CN111763793A - Smelting method for manufacturing stainless steel with high oxygen content - Google Patents
Smelting method for manufacturing stainless steel with high oxygen content Download PDFInfo
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Abstract
The invention discloses a smelting method for manufacturing stainless steel with high oxygen content, which comprises the following steps: step S1, desiliconizing, desulfurizing and dephosphorizing the molten iron; step S2, carrying out primary oxygen blowing decarburization, alloying and ferrosilicon reduction on stainless steel mother liquor in a converter to obtain a first stainless steel solution, wherein the Si content in steel is controlled to be 0.05-0.15%, and the slag alkalinity R is adjusted to 1.5-1.9 tapping; step S3, slagging off the ladle slag; step S4, after the secondary oxygen blowing decarburization and high vacuum boiling stage are carried out in a VOD refining furnace, a second stainless steel solution is obtained by top blowing oxygen supplementing blowing, so that the content of Si in the steel is controlled to be 0.05-0.15%; step S5, adding oxides containing manganese, iron or chromium as an oxygen increasing agent, and adding lime, quartz sand and high-MgO slag materials to adjust the slag to be acidic high-MgO slag; step S6, the LF temperature, Si and other alloy compositions are adjusted to the target range of the desired steel grade, and then continuously cast to produce high oxygen content stainless steel. The invention can obtain the stainless steel with high oxygen content and total oxygen content of 0.01-0.035%.
Description
Technical Field
The invention relates to the technical field of steel smelting, in particular to a smelting method for manufacturing stainless steel with high oxygen content.
Background
With the transformation development of the manufacturing industry, stainless steel products are gradually extended to the high-end field. The oxygen content of the conventional stainless steel is below 0.008 percent, but the oxygen content of some special stainless steel varieties, such as free-cutting stainless steel, is required to reach 0.015 to 0.02 percent, so that the ultra-free-cutting performance can be obtained. However, the development of the smelting process of the high-oxygen stainless steel is still in a blank stage at present, and the conventional smelting process is adopted, so that the oxygen content is difficult to control to be more than 0.012%; on the other hand, it is also a difficult problem to ensure a stable operation of the smelting and continuous casting processes at such a high oxygen content.
The chinese patent application No. 201210048701.3 discloses a method for vacuum induction smelting of high oxygen content steel, wherein the method uses iron scale or iron ore as oxygen supply source, and fills oxygen and argon gas into the furnace, adjusts the pressure in the furnace, optimizes the adding sequence of iron scale, alloy material and graphite carbon, thereby ensuring high oxygen content. However, the method is only suitable for the vacuum induction furnace, is not suitable for the process flow and smelting equipment in large-scale industrial production, and does not relate to slag control.
The chinese patent application No. 201510269017.1 discloses a high oxygen content steel and a method for smelting the same, wherein the method produces the high oxygen content steel with total oxygen content in the range of 0.005% -0.030% by molten iron pretreatment, converter smelting, deoxidation alloying, tapping, deep decarburization refining, addition of aluminum shot deoxidation, re-alloying and continuous casting. However, the chemical components of the high-oxygen steel belong to common carbon steel, the alloy content is low, and stainless steel is not involved. Because the smelting principle and the process route of the stainless steel are greatly different from those of carbon steel, the converter weak boiling tapping, deep decarburization refining and aluminum shot deoxidation process described by the invention can cause a great amount of oxidation waste of chromium in the stainless steel, so that the converter weak boiling tapping, deep decarburization refining and aluminum shot deoxidation process cannot be applied to the current stainless steel smelting process. Furthermore, the method does not involve slag control, and if the slag steel is not balanced, the oxygen content cannot be controlled and stabilized.
Accordingly, there is a need in the art for a smelting process for manufacturing high oxygen content stainless steels that eliminates or at least alleviates all or some of the above-mentioned deficiencies in the prior art.
