CN102002637B - Alloy steel and manufacture method thereof - Google Patents
Alloy steel and manufacture method thereof Download PDFInfo
- Publication number
- CN102002637B CN102002637B CN 201010519863 CN201010519863A CN102002637B CN 102002637 B CN102002637 B CN 102002637B CN 201010519863 CN201010519863 CN 201010519863 CN 201010519863 A CN201010519863 A CN 201010519863A CN 102002637 B CN102002637 B CN 102002637B
- Authority
- CN
- China
- Prior art keywords
- content
- molten steel
- steel
- adjustment
- molten
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
The invention provides alloy steel and a manufacture method thereof. The manufacture method comprises the steps of: initially melting molten steel; when C content is 0.03-0.06 percent, P content is not more than 0.015 percent and S content is not more than 0.020 percent, tapping to a steel ladle; during the tapping, regulating the Si content to be 0.17-0.37 percent, the Mn content to be 0.40-0.70 percent, the Cr content to be 0.80-1.10 percent and the Mo content to be 0.40-0.55 percent, and regulating the oxygen content of molten steel to be below 0.0020 percent; controlling the Als content to be 0.015-0.025 percent in a steel ladle refining furnace, wherein Als expresses acid-soluble aluminum; regulating the oxygen content of the molten steel to be below 0.0010 percent in the steel ladle refining furnace; regulating the Ti content of the molten steel to be 0.005-0.010 percent and the V content to be 0.02-0.04 percent in the refining process, the C content of the molten steel to be 0.12-0.18 percent after the refining is finished so as to obtain the alloy steel, wherein the alloy steel comprises the following components in percent by weight of 0.12-0.18 percent of C, 0.17-0.37 percent of Si, 0.40-0.70 percent of Mn, 0.80-1.10 percent of Cr, 0.40-0.55 percent of Mo, 0.005-0.010 percent of Ti, 0.005-0.010 percent of Als, 0.02-0.04 percent of V and the balance of Fe and inevitable impurities.
Description
Technical field
The present invention relates to a kind of steel alloy and method of manufacture thereof, particularly a kind of steel alloy and method of manufacture thereof that can be used for high-duty boiler.
Background technology
Research shows that the Al content of control boiler steel is the key that boiler steel is produced in very low scope, and its reason is that mainly Al content height can cause the cold worked lumber recovery in rear portion extremely low.Yet generally, Al is an alloying element important in the steel.The effect of Al at first is presented as the final deoxygenation that is used for molten steel, can make the molten steel equilibrium oxygen be in lower level, avoids the appearance of high-oxygen steel; Secondly Al is again important thin brilliant element, can improve the obdurability of steel; Al also can be used to fixed nitrogen (N) in addition, thereby alleviates the ageing of steel.The add-on of Al that embodies above-mentioned effect is generally more than 0.020%.
The 15CrMoG steel is that a kind of typical high-duty boiler among the CNS GB5310-2008 (seamless steel tubes and pipes for high pressure boiler) is used structural alloy steel, and it comprises 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo by weight, be not more than 0.025% P, be not more than 0.015% S, be not more than 0.20% Cu, be not more than 0.30% Ni and be not more than 0.08% V.
For the 15CrMoG steel, need control Al content equally in lower level.In steel, lack under the situation of enough Al, can adopt the refining of LF stove or LF stove refining+vacuum treated method to avoid high-oxygen steel, can adopt the crystal grain of controlled rolling method of temperature refinement steel.Yet prior art is not considered can occur the hazardness of the free N of part in the steel because of lacking enough Al all the time.
Even adopt bof process to smelt steel, also residual in the steel have 0.004%～0.006% nitrogen, residual nitrogen even can reach more than 0.007% under indivedual working conditions.This part nitrogen is used the Al administration of fixed, otherwise nitrogen can be present in the form of free state in the steel, and it is ageing to increase steel, reduces impact resistance, and serious also can cause the steel premature failure.
As stated, in the production technology of existing 15CrMoG steel, should take low Al route; Yet low excessively Al content can cause and have a certain amount of free nitrogen in the steel, and it is ageing to increase steel, reduces impact resistance, and serious also can cause the steel premature failure.
Summary of the invention
The invention provides a kind of steel alloy and method of manufacture thereof, thereby overcome the one or more technical problems in the above-mentioned technical problem.
Comprise 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V by weight according to steel alloy of the present invention; Surplus is Fe and unavoidable impurities, and the content of each element is weight percent content in the steel alloy.
Unavoidable impurities can comprise and is not more than 0.025% P, is not more than 0.015% S, is not more than 0.009% N, is not more than 0.20% Cu and is not more than 0.30% Ni in this steel alloy
The method of manufacture of steel alloy according to an aspect of the present invention may further comprise the steps: (a) first steel-making water; (b) be 0.03%～0.06% at the C of molten steel content, P content is not more than 0.015%, and S content is not more than at 0.020% o'clock, taps to ladle; (c) in tapping process, the Si content of adjustment molten steel is 0.17%～0.37%, and Mn content is 0.40%～0.70%, and Cr content is 0.80%～1.10%, and Mo content is 0.40%～0.55%, and the oxygen level of adjustment molten steel is below 0.0020%; (d) the Als content of control molten steel is 0.015%～0.025%, and Als representes the molten aluminium of acid; (e) oxygen level of in ladle refining furnace, adjusting molten steel is below 0.0010%; (f) the Ti content of adjustment molten steel is 0.005%～0.010% in refining process; V content is 0.02%～0.04%; The C content of molten steel was 0.12%～0.18% when refining was accomplished; Thereby obtain steel alloy; This steel alloy comprises 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V, and surplus is Fe and unavoidable impurities, and the content of each element is weight percent content in the steel alloy.
In step (a), can adopt converter to come steel-making water just.
The oxygen level that in step (c), can adopt at least a adjustment molten steel in aluminium ferromanganese, ferro-aluminum, ferrosilicon, manganese metal and the low carbon ferromanganese is below 0.0020%.
In step (c), can adjust Si content, Mn content, Cr content and Mo content through alloying material being added molten steel, alloying material can comprise the aluminium ferromanganese, manganese metal and the ferromanganese that are used for adjusting Mn content at least a, the ferrosilicon that is used to adjust Si content, be used to the molybdenum-iron adjusting the ferrochrome of Cr content and be used to adjust Mo content.
In step (d), can add the Al content that aluminium is controlled molten steel to molten steel.
In step (e), can adopt CaC
2Or CaC
2With the oxygen level of the combination of aluminium adjustment molten steel below 0.0010%.
Step (a) can be included in the interior smelting molten iron of converter and obtain molten steel, in step (e), can adopt CaC
2The adjustment molten steel oxygen level below 0.0010%, CaC
2Usage quantity (kg) can be molten iron add-on (ton) * 95% * (1.8～2.2) * (0.7～1.0).
Can in ladle refining furnace, heat Ti content and the V content of after 10 minutes, adjusting molten steel in 5 minutes to molten steel; The step of Ti content of adjustment molten steel can comprise ferro-titanium is added molten steel, and the step of the V content of adjustment molten steel can comprise ferro-vanadium is added molten steel.
With heating 5 minutes to 10 minutes molten steel after ferro-titanium and the ferro-vanadium adding molten steel, stop heating then, C content from molten steel to molten steel feeding carbon that adjust is 0.12%～0.18%.
This method of manufacture also can comprise: the C content of adjustment molten steel is 0.12%～0.18% in adjustment Si content, Mn content, Cr content and the Mo content in step (c).
This method of manufacture also can comprise: the C content of adjustment molten steel is 0.12%～0.18% in adjustment Ti content and the V content in step (f).
