Volume No. 6 Issue No.: 3A Page No.: 674-680 Jan-Mar 12

 

REUSE OF SLAG IN STAINLESS STEEL CLADDING AND ITS EFFECT ON CHEMISTRY OF CLADDING

 

Jatinder Garg* and Kulwant Singh

Sant Longowal Institute of Engineering and Technology, Longowal, Punjab (INDIA)

 

Received on : October 30, 2011

 

ABSTRACT

 

The flux used in Submerged Arc Welding (SAW) is converted into slag during welding which is treated as waste and is normally discarded. Being non biodegradable, such slag if not disposed off properly may give rise to a number of environmental problems. Safe disposal of such slag requires its proper handling, transportation and need landfill space for its proper dumping, which costs money. Sometimes the slag dumped in the landfills can become a source of soil pollution and groundwater contamination. Furthermore, dumping of slag leads to wastage of natural resourses and minerals which are used in making of flux, which is also an environmental concern. All these problems can be mitigated by developing some methodology that will enable the reuse this slag as flux. In the presented work an attempt was made to ascertain the feasibility of reuse of the SAW slag generated during stainless steel cladding applications, merely by crushing it to the particle size of the original flux. For this study two 4 high weld pads were prepared on SA-516 (Grade 70) base plates using the original flux and the crushed slag. The arc stability, physical appearance, slag detachability and chemistry of top layer of both these weld pads, were compared with each other. It was found that the quality of claddings obtained using crushed slag was inferior to the one obtained using fresh flux, hence, as such these can not be used for critical applica- tions where ASME/AWS code requirements are very stringent; however, if desired, such flux can be used for general non critical applications where strict compliance of the code is not needed. Further it was concluded that to be able to reuse this slag as flux having the same qualities as that of the virgin/fresh flux, one need to develop suitable technology to recycle it properly by replenishing it with suitable alloying elements/deoxidizers, thereby reclaiming its original characteristics. The work on development of such technology will be further undertaken.

 

Keywords : Reuse of welding slag, Submerged Arc Welding, Crushed SAW slag, Waste management

 

 

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