Results of tensile, hardness and bend tests of modified 9Cr 1Mo steel welds: Comparison between cold wire and hot wire gas tungsten arc welding (GTAW) processes. (January 2019)

• Record Type: Journal Article
• Authors: Pai, Aravinda; Sogalad, Irappa; Basavarajappa, S.; Kumar, Prabhat
• Is Part Of: International journal of pressure vessels and piping. Volume 169(2019)
• Page Start: 125
• Page End: 141
• Publication Date: 2019-01
• Subjects: Modified 9Cr 1Mo -- Hot wire -- Cold wire -- GTAW -- Tensile properties -- Hardness; Pressure vessels -- Periodicals; Pipe -- Periodicals; Récipients sous pression -- Périodiques; Tuyaux -- Périodiques; Pipe; Pressure vessels; Periodicals; 681.76041
• DOI: 10.1016/j.ijpvp.2018.12.002
• Languages: English
• ISSNs: 0308-0161

Abstract

Abstract: Hot wire Gas Tungsten Arc Welding (GTAW) process is considered in addition to conventional cold wire GTAW process for the manufacture of Steam Generators (SG) for India's Prototype Fast Breeder Reactor (PFBR). During manufacture, it is an obligatory requirement to weld one test coupon for every 20 m of weld length on the actual SG for ascertaining the properties during fabrication. Weld pads thus prepared were used for characterization of hardness, bend and tensile properties of modified 9Cr 1Mo steel welds produced by hot wire and cold wire GTAW processes and the test results were compared. The results revealed that hardness, bend and tensile properties of modified 9Cr 1Mo steel welds of hot wire and cold wire GTAW processes are similar and no genuine difference exist between these two welding processes. Further, the advantage of high quality with excellent weld profile and high productivity has been realized using hot wire GTAW process. Highlights: Hot wire Gas Tungsten Arc Welding (GTAW) is relatively a new process, which is considered for the manufacture of Steam Generators for India's Prototype Fast Breeder Reactor in parallel to conventional cold wire GTAW process. The hardness, bend and tensile properties of modified 9Cr 1Mo steel welds produced by hot wire and cold wire GTAW processes were found to be similar. Option of using hot wire GTAW process during fabrication of Steam Generators has provided advantages of high weld metal quality and productivity. Hot wire GTAW process can be an option for high thickness components. This process facilitates in maintaining high quality, productivity and provides economic benefits.