Disclosure of Invention
In view of the above problems in the prior art, it is an object of the present invention to provide a smelting process for manufacturing a high oxygen content stainless steel, which can perform a low degree of reduction control of molten steel using O2Or oxygenation is carried out on oxides, measures such as an acidic high MgO slag system are adopted, so that the high oxygen content stainless steel with the total oxygen content of 0.01-0.035% by mass is obtained, and the oxygen content is stably controlled. The high oxygen content stainless steel manufactured according to the method of the present invention may be suitably used as a free-cutting stainless steel having a high oxygen content, which has excellent cutting properties as well as welding properties.
It is emphasized that, unless otherwise indicated, the terms used herein correspond to the ordinary meanings of the various technical and scientific terms in the art, and the meanings of the technical terms defined in the various technical dictionaries, textbooks, etc.
The invention aims to provide a smelting method with high oxygen content stainless steel with total oxygen content of 0.01-0.035% by mass and stable control, which can adopt the technological process of molten iron pretreatment, converter, slag removal, VOD, LF and continuous casting,aiming at the particularity of stainless steel smelting, the low reduction degree of molten steel and the use of O are provided2Or the control idea of the oxide oxygenation and acidic high MgO slag system.
To this end, according to an embodiment of the present invention, there is provided a smelting method for manufacturing a high oxygen content stainless steel, wherein the smelting method includes performing the steps of:
step S1, wherein the molten iron is desiliconized, desulfurized and dephosphorized to obtain a stainless steel mother liquor;
step S2, wherein the stainless steel mother liquor is input into a converter to carry out primary oxygen blowing decarburization, alloying and ferrosilicon reduction on the stainless steel mother liquor so as to obtain a first stainless steel solution, wherein the mass percentage content of Si in the first stainless steel solution is controlled within the range of 0.05% -0.15%, the alkalinity R of converter slag is adjusted to 1.5-1.9, and then tapping is carried out, wherein the alkalinity R represents CaO/SiO2The ratio of (A) to (B);
step S3, wherein after the converter outputs the first stainless steel solution, the ladle slag in the first stainless steel solution is subjected to slag skimming treatment;
step S4, wherein the first stainless steel solution after the slag skimming is input into a VOD refining furnace in a ladle mode, and after the secondary oxygen blowing decarburization and high vacuum boiling stage, oxygen is blown in a top blowing supplementing way to obtain a second stainless steel solution, so that the mass percentage content of Si in the second stainless steel solution generated after reduction is controlled within the range of 0.05-0.15%;
step S5, adding oxides containing manganese, iron or chromium as an oxygen increasing agent into the VOD refining furnace, and adding lime, quartz sand and high MgO slag to adjust the VOD slag in the second stainless steel solution into acidic high MgO slag;
step S6, in which the second stainless steel solution with the acidic high MgO slag is input into the LF refining furnace in the form of a ladle, and the temperature, Si and other alloy components in the LF refining furnace are adjusted to the target ranges of the desired steel grades, and then continuous casting is performed to manufacture the high oxygen content stainless steel.
Further, in an embodiment, in step S3, the thickness of the ladle slag after the slag removing process is controlled to be less than 100 mm.
Further, in one embodiment, in step S4, the total volume of the top-blown supplemental blowing is 0.5-1.0 m3Standard oxygen per ton of steel. The "standard condition" of a gas generally refers to a temperature of 0 deg.C (273.15K) and a pressure of 101.325kPa (1 atm, 760mmHg), and "standard state oxygen" refers to oxygen under standard conditions, having a density of 1.429 g/l.
The main components of the acidic high MgO slag can comprise CaO and SiO2MgO and MeO, wherein the MeO is the total amount of oxides of three metals of iron, chromium and manganese.
Further, in an embodiment, in step S5, the composition of the acidic high MgO slag may be controlled as follows:
alkalinity R: 0.1 to 1.0, MgO: 15-35%, MeO: 5-40%, wherein MeO is the total amount of oxides of iron, chromium and manganese, and the balance of unavoidable impurities.