This method of manufacture also can be included in step (f) and afterwards molten steel carried out continuous casting, and the temperature that continuous casting is operated the molten steel in the employed tundish can be 1530 ℃～1560 ℃.
The method of manufacture of steel alloy according to a further aspect of the invention may further comprise the steps: (a) first steel-making water; (b) be 0.03%～0.06% at the C of molten steel content, P content is not more than 0.015%, and S content is not more than at 0.020% o'clock, taps to ladle; (c) in tapping process, the Si content of adjustment molten steel is 0.17%～0.37%, and Mn content is 0.40%～0.70%, and Cr content is 0.80%～1.10%, and Mo content is 0.40%～0.55%, and the oxygen level of adjustment molten steel is below 0.0020%; (d) the Als content of control molten steel is 0.015%～0.025%, and Als representes the molten aluminium of acid; (e) oxygen level of adjustment molten steel is below 0.0010% in ladle refining furnace, and the C content of molten steel was 0.12%～0.18% when refining was accomplished; (f) molten steel being carried out the circulating vacuum degassing handles; And the Ti content of adjustment molten steel is 0.005%～0.010%; V content is 0.02%～0.04%; Thereby obtain steel alloy; This steel alloy comprises 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V, and surplus is Fe and unavoidable impurities, and the content of each element is weight percent content in the steel alloy.
In step (a), can adopt converter to come steel-making water just.
The oxygen level that in step (c), can adopt at least a adjustment molten steel in aluminium ferromanganese, ferro-aluminum, ferrosilicon, manganese metal and the low carbon ferromanganese is below 0.0020%.
In step (c), can adjust Si content, Mn content, Cr content and Mo content through alloying material being added molten steel, alloying material comprise the aluminium ferromanganese, manganese metal and the ferromanganese that are used for adjusting Mn content at least a, the ferrosilicon that is used to adjust Si content, be used to the molybdenum-iron adjusting the ferrochrome of Cr content and be used to adjust Mo content.
In step (d), can add the Al content that aluminium is controlled molten steel to molten steel.
In step (e), can adopt CaC
2Or CaC
2With the oxygen level of the combination of aluminium adjustment molten steel below 0.0010%.
Step (a) can be included in the interior smelting molten iron of converter and obtain molten steel, in step (e), can adopt CaC
2The adjustment molten steel oxygen level below 0.0010%, CaC
2Usage quantity (kg) can be molten iron add-on (ton) * 95% * (1.8～2.2) * (0.7～1.0).
Can be in ladle refining furnace heating stopped heating in 5 minutes to 10 minutes after to molten steel, feeding carbon to molten steel then, to adjust the C content of molten steel be 0.12%～0.18%.
This method of manufacture also can comprise: the C content of adjustment molten steel is 0.12%～0.18% in adjustment Si content, Mn content, Cr content and the Mo content in step (c).
Molten steel is carried out circulating vacuum degassing processed steps can be included in and in the RH vacuum unit molten steel is carried out the circulating vacuum degassing and handle, be not more than at pressure that the vacuum treated time can be no less than 10 minutes under the condition of 300Pa.
The step of Ti content of adjustment molten steel can comprise ferro-titanium is added molten steel, and the step of the V content of adjustment molten steel can comprise ferro-vanadium is added molten steel.
This method of manufacture also is included in step (f) and afterwards molten steel is carried out continuous casting, and the temperature that continuous casting is operated the molten steel in the employed tundish is 1530 ℃～1560 ℃.
According to steel alloy of the present invention and method of manufacture thereof, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V can be fully the fixing N in the steel, thereby reduce the ageing of steel to greatest extent.In addition, steel alloy of the present invention has lower Al content, can the cold working at rear portion not had a negative impact.
Embodiment
Comprise 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als (aluminium is dissolved in acid) and 0.02%～0.04% V by weight percentage according to steel alloy of the present invention, surplus is Fe and unavoidable impurities.The content of all components that relates in this manual, is weight percent content.
Can comprise according to unavoidable impurities in the steel alloy of the present invention and to be not more than 0.025% P, to be not more than 0.015% S, to be not more than 0.009% N, to be not more than 0.20% Cu and to be not more than 0.30% Ni.
N in the steel is the elemental gas that is difficult to remove.Usually, adopt and residual in the steel that bof process smelts 0.004%～0.006% nitrogen to be arranged.If the exposed for a long time heating of electric arc (submerged arc is bad) during LF stove (ladle refining furnace) refining, perhaps the argon shield in the casting cycle is bad etc., and then nitrogen in steel content possibly reach 0.007%; If re-use nitrogenous high raw material, for example use high nitrogenous pitch coke carburetting, use the sub product aluminium ash of producing electrolytic aluminum to carry out slag making etc., then also can make the molten steel nitrogen content reach 0.009%.According to the present invention, take into full account bof process and smelted the various nitrogen pick-up factors that steel possibly occur, the maximum nitrogen content that limits steel alloy is 0.009%.
Ti fixes the N in the steel through forming firm titanium nitride (TiN) particle with N, but the tiny TiN particle crystal grain of refinement steel also.If Ti content is less than 0.005%; Then steel intermediate gap nitrogen-atoms is fixed fully inadequately; And, can increase the cold worked difficulty in rear portion of steel and/or the toughness of reduction steel in this case because Ti content uses the Als of too high levels and/or V to fix N (of the back literary composition) very little.If Ti content greater than 0.010%, then can produce the square inclusion of large-sized TiN, scratch base steel easily and form the internal fissure source, thereby reduce the fatigue property of steel.Therefore, steel alloy of the present invention comprises 0.005%～0.010% Ti.
Aluminium in the steel is divided into two types.A kind of is to have little time to float to the deoxidation products Al in the slag when smelting
2O
3In aluminium because Al
2O
3Can not be dissolved in the acid, so will combine to form Al with oxygen
2O
3Aluminium be called sour insoluble aluminium.Another kind is to be mainly contained the aluminium in pure aluminum and the aluminium nitride AlN (AlN) by sour dissolved aluminium, and it is called acid and dissolves aluminium, usually with " Als " expression.Molten aluminium of acid and sour insoluble aluminium sum are called full aluminium in the steel, usually with " Al " or " Alt " expression.General molten steel is through after the refining, and having among the Alt more than 90% is Als, and perhaps Als content approximates Alt content.The alleged acid of the present invention dissolves that aluminium refers to be present in as stated in the steel can be by sour dissolved aluminium (Als), the related statement that the amount of aluminium is dissolved in acid refer to above-mentioned can be by the amount of sour dissolved aluminium element.
In the smelting process of steel, add aluminium as deoxidant element.In addition, though the avidity of Al and N is weaker than the avidity of Ti and N, aluminium also can fix the N in the steel through forming the AlN particle with N, but the tiny AlN particle crystal grain of refinement steel also.If Als content less than 0.005%, is then consolidated the N DeGrain, and and because the Ti and/or the V of the too little use of Als content too high levels fix N, the toughness that is easy to produce the square inclusion of large-sized TiN and/or reduces steel.If Als content, then can increase the cold worked difficulty in rear portion of steel greater than 0.010%.Therefore, steel alloy of the present invention comprises 0.005%～0.010% Als.
The avidity of V and N is weaker than the avidity of Al and N, fixes the N in the steel but V can form vanadium nitride (VN) particle with N equally.If V content is less than 0.02%, the DeGrain of fix N then, and use the Ti and/or the Al of too high levels to fix N because V content is too little, the cold worked difficulty in rear portion that is easy to produce the square inclusion of large-sized TiN and/or increases steel.If V content greater than 0.04%, then can reduce the toughness of steel.Therefore, steel alloy of the present invention comprises 0.02%～0.04% V.
