CN103243195B - Smelting process of steel ingot for wind power generating motor shaft with high performance - Google Patents
Smelting process of steel ingot for wind power generating motor shaft with high performance Download PDFInfo
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Abstract
The invention relates to the metallurgical field, and discloses a preparation process of a steel ingot for a wind power generating motor with high performance. The preparation process comprises the following two steps for dephosphorization and desulfurization: performing dephosphorization by using an electric arc furnace; and performing refining desulfurization by using LF (Ladle Furnace). Compared with the prior art, the obtained alloy is high in purity, and the contents of sulfur and phosphorus are respectively below 0.003%, i.e., the contents of sulfur and phosphorus are lowered by ten times compared with the prior art, so that the toughness, the strength and the other performances of the material are enhanced. In addition, the content of nonmetallic inclusions is reduced; the flaw detection level of the product is improved; and the energy consumption is reduced while the product usability is ensured. As a result, the cost is lowered.
Description
Technical field
The present invention relates to field of metallurgy, be specially a kind of high-performance aerogenerator steel ingot preparation technology.
Background technology
In bag " 12 " period, wind-power electricity generation becomes the clean energy that China first develops, and the construction progress of wind-powered electricity generation generating set is very fast, and the core component of wind-powered electricity generation and the production domesticization of critical material also receive widespread attention.This material will bear high dynamic stress, high fatigue period load effect under realistic application conditions, requires to have excellent mechanical property.Alloy steel products mechanical property quality depends primarily on its purity, and wherein the form of non-metallic inclusion and size, participation constituent content etc. become industry technology focal point as purity key index.Tradition method of deoxidation adopts aluminium deoxidation, high basicity slag vacuum melting technique, and steel inclusion exists with oxide compound, sulfide, silicate inclusion, dot non-deformation inclusion thing form, based on brittle inclusion Al2O3.The steel of high dynamic stress, in use brittle inclusion can produce harmful tension field, thus causes generation and the expansion of fatigue cracking, and the use of steel is reduced fatigue lifetime.
General wind power generator arbor adopts German import 17NiCrMo6 material to make, and this is a kind of material with suitable obdurability, can meet aerogenerator and to run up and work the requirement of frequent variable load.But the cost of this material is higher in the market, and because steel ingot size is comparatively large, if teeming temperature and the improper meeting of speed control cause serious loose or generation secondary pipe, cause quality of materials unstable, generally more difficult by strict test of flaw detection; In addition, for guaranteeing satisfied severe working conditions, require tolerance low temperature-40 DEG C marine denudation, and reach mechanical property specification, how the difficult point of smelting mainly controls sulphur, phosphorus content in the high-level composition range of 0.003%.
In steel and alloy smelting process, be molten steel in the steel-making stage by melting sources, then; In oxidation period process, oxygenant (as be blown into oxygen or add iron ore and ferric oxide FeO) need be added with the carbon be oxidized wherein and remove impurity and the gases such as harmful phosphorus.Under normal conditions, need to add excessive oxygenant, to reach the object of decarburization, dephosphorization, removing detrimental impurity and gas (as hydrogen and nitrogen), therefore can form oxide inclusion (based on FeO).Oxide inclusion is harmful to steel, causes obtained iron and steel easily to occur hot-short etc.Usually need to add reductor again and carry out deoxidation treatment, the reduction period namely in smelting iron and steel.
The kind of reductor has a lot, and conventional has ferrosilicon, ferromanganese, silicomanganese, aluminium etc., and be used as reductor and alloying material have ferro-niobium, vanadium iron, ferrotianium etc.
The deoxidation treatment technique of carrying out in electric arc furnace and ladle refining furnace (LF stove) mainly contains bulk deoxidation and diffusive deoxidation.
Bulk deoxidation: the alloy material directly adding deoxidation in molten steel, makes it to form oxide compound; This oxide compound floats and enters slag.This method deoxidation speed is fast, but the inclusion produced is more, and inclusion to be blended in molten steel not easily and to float in slag, therefore more difficult removal.Generally can add a small amount of fluorite (CaF in molten steel before bulk deoxidation
2, consumption is generally 1% of molten steel amount), the slag making materials manufacture such as lime (i.e. calcium oxide, consumption is generally 2% of molten steel amount) swims in the slag of molten steel surface, for adsorbing the inclusion in molten steel.
Diffusive deoxidation: the content of ferric oxide is higher in slag, can add the reductive agents such as carbon dust, silica flour, silicon calcium powder, aluminium powder in slag, for reduced steel slag, the FeO content in slag is reduced, the oxygen be conducive in molten steel is diffused in slag.
