The work reported deals with developing a recycling technology for converting SAW slag into a fresh flux. The slag generated during submerged arc welding is normally thrown away as a waste. Owing to its non-biodegradable nature, this poses problems of storage, disposal, needs landfill space for dumping and this also causes soil pollution. Being glassy and brittle material it cannot be used as a filling material in building construction or elsewhere. Apart from this non-renewable resources will get exhausted due to continuous mining for minerals required for manufacturing fluxes.

 

For building a recycling based society, the first priority is to reduce generation of waste as far as possible. Any waste whose generation can not be prevented, it is important to reuse the waste to whatever degree possible. So an attempt was made to recycle the slag to be used as a fresh flux. Slag was crushed, sieved to the required grain size and mixed with fresh flux in various proportions and used for welding. The chemical and mechanical properties of weld metal were evaluated. The overall soundness of weld metal was assessed through radiography. Test results were satisfactory and fulfill AWS (American Welding Society) requirements. Cost analysis indicates that it is economically viable to use the recycled slag. The use of recycled slag is economical by 68.8%.

 

Results of mechanical testing

Summary: The work deals with developing a recycling technology for converting SAW slag into a fresh flux. The investigations included microstructure and micro-hardness survey of welds prepared with pure slag, fresh flux and recycled slag for comparative studies. The chemical and mechanical properties of the sound weld metal were evaluated.