HRB400 hot-rolled reinforcement bar production technology

Abstract

The invention discloses an HRB400 hot-rolled reinforcement bar production technology, which comprises the following steps: controlling the tapping temperature T and molten steel smelting (C) of a converter, pushing off the slag and tapping, wherein the discharged slag quantity does not exceeds 4kg / t, the tapping time is not less than 3min; conveying the molten steel, which is qualified after being smelted by the converter, into an argon blowing station, wherein the temperature of the molten steel entering the argon blowing station is less than or equal to 1610DEG C, and bottom argon blowing is adopted in the whole process of the molten steel; and carrying out titanium microalloying treatment on the molten steel in a refining station through a titanium nitride feed line technology, and controlling the content of titanium in the molten steel to be 300ppm below. The continuous casting pulling speed is controlled to be less than or equal to 3.5m / min, and the overheating temperature of the molten steel is less than or equal to 30DEG C so as to guarantee the quality of a steel blank. Steel rolling adopts the controlled rolling and controlled cooling technology, and the controlled cooling temperature is less than or equal to 750DEG C. According to the HRB400 hot-rolled reinforcement bar produced by adopting the technology, the strength of steel can be enhanced, the steel performance can be improved, and cost of per ton of steel can be lowered, and the HRB400 hot-rolled reinforcement bar production technology has excellent economic benefits and market prospects.

Description

[0001] technical field [0002] The invention relates to a steel bar production process, in particular to a hot-rolled steel bar production process with a yield strength not less than 400 MPa, which is widely used in industrial and civil buildings, adopts titanium micro-alloying treatment and controlled rolling and controlled cooling. [0003] Background technique [0004] Like niobium and vanadium alloys, titanium is a strong carbonitride forming element. By adding a small amount of titanium to steel, the strength and plasticity of steel can be significantly improved, and the comprehensive properties of steel can be improved. Titanium series alloys have the advantages of abundant resources and low prices. Therefore, the research on the application of titanium microalloying has important technical and economic significance. However, titanium has a strong affinity with nitrogen, sulfur, carbon, and oxygen in steel, which makes the recovery rate of titanium low and unstable d...

AI Technical Summary

Problems solved by technology

However, titanium has a strong affinity with nitrogen, sulfur, carbon, and oxygen in steel, which makes the recovery rate of titanium low and unstable during microalloying; when the dissolved oxygen in molten steel is high, severe oxidation of titanium can cause continuous casting intermediate Nodules in the nozzle, resulting in "dead flow" in continuous casting

These disadvantages of titanium limit its wide application as a microalloying element