0.005%～0.010% Ti in the steel alloy of the present invention, 0.005%～0.010% Als and 0.02%～0.04% V can fixedly be no more than 0.009% N in the steel fully, thereby reduce the ageing of steel to greatest extent.
Method of manufacture according to the steel alloy of first embodiment of the invention comprises just steel-making water and LF stove refined molten steel.Hereinafter, with the method for manufacture of describing in detail according to the steel alloy of first embodiment of the invention.
At first, can in converter, add molten iron, utilize the function of Converter Oxigen Blowing decarburization, molten iron just is smelt molten steel.When molten steel just refines C content is 0.03%～0.06%, and P content is not more than 0.015%, and S content is not more than at 0.020% o'clock, taps to ladle.
In tapping process; Can add pre-deoxidant and alloying material to ladle; The oxygen level of molten steel is removed to below 0.0020%, and control Si content is 0.17%～0.37%, and control Mn content is 0.40%～0.70%; Control Cr content is 0.80%～1.10%, and control Mo content is 0.40%～0.55%.Pre-deoxidant can comprise aluminium matter pre-deoxidant.Aluminium matter pre-deoxidant can comprise at least a among aluminium ferromanganese FeAlMn, the ferro-aluminum FeAl etc.At least a, the ferrochrome (FeCr) (for example low carbon ferrochromium) that is used to control Cr content of aluminium ferromanganese, manganese metal and the ferromanganese (for example low carbon ferromanganese) that alloying material can comprise the ferrosilicon (FeSi) that is used for adjusting Si content, be used to adjust Mn content and the molybdenum-iron (FeMo) that is used to control Mo content.In addition, the Si in the alloying material, Mn also have the effect of deoxidation.Deoxidation mode in this step is the bulk deoxidation mode, and promptly the oxygen in the molten steel and the Al that added, Si and Mn generate the oxide compound that is insoluble to molten steel or composite oxides and separate out, and float in the slag on the deoxidation products that generates then.
Then, with aluminium (for example aluminum steel) feeding molten steel, the Als content of control steel is 0.015%～0.025%.Here, control Als content is 0.015%～0.025%, considers that rear portion refining procedure and optional continuous casting steel machine operation all possibly exist Als to change into Al
2O
3Phenomenon.Find that through further investigation if just in the refining process Als content is being controlled to 0.015%～0.025%, the Als content that then can guarantee the cooled strand of continuous casting is in 0.005%～0.010% scope.
Afterwards, adopt the LF stove under the condition of Argon, to carry out liquid steel refining.Specifically, can at first add CaC as reductor
2Or CaC
2Combination with aluminium (for example Al ball) begins electrically heated then.In refining process, because CaC
2And the proportion of aluminium (for example Al ball) is less than the proportion of molten steel, so reductor (that is CaC, that adds
2Or CaC
2Combination with aluminium) mainly is present in the slag and sloughs the oxygen in the slag.Because the oxygen level of slag less than the oxygen level of molten steel, so the oxygen in the molten steel is delivered in the slag, is removed by the reductor in the slag then, this deoxidation mode is called the diffusive deoxidation mode.Electrically heated in the refining process has guaranteed the molten state of slag, plays a role thereby be convenient to reductor.
Reductor CaC
2Or CaC
2Be as the criterion below 0.0010% with the oxygen level in the control molten steel with the add-on of the combination of aluminium (for example Al ball).
CaC
2Deoxidation products comprise CO gas, can make furnace gas have certain reductibility, can make simultaneously the slag foaming, help the heating of LF stove submerged arc, reduce the possibility that molten steel absorbs airborne nitrogen.Therefore, the present invention preferably uses CaC separately
2As reductor.Using CaC separately
2Content is under the situation of calcium carbide as reductor more than 70%, and the add-on of calcium carbide (unit is kg) can be molten iron add-on (tonnage) * 95% * (1.8～2.2), to guarantee the Control for Oxygen Content in the molten steel below 0.0010%.
In the LF stove to molten steel electrically heated 5 minutes after 10 minutes, the Ti content and the V content of adjustment molten steel make that the Ti content in the molten steel is 0.005%～0.010%, V content is 0.02%～0.04%.For example, ferrotianium (FeTi) alloy is added molten steel adjust Ti content, vanadium iron (FeV) alloy is added molten steel adjust V content.If molten steel underheating was just adjusted Ti content and V content in 5 minutes, then the slag above the molten steel can all not become molten state, is unfavorable for that ferro-titanium and ferro-vanadium pass slag blanket and get into molten steel, promptly can not guarantee the recovery of Ti, V.If adjust Ti content and V content after molten steel heating being longer than time of 10 minutes, then the LF stove activity duration long, can not guarantee the rhythm of production of steel, possibly cause that continuous caster is disconnected to be watered, increase the production cost of steel, the operating efficiency of reduction equipment.
After the Ti content and V content of adjustment molten steel, in the LF stove,, stop heating to molten steel reheat 5 minutes to 10 minutes, afterwards carbon is fed molten steel, the C content of adjusting molten steel is 0.12%～0.18%.In one embodiment, adopt feeding wire machine feeding carbon cored-wire to adjust the C content of molten steel.If adjust C content after in the LF stove, the molten steel reheat being no less than time of 5 minutes, can guarantee that then the ferro-titanium that adds melts with ferro-vanadium, and Ti, V element are evenly distributed in the molten steel.If adjust C content after in the LF stove, the molten steel reheat being surpassed time of 10 minutes, then the LF stove activity duration long, can not guarantee the rhythm of production of steel, possibly cause that continuous caster is disconnected to be watered, increase the production cost of steel, reduce the operating efficiency of equipment.
Selectively; Because the C that contains in the alloying material that adds when pre-deoxidant that is added when just making steel water and/or alloying material and adjustment Ti, V content makes the C content of molten steel be increased in 0.12%～0.18% the scope, so when LF stove refined molten steel, can not add carbon adjustment C content separately from 0.03%～0.06%.In this case, in the LF stove, after 10 minutes, can not adjust C content in addition in 5 minutes after adjustment Ti, the V content to the molten steel reheat.
The C content of molten steel should be in 0.12%～0.18% scope when in a word, the refining of LF stove was accomplished.
The temperature of molten steel is confirmed by the liquidus temperature of steel in the liquid steel refining process.The liquidus temperature of steel alloy of the present invention is 1510-1519 ℃.In the method for manufacture according to the steel alloy of first embodiment of the invention, the temperature of molten steel is the liquidus temperature of molten steel or the temperature slightly higher than liquidus temperature in the refining process.
When ladle is tapped, can bring a certain amount of converter slag inevitably in converter in ladle.The converter slag phosphorus content is high, and under the effect of LF stove reducing atmosphere, a part of phosphorus in the slag is got back in the molten steel once more, and the P element is slightly increased.Yet, be not more than 0.015% because when the converter smelting molten steel, P content is controlled to, so, can not surpass 0.025% although P content slightly increases.
In refining process, can remove the S in the molten steel significantly.This is because the CaC in the reductor
2Make slag that good reductibility arranged, and increase the CaO content in the slag, so FeS in molten steel and the slag and CaO reaction generate CaS and remove significantly.
The impurity element that possibly comprise in the steel alloy of the present invention (or being called residual element) Cu and Ni can not remove from molten steel through above-mentioned first steel-making water and LF stove refined molten steel.Therefore, can control the content of these elements in the steel alloy of the present invention through the content of these impurity elements in the control raw material (being molten iron).
According to the method for manufacture of the steel alloy of first embodiment of the invention, through smelting molten steel in converter, pass through the refining of LF stove again, can N content in the steel be controlled at below 0.009%.For example, at least a mode in can be in the following manner is controlled at N content in the steel below 0.009%: in the process of bessemerizing, carry out bottom blowing with Ar gas all the time; Change bottom blown gas into Ar gas by nitrogen bessemerizing the later stage; In LF stove refining process, make the slag foamed, avoid the direct and airborne nitrogen of air contact ionization of electric arc.
