Technical Study Of N80Grade Non-Quenching And Non-tempering OCTG

With the quick development of world economy, the energy requirement and energy crisis willcoexist. Especially the requirement for oil well pipe will rise along with the increased demand forpetroleum and natural gas. Because of the specially operational environment, it requires oil wellpipe with high-quality, in which the production of special oil well pipe is blank in China. Therefore,it is imperative to develop special oil well pipe with high-quality and low-cost. In this paper, wetake the N80Grade Non-quenching and Non-tempering OCTG micro-alloyed non-quenched andnon-tempered steel as the investigated subject, which is with low manufacturing energyconsumption, low-cost and high-quality. We focused on the resistance of deformation and dynamicrecrystallization of N80Grade Non-quenching and Non-tempering OCTG, which has importantsignificance for the application of N80Grade Non-quenching and Non-tempering OCTG on the oilwell pipe.The paper has designed the60different deformation condition to simulate40Mn2V and36Mn2V steel rolling bearing and sizing process of deformation on the oil pipe production, studied36Mn2V and40Mn2V steel of the stress-strain curve and determined the yield strength and theimpact toughness of the samples after thermal simulation,with the microstructure observation,studied36Mn2V and40Mn2V steel phase change in heat treatment process.Establishment two kinds of steel quantitative relationship between sizing process parametersand the cooling speed, with the increase of temperature deformation, strength is continuously risingbut toughness is continuously reducing; With the speeding up of the cooling speed, strength iscontinuously rising, and toughness firstly slow increases, when the cooling speed over a certainvalue, toughness sharply reduce. provided a reliable data basis for the two kinds of controlledcooling technology research,and observed organization and micro-alloying carbonitrideprecipitation, of the different processing conditions,analysis the most basic principle toughness andthe strengthening of carbon-manganese contain vanadium steel, further improve the N80GradeNon-quenching oil well control rolling technology controlled cooling related theory basis.