Studies on Shielded Active Gas Forge Welded API 5CT L80 Material at Different Cooling Rates
Shielded Active Gas Forge Welding (SAG-FW) is a solid state bonding process in which two mating surfaces are locally heated and forged together to form a bond. SAG-FW has so far mainly been used to join materials for pipe-line and casing applications. The present study has been conducted on an API 5CT L80 grade material in a prototype forge welding machine. Small-scale pipe specimens have been extracted from the wall of the production casing. The SAG-FW process is completed within a few seconds of heating and forging followed by controlled cooling. The microstructure of the weld is determined by the processing parameters. In this paper, microstructure results for SAG-FW processed L80 material have been obtained for a range of cooling rates and systematically compared with microhardness values. Microstructure observations at different regions of the weld have been made. Faster heating rate and controlled cooling resulted in a mixture of non equilibrium microstructures, but satisfactory mechanical properties have been obtained for optimized processing parameters.
T. Chandra, M. Ionescu and D. Mantovani
P. Vinothkumar et al., "Studies on Shielded Active Gas Forge Welded API 5CT L80 Material at Different Cooling Rates", Advanced Materials Research, Vol. 409, pp. 871-876, 2012