Niobium microalloyed HRB400E hot-rolled ribbed steel bar and efficient manufacturing method thereof

A hot-rolled ribbed steel bar and micro-alloying technology, which is applied in the field of iron and steel metallurgy, can solve the problems of low production efficiency and achieve the effect of low bainite content, high efficiency and stable production

Pending Publication Date: 2020-02-04
SGIS SONGSHAN CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The above niobium microalloyed HRB400E production method

Method used

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  • Niobium microalloyed HRB400E hot-rolled ribbed steel bar and efficient manufacturing method thereof
  • Niobium microalloyed HRB400E hot-rolled ribbed steel bar and efficient manufacturing method thereof
  • Niobium microalloyed HRB400E hot-rolled ribbed steel bar and efficient manufacturing method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1-9

[0094] A high-efficiency manufacturing method for niobium microalloyed HRB400E hot-rolled ribbed steel bar is provided, and the specific production process is as follows:

[0095] 130t converter smelting—argon station bottom blowing treatment or LF furnace refining—8 machines and 8 streams 170×170mm square billet continuous casting—slab heating—continuous bar mill rolling—upper cooling bed cooling—shearing—cutting to length—stretching bundle.

[0096] The steel billets are respectively rolled in three continuous bar mill production lines into steel bars with a diameter of 12-25mm.

[0097] Smelted in a 130t converter, nitrogen is blown at the bottom during the blowing process, manganese-silicon alloy, ferrosilicon, and ferroniobium are added in the tapping process of the converter for alloying, after tapping, the bottom blowing gas of the ladle is uniform, the composition and temperature of molten steel are fine-tuned, or LF furnace is used for refining treatment.

[0098] Th...

experiment example 1

[0111] The mechanical properties of steel bars are tested by the GB / 1499.2-2018 standard.

[0112] The results are shown in the table below:

[0113] Table 3 Mechanical properties and bainite content of steel bars in Examples 1-9 and Comparative Examples 1-6

[0114]

[0115] Combined with the above table data, Examples 1-9 show that when the Nb in the steel is 0.018%-0.025%, and the Mn is 1.10%-1.25%, and the content is low, a high heating and rolling temperature is used, although different production lines There is a difference of 20-40°C in the heating and rolling temperature, and the bainite content in the reinforced steel produced by different production lines is in the lower range of 4.5-7.0%, and there is no obvious difference.

[0116] Comparative examples 1 and 2 show that when the Nb in the steel is 0.025% to 0.035%, and the Mn is 1.45% to 1.55%, when the content is high, the bainite content in the steel is as high as 50 to 58.0% with high heating and rolling tem...

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Abstract

The invention relates to the field of ferrous metallurgy, in particular to a niobium microalloyed HRB400E hot-rolled ribbed steel bar and an efficient manufacturing method thereof. Steel is prepared from the chemical compositions including, by mass, 0.21%-0.25% of C, 0.45%-0.65% of Si, 1.00%-1.25% of Mn, 0.02%-0.025% of Nb, less than or equal to 0.045% of P, less than or equal to 0.045% of S, 0.004%-0.01% of N and the balance Fe and inevitable impurities. When steel rolling is performed, the heating temperature of a billet is 1190-1230 DEG C. When the method is used for steel rolling, the heating temperature of the billet is high, so that the production efficiency is effectively increased. Due to the low Nb and Mn content of the steel, it is guaranteed that the niobium microalloyed HRB400Ehot-rolled ribbed steel bar has a significant yield point.

Description

technical field [0001] The present application relates to the field of iron and steel metallurgy, in particular, to a niobium microalloyed HRB400E hot-rolled ribbed steel bar and a high-efficiency manufacturing method thereof. Background technique [0002] The hot-rolled ribbed steel bar mainly HRB400E is a steel product with wide application and large output. [0003] The manufacture of HRB400E steel bars generally requires a microalloying process, and the HRB400E steel bars manufactured by the single niobium microalloying process often have the problem of no obvious yield point. [0004] In order to solve the problem of no yield point of steel bars, the current common practice is to reduce the heating, rolling temperature and upper cooling bed temperature in the steel rolling process. Although it can solve the problem of no obvious yield point of niobium-added HRB400E steel bars, it can reduce the rolling temperature. When the rolling temperature is high, the deformation ...

Claims

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Application Information

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IPC IPC(8): C22C38/02C22C38/04C22C38/12C21D8/08
CPCC21D8/065C21D8/08C22C38/001C22C38/02C22C38/04C22C38/12
Inventor 张志明宋建勤寻忠忠邱卫峰冯宝王才仁郑家贤周汉全罗斌谢杰智杨其敏
Owner SGIS SONGSHAN CO LTD
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