Pass through aforesaid method; Obtain steel alloy of the present invention; It comprises 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V by weight, and surplus is Fe and unavoidable impurities.The unavoidable impurities of this steel alloy can comprise and is not more than 0.025% P, is not more than 0.015% S, is not more than 0.009% N, is not more than 0.20% Cu and is not more than 0.30% Ni.
According to the method for manufacture of the steel alloy of first embodiment of the invention, only in the first refining process of molten steel, add aluminium as pre-deoxidant, in the refined molten steel at rear portion, can not add aluminium, so deoxidation products Al
2O
3Ascent time is long, is easy to produce Al
2O
3Poor high quality steel.
Be also to be included in the step of the continuous casting after the LF stove refined molten steel according to the method for manufacture of the steel alloy of second embodiment of the invention and difference according to the method for manufacture of the steel alloy of first embodiment of the invention.The liquidus temperature of steel alloy of the present invention is 1510 ℃ to 1519 ℃, and the temperature of continuous casting tundish is controlled at 1530 ℃～1560 ℃.This TR can realize through the electrically heated of front LF stove; Specifically, the temperature of molten steel is a liquidus temperature or than temperature loss (for example 40～50 ℃)+tundish superheating temperature (for example 20～35 ℃) of the slightly high temperature+ladle of liquidus temperature to tundish in the LF stove refining process.The temperature of tundish molten steel is controlled at 1530 ℃～1560 ℃, can guarantees molten steel all casting completion under the low overheat condition.
Method of manufacture according to the steel alloy of third embodiment of the invention comprises steel-making water, LF stove refined molten steel and RH vacuum outgas (the circulating vacuum degassing) just.Hereinafter, with the method for manufacture of describing in detail according to the steel alloy of third embodiment of the invention.
At first, can in converter, add molten iron, utilize the function of Converter Oxigen Blowing decarburization, molten iron just is smelt molten steel.When molten steel just refines C content is 0.03%～0.06%, and P content is not more than 0.015%, and S content is not more than at 0.020% o'clock, taps to ladle.
In tapping process; Can add pre-deoxidant and alloying material to ladle; The oxygen level of molten steel is removed to below 0.0020%, and control Si content is 0.17%～0.37%, and control Mn content is 0.40%～0.70%; Control Cr content is 0.80%～1.10%, and control Mo content is 0.40%～0.55%.Pre-deoxidant can comprise aluminium matter pre-deoxidant.Aluminium matter pre-deoxidant can comprise at least a among aluminium ferromanganese FeAlMn, the ferro-aluminum FeAl etc.At least a, the ferrochrome (FeCr) (for example low carbon ferrochromium) that is used to control Cr content of aluminium ferromanganese, manganese metal and the ferromanganese (for example low carbon ferromanganese) that alloying material can comprise the ferrosilicon (FeSi) that is used for adjusting Si content, be used to adjust Mn content and the molybdenum-iron (FeMo) that is used to control Mo content.In addition, the Si in the alloying material, Mn also have the effect of deoxidation.Deoxidation mode in this step is the bulk deoxidation mode, and promptly the oxygen in the molten steel and the Al that added, Si and Mn generate the oxide compound that is insoluble to molten steel or composite oxides and separate out, and float in the slag on the deoxidation products that generates then.
Then, with aluminium (for example aluminum steel) feeding molten steel, the Als content of control steel is 0.015%～0.025%.Here, control Als content is 0.015%～0.025%, considers that rear portion refining procedure, RH vacuum outgas and optional continuous casting steel machine operation all possibly exist Als to change into Al
2O
3Phenomenon.Find that through further investigation if just in the refining process Als content is being controlled to 0.015%～0.025%, the Als content that then can guarantee the cooled strand of continuous casting is in 0.005%～0.010% scope.
Afterwards, adopt the LF stove under the condition of Argon, to carry out liquid steel refining.Specifically, can at first add CaC as reductor
2Or CaC
2Combination with aluminium (for example Al ball) begins electrically heated then.In refining process, because CaC
2And the proportion of aluminium (for example Al ball) is less than the proportion of molten steel, so reductor (that is CaC, that adds
2Or CaC
2Combination with aluminium) mainly is present in the slag and sloughs the oxygen in the slag.Because the oxygen level of slag less than the oxygen level of molten steel, so the oxygen in the molten steel is delivered in the slag, is removed by the reductor in the slag then, this deoxidation mode is called the diffusive deoxidation mode.Electrically heated in the refining process has guaranteed the molten state of slag, plays a role thereby be convenient to reductor.
Reductor CaC
2Or CaC
2Be as the criterion below 0.0010% with the oxygen level in the control molten steel with the add-on of the combination of aluminium (for example Al ball).
CaC
2Deoxidation products comprise CO gas, can make furnace gas have certain reductibility, can make simultaneously the slag foaming, help the heating of LF stove submerged arc, reduce the possibility that molten steel absorbs airborne nitrogen.Therefore, the present invention preferably uses CaC separately
2As reductor.Using CaC separately
2Content is under the situation of calcium carbide as reductor more than 70%, and the add-on of calcium carbide (unit is kg) can be molten iron add-on (tonnage) * 95% * (1.8～2.2), to guarantee the Control for Oxygen Content in the molten steel below 0.0010%.
In the LF stove to molten steel electrically heated 5 minutes after 10 minutes, stop heating.If in the LF stove, the molten steel reheat is no less than 5 minutes time, then can guarantees reductor CaC
2Or CaC
2With the fusing of the combination of aluminium (for example Al ball), just can slough the oxygen in the slag after having only the reductor fusing, further make molten steel carry out diffusive deoxidation.If in the LF stove, the molten steel reheat surpassed 10 minutes time, then the LF stove activity duration long, can not guarantee the rhythm of production of steel, possibly cause that continuous caster is disconnected to be watered, increase the production cost of steel, reduce the operating efficiency of equipment.
Selectively, after stopping heating, carbon is fed molten steel, the C content of adjustment molten steel is 0.12%～0.18%; In one embodiment, adopt feeding wire machine feeding carbon cored-wire to adjust the C content of molten steel.Selectively; Because the C that contains in pre-deoxidant that is added when just making steel water and/or the alloying material makes the C content of molten steel be increased in 0.12%～0.18% the scope from 0.03%～0.06%, so when LF stove refined molten steel, can not add carbon adjustment C content separately.The C content of molten steel should be in 0.12%～0.18% scope when in a word, the refining of LF stove was accomplished.
The temperature of molten steel is confirmed by the liquidus temperature of steel in the liquid steel refining process.The liquidus temperature of steel alloy of the present invention is 1510-1519 ℃.In the method for manufacture according to the steel alloy of third embodiment of the invention, the temperature of molten steel is the loss temperature (for example 30～40 ℃) of the liquidus temperature of molten steel or the temperature slightly higher than liquidus temperature+RH vacuum outgas in the refining process.
Then, molten steel is carried out the RH vacuum outgas handle, the main effect that the RH vacuum outgas is handled is the hydrogen in the steel is removed to lower level.Specifically, can in the RH vacuum unit, carry out vacuum-treat to molten steel, the treatment time that is not more than 300Pa vacuum treated total time with pressure was as the criterion more than 10 minutes.
In the process that the RH vacuum outgas is handled, the Ti content and the V content of adjustment molten steel make that the Ti content in the molten steel is 0.005%～0.010%, and V content is 0.02%～0.04%.For example, ferrotianium (FeTi) alloy is added molten steel adjust Ti content, vanadium iron (FeV) alloy is added molten steel adjust V content.
