Establishment of Cold Wire addition technique in single wire Submerged Arc Welding process for cealing girder assembly

摘要

Cold wire addition has been widely accepted to be potential tool for reducing the number of passes and increasing the productivity of thick section joints. Multi wire technique of submerged arc welding process enhances the productivity in welding of structural components etc. However the cold wire addition in single wire SAW welds have the inherent advantages of higher metal deposition as compared to conventional SAW, enhancing the joint completion rate and resulting in less flux consumption. Further Cold wire addition technique does not require addition of heat input. This technique enables lower heat input per gram of wire deposited. The equipment for this technique apart from using an additional wire feeding arrangement for cold wire feeding is same as that for the submerged arc welding. The influence of the diameter of cold wire addition on the metal deposition also investigated for the same quantum of heat input, leading to finer microstructure and better mechanical properties. This paper describes the experimental work carried out at WRI and M/S Lakshmi Engg Industries, Trichy to study the effect of process parameters on bead characteristic like, bead geometry, dilution, deposition rate, hardness survey, mechanical properties, macro and microstructure analysis. The results are compared with that of submerged arc-welding technique.