PRODUCTION OF Cu–Cr ALLOYS BY IN SITU REDUCTION OF CHROMIUM OXIDE DURING ELECTRO SLAG CRUCIBLE MELTING (ESCM)

Abstract

An electro slag crucible melting process for production of copper–chromium alloys is described. The process uses fine copper scrap as a raw material. After the copper scrap is melted, chromium is alloyed with copper by direct reduction of chromium oxide added to the slag. Carbon and aluminum can be used as reductants and the reduction is carried out in situ in the molten slag. Copper chromium ingots containing up to ∼1 wt % chromium were produced by this process. The process serves the dual purpose of recycling copper scrap and alloying remelted copper by chromium. This is the first time that direct reduction has been employed during an electro slag melting process. The in situ reduction technique described has the potential of being a production route for a variety of alloys. It is particularly suitable for production of difficult-to-melt alloys such as copper–chromium.

Keywords:

• Chemical homogeneity
• Chromium alloying
• Chromium oxide
• copper-chromium alloy
• Copper scrap
• Electro slag crucible melting
• Heat treatment
• Hot working
• Ingot surface quality
• In situ reduction
• Nonconsumable electrode
• Reducing agent
• Slag system
• Sound castings
• Tensile properties

5.0 ACKNOWLEDGMENTS

The authors are grateful to Defence Research and Development Organisation, Ministry of Defence, New Delhi, for the financial support in carrying out this research work. The authors wish to thank Dr. D. Banarjee, Director, DMRL, for his keen interest and encouragement.