CN102899558A

CN102899558A - 500Mpa-grade building aseismic reinforcement

Info

Publication number: CN102899558A
Application number: CN2012104639848A
Authority: CN
Inventors: 姜德刚; 智建国; 白月琴
Original assignee: Baotou Iron and Steel Group Co Ltd
Current assignee: Baotou Iron and Steel Group Co Ltd; Inner Mongolia Baotou Steel Union Co Ltd
Priority date: 2012-11-16
Filing date: 2012-11-16
Publication date: 2013-01-30

Abstract

The invention relates to 500Mpa-grade building aseismic reinforcement. The 500Mpa-grade building aseismic reinforcement is characterized in that by adding V element and blowing nitrogen gas for increasing nitrogen in smelting, the final reinforcement material comprises the following components in percentage by weight: 0.20-0.25% of carbon, 0.40-0.60% of silicon, 1.40-1.60% of manganese, 0.07-0.12% of vanadium, less than or equal to 0.030% of phosphorus, less than or equal to 0.020% of sulfur, 0.0090-0.0130% of nitrogen and the balance of iron and unavoidable impurities. The 500Mpa-grade building aseismic reinforcement has the advantages that by adopting vanadium-nitrogen microalloying, the strength and toughness are improved simultaneously, and the matching between strength and toughness is much better; and the 500Mpa-grade building aseismic reinforcement meets the requirements for reinforcement performance of building aseismic design, improves the product quality and technical content, and is reasonable in component ratio, high in steel comprehensive performance, and good in welding performance with greatly improved safety in use; the steel consumption is relatively reduced due to the improvement of strength, so that the aseismic reinforcement is energy-saving, low-carbon and economical; and the aseismic reinforcement can be delivered in a hot rolling state so as to avoid the defect that the steel is high in strength but low in plasticity as more quenching martensite and dislocation exist inside the steel by adopting a waste heat quenching (water cooling) process for production.

Description

A kind of 500 Mpa level anti-seismic steel bar for building

Technical field

The present invention relates to a kind of 500 Mpa level anti-seismic steel bar for building, belong to the metal material field that metallurgical industry is produced.

Background technology

On March 1st, 2008, China starts to carry out GB1499.2-2007 hot rolled ribbed steel bar production standard, has increased the anti-seismic steel bar trade mark in new standard, and provides corresponding mechanical performance index.Domestic do not have the enterprise of professional production anti-seismic steel bar and the standard of relevant anti-seismic steel bar before this.

From reinforcing bar chemical composition and production technique aspect, analyze, domestic most reinforcing bar manufacturing enterprise has adopted immediate quenching (wearing water) explained hereafter Deformed Steel Bars.Adopt immediate quenching technique, steel inside exists more quenched martensite tissue and dislocation, causes that steel strength is high, plasticity is poor, is difficult to meet anti-seismic steel bar to aspect requirements such as yield tensile ratio and unit elongation.

What China's building bar generally adopted is II level HRB335 Ribbed Bar, and what developed country was generally used as the U.S., West Europe, Japan etc. is III level HRB400 Ribbed Bar, even the higher Ribbed Bar of rank.

Along with developing rapidly of building industry, the industrial structures such as Highrise buildings are more and more higher to the requirement of reinforcing bar supporting capacity, and anti-seismic problem has also caused common concern.Research and develop high-level anti-seismic steel bar, when making it not only meet the requirement of GB1499.2-2007 hot rolled ribbed steel bar national standard property indices, meet again the requirement of Seismic Design of Building to reinforcement property, will improve product technology content, further enlarge kind series and the supporting series of function that Baogang produces building iron, meet better user's requirement.

Summary of the invention

The purpose of this invention is to provide a kind ofly by Composition Design and optimization, can improve performance and the rank of reinforcing bar, meet the 500 Mpa level anti-seismic steel bar for building that anti-seismic performance requires.

Anti-seismic steel bar of the present invention when smelting by adding V element and nitrogen blowing nitrogen pick-up, the one-tenth of final reinforcing bar material is grouped into percentage by weight: carbon 0.20～0.25%, silicon 0.40～0.60%, manganese 1.40～1.60%, vanadium 0.07～0.12%, phosphorus is less than or equal to 0.030%, and sulphur is less than or equal to 0.020%, nitrogen 0.0090～0.0130% (i.e. 90～130ppm), all the other are iron and inevitable impurity.

Describedly when smelting, adding V element, is that the form with V alloy adds;

Described V alloy is VN alloy, MnSiN alloy or FeV alloy, and wherein: the VN alloy is VN16 or VN12 alloy;

Described anti-seismic steel bar is the hot rolled ribbed steel bar that the nominal diameter scope is 6mm～50mm;

The mechanical property of described anti-seismic steel bar for building is: yield strength>=500MPa, tensile strength>=630MPa, unit elongation>=15%, actual measurement tensile strength and the ratio R that surveys yield strength ^. _m／R ^。 _eL>=1.25, the ratio R of actual measurement yield strength and the yield strength eigenwert of standard code ^. _eL/ R _eL≤ 1.30, maximum, force percentage of total elongation Agt>=9%.

