Strategic petroleum reserve tank steel plate based on oxide metallurgy and manufacturing method thereof

Abstract

The invention discloses a strategic petroleum reserve tank steel plate based on oxide metallurgy and a manufacturing method of the strategic petroleum reserve tank steel plate. The yield strength of the steel plate is large than or equal to 490 MPa, the tensile strength is 610-730 MPa, and the yield ratio is smaller than or equal to 0.90. The manufacturing method comprises the steps that a continuous casting billet is manufactured, heated for heat preservation, roughly rolled, finely rolled, directly quenched and cooled at the speed being larger than or equal to 50 DEG C / s, heated, tempered and subjected to air cooling. The steel plate is also applicable to manufacturing of large strategic petroleum reserve tanks with the volume being 100000 m<3>, 150000 m<3> or more; when the steel plateis subjected to large heat input welding when heat input is large than 200 KJ / cm, after welding, the welding heat affected zone -20 DEG C impact energy is not lower than 80 J; a two-face two-pass X-type welding way which sets limitations for 25-60 mm steel plates in existing petroleum reserve tank construction is expected to be changed into single-face single-pass V-type welding, welding labor hours can be reduced by one half almost, the petroleum reserve tank construction speed is remarkably improved, the strategic petroleum reserve tank building cost is greatly reduced, and the application and popularization prospect is quite good.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a strategic oil reserve tank steel plate based on oxide metallurgy and a manufacturing method thereof. Background technique [0002] Strategic oil reserves are crucial to ensuring national energy security. The first phase of my country's oil reserve construction has been completed in the four coastal cities of Zhenhai, Zhoushan, Dalian, and Huangdao at the end of 2008, initially forming a net import volume of about 30 days. The size of crude oil reserves. [0003] Usually 1 set 100,000m 3 A total of 1948.5 tons of steel are required for oil storage tanks, and the cost of the tank body plus the value of crude oil is as high as hundreds of millions of yuan. If an accident occurs, the consequences of economic losses and environmental pollution will be serious; therefore, the comprehensive performance requirements for oil storage tank steel plates It is high-strength,...

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Problems solved by technology

[0004] From the second phase of the construction project of 100,000 cubic meters of oil storage tanks in China, domestic steel plates have been used successively. The invention patents such as application number 200810119502.0, application number 200810224734.2 and application number 201410791633.9 are the domestic oil storage tank steel plate production that was formed at that time and has been used until now. Mainstream technology, its main feature is that it adopts off-line quenching + tempering or TMCP + tempering process to produce steel plates with a thickness of 12-33mm, a yield strength of 490MPa, and a tensile strength of 610-730MPa. In terms of grain coarsening, the traditional fine TiN particle pinning austenite growth mechanism is adopted. With this mechanism, under the condition of reasonable and stable production process, although the steel plate can withstand a large heat input of 100kJ / cm Welding requirements, however, since TiN will start to dissolve when the temperature reaches 1350°C, when the temperature of the welding heat-affected zone reaches or exceeds 1400°C, the volume fraction of TiN dissolved will even reach 88%, resulting in the loss of most of the TiN particles Inhibiting the growth of austenite grains, if considering the process or chemical composition fluctuation factors that may occur during the actual operation of the steel plate production plant, it is difficult to ensure that each steel plate actually used in the oil storage tank construction base can meet the thermal requirements. The input reaches the HAZ quality and performance requirements under the welding condition of 100kJ / cm; therefore, the current status quo is that the oil storage tank construction unit has to strictly limit the heat input to weld under the condition of far below 100kJ / cm, resulting in a thickness greater than 25mm The longitudinal seam of the steel plate can only be made with X-shaped grooves, and the front and back sides are welded once respectively, but the single-sided single-pass welding of V-shaped grooves cannot be realized, which virtually increases the welding construction cost of the oil reserve depot by nearly 1. In addition, the maximum thickness of steel plates used for oil storage tanks of 100,000 cubic meters is only 33mm, while the maximum thickness of steel plates used for oil storage tanks of 150,000 cubic meters and above will reach 60mm. The input welding performance must also be enhanced by nearly double. Therefore, in order to improve the quality and performance level of domestic oil storage tank steel plates and meet the construction needs of large oil storage tanks of 150,000 cubic meters and above, it is urgent to solve the insurmountable problems of existing technologies. Research Development of thick-gauge steel plates for domestic oil storage tanks capable of withstanding welding heat input greater than 200kJ / cm and its production method

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