Further, in an embodiment, in step S5, the composition of the acidic high MgO slag may be controlled as follows:
alkalinity R: 0.4 to 0.8, MgO: 25% -30%, w(O)＝－2.85+w[T.O]× 423, wherein w(O)The mass of O in MeO accounts for the total mass (%) of the acidic high MgO slag, and w[T.O]The target total oxygen content (%) of the molten steel.
The t.o mentioned above means the content of all oxygen components in molten steel, including the content of oxygen present in the form of oxides.
Further, the high oxygen content stainless steel manufactured by the smelting method according to any one of the above embodiments may include a total oxygen content in a range of 0.01 to 0.035% by mass.
The smelting method for manufacturing the high-oxygen-content stainless steel according to the embodiment of the invention is mainly based on the following principle:
① unlike carbon steel, since stainless steel contains a large amount of chromium, Cr is formed after oxygen blowing in a converter or a VOD refining furnace2O3If the reduction is insufficient, Cr resources are wasted;however, if the reducing agent is added excessively, the Si content is high and [ O ] in the steel is balanced]Low, and high oxygen content requirements cannot be met, so steps S2 and S4 require controlling the addition amount of a reducing agent such as reduced ferrosilicon so that the Si content in the steel is controlled within a suitable range. In the later stage of smelting, the slag steel reaction is weaker, namely the Si alloying is carried out in the step S6, so that the Si content reaches the target range of the expected steel grade;
tests show that T.O in the steel is in direct proportion to the oxidability of the slag, as shown in figure 1, so that oxygen is blown into the molten steel through the step S4, and the contents of oxides of manganese, iron and chromium in the slag are increased through the step S5, so that the oxygen enrichment of the molten steel can be effectively realized;
the balanced oxygen content in the steel is increased along with the reduction of the alkalinity R of the slag, and the acid slag can be balanced with the high oxygen content in the steel to avoid the removal of T.O in the steel by the alkaline slag, thereby ensuring the stability of the high oxygen content; however, since acid slag is extremely corrosive to steel-making alkaline refractory, the content of MgO in slag needs to be increased to reduce the melting loss of refractory.
The smelting method for manufacturing the high-oxygen-content stainless steel provided by the embodiment of the invention has the following beneficial effects:
firstly, aiming at the characteristics of stainless steel and smelting process characteristics thereof, the invention can realize high oxygen content control under the existing large-scale industrial production condition, and produce the high oxygen content stainless steel with the total oxygen content of 0.01-0.035% by mass, and avoid the waste of chromium resources in the stainless steel;
secondly, the invention can realize the stable and accurate control of the T.O content within the range of 0.01-0.035% by adjusting the slag alkalinity and the contents of oxides of manganese, iron and chromium according to different target T.O contents, and the difference between the test result and the target value is less than 5%;
thirdly, since the present invention does not control the oxygen content by adding aluminum, it does not contain Al2O3、MgO-Al2O3Hard inclusions are equal; stainless steels produced according to the invention, the inclusions being SiO2MnO and MnS are mainly distributed in the steel in a dispersion way; in addition, the high oxygen content can promote MnS inclusions in high-sulfur steelsImpurities are separated out, the proportion of MnS phase is improved, and spindle-shaped impurities are formed after rolling, so that the turning processing and welding performance of the stainless steel are enhanced.
Drawings
The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 schematically illustrates a flow diagram of a metallurgical process for making a high oxygen content stainless steel according to an embodiment of the present invention;
FIG. 2 shows the relationship between the oxidizability of high-oxygen stainless steel slag and the T.O content balance in steel in industrial production;
FIG. 3 illustrates an electron microscope image of oxide inclusions in a high oxygen stainless steel made in accordance with the present invention;
FIG. 4 illustrates the morphology of MnS inclusions in a 5mm phi rolled high oxygen, high sulfur stainless steel made in accordance with the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
FIG. 1 schematically shows a flow diagram of a smelting process for producing a high oxygen content stainless steel according to an embodiment of the present invention.
