CN100455689C - Niobium, vanadium composite micro-alloying low-carbon boron steel for cold heading and production method thereof - Google Patents

Niobium, vanadium composite micro-alloying low-carbon boron steel for cold heading and production method thereof Download PDF

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CN100455689C
CN100455689C CNB2007100530972A CN200710053097A CN100455689C CN 100455689 C CN100455689 C CN 100455689C CN B2007100530972 A CNB2007100530972 A CN B2007100530972A CN 200710053097 A CN200710053097 A CN 200710053097A CN 100455689 C CN100455689 C CN 100455689C
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steel
niobium
low
carbon boron
boron steel
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CN101113507A (en
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周新龙
陈伟庆
刘正清
桂江兵
叶飞
蒋跃东
任安超
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Wuhan Iron and Steel Group Corp
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Abstract

Niobium-vanadium microalloyed low-carbon boron steel used for cold heading and a preparation method thereof pertain to steel smelting and material field. In order to solves the problems of low standard grade, high production cost and poor product quality of the existing low-carbon boron steel products, the niobium-vanadium microalloyed low-carbon boron steel of the invention comprises the components according to certain weight proportion: 0.18-0.24 of C, 0.80-1.2 of Mn, 0.01-0.03 of Ti, 0.001-0.003 of B, 0.02-0.08 of Nb, 0.02-0.08 of V, 0.01-0.05 of Als, Si is less than 0.20, P is less than 0.03 and S is less than 0.03, the rest is Fe. The process method comprises the technique process in sequence under specific technology parameters: smelting by a converter or an electric furnace; fine smelting by an LF furnace; continuous casting; heating; rolling, controlled cooling. The invention utilizes the compound microalloyed function of niobium and vanadium and ensures the comprehensive performance of the low-carbon boron steel when strengthening, and the invention can be used for the boron steel products of high strength standard parts from grade 10.9 to grade 12.9, and can completely substitute for CrMo steel alloy used presently, which is suitable for broad popularization and application.