In bulk deoxidation process, conventional reductor material has ferromanganese, ferrosilicon, ferro-silico-manganese and aluminium, and the price of this different materials is lower.Generally, reductor is converted into silicon, manganese and aluminium element, is 0.17% ~ 0.37%, 0.3% ~ 0.6% and 0.05% ~ 0.10% with the amount ratio of molten steel.In existing technique, reductor ferromanganese, ferrosilicon, ferro-silico-manganese and aluminium add in molten steel respectively and react; According to the power to oxygen affinity, addition sequence is ferromanganese, ferrosilicon, ferro-silico-manganese and aluminium, because the avidity of manganese and oxygen is weak, needs the time that reaction is longer, therefore adds at first; Aluminium is comparatively active, and the reaction times is shorter.Because the temperature of molten steel is generally at about 1600 DEG C, in smelting process, individually add above-mentioned reductor, just can not form the liquid macrobead (Al of low melting point, light specific gravity
2o
3, SiO
22050 DEG C, 1713 DEG C and 1785 DEG C are respectively, higher than liquid steel temperature with the fusing point of MnO), these deoxidation productss exist with solid state in molten steel, are blended in molten steel, are difficult to float enter slag to depart from molten steel.
Therefore, need to be improved existing technique, enable reductor form light specific gravity, fusing point is low, particle is large deoxidation products, float in slag to depart from molten steel, thus molten steel is purified.
Owing to not finding good reductor material, its deoxidation all adopts conventional reductor, as ferromanganese, ferrosilicon, aluminium individually carry out deoxidation.Molten steel cannot be made like this to obtain purification further, be thus difficult to reach and meet the requirement of client to special staple product technical quality.The equal difficulty of existing conventional reductor is adopted all to reach and meet its requirement.Therefore, need to overcome an above-mentioned difficult problem, thus guarantee that the high power of national each major project to product is mingled with and the requirement of high level of detecting a flaw.
Summary of the invention
The present invention aims to provide a kind of high-performance wind power generating motor axle-steel ingot smelting technology.
Technical scheme is, high-performance wind power generating motor axle-steel ingot smelting technology, comprises the steps:
(1) add little muck or iron scale at the bottom of electric arc furnace, and add lime, then add the clean steel scrap of low-sulfur phosphorus, energising fusing; And add Mo and Ni, increase mixed carbon comtent simultaneously, make the carbon content of molten steel reach 0.6% ~ 2.0%; Mo and Ni can add before energising fusing, in energising melting process or after forming molten steel;
Described little muck is the iron ore containing 50wt% ~ 70wt% ferric oxide;
Preferably, carbon content≤0.2% of described low-sulfur phosphorus Clean Steel, content≤0.03% of sulphur and phosphorus; The ferric oxide added at the bottom of arc furnace and unslaked lime and low-sulfur phosphorus Clean Steel amount ratio are 20 ~ 30 kgs/tonne and 30 ~ 40 kgs/tonne;
(2) formed after molten steel, oxygen blast gas also point continues for 3 ~ 6 times to add little muck or iron scale in molten steel, and adds lime, changes slag simultaneously, smelts oxidation and carry out decarburization dephosphorization at 1530 ~ 1560 DEG C; The consumption of iron scale or little muck and molten steel ratio are 10 ~ 20 kgs/tonne, and lime consumption is 15 ~ 25 kgs/tonne;
(3) liquid steel temperature after dephosphorization and decarburization rises to 1700 ~ 1750 DEG C and pours in ladle refining furnace, and after slag making forms thin slag, add composite deoxidant and carry out pre-deoxidation, composite deoxidant and molten steel amount ratio are 4 ~ 5 kgs/tonne; Described composite deoxidant is the alloy containing silicon, manganese, aluminium, and wherein the content of manganese is 16 ~ 20%, and the content of silicon is 8 ~ 10%, and the content of aluminium is 8 ~ 10%, is all weight percentage;
Preferably, with lime and fluorite slag making, it is 10 ~ 15 kgs/tonne and 5 ~ 8 kgs/tonne with the amount ratio of molten steel;
(4) in molten steel, add Cr and Mn, and add powdery reductor on slag surface, refining 1 ~ 1.5 hour at 1600 ~ 1650 DEG C, utilize LF furnace bottom blown inert gas to stir simultaneously;
Described reductor is AD powder, and any one or a few in carbon dust, silicon calcium powder or calcium carbide; The amount ratio of AD powder and molten steel is 4 ~ 6 kgs/tonne, and the total amount of carbon dust, silicon calcium powder or calcium carbide and the amount ratio of molten steel are 2 ~ 4 kgs/tonne;
(5) in molten steel, supplement Si, continue smelting 5 ~ 10 minutes; In molten steel, the weight percent content of Mn, Si, Cr, Mo, Ni and C is respectively: Mn0.60% ~ 0.90%, Si0.05% ~ 0.38%, Cr0.80% ~ 1.1%, Mo0.15% ~ 0.25%, Ni1.25% ~ 1.5%; C0.14% ~ 0.20%;
(6) Fruit storage, cast of coming out of the stove.The method of vacuum outgas is: rapidly liquid steel temperature is risen to more than 1680 DEG C, then ladle is moved to degassed station, under the state that vacuum tightness is 4 ~ 67pa, process 20 ~ 30 minutes; Described pouring technology condition is: teeming temperature 1510 ~ 1538 DEG C; Pouring speed is: ingot body pouring speed 1.1 ~ 1.4 tons/minute, and time of riser gating is 2/3 ~ 1 times of ingot body duration of pouring; With the air in inert gas replacement mould before cast, and blanketing with inert gas in casting process.