According to an embodiment of the present invention, there is provided a smelting method for manufacturing a high oxygen content stainless steel, wherein the smelting method includes performing the steps of:
step S1, wherein the molten iron is desiliconized, desulfurized and dephosphorized to obtain a stainless steel mother liquor;
step S2, wherein the stainless steel mother liquor is transfusedPutting the stainless steel mother liquor into a converter to perform primary oxygen blowing decarburization, alloying and ferrosilicon reduction on the stainless steel mother liquor so as to obtain a first stainless steel solution, wherein the mass percentage content of Si in the first stainless steel solution is controlled within the range of 0.05-0.15%, the alkalinity R of converter slag is adjusted to 1.5-1.9, and then tapping, wherein the alkalinity R represents CaO/SiO2The ratio of (A) to (B);
step S3, wherein after the converter outputs the first stainless steel solution, the ladle slag in the first stainless steel solution is subjected to slag skimming treatment;
step S4, wherein, the first stainless steel solution after the slag skimming is input into a processing position in a VOD refining furnace in a ladle mode, and after the secondary oxygen blowing decarburization and high vacuum boiling stage, oxygen is blown in a top blowing supplementing way to obtain a second stainless steel solution, so that the mass percentage content of Si in the second stainless steel solution generated after reduction is controlled within the range of 0.05-0.15%;
step S5, adding oxides containing manganese, iron or chromium as an oxygen increasing agent into the VOD refining furnace, and adding lime, quartz sand and high MgO slag to adjust the VOD slag in the second stainless steel solution into acidic high MgO slag;
step S6, in which the second stainless steel solution with the acidic high MgO slag is input in a ladle form to a treatment site in the LF refining furnace, and the temperature, Si and other alloy components in the LF refining furnace are adjusted to a target range of a desired steel grade, and then continuous casting is performed to manufacture a high oxygen content stainless steel.
FIG. 2 shows the relationship between the oxidizability of high-oxygen stainless steel slag and the T.O content in steel in industrial production.
FIG. 3 is an exemplary electron microscope image showing oxide inclusions in a high oxygen stainless steel produced by the smelting process according to the present invention, showing the oxide distribution dispersion.
FIG. 4 is a view exemplarily showing the morphology of MnS inclusions in a 5mm rolled material of a high-oxygen high-sulfur stainless steel manufactured by the smelting method according to the present invention, which has a spindle shape as indicated by a black pattern.
The technical scheme provided by the embodiment of the invention is illustrated by taking 430F stainless steel as an example.
(1) Steel grade: 430F stainless steel
(2) The process flow comprises the following steps: molten iron pretreatment, converter, slag skimming station, 80tVOD, LF and continuous casting
(3) And (3) effect comparison:
T.O content of the casting blanks of examples 1-4 and comparative examples, proportion of MnS inclusion area in the metallographic sample of the casting blanks to the total analysis area, and average diameter of MnS inclusions were analyzed by an oxygen-nitrogen analyzer, as shown in Table 1.
TABLE 1
(4) The following details will be given to the smelting methods of examples 1 to 4 and comparative examples thereof.
Example 1
Step S1: and desiliconizing, desulfurizing and dephosphorizing the molten iron to obtain the stainless steel mother liquor.
Step S2: feeding the stainless steel mother liquor into a converter, blowing oxygen, alloying and decarbonizing the stainless steel mother liquor in the converter until the mass percent of carbon is 0.22%, reducing by using ferrosilicon, controlling the mass percent of Si in the steel to be 0.08%, and adjusting the alkalinity R (CaO/SiO) of converter slag2) To 1.80, thereby obtaining a first stainless steel solution, and then tapping, wherein the chromium yield is 95.2%.