Description

A kind of cold-heading niobium, vanadium composite micro-alloying low-carbon boron steel and production method thereof
Technical field
The present invention relates to a kind of low-carbon boron steel and production method thereof, belong to the field of ferrous metallurgy and material.
Technical background
Boron-containing cold heading steel utilizes the characteristic of boron to substitute other alloying element with small amount of boron, reaches the requirement of strength of high-intensity fasteners by the hardening capacity that improves steel.Be characterized in having lower resistance to deformation and good deformability, after cold deformation is finished,, can obtain higher relatively strength level by certain thermal treatment process at hot-rolled state.Because the adding of B can reduce the add-on of alloying elements such as Cr, Mo, thereby reduce the production cost of steel significantly.Yet low-carbon boron steel has been subjected to the restriction of intensity rank in the use of high-intensity fasteners, studies show that of past, and low-carbon boron steel generally can only be produced 8.8 grades and following other standardized component product of level.Have only a few countries can produce 9.8 grades, the low-carbon boron steel product of 10.9 grade standard spares at present.Domestic still do not have a special-purpose low-carbon and low-alloy boron-containing cold heading steel kind, some factories improve the back to 15MnVB, 20MnTiB etc. and use as cold heading steel, because its composition is not to design at cold heading steel, must have many incompatibility parts in the use, its intensity rank does not generally reach the production needs of 10.9 grade standard spares yet.
Microalloying technology research with regard to low-carbon boron steel sees still do not have the Nb of low-carbon boron steel, the report of V combined microalloying research both at home and abroad.
Summary of the invention
The standardized component product strength rank that the present invention is directed to existing low-carbon boron steel production is low, and the problem of production cost height and poor product quality provides a kind of cold-heading niobium, vanadium composite micro-alloying low-carbon boron steel and production method thereof.The present invention can improve low-carbon boron steel product strength rank, reaches 10.9 grades～12.9 grades, the quality that reduces production costs and improve product.
A kind of cold-heading niobium, vanadium composite micro-alloying low-carbon boron steel, the chemical ingredients that it is characterized in that steel percentage is by weight counted: C 0.18～0.24, Mn 0.80～1.2, Ti 0.01～0.03, B 0.001～0.003, Nb 0.02～0.08, V 0.02～0.08, Als 0.01～0.05, Si＜0.20, P＜0.03, S＜0.03, surplus are Fe.
Illustrate that below Nb, V strengthening mechanism and Nb, V combined microalloying are to Effect on Performance of the present invention.
The main strengthening mechanism of Nb, V is respectively grain refining and precipitation strength, and precipitation strength is different with grain refining, also improves brittle transition temperature when improving intensity.When two kinds of mechanism stacks, the influence in different steel grades is just made a world of difference.The intensity increment of Nb mainly leans on grain refining, and very fast in increase below 0.04%, and the intensity of V increases the main precipitation strength of leaning on, and the component of reinforcement is less relatively.Because grain refining can reduce transition temperature, and precipitation strength improves transition temperature, and comprehensive result is that Nb reduces brittle transition temperature below 0.03-0.04%, no matter and V content all will improve brittle transition temperature.
The compound adding of microalloy element is more much bigger than the mathematical addition of the influence of individual element adding to Effect on Performance.Here the reciprocal effect between the alloying element has produced effect.For low-carbon boron steel, prove through this research trial, the combined microalloying of microalloy element Nb, V also has better effect than the independent microalloying of Nb, V, studies show that, the Nb of low-carbon boron steel, V combined microalloying will be because the hardening capacity effect of boron will make the microalloying effect more obvious, through technology of the present invention, product can reach 12.9 grade standard spare production needs.