By this technique products obtained therefrom chemical composition and content (weight percent): C0.14% ~ 0.20%, Mn0.60% ~ 0.90%, Si0.05% ~ 0.38%, Cr0.80% ~ 1.1%, Mo0.15% ~ 0.25%, Ni1.25% ~ 1.5%; P≤0.003%, S≤0.003%, Cu≤0.3%
The composite deoxidant of step (3), preferably, wherein the weight ratio of manganese, Silicified breccias is 1.9 ~ 2.05:0.95 ~ 1.05:1, carbon content≤0.5wt%, sulphur and phosphorus content difference≤0.05wt%; Preferred, in described composite deoxidant, the content of manganese is 18%, and the content of silicon is 9%, and the content of aluminium is 9%.
The preparation method of above-mentioned composite deoxidant comprises the steps:
(A) by the soft steel of the proportioning mixing ferromanganese of manganese, Silicified breccias, ferrosilicon, aluminium and cleaning; In described ferromanganese, the content of manganese is 70% ~ 80%, and the content of Silicon in Ferrosilicon is 45% ~ 75%, iron level >=95% of soft steel, carbon content≤0.2%, and content≤0.05% of sulphur and phosphorus, is all weight percentage;
(B) by after step (A) mixed melting sources, smelt at 1350 ~ 1400 DEG C, the time of smelting is 0.5 ~ 1 hour, then casting.
This composite deoxidant is used for molten steel and does pre-deoxidation and carry out deoxidation, and deoxidation effect is good, and inclusion remaining seldom in molten steel, makes molten steel more pure.
The composite deoxidant of siliceous, manganese provided by the present invention and aluminium, the deoxidation products fusing point formed after carrying out deoxidation is far below 1270 DEG C, and the particle diameter of the deoxidation products inclusion particle generated is large, light specific gravity, is easy to float in slag,
According to stoke principle, the ascent rate v calculation formula of deoxidation products is:
V=2/9×g×（P
0-P
1）/η×r
2
Wherein, P
0and P
1be respectively the proportion (kg/m of molten steel and deoxidation products
3), η is molten steel viscosity, and g is universal gravity constant 9.8m/s
2, r is the radius of deoxidation products particle.
As can be seen here, r having the greatest impact for v; At P
0, P
1, η, g be when being all defined as constant, ascent rate v depends on the particle radius of deoxidation thing.
Above-mentioned composite deoxidant, add the deoxidation products fusing point that formed after molten steel carries out deoxidation far below 1270 DEG C, the form existed in molten steel is the liquid particle of easily reuniting, and easily rises in the scum silica frost on molten steel top layer, instead of is suspended in the fine-powder shape solid particulate in molten steel; The particle diameter of deoxidation products inclusion particle is large, light specific gravity, and ascent rate is obviously accelerated, and is easy to floating and enters in slag, molten steel is purified.This composite deoxidant not only deoxidation effect is good, and the inclusion formed after deoxidation residual significantly reduction in molten steel, product high purity, thus meets the requirement of client to high quality high standard steel.By this composite deoxidant steel ingot out, its quality even can match in excellence or beauty with the steel ingot through esr.
Smelting process of the present invention, adopts electric arc furnace dephosphorization, LF refining desulfuration technique, in two steps dephosphorization, desulfurization, compared with prior art, the steel alloy purity obtained is high, and sulphur, phosphorus content are all lower than 0.003%, reduce by ten times than prior art, improve the mechanical property such as toughness and intensity of material.Reduce non-metallic inclusion content simultaneously, improve product carrying out flaw detection level, under the prerequisite ensureing use properties, reduce energy consumption, reduce cost.