Advantage of the present invention is: adopt v n micro alloying, improve intensity and toughness simultaneously, combination of strength and toughness is better; Meet the requirement of Seismic Design of Building to reinforcement property, improved quality and the technology content of product; Composition proportion is reasonable, and the steel over-all properties is high, good welding performance, and the security of use greatly improves; Intensity improves and has relatively reduced rolled steel dosage, belongs to energy-saving low-carbon economy; As rolled delivery, avoided owing to adopting immediate quenching (wearing water) explained hereafter, and steel inside exists more quenched martensite tissue and dislocation, makes the defect that steel strength is high, plasticity is poor.

Embodiment

Through specially grinding of scientific and technical personnel, by designing and draw through optimization the composition of reinforcing bar material, scope is as shown in table 1, this steel grade called after HRB500E.

Table 1 HRB500E anti-seismic steel bar ingredient w %

Steel grade

C

Si

Mn

V

P

S

[N]ppm

HRB500E

0.20～0.25

0.40～0.60

1.40～1.60

0.07～0.12

≤0.030

≤0.020

90～130

Technical process is: 100t converter smelting → LF stove refining → continuous casting (casting blank specification is 152mm * 152mm) → rolling.

THE INDUSTRIAL TRIAL 2 stove steel, concrete process parameter control is as follows:

1) converter production

The carbon content of converter terminal molten steel, phosphorus content and tapping temperature are as shown in table 2.

Composition and the temperature of table 2 HRB500E tapping

Test number	Tapping temperature, ℃	The tapping carbon content, w%	The tapping phosphorus content, w%
				1 ^#	1636	0.03	0.019
2 ^#	1630	0.04	0.017

2) the LF stove is produced

Table 3 HRB500E refining station off normal composition and temperature

Test number	C，w%	Si，w%	Mn，w%	V，w%	P，w%	S，w%	Temperature, ℃
								1 ^#	0.23	0.50	1.49	0.09	0.026	0.009	1566
2 ^#	0.24	0.54	1.53	0.09	0.023	0.012	1572

[0025]3) continuous casting production

Table 4 HRB500E continuous casting superheating temperature and pulling rate are controlled

Test number	Superheating temperature, ℃	Pulling rate, m/min
			1 ^#	30	2.32
2 ^#	27	2.24

So far completed the bloom production of steel of the present invention, below, for adopting described continuous casting steel billet to produce the technique of reinforcing bar, technical process is: steel billet → process furnace heating → rolling.

4) steel rolling production

Steel billet is greater than 2 hours heat-up time in process furnace, and the steel billet start rolling temperature is at 1150 ℃.

5) service check

The mechanical property requirements of table 5 HRB500E reinforcing bar

The mechanical properties test result of table 6 HRB500E reinforcing bar

From table 6,2 stove steel mechanical properties of trial production have reached 500 Mpa levels, belong to the anti-seismic steel bar for building of highest level, meet standard-required fully, so the steel grades design is rational.

Claims

1. a Mpa level anti-seismic steel bar for building, it is characterized in that: when smelting by adding V element and nitrogen blowing nitrogen pick-up, the one-tenth of final reinforcing bar material is grouped into percentage by weight: carbon 0.20～0.25%, silicon 0.40～0.60%, manganese 1.40～1.60%, vanadium 0.07～0.12%, phosphorus is less than or equal to 0.030%, sulphur is less than or equal to 0.020%, nitrogen 0.0090～0.0130%, and all the other are iron and inevitable impurity.

2. 500 Mpa level according to claim 1 anti-seismic steel bar for building is characterized in that: describedly when smelting, adding V element, is that the form with V alloy adds.

3. 500 Mpa level according to claim 2 anti-seismic steel bar for building, it is characterized in that: described V alloy is VN alloy, MnSiN alloy or FeV alloy, wherein: the VN alloy is VN16 or VN12 alloy.

4. 500 Mpa level according to claim 3 anti-seismic steel bar for building, it is characterized in that: described anti-seismic steel bar is the hot rolled ribbed steel bar that the nominal diameter scope is 6mm～50mm.

5. according to claim 1,2,3 or 4 described 500 Mpa level anti-seismic steel bar for building, it is characterized in that: the mechanical property of described anti-seismic steel bar for building is: yield strength>=500MPa, tensile strength>=630MPa, unit elongation>=15%, actual measurement tensile strength and the ratio R that surveys yield strength ^. _m／R ^。 _eL>=1.25, the ratio R of actual measurement yield strength and the yield strength eigenwert of standard code ^. _eL/ R _eL≤ 1.30, maximum, force percentage of total elongation Agt>=9%.