CN111020365A

CN111020365A - Weather-resistant steel, steel plate manufacturing method thereof and angle steel manufacturing method

Info

Publication number: CN111020365A
Application number: CN201811212263.3A
Authority: CN
Inventors: 黄耀; 韩军科; 刘蔚宁; 李峰; 吴静; 汪长智; 王旭明; 王景朝; 胡晓光; 王飞; 罗义华; 汪和龙; 王自成; 平朗; 吴赛; 黄国; 杨风利; 张宏杰
Original assignee: ANHUI HONGYUAN IRON TOWER CO LTD; State Grid Corp of China SGCC; China Electric Power Research Institute Co Ltd CEPRI; State Grid Anhui Electric Power Co Ltd
Current assignee: ANHUI HONGYUAN IRON TOWER CO LTD; State Grid Corp of China SGCC; China Electric Power Research Institute Co Ltd CEPRI; State Grid Anhui Electric Power Co Ltd
Priority date: 2018-10-09
Filing date: 2018-10-09
Publication date: 2020-04-17

Abstract

The invention provides a weathering steel, a method for manufacturing a steel plate and a method for manufacturing an angle steel. The weathering steel includes the following components in terms of mass fraction: C: 0.05-0.20%, Si: 0.20-0.40%, Mn: 0.80 ～1.60%, Cu: 0.50～0.80%, Cr: 0.05～0.85%, Nb: 0.01～0.1%, Ni: 0.15～0.70%, Ti≤0.12%, Mo≤0.30%, V≤0.12%, Zr≤0.15 %, P≤0.03%, S≤0.006%, Al: 0.01-0.05%, N: 0.002-0.005%, O≤0.002%, and the rest are Fe and inevitable impurities. Weathering steel has excellent corrosion resistance, excellent mechanical properties such as tensile, impact and bending. After thinning treatment, it can still meet the mechanical requirements of power transmission and transformation tower applications, and reduce the cost of raw materials. At the same time, weathering steel power transmission towers have no hot-dip galvanizing. The processing cost can also reduce the post-corrosion maintenance cost, which helps to reduce the project cost; on the other hand, there is no hot-dip galvanizing process, which reduces the pollution to the atmosphere and soil environment; it has obvious economic benefits and environmental protection effects, and the mechanical and The anti-corrosion performance is improved, which greatly improves its service life.

Description

Weather-resistant steel, steel plate manufacturing method thereof and angle steel manufacturing method

Technical Field

The invention relates to raw materials used in power transmission and transformation engineering and a forming process thereof, in particular to weathering resistant steel, a manufacturing method of a steel plate thereof and a manufacturing method of angle steel.

Background

With the development of technological progress, more and more materials and products are unprecedentedly developed. Metallic materials are used in a wide variety of applications both in production and in life, and have been irreplaceable in many fields. The demand for metals in power transmission and transformation engineering is continuously increasing, and particularly, the non-metallic materials of the construction materials of power transmission towers are the morsels. Over time, however, the metallic materials in towers have also been exposed to a number of problems and drawbacks.

At present, many power transmission towers are easy to rust and corrode, the strength requirement can be met only when the power transmission towers reach a certain thickness, the processing process is complex and time-consuming, complex acid pickling, hot galvanizing manufacturing and other processes are needed, certain pollution is caused to the atmosphere and the soil environment, and the maintenance process is frequent and complex.

Therefore, the weathering steel, the steel plate manufacturing method thereof and the angle steel manufacturing method are needed to meet the defects of the prior art.

Disclosure of Invention

Aiming at the defects of the prior art, the applicant designs weather-resistant steel, a steel plate manufacturing method and an angle steel manufacturing method; the weathering steel has excellent corrosion resistance and excellent mechanical properties such as stretching, impact, bending and the like, can still meet the mechanical requirements of the power transmission and transformation iron tower application after thinning treatment, reduces the cost of raw materials, has no hot galvanizing processing cost for the weathering steel power transmission iron tower, can also reduce the later-stage corrosion prevention maintenance cost, and is beneficial to reducing the construction cost; on the other hand, the hot dip galvanizing process is not needed, so that the pollution to the atmosphere and the soil environment is reduced; has obvious economic benefit and environmental protection effect, improves the mechanical and anti-corrosion performance and greatly prolongs the service life.

The purpose of the invention is realized by the following technical scheme:

the invention provides weathering steel which comprises the following components in parts by mass:

c: 0.05 to 0.20%, Si: 0.20 to 0.40%, Mn: 0.80-1.60%, Cu: 0.50-0.80%, Cr: 0.05 to 0.85%, Nb: 0.01 to 0.1%, Ni: 0.15-0.70%, Ti is less than or equal to 0.12%, Mo is less than or equal to 0.30%, V is less than or equal to 0.12%, Zr is less than or equal to 0.15%, P is less than or equal to 0.03%, S is less than or equal to 0.006%, Al: 0.01-0.05%, N: 0.002-0.005%, less than or equal to 0.002% of O, and the balance of Fe and inevitable impurities.