The yield strength σ of product
s>=830MPa, tensile strength sigma
bbe 1180 ~ 1420MPa, unit elongation δ
5more than 20%, relative reduction in area ψ is more than 50%, and Impact energy Ak v is more than 50J, and hardness is no more than 229HB.Final forging passes through
non-destructive testing standard is tested.
Embodiment
Embodiment 1
(1) smelt gauge with 30 tons, in first at the bottom of arc furnace, add 0.5 ~ 0.55 ton of little muck (iron ore, main component Fe
2o
3content 60wt% ~ 70wt%) and 0.7 ~ 0.8 ton of lime (calcium oxide) for slag making ahead of time, then drop into 28.8 ~ 29 tons of low-sulfur phosphorus clean steel scrap (wherein iron level>=98wt%, carbon content≤0.2wt%, sulphur and phosphorus content difference≤0.03wt%), energising fusing; In molten steel, 51 kilograms of Mo and 381 kilogram Ni are added in melting process;
(2) under mixed carbon comtent 0.6% ~ 1%, the condition of oxygen blast simultaneously, at 1540 ± 10 DEG C, be oxidized smelting carry out oxidation and decarbonization dephosphorization in 1 ~ 1.5 hour; Divide during decarburization dephosphorization and add 0.4 ~ 0.45 ton of little muck or iron scale for 3 ~ 5 times, and 0.45 ~ 0.55 ton of lime carries out slag making, carries out stream slag and change slag while slag making; Oxidation period decarburized amount >=0.4%;
(3) liquid steel temperature after step (2) dephosphorization decarburization being risen to 1700 ~ 1750 DEG C pours in ladle refining furnace (LF stove), in the ratio of 10 ~ 15kg/ ton (molten steel) and 5 ~ 6kg/ ton (molten steel), adds lime and fluorite; After thin slag is formed, get composite deoxidant (content of silicon, manganese, aluminium is respectively 9wt%, 18wt% and 9wt%), be broken into the fritter of about median size 50mm, in the ratio of 4kg/ ton, join in molten steel and carry out pre-deoxidation;
(4) in molten steel, supplement Cr and Mn and its content is adjusted to 0.9% and 0.74%, and divide 3 times on slag surface, by the consumption of 4 ~ 6kg/ ton (molten steel), (containing 12wt% ~ 15wt% aluminium, all the other are Al to add AD powder
2o
3), add carbon dust, silicon calcium powder or calcium carbide by the consumption of 2 ~ 4kg/ ton, refining 1 hour at 1620 ± 10 DEG C, utilize LF furnace bottom blowing argon gas to stir simultaneously, to impel inclusion to be polymerized better, make oxide inclusion more easily on float in slag, thus make molten steel obtain further purification;
(5) in molten steel, supplementary Si adjusts its content is 0.20%, continues smelting 5 ~ 10 minutes;
(6) rapid again liquid steel temperature is risen to 1680 ~ 1700 DEG C, then ladle is moved to degassed station, carry out vacuum outgas (degasification) process, 20 ~ 30 minutes are processed under the state that vacuum tightness is 4 ~ 67pa, thus the foreign gas such as hydrogen, nitrogen in molten steel is removed, make molten steel obtain better purification;
(6) ladle is hung degassed station (VD station) to pour into a mould, before cast, use rare gas element as the air in argon replaces mould, by argon for protecting pouring in casting process, prevent casting process secondary pollution and oxidation.
Molten steel total amount 30 tons, ingot body 22 tons; Teeming temperature is 1520 ~ 1530 DEG C, ingot body pouring speed 1.3 ~ 1.35 tons/minute (15 ~ 16 minutes time); The riser gating time is 12 ~ 15 minutes.
The 20 stove finished products obtained carry out non-destructive test(ing)(NDT) detection, examine by the II grade standard of JB/T4730.3-2005, all qualified.
Products obtained therefrom chemical composition and content (weight percent): C0.15%, Mn0.74%, Si0.2%, Cr0.9%, Mo0.17%, Ni1.27%; P0.002%, S0.002%, Cu0.058%.Wherein non-metallic inclusion is if sulfide (lower than 0.5 grade) and oxide compound (lower than 0.5 grade) are all much smaller than 1.5 grades, and the steel obtained have higher purity.