Step S3: after the converter outputs the first stainless steel solution, ladle slag in the first stainless steel solution is subjected to slagging-off treatment, so that the thickness of the ladle slag is 30 mm.
Step S4: the first stainless steel solution after slagging-off treatment is input into a treatment position in a VOD refining furnace in a ladle form, and after secondary oxygen blowing decarburization and high vacuum boiling stage, the total volume is blown additionally by a top blowing pipe to be 50m3Thereby obtaining a second stainless steel solution, and controlling the content of Si in the second stainless steel solution generated after reduction to be 0.08% by mass.
Step S5: since the target T.O content is 0.012%, in terms of w(O)＝－2.85+w[T.O]× 423 (2.226%), taking into account the residual MeO in the slag, the calculation resulted in the addition of 160kg manganese ore (MnO)295 percent of the mass percent, and the balance of iron oxide and impurities) as an oxygenation agent, and then adding 400kg of lime, 100kg of quartz sand and 250kg of high MgO slag charge for slag mixing. The alkalinity R (CaO/SiO) of the slag can be known through the chemical analysis of the slag sample composition2)：0.96，MgO：19.06％，MnO：7.47％，FeO：0.60％，Cr2O3：1.35％。
Step S6: the second stainless steel solution with the acidic high MgO slag is input in a ladle form to a treatment site in the LF refining furnace, and the temperature, Si and other alloy components in the LF refining furnace are adjusted to a target range of a desired steel grade, followed by continuous casting to manufacture a high oxygen content stainless steel.
Example 2
Step S1: and desiliconizing, desulfurizing and dephosphorizing the molten iron to obtain the stainless steel mother liquor.
Step S2: feeding the stainless steel mother liquor into a converter, blowing oxygen, alloying and decarbonizing the stainless steel mother liquor in the converter until the mass percent of carbon is 0.18%, reducing by using ferrosilicon, controlling the mass percent of Si in the steel to be 0.10%, and adjusting the alkalinity R (CaO/SiO) of converter slag2) To 1.76, thus obtaining a first stainless steel solution, then tapping, wherein the chromium yield is 94.7%.
Step S3: after the converter outputs the first stainless steel solution, ladle slag in the first stainless steel solution is subjected to slagging-off treatment, so that the thickness of the ladle slag is 30 mm.
Step S4: the first stainless steel solution after slagging-off treatment is input into a treatment position in a VOD refining furnace in a ladle form, and after secondary oxygen blowing decarburization and high vacuum boiling stage, the total volume is blown again by a top blowing pipe to be 60m3Thereby obtaining a second stainless steel solution, and controlling the content of Si in the second stainless steel solution generated after reduction to be 0.12% by mass.
Step S5: since the target T.O content is 0.0160% in terms of w(O)＝－2.85+w[T.O]× 423 (3.918%) taking account of the residual MeO in the slagAnd (3) adding 270kg of manganese ore as an oxygen increasing agent, and then adding 400kg of lime, 200kg of quartz sand and 400kg of high MgO slag charge for slag mixing. The alkalinity R (CaO/SiO) of the slag can be known through the chemical analysis of the slag sample composition2)：0.79，MgO：22.5％，MnO：14.5％，FeO：0.90％，Cr2O3：1.55％。
Step S6: the second stainless steel solution with the acidic high MgO slag is input in a ladle form to a treatment site in the LF refining furnace, and the temperature, Si and other alloy components in the LF refining furnace are adjusted to a target range of a desired steel grade, followed by continuous casting to manufacture a high oxygen content stainless steel.
Example 3
Step S1: and desiliconizing, desulfurizing and dephosphorizing the molten iron to obtain the stainless steel mother liquor.
