HRB400E ribbed steel bar produced by replacing vanadium with chromium and method

Abstract

The invention provides an HRB400E ribbed steel bar produced by replacing vanadium with chromium and a method. The HRB400E ribbed steel bar produced by replacing the vanadium with the chromium comprises the following components of, in percentage by weight, 0.20% to 0.25% of C, 0.40% to 0.50% of Si, 1.30% to 1.45% of Mn, 0.010% to 0.020% of V, 0.30% to 0.40 of Cr, P less than or equal to 0.035%, S less than or equal to 0.035%, 0.008% to 0.013% of N, Ceq less than or equal to 0.52% and the balance Fe and residual elements. The method comprises the following steps of 65t converter smelting, 70t LF refining, 170 * 170 mm continuous casting, heating in a heating furnace, high-pressure water descaling, rolling through 18 continuous rolling units, cooling through a cooling bed, shearing, test, inspection, packaging and finished product delivery. According to the method involved in the invention, through the procedures of heating, rolling and cooling control, low-temperature heating and the like, the purpose of controlling the growth degree of austenite is achieved, and therefore austenite grains are refined, finally, a microstructure is controlled, the strength and plasticity of the steel bar are improved, the performance of steel is stabilized, and the purpose of rolling is to crush the austenite grains, so that the purpose of refining the grains is achieved.

Description

technical field [0001] The invention belongs to the technical field of metallurgy; in particular, it relates to a method for producing HRB400E ribbed steel bars by substituting chromium for vanadium. Background technique [0002] Rebar HRB400E is the most important steel used in construction. It is characterized by wide application and large annual consumption. Therefore, for manufacturers, a small reduction in production cost per ton of steel will generate huge benefits. At present, the production of rebar is mainly based on Nb, V, Ti micro-alloy strengthening process. However, due to the generally high price of Nb, V, Ti alloys, they account for a large proportion of the production cost of rebar. [0003] The production of rebar in the industry has been using the V alloying process for many years. In 2018, due to the large fluctuations in the price of V alloys, in order to reduce the impact of changes in the price of a single alloy on the production cost of rebar, after ex...

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Problems solved by technology

At present, the production of rebar is mainly based on Nb, V, Ti micro-alloy strengthening process. However, due to the generally high price of Nb, V, Ti alloys, they account for a large proportion of the production cost of rebar.

[0003] The production of rebar in the industry has been using the V alloying process for many years. In 2018, due to the large fluctuations in the price of V alloys, in order to reduce the impact of changes in the price of a single alloy on the production cost of rebar, after extensive research, many steel companies have successfully developed Nb and Nb~V composite strengthening production process, but it is of little significance to reduce the production cost of rebar under normal alloy market conditions

In recent years, in order to reduce the production cost of rebar, many iron and steel companies have carried out a lot of optimization on the composition of rebar. The main direction of optimization is to reduce the amount of Si, Mn and microalloy, but the effect is not obvious, and a series of problems are derived. , such as too low alloy content leads to low yield strength, high Si, high Mn and low microalloy lead to poor plasticity of rebar, etc.

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