Process for manufacturing low-silicon low-carbon deep punching/drawing steel

Abstract

The invention discloses a production method for low-silicon and low-carbon deep punching / drawing steel. Bottom-blowing argon is performed in the whole smelting process of a converter, a single slag / double slag technique is adopted to pour out the dephosphorized slag, high-basicity slag is produced in the later period, the dualistic basicity of final slag R is higher than 3.5, the terminal temperature of molten steel is 1620 DEG C to 1650 DEG C, and tapping (P) is less than 0.012 percent. The molten steel is refined by adopting low-silicon and low-carbon high-basicity reductive slag in a refining station of an LF furnace to manufacture reductive slag for desulphurization, and the (Al) in the molten steel is less than 0.005 percent. The molten steel refined by the LF furnace is vacuum-treated by an RH vacuum furnace, carbon and silicon in the molten steel are circularly removed, the molten steel is continuously cast into a casting blank through a CSP sheet bar conticaster, the casting blank is sent into CSP sheet bar heat continuous rolling mill and rolled into a coiled sheet after being heated in a roller hearth soaking furnace, a hot rolled coiled sheet is cold-rolled into the cold rolled coiled sheet through a cold tandem mill or a single mill after acid washing, and is leveled through a leveling machine after being annealed by a cover furnace, and a leveling divided coil is stretched and divided. The invention has the advantages that the production cost of the working procedure is saved, the consumption of the refractory consumption of the converter is reduced, the equipment investment is saved, the process of the production technique is steady and smooth, the n value of the cold rolled plate is bigger than 0.23, the r value thereof is bigger than 2.1, and both the deep punching performance and the extensibility are good.

Description

technical field [0001] The invention relates to a production method of steel, in particular to a method for producing low-silicon and low-carbon deep drawing / drawing steel by adopting CSP thin slab continuous casting and rolling process. Background technique [0002] Low-silicon and low-carbon steel is mainly used in structural parts with high deep drawing requirements, such as automotive structural parts with complex structural shapes (common car or truck cab structural parts, car or various types of passenger car structural parts and wheel hubs, etc.), Various other components with complex structures (such as compressor shells, steel cups, etc.), all these structural parts are generally delivered as flat parts after cold rolling and annealing, and a small amount of them are delivered in a hot rolled state. They have a wide range of applications and require It has very good deep drawing properties, such as high elongation, high n and r values. [0003] Low-silicon low-carb...

AI Technical Summary

Problems solved by technology

The production of low-silicon and low-carbon deep-drawing steel by these two processes has the advantages of low equipment investment, short production cycle and relatively low energy cost, but the obvious disadvantages are: ①The carbon in molten steel in the production process described in the second method The control accuracy of silicon and silicon is not high, and after the molten steel is refined by the LF furnace, the increase of carbon and silicon in the molten steel is obvious, the product composition fluctuates greatly, the hit rate is low, and the performance stability is poor; the production process described in the third method produces Low-silicon and low-carbon molten steel has poor castability during CSP thin slab continuous casting, causing nodules in the tundish nozzle and rising stopper rods, which affects the multi-furnace continuous casting of CSP thin slab continuous casting; ②The inclusion particles in molten steel are small and evenly distributed , it is difficult to accumulate and grow, and the floating is absorbed by the top slag. These small inclusions are formed and precipitated as second particles during the solidification of molten steel, the rolling of cast slabs and the cooling of steel plates (strips), which seriously affect the deep drawing of low-silicon and low-carbon steels. Performance and drawing performance, even restricting the large-scale production of high-grade steel (such as DC04, DC06, etc.)