Cold-heading of the present invention comprises converter or electrosmelting, the refining of LF stove, continuous casting successively, heats, rolls, controls cold process with the production method of niobium, vanadium composite micro-alloying low-carbon boron steel, and the parameter of each step control is:
Smelt: 1660～1680 ℃ of tapping temperatures are smelted in control;
LF stove refining: LF stove refining time 〉=25min; Add aluminium ferromanganese and give deoxidation, add alloy: MnFe → NiFe → VFe → TiFe → BFe then in the following order successively, feed the Al line again and carry out final deoxygenation, feed the Si-Ca silk and carry out the calcium processing, the purpose that hello Si-Ca silk carries out the calcium processing is for the inclusion in the steel is carried out denaturing treatment;
Continuous casting: 1560～1570 ℃ of pouring temperatures, pulling rate and secondary cooling water are controlled by the soft steel requirement;
Heating: 1100～1150 ℃ of billet heating temperature;
Roll: 1050～1100 ℃ of start rolling temperatures, 850～880 ℃ of finishing temperatures;
Control cold: roll postcooling speed and control by 1～3 ℃/S.
Cold-heading of the present invention has following advantage with niobium, vanadium composite micro-alloying low-carbon boron steel and production method thereof:
1) the present invention utilizes the combined microalloying effect of Nb, V, when strengthening, guarantees the over-all properties of low-carbon boron steel, can be used for 10.9 grades and even 12.9 grade high-strength standardized component boron steel products, and the CrMo that can substitute present use fully is a steel alloy.
2) the present invention has substituted Cr, Mo alloy by Nb, the V combined microalloying of trace, has reduced production cost.
3) utilize the combined microalloying effect of Nb, V, improved the toughness of low-carbon boron steel, therefore be beneficial to and apply.
Embodiment
Embodiment 1: according to the requirement of composition of steel of the present invention, experimentize in the carbon tube furnace laboratory, the main chemical compositions of steel (weight percent) sees Table 1, and the surplus of listed chemical ingredients is Fe in the table.
The cold-heading of the described composition of table 1 comprises converter or electrosmelting, the refining of LF stove, continuous casting, heats, rolls and controls cold process that with the production method of niobium, vanadium composite micro-alloying low-carbon boron steel the parameter of each step control is successively:
Smelt: 1660～1680 ℃ of tapping temperatures are smelted in control;
LF stove refining: LF stove refining time 〉=25min; Add aluminium ferromanganese and give deoxidation, add alloy: MnFe → NiFe → VFe → TiFe → BFe then in the following order successively, feed the Al line again and carry out final deoxygenation, feed the Si-Ca silk and carry out the calcium processing, the purpose that hello Si-Ca silk carries out the calcium processing is for the inclusion in the steel is carried out denaturing treatment;
Continuous casting: 1560～1570 ℃ of pouring temperatures, pulling rate and secondary cooling water are controlled by the soft steel requirement;
Heating: 1100～1150 ℃ of billet heating temperature;
Roll: 1050～1100 ℃ of start rolling temperatures, 850～880 ℃ of finishing temperatures;
Control cold: roll postcooling speed and control by 1～3 ℃/S.
The steel that the steel of mentioned component adopts aforementioned production method to obtain is heat-treated service check, and assay sees Table 2.
Embodiment 2: according to the requirement of composition of steel of the present invention, experimentize in the vacuum oven laboratory, the main chemical compositions of steel (weight percent) sees Table 3, and the surplus of listed chemical ingredients is Fe in the table.
Be the stability of checking steel, the steel of every kind of composition produces twice by same procedure, and concrete grammar is identical with embodiment 1.
Steel to present embodiment production is heat-treated service check, and assay sees Table 4, and (11-1,11-2 are that the composition of 11 steel carries out producing for twice gained Heat Treatment Of Steel service check to label in the expression table 3 respectively in the table 4.The back label meaning is identical therewith).
Embodiment 3: according to the requirement of composition of steel of the present invention, carry out the experiment of half Industrial products, the main chemical compositions of steel (weight percent) sees Table 5, and the surplus of listed chemical ingredients is Fe in the table.Adopt converter or electric furnace to smelt, detailed process is identical with embodiment 1.
