A kind of high temperature resistant steel bar and production method

Abstract

A finish-rolled rebar with yield strength ≥ 960MPa, the components and wt% of which are: C 0.235-0.33%, Si 0.45-0.7%, Mn 2.2-2.4%, P≦0.025%, S≦0.025%, Cr 0.1- 0.3%, Ti 0.015~0.03%, V 0.04~0.06%, Als0.006~0.01%; bainite volume percentage not less than 85%; production steps: conventional smelting and billet casting; to room temperature; heating the slab; rough rolling; finish rolling; naturally air-cooled to room temperature and set aside. The present invention avoids the addition of cooling control equipment under the condition that the existing equipment does not need to be modified, and the hot-rolled state can meet the requirement that the yield strength of the steel bar can withstand a high temperature of 600°C for half an hour and the drop of yield strength is less than 1 / 3, thereby reducing the production cost.

Description

technical field [0001] The invention relates to a steel bar for construction and a production method thereof, in particular to a high-temperature-resistant steel bar and a production method thereof. Especially the requirement that the yield strength should not drop by more than 1 / 3 in half an hour at a high temperature of 600°C. Background technique [0002] With the development of domestic residential buildings to high-rise buildings, the floors are getting higher and higher, which makes the fire protection problem of steel bars more prominent. Under the high temperature of fire, the strength and rigidity of steel materials will be significantly reduced, and buildings may collapse and cause huge damage. disaster. Once a fire breaks out, the burning material will cause the surrounding temperature to quickly exceed 300°C, while the general temperature of concrete will not change much below 300°C, and the compressive strength will attenuate by half at 600°C, and only 10% of t...

AI Technical Summary

Problems solved by technology

Its shortcomings are: the yield strength at 600°C is about 50% of that at normal temperature, and the relative fire resistance is still insufficient, and the cooling speed needs to be controlled in sections during the rolling process, which requires high equipment requirements

The disadvantage is that the production process of the steel bar is complex, and the composition is more likely to cause large fluctuations in performance, and the steel bar does not have high temperature resistance

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