eat treatment of oil casing strength
27 MNCRV is producing TP110T steel grade oil pipeline of new steel grade, the regular production TP110T steel grade oil pipeline steel is 29 crmo44 and 26 crmo4. Relative to the latter two, 27 MNCRV contains less Mo element, can greatly reduce the production cost. But the austenitizing quenching process of the normal production of 27 MNCRV obvious after high temperature tempering brittleness, the impact toughness is low and unstable.
Solve such problems are usually adopts two methods: one is to use rapid cooling method to avoid high temperature after tempering brittleness, obtain toughness. , the second is the temperature quenching method through the steel grade of incomplete austenitizing to effectively improve the harmful elements and impurities, improve the toughness. The first method, relatively strict with heat treatment equipment, you need to add additional cost.
310s stainless steel tube and medium temperature quenching heating temperature between 1000-1200 ℃. The selected temperature quenching heating temperature 780 ℃, quenching heating heat preservation time of 15 min. After quenching tempering temperature 630 ℃, tempering heat holding time 50 min. Because in the alpha + gamma two-phase area temperature quenching heating, in keep some dissolved ferrite quenching under state, while maintaining high strength, toughness was improved.
Low temperature quenching was lower than those of conventional temperature at the same time, reduced the quenching stress, thereby reducing the quenching deformation, so that to ensure the smooth operation of heat treatment production, and car silk for subsequent processing provides a good raw material.
At present this technology has been to used in tianjin steel pipe factory, quality assurance data show that after heat treatment of steel tube in 820-860 mpa, yield strength Rt0.6 Rm in 910-940 mpa tensile strength, impact toughness Akv between 65-85 - j, anti-damage performance of 100% qualified. Data show that the 904L stainless steel tube is quite high quality high grade oil casing, on the other hand also shows that the temperature quenching process is to avoid high temperature brittleness in the production of steel products of a kind of very good method.
Oil sets of 2205 stainless steel pipe is a kind of large diameter pipes, a fixed oil and gas oil casing or the role of the hole. Casing is inserted into the hole and fixed with cement, in order to prevent the borehole and separated strata borehole collapse, and ensure the drilling mud circulating flow, so that the drilling. Used in the process of oil exploration of the different types of casing, drilling, surface oil casing - protection to avoid polluted by shallow layer and shallow gas, - to support the wellhead equipment and keep the other layer weight of the casing. Technology of oil casing - dividing different levels of pressure, so that the normal circulation and protect the production casing drilling fluid lines. - in order to install the blowout drilling device, blowout preventer and tail pipe. Reservoir oil casing, oil and natural gas derived from the storage layer under the surface of the earth. - protects the drilling, drilling mud layer. Oil casing production, usually is 114.3 mm to 508 mm diameter.