Mechanical property: the yield strength σ of product
sfor 851MPa, tensile strength sigma
bfor 1238MPa, unit elongation δ
5be 24.5%, relative reduction in area ψ=63%, Impact energy Ak v is 55 ~ 57J, hardness 185HB.The mechanical property that draws high from room temperature to 500 DEG C of high temperature changes little, σ
sbe not less than 200MPa, σ
b>400MPa.After forging there is not waste product appearance in test of flaw detection, and product is all qualified, all passes through
test of flaw detection.
Composite deoxidant in step (3) is prepared by the following method:
Get the raw materials ready: the content of low carbon manganese steel 54kg(wherein manganese is 80wt%, be converted into 43.2kg manganese, carbon content≤0.7wt%), the content of ferrosilicon 30kg(wherein silicon is 72%, be converted into 21.6kg silicon), aluminium block 22kg(purity >=98%, be converted into 21.6kg aluminium), clean low S.P steel scrap 134kg(iron level >=95wt%, carbon content≤0.2wt%, sulphur and phosphorus content difference≤0.05wt%), smelting molten steel total amount is 240kg.
Above-mentioned raw materials is placed in 250kg intermediate frequency furnace, after being molten into molten steel, smelting is continued 0.5 ~ 1 hour at 1380 ± 10 DEG C, molten steel surface scum silica frost is skimmed with iron staff, then come out of the stove when temperature is at 1380 ± 10 DEG C, pour in ladle, at 1330 ± 10 DEG C of temperature, be cast into little billet 40kg × 6 without rising head, be composite deoxidant.
In the composite deoxidant obtained, in mass ratio, Fe content is 18%, and the content of Silicified breccias is 9%, and carbon content≤0.5wt%, sulphur and phosphorus content difference≤0.05wt%.
This composite deoxidant to be pulverized after the particle for particle diameter 1mm heated oxide in oxygen, the temperature of product fusing point is lower than 1200 DEG C.
Reference examples 1
(1) by the proportioning of embodiment 1, low-sulfur phosphorus Clean Steel Mo, Ni are added electric arc furnace electric furnace, energising fusing;
(2), under mixed carbon comtent 0.6% ~ 1%, the condition of oxygen blast simultaneously, add 0.5 ~ 0.55 ton of little muck or iron scale and 0.7 ~ 0.8 ton of lime for slag making, at 1540 ± 10 DEG C, be oxidized smelting 1 ~ 1.5 hour decarburization dephosphorization;
(3) liquid steel temperature after dephosphorization decarburization being risen to 1700 ~ 1750 DEG C pours in LF stove, in the ratio of 10 ~ 15kg/ ton (molten steel) and 6kg/ ton (molten steel), adds calcium oxide and fluorite; After thin slag is formed, get ferromanganese and be broken into about 50mm particle (carbon content≤0.7wt%, Fe content 80wt%,) add molten steel by 10 ~ 10.5kg/ ton consumption, getting the particle that ferrosilicon (wherein the content of silicon is 72wt%) is broken into about 50mm after 0.5 hour adds in molten steel by 3.2 ~ 3.3kg/ ton consumption, adds aluminium powder (purity 98%) again after 0.5 hour by adding 0.35 ~ 0.37kg/ ton consumption;
(4) divide 3 times on slag surface, by the consumption of 4 ~ 6kg/ ton (molten steel), (containing 12wt% ~ 15wt% aluminium, all the other are Al to add AD powder
2o
3), add carbon dust, silicon calcium powder or calcium carbide by the consumption of 2 ~ 4kg/ ton, refining 1 ~ 1.5 hour at 1620 ± 10 DEG C, utilize LF furnace bottom blowing argon gas to stir simultaneously;
(5) degassed technique is with the step (6) of embodiment 1;
(6) ladle is hung degassed station (VD station), pour into a mould at 1640 ~ 1660 DEG C.Molten steel total amount 30 tons, ingot body 22 tons, pouring speed 1.5 ~ 1.8 tons/minute.
In 20 stove finished products of gained, sulphur phosphorus content is all more than 0.01%, and find during non-destructive test(ing)(NDT) detects to occur loose crack, condemnation factor is high, can not all pass through
test of flaw detection.By carrying out metallurgical analysis to the forging after forging, the brittle inclusion main component forming strip particle after finding crystallization in steel ingot is Al
2o
3, after forging and stamping processing, form crack.