The impurity element that possibly comprise in the steel alloy of the present invention (or being called residual element) Cu and Ni can not remove from molten steel through above-mentioned first steel-making water, LF stove refined molten steel and RH vacuum outgas.Therefore, can control the content of these elements in the steel alloy of the present invention through the content of these impurity elements in the control raw material (being molten iron).
According to the method for manufacture of the steel alloy of third embodiment of the invention,, through LF stove refining and RH vacuum outgas processing, can N content in the steel be controlled at below 0.009% again through smelting molten steel in converter.For example, at least a mode in can be in the following manner is controlled at N content in the steel below 0.009%: in the process of bessemerizing, carry out bottom blowing with Ar gas all the time; Change bottom blown gas into Ar gas by nitrogen bessemerizing the later stage; In LF stove refining process, make the slag foamed, avoid the direct and airborne nitrogen of air contact ionization of electric arc.
The method of manufacture of the steel alloy through third embodiment of the invention; Obtain steel alloy of the present invention; It comprises 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V by weight, and surplus is Fe and unavoidable impurities.The unavoidable impurities of this steel alloy can comprise and is not more than 0.025% P, is not more than 0.015% S, is not more than 0.009% N, is not more than 0.20% Cu and is not more than 0.30% Ni.
According to the method for manufacture of the steel alloy of third embodiment of the invention, only in the first refining process of molten steel, add aluminium as pre-deoxidant, in the refined molten steel at rear portion and RH vacuum outgas, can not add aluminium, so deoxidation products Al
2O
3Ascent time is long, is easy to produce Al
2O
3Poor high quality steel.
Be the step of the continuous casting after also being included in the RH vacuum outgas handles according to the method for manufacture of the steel alloy of fourth embodiment of the invention and difference according to the method for manufacture of the steel alloy of third embodiment of the invention.The liquidus temperature of steel alloy of the present invention is 1510 ℃ to 1519 ℃, and the temperature of continuous casting tundish is controlled at 1530 ℃～1560 ℃.This TR can realize through the electrically heated of front LF stove; Specifically, the temperature of molten steel is temperature loss (for example 40～50 ℃)+tundish superheating temperature (for example 20～35 ℃) of loss temperature (for example 30～40 ℃)+ladle of liquidus temperature or the temperature+RH vacuum outgas slightly higher than liquidus temperature to tundish in the LF stove refining process.The temperature of tundish molten steel is controlled at 1530 ℃～1560 ℃, can guarantees molten steel all casting completion under the low overheat condition.
Further specify steel alloy of the present invention and method of manufacture thereof below in conjunction with example.
Example 1:
In nominal capacity is the converter of 120 tons (actual tap is 125 tons～135 tons), add 140 tons of molten iron, utilize the function of Converter Oxigen Blowing decarburization that molten iron just is smelt molten steel.When molten steel just refines C content is 0.03%, and P content is 0.011%, and S content is 0.010%, and Si content is 0.02%, and Mn content is 0.03%, and Cr content is 0.05%, and Mo content is 0.03% o'clock, begins to tap to ladle.The amount of the molten steel after converter smelting is accomplished is 133 tons.
In tapping process; Add to ladle and can the molten steel oxygen level be removed to FeAl below 0.0020% (aluminium content is 40%; All the other are Fe) 350kg; And FeSi (Si content is 73%, and all the other are Fe) 500kg, metal M n (Mn content is 98%) 660kg, low carbon ferrochromium (Cr content is 66%) 1670kg and molybdenum-iron (Mo content is 59%) 875kg.After adding, using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0017%, and Si, Mn, Cr and Mo content are increased to 0.24%, 0.48%, 0.83% and 0.43% respectively in the molten steel.Then, with the Al line 32kg feeding molten steel of feeding wire machine with φ 10mm, the Als content of control molten steel is 0.024%.
Afterwards, in the LF stove with 50kg Al ball and 270kg calcium carbide (CaC
2Content is more than 75%) add molten steel, heat then.Heat after 5 minutes, sampling analysis, the N content of molten steel is 0.0070%, C content was 0.09% (adding of various iron alloys causes carburetting inevitably).Continue heating then; (the raw material molten iron is for containing the Ti molten iron to add FeTi30-A (the ferrotianium trade mark among the GB GB/T3282-2006) 40kg (Ti content is 30%, and all the other are Fe, and the Ti recovery is about 75%) simultaneously; Even so do not add ferrotianium; All the time residual 0.003% the Ti of having an appointment in the molten steel) and FeV80A (the vanadium iron trade mark among the GB GB/T4139-2004) 25kg (V content is 80%, and all the other are Fe, and the V recovery is about 95%) (the raw material molten iron is for containing the V molten iron; Even so do not add vanadium iron, residual all the time 0.006% the V of having an appointment in the molten steel).Continue heating then and stop heating after 6 minutes, in molten steel, feed carbon dust 100kg (with the form feeding of carbonaceous cored-wire, this cored-wire is to process with the thick iron sheet parcel carbon dust of 0.6mm, and the carbon dust C content is not less than 90%) with feeding wire machine.Using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0007%.Sampling analysis, the Ti content of molten steel, V content, Als content and C content are respectively 0.010%, 0.02%, 0.011% and 0.15%.
At last, on 6 machines 6 stream billet casters, molten steel casting become the strand of 280mm * 380mm.Tundish temperature is 1540 ℃ during continuous casting.The chemical composition of getting tundish steel sample analysis steel is 0.15% C, 0.25% Si, 0.48% Mn, 0.85% Cr, 0.42% Mo, 0.010% Ti, 0.02% V, 0.010% Als, 0.011% Alt, 0.011% P, 0.009% S, 0.05% Cu and 0.04% Ni, and all the other are Fe and other unavoidable impurities.
280mm * 380mm continuously cast bloom forges into φ 30mm pole, and then is machined to the pole of φ 5 * 10mm and φ 15 * 60mm.Press total N content that GB/T 20124-2006 measures the pole of φ 5 * 10mm.The pole of φ 15 * 60mm dissolves → distillation through constant-current electrolysis → collection residue → (phosphoric acid+sulfuric acid) is sour, adopts the indophenol blue absorption spectrophotometry to measure chemical combination N content at last.Total N content is 0.0084%, and chemical combination N content is 0.0083%, and the Ti of this explanation 0.010%, 0.02% V, 0.010% Als be the N in the steel fully fixedly.
Example 2:
In nominal capacity is the converter of 120 tons (actual tap is 125 tons～135 tons), add 140 tons of molten iron, utilize the function of Converter Oxigen Blowing decarburization that molten iron just is smelt molten steel.When molten steel just refines C content is 0.04%, and P content is 0.014%, and S content is 0.019%, and Si content is 0.02%, and Mn content is 0.04%, and Cr content is 0.05%, and Mo content is 0.04% o'clock, begins to tap to ladle.The amount of the molten steel after converter smelting is accomplished is 133 tons.
In tapping process; Add to ladle and can the molten steel oxygen level be removed to FeAl below 0.0020% (aluminium content is 40%; All the other are Fe) 320kg; And FeSi (Si content is 73%, and all the other are Fe) 390kg, metal M n (Mn content is 98%) 940kg, low carbon ferrochromium (Cr content is 66%) 1800kg and molybdenum-iron (Mo content is 59%) 920kg.After adding, using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0016%, and Si, Mn, Cr and Mo content are increased to 0.19%, 0.68%, 0.90% and 0.43% respectively in the molten steel.Then, with the Al line 25kg feeding molten steel of feeding wire machine with φ 10mm, the Als content of control molten steel is 0.015%.
