Method of manufacturing high-strength hot rolled ribbed steel bar

A technology of hot-rolled ribbed steel bar and ribbed steel bar, which is applied in metal rolling, temperature control, metal rolling and other directions, can solve the problems of increased consumption of vanadium-nitrogen alloy, insufficient production power, and inability to scale output, etc. The effect of reducing the amount of microalloys added, stable mechanical properties of the process, and economical society

Active Publication Date: 2009-05-13
WUKUN STEEL
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the main problems of this process are: 1. In recent years, the country has vigorously promoted the use of HRB400 and above steel bars, gradually replacing the currently widely used HRB335 hot-rolled ribbed steel bars
This move has led to a sharp increase in the price of micro-alloys such as vanadium alloys and ferroniobium, which are necessary for the production of HRB500 grade steel bars according to conventional processes. The production cost is too high, which completely squeezes the profit margin of the enterprise, which is not conducive to improving the competitiveness of the enterprise.
2. The cost of producing HRB500 high-strength steel bars by the conventional microalloying process is relatively high, the production motivation of enterprises is insufficient, and the output cannot be scaled up, so it is not conducive to the promotion and application of HRB500 steel bars, and is contrary to the purpose of the central government to build a harmonious society
3. The reserves of ferroniobium and vanadium-nitrogen alloy mineral resources, which are important national strategic reserves, are very limited. The conventional production process has greatly increased the consumption of micro-alloyed ferroniobium and vanadium-nitrogen alloys, and the reserves of ferroniobium and vanadium-nitrogen alloy mineral resources have declined sharply , not conducive to the protection of rare mineral resources and the ecological environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] A. Steel slabs with the following chemical composition: C 0.18%, Si 0.46%, Mn 1.22%, V 0.033%, S 0.021%, P 0.027%, and the rest is Fe and unavoidable impurities;

[0023] B. Put the billet above into a heating furnace with a furnace temperature of 1160°C. When heated to a billet temperature of 1010°C, send it to a rolling mill for rolling. During rolling, rough rolling is carried out for 65 seconds at a rolling speed of 1m / s. Afterwards, under the rolling condition of 4m / s, the middle rolling was carried out for 60 seconds at a speed, and at last, the finishing rolling was carried out for 75 seconds under the rolling condition of 16m / s;

[0024] C, the finishing rolled steel product of B step is 360m in cooling water 3 / h, under the condition of cooling water pressure of 1.4MPa, rapid cooling for 3 seconds to obtain steel with a temperature of 880°C, and then placed in the air to naturally cool to 250°C, that is, to obtain HRB500 fine-grained high-strength steel bars wi...

Embodiment 2

[0026] A. Steel slabs with the following chemical compositions: C 0.24%, Si 0.56%, Mn 1.51%, V 0.031%, S 0.016%, P 0.023%, and the rest are Fe and unavoidable impurities;

[0027] B. Send the above billet into a heating furnace with a furnace temperature of 1200°C. When the billet is heated to a temperature of 1050°C, it is sent to a rolling mill for rolling. During rolling, rough rolling is carried out for 60 seconds at a rolling speed of 1m / s. , followed by rolling for 60 seconds at a speed of 4m / s, and finishing rolling for 72 seconds at a speed of 7.8m / s;

[0028] C, the finish-rolled steel product of B step is 370m in cooling water total water 3 / h, under the condition of cooling water pressure of 1.9MPa, rapid cooling for 2 seconds to obtain steel with a temperature of 870°C, which is naturally air-cooled to 270°C on the upper cooling bed, collected and bundled, and the HRB500 fine-grained steel with a specification of Φ32mm is obtained. Strength steel bars.

[0029] T...

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Abstract

The invention provides a method for manufacturing high-strength hot rolled ribbed steel bars, which comprises steps of feeding steel billets into a heating furnace at a furnace temperature of 1,100-1,200 DEG C, heating the steel billets to 1,000-1,100 DEG C, rough rolling at a rolling speed of 0.8-1.4 m / s for 50-88 s, rolling at a rolling speed of 3.4-5.0 m / s for 48-90 s, and fine rolling at a rolling speed of 6.8-17 m / s for 52-88 s; rapidly cooling under conditions of a cooling water flow rate of 240-410 m3 / h under a cooling water pressure of 1.0-2.0 Mpa for 0.6-2.4 s to obtain rolled steel bars with temperature of 810-900 DEG C, and naturally air-cooling to 220-300 DEG C to obtain fine-grain high-strength ribbed steel bars. The invention can remarkably reduce consumption of micro-alloy element V in steel, thereby facilitating protection of rare mineral resources, further reducing cost of hot rolled ribbed steel bars per ton by 300 RMB / ton, having significant economic benefit, improving the strength of steel bars at the same time, and solving the problems in welding and aging of fine-grain high-strength steel bars.

Description

Technical field: [0001] The invention relates to a method for preparing a hot-rolled ribbed steel bar, in particular to a method for preparing a high-strength hot-rolled ribbed steel bar HRB500, and belongs to the technical field of metal material processing and forming. Background technique [0002] my country's annual construction projects use more than 600 million cubic meters of concrete and consume nearly 25 million tons of steel. Except for a small amount of prestressed steel wire strands, most of them are steel bars used in concrete. There are three grades of hot-rolled ribbed steel bars in my country: HRB335, HRB400 and HRB500. H, R, and B represent hot rolled (Hot rolled), ribbed (Ribbled), and steel bars (bars), respectively, and 335, 400, and 500 represent steel bars, respectively. The minimum yield strength, in MPa. The higher the grade of the steel bar, the better the quality, and the better the strength, toughness and elongation performance, so it is more bene...

Claims

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Application Information

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IPC IPC(8): B21B1/16B21B37/00B21B37/74C21D9/70C21D9/52C21D11/00C22C38/12C22C38/04
Inventor 苏鹤洲和智君陈伟庾郁梅张卫强李金柱詹道平
Owner WUKUN STEEL
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