Embodiment 2
(1) smelt gauge with 30 tons, in first at the bottom of arc furnace, add 0.45 ~ 0.5 ton little muck (main component Fe
2o
3) and 0.65 ~ 0.75 ton of lime be used for slag making, then drop into 28.8 ~ 29 tons of low-sulfur phosphorus Clean Steels (wherein iron level>=98wt%, carbon content≤0.2wt%, sulphur and phosphorus content difference≤0.03wt%), energising is melted; In molten steel, 57 kilograms of Mo and 378 kilogram Ni are added in melting process;
(2) under mixed carbon comtent 0.8% ~ 1.2%, oxygen blast condition, at 1540 ± 10 DEG C, 1 ~ 1.5 hour oxidation and decarbonization dephosphorization is smelted; In melting process, add 0.6 ton of iron scale or little muck again, change slag during dephosphorization 5 ~ 8 times; Oxidation period decarburized amount >=0.4%;
(3) molten steel after step (2) dephosphorization decarburization is poured in LF stove, in the ratio of 4kg/ ton (molten steel) and 6kg/ ton (molten steel), add calcium oxide and fluorite; After thin slag is formed, get composite deoxidant (content of silicon, manganese, aluminium is respectively 9wt%, 18wt% and 9wt%), be broken into the fritter of about median size 50mm, in the ratio of 4.5kg/ ton, join in molten steel and carry out pre-deoxidation; The preparation method of composite deoxidant is with embodiment 1;
(4) in molten steel, supplement Cr and Mn and its content is adjusted to 0.98% and 0.82%, and divide 3 times on slag surface, by the consumption of 4 ~ 6kg/ ton (molten steel), (containing 12wt% ~ 15wt% aluminium, all the other are Al to add AD powder
2o
3), by the consumption of 2 ~ 4kg/ ton, add carbon dust, silicon calcium powder or calcium carbide, refining 1 hour at 1620 ± 10 DEG C, utilize LF furnace bottom blowing argon gas to stir simultaneously, to impel inclusion to be polymerized better, make oxide inclusion more easily on float in slag, thus make molten steel obtain further purification;
(4) in molten steel, adding Si, to adjust its content be 0.12%, continues smelting 5 ~ 10 minutes;
(5) rapid again liquid steel temperature is risen to 1680 ~ 1700 DEG C, then ladle is moved to degassed station, carry out vacuum outgas (degasification) process, 20 ~ 30 minutes are processed under the state that vacuum tightness is 4 ~ 67pa, thus the foreign gas such as hydrogen, nitrogen in molten steel is removed, make molten steel obtain better purification;
(6) ladle is hung degassed station (VD station) to pour into a mould, before cast, use rare gas element as the air in argon replaces mould, by argon for protecting pouring in casting process, prevent casting process secondary pollution and oxidation.
Molten steel total amount 30 tons, ingot body 21 tons; Teeming temperature is 1520 ~ 1530 DEG C, and ingot body duration of pouring is 16 ~ 17 minutes (speed 1.2 ~ 1.3 tons/minute); The riser gating time is 12 ~ 15 minutes.
The 20 stove finished products obtained carry out non-destructive test(ing)(NDT) detection, examine by the II grade standard of JB/T4730.3-2005, all qualified.
Products obtained therefrom chemical composition and content (weight percent): C0.14%, Mn0.82%, Si0.12%, Cr0.98%, Mo0.19%, Ni1.26%; P0.002%, S0.002%, Cu0.058%.Wherein non-metallic inclusion is if sulfide (lower than 0.5 grade) and oxide compound (lower than 0.5 grade) are all much smaller than 1.5 grades, and the steel obtained have higher purity.
Mechanical property: the yield strength σ of product
sfor 852MPa, tensile strength sigma
bfor 1231MPa, unit elongation δ
5be 23.5%, relative reduction in area ψ=61%, Impact energy Ak v is 55 ~ 57J, hardness 187HB.The mechanical property that draws high from room temperature to 500 DEG C of high temperature changes little, σ
sbe not less than 200MPa, σ
b>400MPa.After forging there is not waste product appearance in test of flaw detection, and product is all qualified, all passes through
test of flaw detection.
