Experimental Investigation of Galling Resistance in OCTG Connections

The results of galling experiments are strongly dependent on the method used and vary from test machine to test machine. However, by a well-developed test method and testing machine, one can obtain reliable and repeatable results. The primary objective of this research is to develop a new test method and machine for evaluating galling resistance in OCTG (oil country tubular goods) connections. Through the application of basic principles of statistical design of experiments, the galling resistance in OCTG threaded connections has been investigated. For estimating the nominal failure stress, two statistical methods, namely, up-and-down and frequency distribution, have been applied and compared. Galling resistance, one of the most important design factors of OCTG connections, has been studied and discussed.