Step S2: feeding the stainless steel mother liquor into a converter, blowing oxygen, alloying and decarbonizing the stainless steel mother liquor in the converter until the mass percent of carbon is 0.25%, reducing by using ferrosilicon, controlling the mass percent of Si in the steel to be 0.08%, and adjusting the alkalinity R (CaO/SiO) of converter slag2) To 1.83, thus obtaining a first stainless steel solution, then tapping.
Step S3: after the converter outputs the first stainless steel solution, ladle slag in the first stainless steel solution is subjected to slagging-off treatment, so that the thickness of the ladle slag is 30 mm.
Step S4: the first stainless steel solution after slagging-off treatment is input into a treatment position in a VOD refining furnace in a ladle form, and after secondary oxygen blowing decarburization and high vacuum boiling stage, the total volume is blown additionally by a top blowing pipe to be 80m3Thereby obtaining a second stainless steel solution, and controlling the content of Si in the second stainless steel solution generated after reduction to be 0.08% by mass.
Step S5: since the target T.O content is 0.028%, in terms of w(O)＝－2.85+w[T.O]× 423 kg (8.994%), and the residual MeO in the slag is considered, and 800kg of manganese ore (MnO) is calculated298 percent of the mass percent) as an oxygen increasing agent, and then 100kg of lime, 300kg of quartz sand and 700kg of high MgO slag charge are added for slag mixing. Warp beamThe chemical analysis of the components of the slag sample shows that the alkalinity R (CaO/SiO) of the slag2)：0.37，MgO：25.89％，MnO：28.4％，FeO：1.48％，Cr2O3：7.15％。
Step S6: the second stainless steel solution with the acidic high MgO slag is input in a ladle form to a treatment site in the LF refining furnace, and the temperature, Si and other alloy components in the LF refining furnace are adjusted to a target range of a desired steel grade, followed by continuous casting to manufacture a high oxygen content stainless steel.
Example 4
Step S1: and desiliconizing, desulfurizing and dephosphorizing the molten iron to obtain the stainless steel mother liquor.
Step S2: feeding the stainless steel mother liquor into a converter, blowing oxygen, alloying and decarbonizing the stainless steel mother liquor in the converter until the mass percent of carbon is 0.22%, reducing by using ferrosilicon, controlling the mass percent of Si in the steel to be 0.05%, and adjusting the alkalinity R (CaO/SiO) of converter slag2) To 1.73, thus obtaining a first stainless steel solution, then tapping.
Step S3: after the converter outputs the first stainless steel solution, ladle slag in the first stainless steel solution is subjected to slagging-off treatment, so that the thickness of the ladle slag is 20 mm.
Step S4: the first stainless steel solution after slagging-off treatment is input into a treatment position in a VOD refining furnace in a ladle form, and after secondary oxygen blowing decarburization and high vacuum boiling stage, the total volume is blown additionally by a top blowing pipe to be 80m3Thereby obtaining a second stainless steel solution, and controlling the content of Si in the second stainless steel solution generated after reduction to be 0.05% by mass.
Step S5: since the target T.O content is 0.035%, according to w(O)＝－2.85+w[T.O]× 423 kg (2.226%) and the residual MeO in the slag is taken into account and calculated to obtain the addition of 800kg manganese ore (MnO)298 percent of mass percent) and 350kg of chromium ore powder (Cr)2O395 percent by mass) as an oxygen increasing agent, and then 500kg of quartz sand and 700kg of high MgO slag charge are added for slag mixing. Through chemical analysis of slag sample components, the basicity R (CaO/SiO) of the slag is determined2)：0.15，MgO：21.2％，MnO：25.8％，FeO：2.35％，Cr2O3：17.8％。
Step S6: the second stainless steel solution with the acidic high MgO slag is input in a ladle form to a treatment site in the LF refining furnace, and the temperature, Si and other alloy components in the LF refining furnace are adjusted to a target range of a desired steel grade, followed by continuous casting to manufacture a high oxygen content stainless steel.
