Weldability and weld joint failures

Abstract

Welding plays a prominent role in the fabrication and erection of structures and components in the industry. Weld failures when they do occur, either during fabrication or service, involve considerable rework, apart from production, time and material losses. Hence, it is essential to adopt appropriate welding procedures depending on the material, weld configuration and the service requirement. In addition, the weldability of the material should be established with adequate laboratory tests in order to minimise the tendency towards hot and cold cracking susceptibilities. The mechanisms of such cracking and the tests to be undertaken to evaluate the cracking susceptibility are enumerated in this paper along with a brief report on weld failures and criteria to be adopted for their repair.

Acicular Ferrite Identification in Heat‐Affected Zone of a Ti‐Killed High Strength Low Alloy Steel

“…[7,8] AF was first found in steel welds as laths that nucleate heterogeneously on small nonmetallic inclusions and grow in many different directions from these point nucleation sites. [9,10] Based on extensive investigations on the nature of AF, [11][12][13][14][15][16] it was found that the transformation mechanism of AF in steel welds is similar to that of bainite, except for the requirement of intragranular inclusions for AF nucleation. Therefore, AF in steel welds has been known as intragranularly nucleated bainite.…”

Ductile Fracture Behaviour of Hot Isostatically Pressed Inconel 690 Superalloy

“…[4,7] Through the elimination of welded joints, HIP can produce components exhibiting homogenous metallurgy; omitting common issues associated with problematic welded components such as hot cracking, heat-affected zones, and induced residual stresses. [8][9][10] The lack of heat-affected zones and lower residual stresses as a result of the HIP diffusion bonding could enhance resistance to environmentally assisted cracking (EAC). [11,12] Furthermore, the ability to completely avoid welding and subsequent machining not only reduces production lead times, costs, and volume of wasted material, but also eliminates significant expenses associated with costly manufacture and through-life weld inspection procedures.…”