The Tempering Process The Crude Oil Storage Tanks Steel Organizational Structure And Performance

Large-oil-storage-tank plate is used to make plate into Large-oil-storage-tank. With the devolpment of country ecnomic the wastage of petroleum increase year after year. Import base oil also increase by degrees in phase. Nowdays, World condition is turbulence unease, Petroleum price changes roll no calm, oil repertory is imperative under the situation. Due to empolder history of Large-oil-storage-tank plate is shorter, mircrostrcture and property require rigor even effect factor is legion, component and produce technics cortrols fine , manufacure technics is more difficult. Investigation of our country is leg. Anciently, The high intension plate used by Large-oil-storage-tank plate depended on import entirely. Oil repertory relates to the safe of politics and economy and technology, national enterprise wouldn't export such as this kind of plate to our country. Formed our passivity phase. Thus, In the thesis, The influencing of microstructure and properties by tempering technics have been studied in order to establish a heat treatment craftwork adapt to practical produce condition. To offer the theory thereunder exploitation of test plate.The dynamic CCT curve of the test plate is measured by means of thermal expansion equipment firstly. The law that tempering technology influence the microstructure and performance of the test steel have been studied by means of tempering temperature and hold time test, metalloscope, TEM etc. According to the results, an optimum heat treatment technology of test plate has been put forward, which lay a solid foundation for empoldering the test plate.The results show that:(1) Microstructure of the test plate is Ferrite + Pearlite by hot-rolled and controlled cooling. And temper Sorbite after high temperature tempering.(2) Increase with cooling rate microstructure turnes Ferrite + Pearlite into Ferrite+Bainite during the continuous cooling. at the same time ,grain becomes smaller and uniform.(3) Test plate purity is well, sulphide inclusion doesn't be found.And there is less oxide inclusion in it by iron pretreatment, LF and VD.