Afterwards, in the LF stove with 50kg Al ball and 270kg calcium carbide (CaC
2Content is more than 75%) add molten steel, heat then.Heat after 5 minutes, sampling analysis, the N content of molten steel is 0.0062%, C content was 0.10% (adding of various iron alloys causes carburetting inevitably).Continue heating then, (Ti content is 30%, and all the other are Fe to add FeTi30-A (the ferrotianium trade mark among the GB GB/T3282-2006) 35kg simultaneously; The Ti recovery is about 75%) (the raw material molten iron is for containing the Ti molten iron, thus even do not add ferrotianium, residual all the time 0.003% the Ti of having an appointment in the molten steel) and FeV80A (the vanadium iron trade mark among the GB GB/T4137-2004) (V content is 80% to 43kg; All the other are Fe; The V recovery is about 95%) (the raw material molten iron is for containing the V molten iron, so even do not add vanadium iron, residual all the time 0.006% the V of having an appointment in the molten steel); Continue heating then and stop heating after 7 minutes; In molten steel, feed carbon dust 130kg (with the form feeding of carbonaceous cored-wire, this cored-wire is to process with the thick iron sheet parcel carbon dust of 0.6mm, and the carbon dust C content is not less than 90%) with feeding wire machine.Using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0007%.Sampling analysis, the Ti content of molten steel, V content, Als content and C content are respectively 0.008%, 0.03%, 0.006% and 0.18%.
At last, on 6 machines 6 stream billet casters, molten steel casting become the strand of 280mm * 380mm.Tundish temperature is 1545 ℃ during continuous casting.The chemical composition of getting tundish steel sample analysis steel is 0.18% C, 0.18% Si, 0.69% Mn, 0.91% Cr, 0.45% Mo, 0.008% Ti, 0.028% V, 0.005% Als, 0.006% Alt, 0.016% P, 0.015% S, 0.05% Cu and 0.04% Ni, and all the other are Fe and other unavoidable impurities.
280mm * 380mm continuously cast bloom forges into φ 30mm pole, and then is machined to the pole of φ 5 * 10mm and φ 15 * 60mm.Press total N content that GB/T 20124-2006 measures the pole of φ 5 * 10mm.The pole of φ 15 * 60mm dissolves → distillation through constant-current electrolysis → collection residue → (phosphoric acid+sulfuric acid) is sour, adopts the indophenol blue absorption spectrophotometry to measure chemical combination N content at last.Total N content is 0.0069%, and chemical combination N content is 0.0069%, and the Ti of this explanation 0.008%, 0.028% V, 0.005% Als be the N in the steel fully fixedly.
Example 3:
In nominal capacity is the converter of 120 tons (actual tap is 125 tons～135 tons), add 135 tons of molten iron, utilize the function of Converter Oxigen Blowing decarburization that molten iron just is smelt molten steel.When molten steel just refines C content is 0.06%, and P content is 0.010%, and S content is 0.008%, and Si content is 0.02%, and Mn content is 0.05%, and Cr content is 0.05%, and Mo content is 0.04% o'clock, begins to tap to ladle.The amount of the molten steel after converter smelting is accomplished is 128 tons.
In tapping process; Add to ladle and can the molten steel oxygen level be removed to FeAl below 0.0020% (aluminium content is 40%; All the other are Fe) 350kg; And FeSi (Si content is 73%, and all the other are Fe) 720kg, metal M n (Mn content is 98%) 720kg, low carbon ferrochromium (Cr content is 66%) 2000kg and molybdenum-iron (Mo content is 59%) 830kg.After adding, using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0016%, and Si, Mn, Cr and Mo content are increased to 0.35%, 0.56%, 1.07% and 0.41% respectively in the molten steel.Then, with the Al line 25kg feeding molten steel of feeding wire machine with φ 10mm, the Als content of control molten steel is 0.015%.
Afterwards, in the LF stove with 25kg Al ball and 260kg calcium carbide (CaC
2Content is more than 75%) add molten steel, heat then.Heat after 5 minutes, sampling analysis, the N content of molten steel is 0.0070%, C content is 0.10%; Continue heating 5 minutes then, after heating finishes, in molten steel, feed carbon dust 95kg (with the form feeding of carbonaceous cored-wire, this cored-wire is to process with the thick iron sheet parcel carbon dust of 0.6mm, and the carbon dust C content is not less than 90%) with feeding wire machine.Using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0005%.
Then, the molten steel after the processing of LF stove is transferred to the RH vacuum unit.The pure treatment time of vacuum unit is 12 minutes, and ultimate pressure is controlled to be 300Pa.Under ultimate pressure, handle and add FeTi30-A (the ferrotianium trade mark among the GB GB/T3282-2006) 30kg after 5 minutes (Ti content is 30%; All the other are Fe; The Ti recovery is about 75%) (the raw material molten iron is for containing the Ti molten iron, thus even do not add ferrotianium, residual all the time 0.003% the Ti of having an appointment in the molten steel) and FeV80A (the vanadium iron trade mark among the GB GB/T4137-2004) (V content is 80% to 58kg; All the other are Fe; The V recovery is about 95%) (the raw material molten iron is for containing the V molten iron, so even do not add vanadium iron, residual all the time 0.006% the V of having an appointment in the molten steel).After vacuum-treat finishes, sampling analysis, the Ti content of molten steel, V content, Als content and C content are respectively 0.008%, 0.040%, 0.007% and 0.16%.
At last, on 6 machines 6 stream billet casters, molten steel casting become the strand of 280mm * 380mm.Tundish temperature is 1550 ℃ during continuous casting.The chemical composition of getting tundish steel sample analysis steel is 0.16% C, 0.35% Si, 0.52% Mn, 1.08% Cr, 0.40% Mo, 0.008% Ti, 0.04% V, 0.006% Als, 0.007% Alt, 0.014% P, 0.005% S, 0.05% Cu and 0.05% Ni, and all the other are Fe and other unavoidable impurities.
280mm * 380mm continuously cast bloom forges into φ 30mm pole, and then is machined to the pole of φ 5 * 10mm and φ 15 * 60mm.Press total N content that GB/T 20124-2006 measures the pole of φ 5 * 10mm.The pole of φ 15 * 60mm dissolves → distillation through constant-current electrolysis → collection residue → (phosphoric acid+sulfuric acid) is sour, adopts the indophenol blue absorption spectrophotometry to measure chemical combination N content at last.Total N content is 0.0085%, and chemical combination N content is 0.0085%, and the Ti of this explanation 0.008%, 0.04% V, 0.006% Als be the N in the steel fully fixedly.
Example 4:
In nominal capacity is the converter of 120 tons (actual tap is 125 tons～135 tons), add 130 tons of molten iron, utilize the function of Converter Oxigen Blowing decarburization that molten iron just is smelt molten steel.When molten steel just refines C content is 0.05%, and P content is 0.008%, and S content is 0.007%, and Si content is 0.03%, and Mn content is 0.05%, and Cr content is 0.05%, and Mo content is 0.04% o'clock, begins to tap to ladle.The amount of the molten steel after converter smelting is accomplished is 123 tons.
In tapping process; Add to ladle and can the molten steel oxygen level be removed to FeAl below 0.0020% (aluminium content is 40%; All the other are Fe) 350kg; And FeSi (Si content is 73%, and all the other are Fe) 550kg, metal M n (Mn content is 98%) 550kg, low carbon ferrochromium (Cr content is 66%) 1900kg and molybdenum-iron (Mo content is 59%) 1000kg.After adding, using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0019%, and Si, Mn, Cr and Mo content are increased to 0.29%, 0.45%, 1.02% and 0.50% respectively in the molten steel.Then, with the Al line 25kg feeding molten steel of feeding wire machine with φ 10mm, the Als content of control molten steel is 0.016%.