Comparative example
Step S1: and desiliconizing, desulfurizing and dephosphorizing the molten iron to obtain the stainless steel mother liquor.
Step S2: feeding stainless steel mother liquor into converter, blowing oxygen, alloying, decarbonizing to 0.25%, reducing by using ferrosilicon to make the Si content in steel be 0.12%, regulating slag basicity R (CaO/SiO)2) And tapping till 1.8.
Step S3: after converter tapping, ladle slag is subjected to slagging-off treatment, and the thickness of the ladle slag is 50 mm.
Step S4: after oxygen blowing deep decarburization and high vacuum boiling period in a VOD refining furnace, adding ferrosilicon for reduction without additionally blowing oxygen, and directly controlling the Si mass percentage content in the steel to be 0.28 percent of the target range.
Step S5: 1200kg of lime and fluorite are added into the VOD refining furnace for slag regulation, and no oxygenation agent is added. Through chemical analysis of slag sample components, the basicity R (CaO/SiO) of the slag is determined2): 1.75, the slag system is alkaline slag system.
Step S6: after adjusting the temperature in the LF refining furnace, Si and other alloy components to a target range of steel grades, continuous casting is performed to manufacture stainless steel.
As can be seen from the comparison, in examples 1 to 4, the oxidizing conditions of the slag and the molten steel are precisely controlled mainly by adjusting different oxygen blowing amounts, oxygen increasing agents and slag system components, so as to obtain stainless steels with different oxygen contents. And the comparative example is smelting under the condition of not adopting any oxygenation measure and conventional slag system.
In summary, the high oxygen stainless steel manufactured by the smelting method for manufacturing the high oxygen stainless steel according to the embodiment of the invention can contain the total oxygen content range of 0.01-0.035% by mass. Therefore, the invention can realize the stable and accurate control of the total oxygen content while ensuring that the chromium yield is not reduced, thereby improving the cutting performance and the welding performance of the steel.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Finally, it should be noted that: the above examples are only for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (6)
1. A smelting process for manufacturing a high oxygen content stainless steel, characterized in that it comprises performing the following steps:
step S1, wherein the molten iron is desiliconized, desulfurized and dephosphorized to obtain a stainless steel mother liquor;
step S2, wherein the stainless steel mother liquor is input into a converter to carry out primary oxygen blowing decarburization, alloying and ferrosilicon reduction on the stainless steel mother liquor so as to obtain a first stainless steel solution, wherein the mass percentage content of Si in the first stainless steel solution is controlled within the range of 0.05% -0.15%, the alkalinity R of converter slag is adjusted to 1.5-1.9, and then tapping is carried out, wherein the alkalinity R represents CaO/SiO2The ratio of (A) to (B);
step S3, wherein after the converter outputs the first stainless steel solution, the ladle slag in the first stainless steel solution is subjected to slag skimming treatment;
step S4, wherein the first stainless steel solution after the slag skimming is input into a VOD refining furnace in a ladle mode, and after the secondary oxygen blowing decarburization and high vacuum boiling stage, oxygen is blown in a top blowing supplementing way to obtain a second stainless steel solution, so that the mass percentage content of Si in the second stainless steel solution generated after reduction is controlled within the range of 0.05-0.15%;
step S5, adding oxides containing manganese, iron or chromium as an oxygen increasing agent into the VOD refining furnace, and adding lime, quartz sand and high MgO slag to adjust the VOD slag in the second stainless steel solution into acidic high MgO slag;
step S6, in which the second stainless steel solution with the acidic high MgO slag is input into the LF refining furnace in the form of a ladle, and the temperature, Si and other alloy components in the LF refining furnace are adjusted to the target ranges of the desired steel grades, and then continuous casting is performed to manufacture the high oxygen content stainless steel.
2. The method according to claim 1, wherein in step S3, the thickness of the ladle slag after slagging-off treatment is controlled to be 100mm or less.