Reference examples 2
(1) the clean steel scrap of low-sulfur phosphorus and Mo, Ni raw material is prepared by the proportioning of embodiment 2, energising fusing;
(2), under mixed carbon comtent 0.8% ~ 1.2%, the condition of oxygen blast simultaneously, add 0.45 ~ 0.5 ton of little muck or iron scale and 0.65 ~ 0.75 ton of lime for slag making, at 1540 ± 10 DEG C, be oxidized smelting 1 ~ 1.5 hour decarburization dephosphorization; Oxidation period decarburized amount >=0.4%;
(3) liquid steel temperature after dephosphorization decarburization being risen to 1700 ~ 1750 DEG C pours in LF stove, in the ratio of 10 ~ 15kg/ ton (molten steel) and 6kg/ ton (molten steel), adds calcium oxide and fluorite; After thin slag is formed, get ferromanganese and be broken into about 50mm particle (carbon content≤0.7wt%, Fe content 80wt%,) add molten steel by 11 ~ 11.5kg/ ton consumption, getting the particle that ferrosilicon (wherein the content of silicon is 72wt%) is broken into about 50mm after 0.5 hour adds in molten steel by 2 ~ 2.1kg/ ton consumption, adds aluminium powder (purity 98%) again after 0.5 hour by adding 0.4 ~ 0.42kg/ ton consumption;
(4) divide 3 times on slag surface, by the consumption of 4 ~ 6kg/ ton (molten steel), (containing 12wt% ~ 15wt% aluminium, all the other are Al to add AD powder
2o
3), add carbon dust, silicon calcium powder or calcium carbide by the consumption of 2 ~ 4kg/ ton, refining 1 ~ 1.5 hour at 1620 ± 10 DEG C, utilize LF furnace bottom blowing argon gas to stir simultaneously;
(5) degassed technique is with the step (6) of embodiment 1;
(6) ladle is hung degassed station (VD station), pour into a mould at 1640 ~ 1650 DEG C.Molten steel total amount 30 tons, ingot body 22 tons, pouring speed 1.5 ~ 1.8 tons/minute.
In gained 20 stove finished product, sulphur phosphorus content is all more than 0.01%, and find to occur crack during non-destructive test(ing)(NDT) detects, condemnation factor is high, can not all pass through
test of flaw detection.By carrying out metallurgical analysis to the forging after forging, the brittle inclusion main component forming strip particle after finding crystallization in steel ingot is Al
2o
3, after forging and stamping processing, form crack.
Claims (5)
1. a high-performance wind power generating motor axle-steel ingot smelting technology, is characterized in that, comprise the steps:
(1) at the bottom of electric arc furnace, add little muck or iron scale, and add lime, then add the clean steel scrap of low-sulfur phosphorus, energising fusing; And add Mo and Ni, increase mixed carbon comtent simultaneously, make the carbon content of molten steel reach 0.6% ~ 2.0%;
Described little muck is the iron ore containing 50wt% ~ 70wt% ferric oxide;
The iron scale added at the bottom of arc furnace or little muck and low-sulfur phosphorus cleaning steel scrap amount ratio are 15 ~ 20 kgs/tonne, and the consumption of lime is 20 ~ 30 kgs/tonne;
(2) formed after molten steel, oxygen blast gas also point continues for 3 ~ 6 times to add little muck or iron scale in molten steel, and adds lime, changes slag simultaneously, smelts oxidation and carry out decarburization dephosphorization at 1530 ~ 1560 DEG C; The consumption of iron scale or little muck and molten steel ratio are 10 ~ 20 kgs/tonne, and lime consumption is 15 ~ 25 kgs/tonne;
(3) liquid steel temperature after dephosphorization and decarburization rises to 1700 ~ 1750 DEG C and pours in ladle refining furnace, and after slag making forms thin slag, add composite deoxidant and carry out pre-deoxidation, composite deoxidant and molten steel amount ratio are 4 ~ 5 kgs/tonne;
(4) in molten steel, add Cr and Mn, and add reductor on slag surface, refining 1 ~ 1.5 hour at 1600 ~ 1650 DEG C, utilize LF furnace bottom blown inert gas to stir simultaneously;
Described reductor is AD powder, and any one or a few in carbon dust, silicon calcium powder or calcium carbide; The amount ratio of AD powder and molten steel is 4 ~ 6 kgs/tonne, and the amount ratio of carbon dust, silicon calcium powder or calcium carbide and molten steel is 2 ~ 4 kgs/tonne;
(5) in molten steel, add Si, continue smelting 5 ~ 10 minutes; In molten steel after adjustment, the weight percent content of Mn, Si, Cr, Mo and Ni is respectively: Mn 0.60% ~ 0.90%, Si 0.05% ~ 0.38%, Cr 0.80% ~ 1.1%, Mo 0.15% ~ 0.25%, Ni 1.25% ~ 1.5%; With lime and fluorite slag making, it is 10 ~ 15 kgs/tonne and 5 ~ 8 kgs/tonne with the amount ratio of molten steel;
(6) Fruit storage, bull ladle is poured into a mould; The method of described vacuum outgas is: rapidly liquid steel temperature is risen to more than 1680 DEG C, then ladle is moved to degassed station, under the state that vacuum tightness is 4 ~ 67pa, process 20 ~ 30 minutes;
Step (3) described composite deoxidant is the alloy containing silicon, manganese, aluminium, and wherein the content of manganese is 16 ~ 20%, and the content of silicon is 8 ~ 10%, and the content of aluminium is 8 ~ 10%, is all weight percentage; Wherein the weight percent amount of sulphur and phosphorus is all no more than 0.05%.