Preferably, the weathering steel comprises the following components in parts by mass:

C：0.06～0.20％、Si：0.25～0.40％、Mn：0.90～1.60％、Cu：0.50～0.70％、Cr：0.05～0.80％、Nb：0.03～0.1％。

C：0.06～0.15％、Si：0.25～0.35％、Mn：0.90～1.50％、Cu：0.60～0.70％、Cr：0.25～0.80％、Nb：0.03～0.08％。

C：0.10％、Si：0.20％、Mn：1.20％、Cu：0.65％、Cr：0.50％、Nb：0.05％。

Ni：0.15～0.50％、Ti：0.05～0.12％、Mo：0.10～0.30％、V：0.05～0.12％、Zr：0.05～0.15％、P：0.01～0.03％、S：0.002～0.006％、Al：0.01～0.05％、N：0.002～0.005％、O：0.001～0.002％。

Ni：0.30～0.50％、Ti：0.05～0.10％、Mo：0.10～0.20％、V：0.05～0.08％、Zr：0.05～0.10％、P：0.01～0.02％、S：0.002～0.005％、Al：0.01～0.04％、N：0.002～0.003％、O：0.0015～0.002％。

Ni：0.40％、Ti：0.08％、Mo：0.15％、V：0.06％、Zr：0.08％、P：0.015％、S：0.004％、Al：0.03％、N：0.0025％、O：0.0018％。

based on the same inventive concept, the invention also provides a steel plate forming method of the weathering steel, which comprises the following steps:

(1) smelting the weathering steel molten steel in a converter or an electric furnace, and then sequentially carrying out LF refining, RH vacuum treatment and continuous casting;

(2) keeping the temperature of the continuously cast steel billet at 1200-1300 ℃ according to the time requirement of 1.5min/mm, roughly rolling the steel billet to 9-15 times the thickness of a finished product, and finish rolling; the inlet temperature of the finish rolling is 980-620 ℃, and the finish rolling temperature is 890-900 ℃;

(3) and carrying out laminar flow cooling on the finish-rolled steel plate according to a front-section cooling mode, coiling the steel plate at 580-620 ℃ to form a coil, and carrying out heat preservation for 1h and then air cooling.

Based on the same inventive concept, the invention also provides an angle steel forming method of the weathering steel, which comprises the following steps:

(2) and (3) preserving the heat of the continuously cast steel billet at 1200-1300 ℃ according to the time requirement of 1.5min/mm, and then sequentially carrying out rough rolling and section rolling.

Preferably, the section rolling is carried out by 4-pass rolling by 4 butterfly hole type rolling mills with vertical rolling, and the 4 rolling mills are BD1, BD2, F1 and F2 respectively;

the BD2 and the BD1 adopt a shared guide;

the inlet of the F2 adopts a rolling guide, and the rolling guide comprises an upper guide wheel, a lower guide wheel and three guide wheels.

Compared with the closest prior art, the invention has the beneficial effects that:

1. according to the technical scheme provided by the invention, the weathering steel has excellent corrosion resistance and excellent mechanical properties such as stretching, impact and bending, can still meet the mechanical requirements of power transmission and transformation iron towers after thinning treatment, and reduces the cost of raw materials; on the other hand, the hot dip galvanizing process is not needed, so that the pollution to the atmosphere and the soil environment is reduced; has obvious economic benefit and environmental protection effect, improves the mechanical and anti-corrosion performance and greatly prolongs the service life.

Drawings

The invention will be further described with reference to the accompanying drawings in which:

FIG. 1: a circuit diagram of an electrochemical test provided by the present invention;

FIG. 2: the electrochemical parameter R provided by the invention_tAnd R_rustElectrochemical parameters were plotted as a function of cycle time.

Detailed Description

The technical solutions in the embodiments of the present application are clearly and completely described below with reference to the drawings in the embodiments of the present application.

Example 1

This example provides two weathering steels, Q345 weathering angle and Q420 weathering angle, respectively, comprising Fe and unavoidable impurities, the remaining ingredients being as shown in table 1.

TABLE 1 chemical composition table (wt%) of two kinds of weather-resistant steel angle iron

The tensile, impact and bending mechanical properties of the two weather-resistant angle steels provided in this example were respectively tested, and the results are shown in table 2.

Table 2: two kinds of weathering steel mechanical property test result table

From the table, the tensile, impact and bending mechanical properties of the Q345 weather-resistant angle steel and the Q420 weather-resistant angle steel are excellent, and are obviously improved compared with the existing angle steel.

The Q420 weathering angle steel and the Q420 plain carbon steel provided in this example were subjected to an indoor accelerated corrosion test, and then electrochemical experiments were performed using the electrochemical test circuit diagram shown in fig. 1, respectively, to test an electrochemical parameter R_tAnd R_rustCarrying out a test and obtaining an electrochemical parameter R according to the test_tAnd R_rustPlotting the electrochemical parameters as a function of cycle period, as shown in FIG. 2;

as can be seen from the attached figure 2, after chemical tests, compared with Rrustt and Q420 common carbon steel, the resistance Rt of the Q420 weather-resistant angle steel is obviously higher than that of the Q420 common carbon steel in a cycle period, and the corrosion resistance of the Q420 weather-resistant angle steel is better.