Stability for the checking steel, the steel of every kind of composition is produced twice by same procedure, twice gained steel heat-treated service check respectively, the results are shown in Table 6 and table 7, table 6 is that (21-1,21-2 are that the composition of 21 steel carries out producing for twice gained Heat Treatment Of Steel service check to label in the expression table 5 respectively in the table 6 for the heat treatment performance of the described component steel of present embodiment.The label meaning in back is identical therewith), table 7 is that (21-1,21-2 are that the composition of 21 steel carries out producing for twice the heat treatment performance that the gained steel is processed into behind the standardized component finished product and checks to label in the expression table 5 respectively in the table 7 for the heat treatment performance of the standardized component finished product made with aforementioned steel.The back label meaning is identical therewith).
Table 1 (weight percent wt%)
C Si Mn P S Ti B Nb V Als
1 0.235 0.05 0.83 0.018 0.016 0.021 0.0005 0.011 0.004 0.01
2 0.182 0.027 0.74 0.019 0.016 0.017 0.0017 0.022 0.006 0.063
3 0.228 0.042 0.83 0.019 0.016 0.018 0.0005 - 0.050 0.048
4 0.232 0.054 0.85 0.019 0.015 0.017 0.0016 0.028 0.032 0.075
5 0.18 ＜0.20 1.2 ＜0.03 ＜0.03 0.01 0.003 0.02 0.08 0.01
6 0.24 ＜0.20 0.80 ＜0.03 ＜0.03 0.03 0.001 0.08 0.02 0.05
7 0.182 ＜0.20 0.95 ＜0.03 ＜0.03 0.013 0.0021 0.022 0.048 0.016
8 0.193 ＜0.20 0.83 ＜0.03 ＜0.03 0.017 0.0015 0.052 0.023 0.030
9 0.236 ＜0.20 0.97 ＜0.03 ＜0.03 0.029 0.0022 0.078 0.050 0.048
10 0.212 ＜0.20 1.18 ＜0.03 ＜0.03 0.018 0.0028 0.054 0.078 0.032
Table 2
Heat (batch) number Rm(MPa) A(％) Z(％) Heat (batch) number Rm(MPa) A(％) Z(％)
1 1420 6.5 25 3 1480 8.0 37.5
2 1280 6.5 28.5 4 1430 6.5 23.5
5 1430 7.0 26.5 6 1470 8.5 36.5
7 1485 6.8 27 8 1500 8.0 35
9 1350 7.2 29 10 1550 7.5 30
Table 3
C Si Mn P S Ti B Nb V Als
11 0.230 0.028 0.95 0.003 0.004 0.014 0.0022 0.078 0.051 -
12 0.193 0.021 0.97 0.005 0.004 0.033 0.0030 - 0.052 0.017
13 0.190 0.021 0.95 0.003 0.004 0.007 0.0010 0.052 0.050 0.016
14 0.185 0.016 0.97 0.005 0.004 0.029 0.0021 0.054 0.048 0.009
15 0.18 ＜0.20 1.2 ＜0.03 ＜0.03 0.01 0.003 0.02 0.08 0.01
16 0.24 ＜0.20 0.80 ＜0.03 ＜0.03 0.03 0.001 0.08 0.02 0.05
17 0.182 ＜0.20 0.95 ＜0.03 ＜0.03 0.013 0.0021 0.022 0.048 0.016
18 0.193 ＜0.20 0.83 ＜0.03 ＜0.03 0.017 0.0015 0.052 0.023 0.030
19 0.236 ＜0.20 0.97 ＜0.03 ＜0.03 0.029 0.0022 0.078 0.050 0.048
20 0.212 ＜0.20 1.18 ＜0.03 ＜0.03 0.018 0.0028 0.054 0.078 0.032
Table 4
Specimen coding Rm(Mpa) A(％) Z(％)
11-1 1070 8.0 34.5
11-2 930 7.0 46.0
12-1 1360 9.0 46.0
12-2 1340 10.5 48.5
13-1 1350 11.5 55.0
13-2 1330 10.0 52.5
14-1 1320 9.5 42.5
14-2 1340 10.0 47.0
15-1 1400 9.5 35.5
15-2 1420 8.8 40.5
16-1 1380 7.8 55.0
16-2 1300 8.2 58.5
17-1 1350 9.0 42.5
17-2 1280 9.2 40.0
18-1 1210 9.5 42.8
18-2 1100 7.0 48.5
19-1 1550 8.5 52.5
19-2 1380 9.0 51.0
20-1 1320 10.5 47.0
20-2 1280 8.8 48.0
Table 5
C Si Mn P S Ti B Nb V Als
21 0.221 0.14 0.60 0.019 0.029 0.015 0.0028 - 0.037 0.030
22 0.236 0.14 0.63 0.019 0.029 0.017 0.0028 - 0.038 0.047
23 0.231 0.19 0.88 0.022 0.029 0.005 0.0015 0.023 0.044 0.062
24 0.212 0.18 0.9 0.019 0.027 0.013 0.0030 0.078 0.035 0.044
25 0.18 ＜0.20 1.2 ＜0.03 ＜0.03 0.01 0.003 0.02 0.08 0.01
26 0.24 ＜0.20 0.80 ＜0.03 ＜0.03 0.03 0.001 0.08 0.02 0.05
27 0.182 ＜0.20 0.95 ＜0.03 ＜0.03 0.013 0.0021 0.022 0.048 0.016
28 0.193 ＜0.20 0.83 ＜0.03 ＜0.03 0.017 0.0015 0.052 0.023 0.030
29 0.236 ＜0.20 0.97 ＜0.03 ＜0.03 0.029 0.0022 0.078 0.050 0.048
30 0.212 ＜0.20 1.18 ＜0.03 ＜0.03 0.018 0.0028 0.054 0.078 0.032
Table 6
Specimen coding Rm(Mpa) A(％) Z(％)
21-1 1210 11.0 39
21-2 1160 10.0 36.5
22-1 1300 9.0 33.5
22-2 1220 8.5 37.5
23-1 1390 10.0 36.5
23-2 1360 8.5 39.5
24-1 1340 10.0 44
24-2 1350 9.0 43.5
25-1 1460 9.5 38.5
25-2 1420 8.8 40.5
26-1 1350 8.8 57.0
26-2 1330 8.6 58.5
27-1 1650 9.0 43.5
27-2 1680 9.2 42.0
28-1 1210 9.5 46.8
28-2 1180 8.9 47.5
29-1 1550 8.5 51.5
29-2 1580 9.0 52.0
30-1 1320 9.5 48.0
30-2 1280 9.8 48.0
Table 7
Specimen coding Rm(Mpa) A(％) Z(％)
21-1 1250 11.0 44.5
21-2 1180 11.5 34.0
22-1 1230 9.0 33.5
22-2 1310 8.0 37.0
23-1 1440 9.0 37.5
23-2 1420 9.0 38.5
24-1 1310 9.5 43.5
24-2 1320 9.0 42.0
25-1 1450 10.3 45.5
25-2 1420 9.6 65.0
26-1 1360 9.8 65.0
26-2 1350 9.6 68.0
27-1 1550 9.0 50.0
27-2 1700 10.2 48.0
28-1 1220 10.8 52.5
28-2 1150 9.2 50.0
29-1 1550 8.5 55.0
29-2 1620 9.0 51.0
30-1 1315 10.8 50.5
30-2 1290 10.5 58.5

