on the fracture behaviour of weldments. Probably the most important consequence of the development of various test procedures of fracture mechanics is the possibility of applying these quantitative principles to structural steels, with reasonably small specimens. In this respect, first attempt has been made to determine the fracture toughness parameters of one of the most widely used fusion-weldable quality structural steel, IS 2062. It is hoped that these parameters will help the designers and fabricators in welding industry to arrive at a fail-safe design and understand the consequences of defects that may be present in these joints.

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