Example 2

Example 3

The section rolling adopts 4 butterfly hole type rolling mills with vertical rolling to carry out 4-pass rolling, and the 4 rolling mills are respectively BD1, BD2, F1 and F2;

the BD2 and the BD1 adopt a shared guide;

Finally, it should be noted that: the embodiments described are only a part of the embodiments of the present application, and not all embodiments, and all other embodiments obtained by those skilled in the art without making creative efforts based on the embodiments in the present application belong to the protection scope of the present application.

Claims

1. A weathering steel, characterized in that the weathering steel comprises the following components by mass fraction:

C: 0.05 to 0.20%, Si: 0.20 to 0.40%, Mn: 0.80 to 1.60%, Cu: 0.50 to 0.80%, Cr: 0.05 to 0.85%, Nb: 0.01 to 0.1%, Ni: 0.15 to 0.70%, Ti ≤0.12%, Mo≤0.30%, V≤0.12%, Zr≤0.15%, P≤0.03%, S≤0.006%, Al: 0.01～0.05%, N: 0.002～0.005%, O≤0.002%, the rest are Fe and inevitable impurities.

2. a kind of weathering steel according to claim 1, is characterized in that, described weathering steel comprises the following components by mass fraction:

C: 0.06 to 0.20%, Si: 0.25 to 0.40%, Mn: 0.90 to 1.60%, Cu: 0.50 to 0.70%, Cr: 0.05 to 0.80%, Nb: 0.03 to 0.1%.

3. a kind of weathering steel according to claim 2, is characterized in that, described weathering steel comprises the following components by mass fraction:

C: 0.06 to 0.15%, Si: 0.25 to 0.35%, Mn: 0.90 to 1.50%, Cu: 0.60 to 0.70%, Cr: 0.25 to 0.80%, Nb: 0.03 to 0.08%.

4. a kind of weathering steel according to claim 3, is characterized in that, described weathering steel comprises the following components by mass fraction:

C: 0.10%, Si: 0.20%, Mn: 1.20%, Cu: 0.65%, Cr: 0.50%, Nb: 0.05%.

5. a kind of weathering steel according to claim 1, is characterized in that, described weathering steel comprises the following components by mass fraction:

Ni: 0.15 to 0.50%, Ti: 0.05 to 0.12%, Mo: 0.10 to 0.30%, V: 0.05 to 0.12%, Zr: 0.05 to 0.15%, P: 0.01 to 0.03%, S: 0.002 to 0.006%, Al : 0.01 to 0.05%, N: 0.002 to 0.005%, O: 0.001 to 0.002%.

6. A weathering steel according to claim 1, characterized in that, the weathering steel comprises the following components by mass fraction:

Ni: 0.30 to 0.50%, Ti: 0.05 to 0.10%, Mo: 0.10 to 0.20%, V: 0.05 to 0.08%, Zr: 0.05 to 0.10%, P: 0.01 to 0.02%, S: 0.002 to 0.005%, Al : 0.01 to 0.04%, N: 0.002 to 0.003%, O: 0.0015 to 0.002%.

7. A weathering steel according to claim 6, characterized in that, the weathering steel comprises the following components by mass fraction:

Ni: 0.40%, Ti: 0.08%, Mo: 0.15%, V: 0.06%, Zr: 0.08%, P: 0.015%, S: 0.004%, Al: 0.03%, N: 0.0025%, O: 0.0018%.

8. A method for forming a steel sheet for weathering steel according to any one of claims 1 to 7, wherein the method comprises the following steps:

(1) LF refining, RH vacuum treatment and continuous casting are carried out successively after the weathering steel molten steel is smelted in a converter or an electric furnace;

(2) Rough rolling to 9 to 15 times the thickness of the finished product at 1200 to 1300° C. for a time requirement of 1.5 min/mm, and finish rolling; the finish rolling inlet temperature is 980 to 620° C. The final rolling temperature is 890～900℃;

(3) Laminar cooling is performed on the finished steel sheet according to the cooling mode in the first stage, and it is coiled into coils at 580-620°C.

9. A method for forming an angle steel of weathering steel according to any one of claims 1 to 7, wherein the method comprises the following steps:

(2) Rough rolling and profile rolling are performed in sequence after the continuous casting of the billet is kept at 1200-1300° C. for a time of 1.5 min/mm.

10. The method for forming an angle steel according to claim 9, wherein the profile rolling adopts 4 butterfly pass rolling mills with vertical rolling for 4 passes, and the 4 rolling mills are respectively BD1 and BD2 , F1, F2;

The BD2 and F1 use a shared guide;

The F2 inlet adopts a rolling guide, and the rolling guide includes a total of three guide wheels, one up and two down.