Introduction of Corrosion resistant oil nicely seamless metal pipe

Oil Wells and gasoline Wells steel pipes involve the drill pipe for mining, perfectly wall security pipe inserted within the very well to avert development collapse and pipeline technique hanged inside of the wall defense tube for generation.nBased on security criteria, oil effectively pipe normally adopts seamless steel pipe.nnAs a result of the oil properly and gasoline effectively mining depth deepening 12 months by 12 months, this kind of high energy oil effectively pipes as N80 (yield strength 551 MPa grade) and P110 (yield toughness 758 MPa) are created, these pipes have achieved the American petroleum institute standards.nnHowever, the sulfide stress cracking accident transpired in the 50s in Canada, so sulfide corrosive surroundings sulfide stress cracking of high power metal aroused people's problem.nSulfide worry cracking of reduced alloy steel is a kind of sort of hydrogen embrittlement, the production fluid with the process of hydrogen sulfide inhibits corrosion reaction in the procedure of hydrogen made by dissipation, to invade the substantially greater the volume of hydrogen in steel.nnThe larger the power of metal, the bigger the sensitivity of sulfide tension cracking, so fantastic to sulfide strain cracking resistance of high power steel for progress.nThe sulfide worry cracking resistance of metal is associated with the microstructure of metal.nFrom martensite period group see reveals the adhering to measures is effective: adding Nb and quenching tempering warmth therapy can kind fine grain composition Reduce the intergranular segregation features this sort of as P and Mn can avoid the grain boundary cracks Expanding tempering temperature can lower the inner strain, etcetera.nnnSince the 60s have developed resistance to sulfide anxiety cracking of very low alloy oil properly drill pipe, and has created constant development.nIn the deep very well, due to the substantial bottom hole temperature (5000m class properly, downhole temperature about 250 e), so the corrosion environment is pretty really serious.nIn oil Wells in intense corrosion setting, ordinarily to inject metal rust preventer safety, but no make any difference technically, or from an financial place of look at, anticorrosive agent software is extremely hard, as a result formulated appropriate for all forms of corrosive natural environment, without injecting antifushiji the corrosion resistance of alloy metal.nnFrom the perspective of corrosion resistance, corrosion resistant alloy steel can be roughly divided into procedure of martensite stainless metal, duplex stainless steel and austenite program large Ni alloy three varieties. The CO2 corrosion environment is often referred to as small sulfur corrosion ecosystem.nCO2 and H2S creation fluid with with each other, but can type weak acid immediately after CO2 dissolved in drinking water, can be made use of as use owing to metal corrosion response of the resource of H + ions, so as opposed with the identical acid aqueous option pH, the corrosion level of carbon steel.nnTo minimize less than the atmosphere of CO2 corrosion price, powerful alternative is to increase Cr, now superior to below the natural environment of CO2 corrosion resistance and overall economy of thirteen Cr steel (AISI420) demand greater promptly.nHowever, for the reason that of 13 Cr steel underneath the temperature of more than 150e, corrosion velocity will boost, and the traces of H2S natural environment with sulfide worry cracking sensitivity, thus produced a new form of 13 Cr metal, specifically by reducing the content of C, site inhibition of Cr carbide precipitation, ensuring efficient total of Cr, which can strengthen the application of the crucial temperature in CO2 atmosphere.nnIn addition, insert the Mo can make in the trace H2S atmosphere passivity oxide movie stability, inhibition of hydrogen in the metal. Particularly beneath the natural environment of significant temperature, duplex stainless metal containing 22% ~ 25% Cr can be employed.nIn oil Wells and gasoline Wells with a lot of H2S, can use the austenite large Ni alloy with superior corrosion resistance.nIts critical temperature and corrosion resistant alloy features of the written content of Mo and W, based on the use surroundings, has produced a Mo and W articles distinctive alloy series.