Claims (4)

1. a cold-heading is with niobium, vanadium composite micro-alloying low-carbon boron steel, the chemical ingredients that it is characterized in that steel percentage is by weight counted: C 0.18～0.24, Mn 0.80～1.2, Ti 0.01～0.03, B0.001～0.003, Nb 0.02～0.08, V 0.02～0.08, Als 0.01～0.05, Si＜0.20, P＜0.03, S＜0.03, surplus are Fe.
2. cold-heading according to claim 1 niobium, vanadium composite micro-alloying low-carbon boron steel, the chemical ingredients that it is characterized in that steel percentage is by weight counted: C 0.182～0.193, Mn 0.83～0.95, Ti 0.013～0.017, B 0.0015～0.0021, Nb 0.022～0.052, V 0.023～0.048, Als 0.016～0,030, Si＜0.20, P＜0.03, S＜0.03, surplus is Fe.
3. cold-heading according to claim 1 niobium, vanadium composite micro-alloying low-carbon boron steel, the chemical ingredients that it is characterized in that steel percentage is by weight counted: C 0.212～0.236, Mn 0.97～1.18, Ti 0.018～0.029, B 0.0022～0.0028, Nb 0.054～0.078, V 0.050～0.078, Als 0.032～0.048, Si＜0.20, P＜0.03, S＜0.03, surplus are Fe.
4. a cold-heading is with the production method of niobium, vanadium composite micro-alloying low-carbon boron steel, comprise successively converter or electrosmelting, the refining of LF stove, continuous casting, heating, rolling, control cold process, it is characterized in that:
The chemical ingredients of steel percentage is by weight counted: C 0.18～0.24, Mn 0.80～1.2, Ti 0.01～0.03, B 0.001～0.003, Nb 0.02～0.08, V 0.02～0.08, Als 0.01～0.05, Si＜0.20, P＜0.03, S＜0.03, surplus are Fe;
The parameter of each step control is;
Smelt: 1660～1680 ℃ of tapping temperatures are smelted in control;
LF stove refining: LF stove refining time 〉=25min; Add aluminium ferromanganese and carry out pre-deoxidation, add alloy then in the following order successively; MnFe → NiFe → VFe → TiFe → BFe feeds the Al line again and carries out final deoxygenation, feeds the Si-Ca silk and carries out the calcium processing;
Continuous casting: 1560～1570 ℃ of pouring temperatures, pulling rate and secondary cooling water are controlled by the soft steel requirement;
Heating: 1100～1150 ℃ of billet heating temperature;
Rolling: 1050～1100 ℃ of start rolling temperatures, 850～880 ℃ of finishing temperatures;
Control cold: roll postcooling speed and control by 1～3 ℃/S.
CNB2007100530972A 2007-08-31 2007-08-31 Niobium, vanadium composite micro-alloying low-carbon boron steel for cold heading and production method thereof Expired - Fee Related CN100455689C (en)

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CN103447492A (en) * 2012-05-30 2013-12-18 通化钢铁股份有限公司 Production process for eliminating boron micro-alloying hot-rolled steel strip edge faults
CN102719613A (en) * 2012-06-11 2012-10-10 内蒙古包钢钢联股份有限公司 Method for deoxidation in ladle furnace (LF) refining furnace by using low calcium ferro-manganese-aluminium
CN103589950B (en) * 2013-11-01 2015-09-16 内蒙古包钢钢联股份有限公司 The thermal treatment process of the boron micro-alloyed high-strength steel of vanadium
CN113215472B (en) * 2021-03-25 2022-04-26 马鞍山钢铁股份有限公司 Niobium-vanadium microalloyed high-strength fine-grain non-quenched and tempered cold forging steel square billet and manufacturing method thereof
CN113737099B (en) * 2021-09-09 2022-06-10 广东韶钢松山股份有限公司 Tool steel suitable for large-deformation cold machining forming and preparation method thereof, and sleeve and preparation method thereof

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WO2004111286A1 (en) * 2003-06-12 2004-12-23 Jfe Steel Corporation Steel plate and welded steel tube exhibiting low yield ratio, high strength and high toughness and method for production thereof
CN1563468A (en) * 2004-04-14 2005-01-12 武汉钢铁(集团)公司 Manufacturing method of cold forming high intensity steel for welded structure

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Publication number Priority date Publication date Assignee Title
WO2004111286A1 (en) * 2003-06-12 2004-12-23 Jfe Steel Corporation Steel plate and welded steel tube exhibiting low yield ratio, high strength and high toughness and method for production thereof
CN1563468A (en) * 2004-04-14 2005-01-12 武汉钢铁(集团)公司 Manufacturing method of cold forming high intensity steel for welded structure

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