Ordinary bar rolling + finishing integrated system based on microstructure isothermal transformation + low temperature accelerated cooling

Abstract

The invention discloses a common bar rolling + finishing integrated system based on structure isothermal transformation + low temperature accelerated cooling. The system involves a heating furnace, adephosphorization device, a rough rolling unit, a first flying shear, a medium rolling unit, a first cold control water tank+ air cooling return temperature cooling device, a second flying shear anda pre-finishing rolling unit which are sequentially arranged; and the system is characterized in that a gap water spraying cooling water tank, an isothermal transformation heat preservation furnace with a roller way, a Venturi tube water tank for accelerating low-temperature rod cooling through strong cold, an on-line sizing flying shear, a variable frequency roller way and an automatic collectingand bundling device are sequentially arranged behind the pre-finishing rolling unit. According to the system, a hot-rolled common bar production process based on the on-line optimal isothermal transformation from austenite to ferrite+pearlite is realized, a cooling bed cooling procedure with the longest consumed time in the bar rolling line production is avoided, the off-size amount is reduced tothe maximum, the sizing cutting is flexible, the yield is improved, the procedure process is remarkably compacted, and the comprehensive manufacturing cost is reduced.

Description

technical field [0001] The field that the invention relates to is an ordinary steel bar rolling production line. Background technique [0002] The hot-rolled bars in the rolled steel long products refer to the 400MPa, 500MPa, and 600MPa-level construction steel bars with a diameter of 6mm-50mm for ordinary bars, including ribbed steel bars and smooth round steel bars, which are widely used in civil engineering such as houses, bridges, and roads. Construction; in recent years, ordinary bars can generally reach about 200 million tons in China. In 2017, the national crude steel output was 831.7 million tons, accounting for about 25% of China's total steel production. In 2017, the global crude steel output was 1.6912 billion tons. The production capacity of 'hot-rolled bars' in the world's total steel production is about 400 million tons, accounting for about 23%. The quality requirements of ordinary rods are generally based on the tolerance of the geometric dimensions of the s...

AI Technical Summary

Problems solved by technology

Due to the limitation of the width of the cooling bed, it is necessary to double-cut the hot rolled piece, and the weight deviation of the cast slab, the uncertainty of cutting the head and tail during the forming process of the rolled material itself, and negative tolerance rolling will make the When the length is fixed, a certain short length is produced, which reduces the yield of finished products

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