IMPROVING THE CORROSION RESISTANCE OF THREADED JOINTS BY USING LUBRICANTS

Abstract

Modern industry places a number of stringent requirements to the performance properties of fasteners. All fastening elements made of metal are subject to corrosion-mechanical wear. Their disassembling is a time-consuming process which is often accompanied by destruction of the part. Damage to threaded connections can be prevented by applying a special thread lubricant to the part. Based on theoretical and experimental research, the authors have developed a formulation of high-temperature thread compound "Udar", which contains the following components: molybdenum disulphide (70 wt.%), titanium dioxide (3 wt.%), colloidal graphite compound (70 wt.%), aluminium (powder) (5 wt.%), OMIK "TELAZ" (10 wt.%), thickener (petrolatum), and industrial oil I-40A. The lubricant efficiency in protecting fasteners against atmospheric corrosion and corrosion setting was tested on six specimens representing a pair of "bolt-nut". The results of comparative laboratory tests of the developed composition with foreign-made greases have shown that the developed thread lubricant is able to protect threaded joints from thermal-oxidative setting occurring at up to 900⁰C. Application of this composition will considerably reduce the equipment disassembling time due to reduction of the absolute value of torque when disassembling fasteners, and prevent thermochemical and corrosion "seizure" of threaded joints