3. The smelting method according to claim 2, wherein in step S4, the total volume of top-blown complementary blowing is 0.5 to 1.0m3Standard oxygen per ton of steel.
4. A smelting method according to claim 3, wherein in step S5, the components of the acidic high MgO slag are controlled as follows by mass percent:
alkalinity R: 0.1 to 1.0, MgO: 15-35%, MeO: 5-40%, wherein MeO is the total amount of oxides of iron, chromium and manganese, and the balance is inevitable impurities.
5. The smelting method according to claim 4, wherein in step S5, the components of the acidic high MgO slag are controlled as follows by mass percent:
alkalinity R: 0.4 to 0.8, MgO: 25% -30%, w(O)＝－2.85+w[T.O]× 423, wherein w(O)The mass of O in MeO accounts for the total mass (%) of the acidic high MgO slag, and w[T.O]The target total oxygen content (%) of the molten steel.
6. The smelting method according to any one of claims 1 to 5, wherein the high oxygen content stainless steel produced contains a total oxygen content in the range of 0.01% to 0.035% by mass.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2003219006A1 (en) * | 2002-04-10 | 2003-10-20 | Sms Demag Aktiengsellschaft | Method and installation for producing stainless steel, especially high-quality steel containing chromium or nickel chromium |
| CN101994054A (en) * | 2009-08-10 | 2011-03-30 | 鞍钢股份有限公司 | Intermediate containing ultrafine oxide ferroalloy and preparation method thereof |
| CN102199689A (en) * | 2011-05-11 | 2011-09-28 | 山西太钢不锈钢股份有限公司 | Refining method of magnesia-calcia-based stainless steel ladle vacuum refining furnace |
| CN106282832A (en) * | 2016-08-06 | 2017-01-04 | 山东泰山钢铁集团有限公司 | Hot-metal bottle dephosphorization, refining furnace and Argon station smelt titaniferous ferritic stainless steel method |
| CN106555124A (en) * | 2016-11-30 | 2017-04-05 | 山西太钢不锈钢股份有限公司 | Gao Ge, the stainless preparation method of high molybdenum-iron ferritic |
| CN109207673A (en) * | 2018-11-16 | 2019-01-15 | 山西太钢不锈钢股份有限公司 | The method for controlling stainless steel oxygen content in steel |
-
2020
- 2020-05-27 CN CN202010458714.2A patent/CN111763793A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2003219006A1 (en) * | 2002-04-10 | 2003-10-20 | Sms Demag Aktiengsellschaft | Method and installation for producing stainless steel, especially high-quality steel containing chromium or nickel chromium |
| CN101994054A (en) * | 2009-08-10 | 2011-03-30 | 鞍钢股份有限公司 | Intermediate containing ultrafine oxide ferroalloy and preparation method thereof |
| CN102199689A (en) * | 2011-05-11 | 2011-09-28 | 山西太钢不锈钢股份有限公司 | Refining method of magnesia-calcia-based stainless steel ladle vacuum refining furnace |
| CN106282832A (en) * | 2016-08-06 | 2017-01-04 | 山东泰山钢铁集团有限公司 | Hot-metal bottle dephosphorization, refining furnace and Argon station smelt titaniferous ferritic stainless steel method |
| CN106555124A (en) * | 2016-11-30 | 2017-04-05 | 山西太钢不锈钢股份有限公司 | Gao Ge, the stainless preparation method of high molybdenum-iron ferritic |
| CN109207673A (en) * | 2018-11-16 | 2019-01-15 | 山西太钢不锈钢股份有限公司 | The method for controlling stainless steel oxygen content in steel |
Non-Patent Citations (2)
| Title |
|---|
| 张立峰等: "《轴承钢中非金属夹杂物和元素偏析》", 31 January 2017, 冶金工业出版社 * |
| 朱苗勇等: "《现代冶金工艺学 钢铁冶金卷》", 31 December 2016, 冶金工业出版社 * |
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