Production method of HRB500E fine-grain high-strength anti-seismic anti-corrosion reinforcing steel bar

Abstract

The invention discloses a production method of an HRB500E fine-grain high-strength anti-seismic anti-corrosion reinforcing steel bar. The method comprises the following steps of converter smelting, deoxidizing alloying, LF refining, square billet continuous casting, steel billet heating, rolling and cooling in sequence to produce the fine-grain high-strength anti-seismic anti-corrosion reinforcing steel bar which is stable in quality, excellent in plasticity and toughness, greater than 1.27 in yield ratio and 11.5-12.0 in ferrite grain size. The Cr, V and Ni composite microalloying process is adopted, converter smelting and LF external refining are matched, the rolling technology for controlling the inner diameter and negative deviation of the reinforcing steel bar at low temperature is adopted, finishing is combined, formation and precipitation of a fine and dispersed microalloy carbon (nitrogen) compound second phase are promoted, the steel strength is improved, meanwhile, the plasticity and toughness are remarkably improved, mechanical connection is further facilitated, reasonable matching of high strength, obdurability, low strain timeliness, shock resistance and corrosion resistance of the reinforcing steel bar is achieved, and the method can be applied to the fields of main stream hydropower station flood discharge tunnel engineering, expressway road and bridge engineering and the like.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and specifically relates to a production method capable of producing HRB500E fine-grained high-strength anti-seismic and anti-corrosion steel bars with high strength, strong toughness, low strain timeliness, shock resistance and corrosion resistance. Background technique [0002] With the development of basic projects such as energy and transportation, the construction of hydropower stations, high-speed railways, and expressways is gradually advancing to areas with harsh environments such as plateaus and mountainous areas. The construction of dams and high bridges with high difficulty and requirements is gradually increasing. The requirements for building materials such as steel bars used are becoming more and more stringent. For example, the hub of a hydropower station is mainly composed of a dam, a flood discharge system, a water diversion power plant, etc., while a general fl...

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Problems solved by technology

However, the production cost of the V and Nb microalloyed hot rolling process is relatively high and the rolling temperature must be above 1100°C. However, the production by the intensive controlled cooling process after rolling not only has tempered martensite in the metallographic structure, but also leads to yielding. The strength is lower than the HRB500E standard requirement, and the rapid cooling after rolling will destroy the dense oxide scale structure formed by hot rolling, resulting in short-term corrosion of steel bars; although the production cost of the weakly controlled cooling process after rolling is low, the temperature of the cooling bed on the rolled piece The fluctuation is large and the process is difficult to operate, which makes the performance of the steel rod cleaner more unstable, and it is difficult to meet the aforementioned high-performance construction requirements

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