Afterwards, in the LF stove with 25kg Al ball and 260kg calcium carbide (CaC
2Content is more than 75%) add molten steel, heat then.Heat after 5 minutes, sampling analysis, the N content of molten steel is 0.0071%, C content is 0.08%; Continue heating 5 minutes then, after heating finishes, in molten steel, feed carbon dust 70kg (with the form feeding of carbonaceous cored-wire, this cored-wire is to process with the thick iron sheet parcel carbon dust of 0.6mm, and the carbon dust C content is not less than 90%) with feeding wire machine.Using apparatus for determination of oxygen to record molten steel actual oxygen content is 0.0006%.
Then, the molten steel after the processing of LF stove is transferred to the RH vacuum unit.The pure treatment time of vacuum unit is 12 minutes, and ultimate pressure is controlled to be 300Pa.Under ultimate pressure, handle and add FeTi30-A (the ferrotianium trade mark among the GB GB/T3282-2006) 10kg after 5 minutes (Ti content is 30%; All the other are Fe; The Ti recovery is about 75%) (the raw material molten iron is for containing the Ti molten iron, thus even do not add ferrotianium, residual all the time 0.003% the Ti of having an appointment in the molten steel) and FeV80A (the vanadium iron trade mark among the GB GB/T4137-2004) (V content is 80% to 28kg; All the other are Fe; The V recovery is about 95%) (the raw material molten iron is for containing the V molten iron, so even do not add vanadium iron, residual all the time 0.006% the V of having an appointment in the molten steel).After vacuum-treat finishes, sampling analysis, the Ti content of molten steel, V content, Als content and C content are respectively 0.005%, 0.023%, 0.008% and 0.12%.
At last, on 6 machines 6 stream billet casters, molten steel casting become the strand of 280mm * 380mm.Tundish temperature is 1550 ℃ during continuous casting.The chemical composition of getting tundish steel sample analysis steel is 0.12% C, 0.28% Si, 0.46% Mn, 1.00% Cr, 0.53% Mo, 0.005% Ti, 0.022% V, 0.005% Als, 0.007% Alt, 0.010% P, 0.005% S, 0.05% Cu and 0.05% Ni, and all the other are Fe and other unavoidable impurities.
280mm * 380mm continuously cast bloom forges into φ 30mm pole, and then is machined to the pole of φ 5 * 10mm and φ 15 * 60mm.Press total N content that GB/T 20124-2006 measures the pole of φ 5 * 10mm.The pole of φ 15 * 60mm dissolves → distillation through constant-current electrolysis → collection residue → (phosphoric acid+sulfuric acid) is sour, adopts the indophenol blue absorption spectrophotometry to measure chemical combination N content at last.Total N content is 0.0082%, and chemical combination N content is 0.0080%, and the Ti of this explanation 0.005%, 0.022% V, 0.005% Als be the N in the steel fully fixedly.
Claims (26)
1. the method for manufacture of a steel alloy may further comprise the steps:
(a) first steel-making water;
(b) be 0.03%～0.06% at the C of molten steel content, P content is not more than 0.015%, and S content is not more than at 0.020% o'clock, taps to ladle;
(c) in tapping process, the Si content of adjustment molten steel is 0.17%～0.37%, and Mn content is 0.40%～0.70%, and Cr content is 0.80%～1.10%, and Mo content is 0.40%～0.55%, and the oxygen level of adjustment molten steel is below 0.0020%;
(d) the Als content of control molten steel is 0.015%～0.025%, and Als representes the molten aluminium of acid;
(e) oxygen level of in ladle refining furnace, adjusting molten steel is below 0.0010%;
(f) the Ti content of adjustment molten steel is 0.005%～0.010% in refining process, and V content is 0.02%～0.04%, and the C content of molten steel was 0.12%～0.18% when refining was accomplished, thereby obtained steel alloy,
Said steel alloy comprises 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V; Surplus is Fe and unavoidable impurities, and the content of each element is weight percent content in the steel alloy.
2. method of manufacture according to claim 1, wherein, unavoidable impurities comprises and is not more than 0.025% P, is not more than 0.015% S, is not more than 0.009% N, is not more than 0.20% Cu and is not more than 0.30% Ni in the said steel alloy.
3. method of manufacture according to claim 1 wherein, adopts converter to come steel-making water just in step (a).
4. method of manufacture according to claim 1, wherein, the oxygen level that in step (c), adopts at least a adjustment molten steel in aluminium ferromanganese, ferro-aluminum, ferrosilicon, manganese metal and the low carbon ferromanganese is below 0.0020%.
5. method of manufacture according to claim 1; Wherein, In step (c), adjust Si content, Mn content, Cr content and Mo content through alloying material being added molten steel, said alloying material comprise the aluminium ferromanganese, manganese metal and the ferromanganese that are used for adjusting Mn content at least a, the ferrosilicon that is used to adjust Si content, be used to the molybdenum-iron adjusting the ferrochrome of Cr content and be used to adjust Mo content.
6. method of manufacture according to claim 1 wherein, adds the Als content that aluminium is controlled molten steel to molten steel in step (d).
7. method of manufacture according to claim 1 wherein, adopts CaC in step (e)
2Or CaC
2With the oxygen level of the combination of aluminium adjustment molten steel below 0.0010%.
8. method of manufacture according to claim 3, wherein, step (a) is included in the interior smelting molten iron of converter and obtains molten steel, in step (e), adopts CaC
2The adjustment molten steel oxygen level below 0.0010%, CaC
2Usage quantity the kilogram number=molten iron add-on tonnage * 95% * (1.8～2.2) * (0.7～1.0).
9. method of manufacture according to claim 1; Wherein, In ladle refining furnace, molten steel is heated Ti content and the V content of after 10 minutes, adjusting molten steel in 5 minutes; The step of Ti content of adjustment molten steel comprises ferro-titanium added molten steel, and the step of the V content of adjustment molten steel comprises ferro-vanadium is added molten steel.
10. method of manufacture according to claim 9 wherein, adds molten steel afterwards to molten steel heating 5 minutes to 10 minutes with ferro-titanium and ferro-vanadium, stops heating then, and C content from molten steel to molten steel feeding carbon that adjust is 0.12%～0.18%.
11. method of manufacture according to claim 1, wherein, said method of manufacture also comprises: the C content of adjustment molten steel is 0.12%～0.18% in adjustment Si content, Mn content, Cr content and the Mo content in step (c).
12. method of manufacture according to claim 9, wherein, said method of manufacture also comprises: the C content of adjustment molten steel is 0.12%～0.18% in adjustment Ti content and the V content in step (f).
13. method of manufacture according to claim 1, wherein, said method of manufacture also is included in step (f) and afterwards molten steel is carried out continuous casting, and the temperature that continuous casting is operated the molten steel in the employed tundish is 1530 ℃～1560 ℃.
14. the method for manufacture of a steel alloy may further comprise the steps:
(a) first steel-making water;
(b) be 0.03%～0.06% at the C of molten steel content, P content is not more than 0.015%, and S content is not more than at 0.020% o'clock, taps to ladle;
(c) in tapping process, the Si content of adjustment molten steel is 0.17%～0.37%, and Mn content is 0.40%～0.70%, and Cr content is 0.80%～1.10%, and Mo content is 0.40%～0.55%, and the oxygen level of adjustment molten steel is below 0.0020%;
(d) the Als content of control molten steel is 0.015%～0.025%, and Als representes the molten aluminium of acid;
(e) oxygen level of adjustment molten steel is below 0.0010% in ladle refining furnace, and the C content of molten steel was 0.12%～0.18% when refining was accomplished;
(f) molten steel carried out the circulating vacuum degassing and handle, and the Ti content of adjustment molten steel is 0.005%～0.010% that V content is 0.02%～0.04%, thereby obtains steel alloy,
Said steel alloy comprises 0.12%～0.18% C, 0.17%～0.37% Si, 0.40%～0.70% Mn, 0.80%～1.10% Cr, 0.40%～0.55% Mo, 0.005%～0.010% Ti, 0.005%～0.010% Als and 0.02%～0.04% V; Surplus is Fe and unavoidable impurities, and the content of each element is weight percent content in the steel alloy.
