Experiment Research On The Hot-dipping Technology Of Multi-component Alloy In The Oilifeld Tube Corrosion

Corrosion problems bring huge economic loss to the national economy and each field ofthe human activity, and due to corrosion failure, a large number of engineering components,equipment and facilities are out of work.According to the statistics,we will loss1/5of thetotal output of iron and steel material each year in the world due to corrosion; the nationalreport also pointed out, China’s annual expenditure of the direct loss for the corrosion costmore than two Hundred billions, if taking into account the indirect loss, accounting for about5%of the GDP, nearly average paying500Yuan for the cost of corrosion every year.Corrosion has become a noticeable safety hidden danger, close to the life in all aspects.IT caused direct losses of more than60000000tons in2009, oil field is no exception, alsothere is corrosion, every year a large number of tubing and sucker rod due to corrosionbecame useless, so the preservation work is the imminent. Hot-dipping as a traditional andeffective anticorrosive method is widely applied the coating with high strength, goodcorrosion resistance. But, it will appear “Sandelin effect” in the hot-dipping process in viewof high silicon steel of the tube, with coating thickness, skin, easy to fall off, in order to solvethis problem, this paper focuses on how to add multi-component alloy to suppress “Sandelineffect” in zinc bath, then improves the coating performance, multi-component alloy coatingwith lightness, high strength, high corrosion resistance. At the same time, it also repairs wastetubing corrosion pits, cracks and other defects, which makes waste into treasure.We test and analysis the large specimen and tube nipple Using metallographicmicroscope, salt spray corrosion test box and a tensile testing machine and other experimentalequipment, with the Results show that, by adding aluminum(Al), nickel(Ni), Bi(Bi), rareearth(RE) and multiple alloy elements in zinc bath, it not only can effectively inhibit“Sandelin effect” in the hot dipping process and improve the corrosion resistance of theplating, but also greatly improve the pipe strength, corrosion resistance and comprehensiveperformance of the rod, through the repairment to the rod pipe defects by phase layer growthof the alloy layer.