2. high-performance wind power generating motor axle-steel ingot smelting technology described in claim 1, it is characterized in that, in step (3) described composite deoxidant, the content of manganese is 18%, and the content of silicon is 9%, and the content of aluminium is 9%.
3. high-performance wind power generating motor axle-steel ingot smelting technology described in claim 1 or 2, it is characterized in that, the preparation method of described composite deoxidant comprises the steps:
(A) by proportioning mixing ferromanganese, ferrosilicon, aluminium powder and the soft steel of manganese, Silicified breccias;
(B) by step (A) mixed melting sources mixed smelting at 1350 ~ 1400 DEG C, then casting;
In described ferromanganese, the content of manganese is 70% ~ 80%, and the content of Silicon in Ferrosilicon is 45% ~ 75%, is all weight percentage, iron level >=95% of described soft steel, carbon content≤0.2%, content≤0.05% of sulphur and phosphorus.
4. high-performance wind power generating motor axle-steel ingot preparation technology described in claim 1, is characterized in that, in the clean steel scrap of the low-sulfur phosphorus described in step (1), and iron level >=98wt%, carbon content≤0.2wt%, sulphur and phosphorus content difference≤0.05wt%.
5. high-performance wind power generating motor axle-steel ingot smelting technology described in claim 1, it is characterized in that, the pouring technology condition described in step (6) is: teeming temperature 1510 ~ 1538 DEG C; Pouring speed is: ingot body pouring speed 1.1 ~ 1.4 tons/minute, and time of riser gating is 2/3 ~ 1 times of ingot body duration of pouring; With the air in inert gas replacement mould before cast, and blanketing with inert gas in casting process.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1068146A (en) * | 1992-06-29 | 1993-01-20 | 黄春林 | Multiple combined deoxidizing agent |
| JP2000345285A (en) * | 1999-06-04 | 2000-12-12 | Kobe Steel Ltd | Low alloy cast steel and heat treatment thereof |
| CN1594633A (en) * | 2004-06-24 | 2005-03-16 | 宝钢集团上海五钢有限公司 | Dampproof hydrogen sulfide stress corrosion steel and preparing method thereof |
| CN101230441A (en) * | 2008-02-21 | 2008-07-30 | 文宇 | Low-temperature impact resistant 42CrMoVNb steel for wind-power variable propeller and yaw bearing ring |
| CN101994062A (en) * | 2010-11-18 | 2011-03-30 | 成都天马铁路轴承有限公司 | Wind power bearing steel |
| CN102199733A (en) * | 2011-04-27 | 2011-09-28 | 山西太钢不锈钢股份有限公司 | Smelting method of axle steel for high-speed motor car |
| CN102965588A (en) * | 2012-11-29 | 2013-03-13 | 南车戚墅堰机车车辆工艺研究所有限公司 | Low-alloy high-strength cast steel, and smelting and heat treatment method thereof |
-
2013
- 2013-04-25 CN CN201310147511.1A patent/CN103243195B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1068146A (en) * | 1992-06-29 | 1993-01-20 | 黄春林 | Multiple combined deoxidizing agent |
| JP2000345285A (en) * | 1999-06-04 | 2000-12-12 | Kobe Steel Ltd | Low alloy cast steel and heat treatment thereof |
| CN1594633A (en) * | 2004-06-24 | 2005-03-16 | 宝钢集团上海五钢有限公司 | Dampproof hydrogen sulfide stress corrosion steel and preparing method thereof |
| CN101230441A (en) * | 2008-02-21 | 2008-07-30 | 文宇 | Low-temperature impact resistant 42CrMoVNb steel for wind-power variable propeller and yaw bearing ring |
| CN101994062A (en) * | 2010-11-18 | 2011-03-30 | 成都天马铁路轴承有限公司 | Wind power bearing steel |
| CN102199733A (en) * | 2011-04-27 | 2011-09-28 | 山西太钢不锈钢股份有限公司 | Smelting method of axle steel for high-speed motor car |
| CN102965588A (en) * | 2012-11-29 | 2013-03-13 | 南车戚墅堰机车车辆工艺研究所有限公司 | Low-alloy high-strength cast steel, and smelting and heat treatment method thereof |
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