15. method of manufacture according to claim 14, wherein, unavoidable impurities comprises and is not more than 0.025% P, is not more than 0.015% S, is not more than 0.009% N, is not more than 0.20% Cu and is not more than 0.30% Ni in the said steel alloy.
16. method of manufacture according to claim 14 wherein, adopts converter to come steel-making water just in step (a).
17. method of manufacture according to claim 14, wherein, the oxygen level that in step (c), adopts at least a adjustment molten steel in aluminium ferromanganese, ferro-aluminum, ferrosilicon, manganese metal and the low carbon ferromanganese is below 0.0020%.
18. method of manufacture according to claim 14; Wherein, In step (c), adjust Si content, Mn content, Cr content and Mo content through alloying material being added molten steel, said alloying material comprise the aluminium ferromanganese, manganese metal and the ferromanganese that are used for adjusting Mn content at least a, the ferrosilicon that is used to adjust Si content, be used to the molybdenum-iron adjusting the ferrochrome of Cr content and be used to adjust Mo content.
19. method of manufacture according to claim 14 wherein, adds the Als content that aluminium is controlled molten steel to molten steel in step (d).
20. method of manufacture according to claim 14 wherein, adopts CaC in step (e)
2Or CaC
2With the oxygen level of the combination of aluminium adjustment molten steel below 0.0010%.
21. method of manufacture according to claim 16, wherein, step (a) is included in the interior smelting molten iron of converter and obtains molten steel, in step (e), adopts CaC
2The adjustment molten steel oxygen level below 0.0010%, CaC
2Usage quantity the kilogram number=molten iron add-on tonnage * 95% * (1.8～2.2) * (0.7～1.0).
22. method of manufacture according to claim 14 wherein, stopped heating in 5 minutes to molten steel heating to 10 minutes after in ladle refining furnace, feeding carbon to molten steel then, to adjust the C content of molten steel be 0.12%～0.18%.
23. method of manufacture according to claim 14, wherein, said method of manufacture also comprises: the C content of adjustment molten steel is 0.12%～0.18% in adjustment Si content, Mn content, Cr content and the Mo content in step (c).
24. method of manufacture according to claim 14; Wherein, Molten steel is carried out circulating vacuum degassing processed steps be included in and in the RH vacuum unit molten steel carried out the circulating vacuum degassing and handle, be not more than at pressure that the vacuum treated time is no less than 10 minutes under the condition of 300Pa.
25. method of manufacture according to claim 14, wherein, the step of Ti content of adjustment molten steel comprises ferro-titanium added molten steel, and the step of the V content of adjustment molten steel comprises ferro-vanadium is added molten steel.
26. method of manufacture according to claim 14, wherein, said method of manufacture also is included in step (f) and afterwards molten steel is carried out continuous casting, and the temperature that continuous casting is operated the molten steel in the employed tundish is 1530 ℃～1560 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010519863 CN102002637B (en) | 2010-10-26 | 2010-10-26 | Alloy steel and manufacture method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010519863 CN102002637B (en) | 2010-10-26 | 2010-10-26 | Alloy steel and manufacture method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102002637A CN102002637A (en) | 2011-04-06 |
| CN102002637B true CN102002637B (en) | 2012-06-13 |
Family
ID=43810340
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010519863 Expired - Fee Related CN102002637B (en) | 2010-10-26 | 2010-10-26 | Alloy steel and manufacture method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102002637B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107828952A (en) * | 2017-11-30 | 2018-03-23 | 攀钢集团攀枝花钢铁研究院有限公司 | Steel Bar and its LF stove production methods are built containing V, Ti, Cr microalloy |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1780929A (en) * | 2003-05-28 | 2006-05-31 | 住友金属工业株式会社 | Oil well steel pipe to be placed under ground and be expanded |
| CN101643882A (en) * | 2009-08-20 | 2010-02-10 | 朝阳西姆莱斯石油铸钢管件有限公司 | Clean steel smelting method of anti-S steel oil well pipe |
| CN101760703A (en) * | 2009-12-17 | 2010-06-30 | 湖南华菱湘潭钢铁有限公司 | High-strength pipe fitting steel and manufacturing method thereof |
| CN101818309A (en) * | 2010-04-22 | 2010-09-01 | 山西太钢不锈钢股份有限公司 | Air bottle steel and manufacturing method thereof |
-
2010
- 2010-10-26 CN CN 201010519863 patent/CN102002637B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1780929A (en) * | 2003-05-28 | 2006-05-31 | 住友金属工业株式会社 | Oil well steel pipe to be placed under ground and be expanded |
| CN101643882A (en) * | 2009-08-20 | 2010-02-10 | 朝阳西姆莱斯石油铸钢管件有限公司 | Clean steel smelting method of anti-S steel oil well pipe |
| CN101760703A (en) * | 2009-12-17 | 2010-06-30 | 湖南华菱湘潭钢铁有限公司 | High-strength pipe fitting steel and manufacturing method thereof |
| CN101818309A (en) * | 2010-04-22 | 2010-09-01 | 山西太钢不锈钢股份有限公司 | Air bottle steel and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102002637A (en) | 2011-04-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102277534B (en) | Hot rolled steel section for gas cylinders and production method thereof | |
| CN103014537B (en) | Smelting method of steel used in high speed passenger train hollow axle | |
| CN101121987B (en) | Smelting method for titanium-containing austenitic stainless steel | |
| CN104962800B (en) | Smelting method for stainless steel material | |
| CN102586685B (en) | Smelting process of steel for high-titanium alloy welding wire | |
| CN102206730B (en) | Method for controlling oxygen and reducing nitrogen in molten steel | |
| CN102268608B (en) | Large capacity high pressure gas cylinder steel and production method thereof | |
| CN108690900A (en) | Ultra-low carbon aluminum killed steel steel treatment method | |
| CN102199682A (en) | Semisteel steelmaking method | |
| CN103468866B (en) | Refining technology for molten medium-high carbon steel | |
| CN102766726A (en) | Method for smelting stainless steel by high-chrome melt and dephosphorized pre-melt | |
| CN111286677B (en) | Ultralow-sulfur low-aluminum high-nitrogen steel and smelting method | |
| CN103642979A (en) | Using method of silicon-aluminum alloy | |
| CN102002634B (en) | Carbon steel containing vanadium and titanium and manufacture method thereof | |
| CN102409133A (en) | Method for producing 23MnB steel by adopting vacuum process | |
| CN112662838B (en) | Smelting method of ZG06Cr13Ni4Mo steel and ZG06Cr13Ni4Mo steel | |
| CN102002633B (en) | Carbon steel and manufacturing method thereof | |
| CN104789738B (en) | A kind of method of less-slag melting super-purity ferrite stainless steel | |
| CN102031451B (en) | Vanadium-titanium containing carbon steel and manufacturing method thereof | |
| CN102002637B (en) | Alloy steel and manufacture method thereof | |
| CN102031452B (en) | Alloy steel and manufacturing method thereof | |
| CN101451209B (en) | Method for adding ferroboron during steel smelting process | |
| CN102051529B (en) | Carbon steel and preparation method thereof | |
| CN102031453A (en) | Titaniferous alloy steel and preparation method thereof | |
| CN102453829B (en) | Free-machining pinion steel smelting method and free-machining pinion steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120613 Termination date: 20161026 |