CN105463298A - Method for smelting low-aluminum high-nitrogen martensitic stainless steel in pressurization and induction manner - Google Patents
Method for smelting low-aluminum high-nitrogen martensitic stainless steel in pressurization and induction manner Download PDFInfo
- Publication number
- CN105463298A CN105463298A CN201510864235.XA CN201510864235A CN105463298A CN 105463298 A CN105463298 A CN 105463298A CN 201510864235 A CN201510864235 A CN 201510864235A CN 105463298 A CN105463298 A CN 105463298A
- Authority
- CN
- China
- Prior art keywords
- nitrogen
- rsqb
- lsqb
- pressure
- steel
- 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.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
- C22C33/06—Making ferrous alloys by melting using master alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0006—Adding metallic additives
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention discloses a method for smelting low-aluminum high-nitrogen martensitic stainless steel in a pressurization and induction manner and belongs to the field of metallurgy, wherein the method is suitable for smelting. The low-aluminum high-nitrogen martensitic stainless steel comprises, 0.1%-0.6% of carbon, 0%-0.5% of manganese, 12%-24% of chromium, not larger than 1% of silicon, 0%-3% of molybdenum, 0.1%-0.6% of nitrogen, 0%-2% of nickel, 0%-1% of vanadium, not larger than 0.02% of aluminum, not large than 0.002% of sulfur and the balance iron and inevitable impurities. The method includes the specific steps of blending, material distribution, temperature increase after vacuumizing, high-pure argon filling after raw material melting-down, graphite adding for deoxygenation, industrial silicon adding for deoxygenation when the environment is vacuumized to 10 Pa, nitrogen filling and alloying, nickel magnesium alloy and rare earth adding for heat preservation for 5 min to 10 min, nitrogen charging and casting and the like.
Description
Technical field
The invention belongs to high nitrogen stainless steel technical field of smelting, be specifically related to a kind of method that low aluminium height nitrogen Martensite Stainless Steel is smelted in induction of pressurizeing.
Background technology
High nitrogen Martensite Stainless Steel refers to the Martensite Stainless Steel that in steel, nitrogen content is greater than 0.08%.In Martensite Stainless Steel, adding of nitrogen expands austenite phase field temperature range, restrained effectively δ-ferrite and is formed; While guarantee gap solution strengthening, can carbide refinement be made, and with the disperse educt of nitride etc., not only significantly improve the intensity of Martensite Stainless Steel, hardness, and still can ensure original toughness of Martensite Stainless Steel.In addition, nitrogen add the corrosion resistance nature being conducive to improving martensite containing nitrogen steel.Owing to having above Good All-around Property, high nitrogen Martensite Stainless Steel can be applicable to the fields such as rolling bearing, cutter and engine.Such as, high nitrogen martensite stainless bearing steel 1.4108 (0.3%C-15%Cr-1%Mo-0.4%N), can be applicable to the gear shaft etc. of space shuttle petrolift bearing, aeroplane engine main bearing and ball-screw; Another kind of typical high nitrogen Martensite Stainless Steel is Corrosion Resistant Stainless Steel for Plastic Mould M340 (0.54%C-17.3%Cr-1.1%Mo-0.2%N), mainly meets the market requirement of high-end anti-corrosion mirror-surface plastic die.
Under normal pressure, nitrogen solubleness in body-centred cubic martensitic steel is lower, is therefore difficult to the Martensite Stainless Steel obtaining the higher and uniform composition of nitrogen content at ambient pressure, and pressurization metallurgy is the important channel of the nitrogenous of processability excellence and high nitrogen Martensite Stainless Steel.Due to the disappearance of China's pressurization metallurgical equipment, seriously constrain variety development and the application of nitrogenous and high nitrogen Martensite Stainless Steel.The production of current high nitrogen stainless steel mainly adopts pressurization electroslag remelting process, and existing technique exists following shortcoming: there is nitrogen Elemental redistribution uneven, sometimes need secondary remelting; Also have in addition and add silicon nitride but cause increasing silicon, preparing combined electrode but cost obviously increases; Further, add nitride and cause slag to seethe with excitement in slag, interference melting process, electrode tip metallic membrane may be caused to be exposed in high pressure nitrogen, and uncontrollable liquid metal is to the absorption etc. of nitrogen.
In contrast to this, adopt pressurized Induction Melting to prepare nitrogenous and high nitrogen Martensite Stainless Steel, stir by induction and create good Nitrogen Absorption Kinetics condition, accelerate the diffusion of nitrogen in molten steel, shorten nitrogen in molten steel and reach the time of balance at a particular pressure.But because the solubleness of martensite nitrogen in steel is very low, how conservative control is smelted and casting two benches pressure, accurately controls the nitrogen content in high nitrogen Martensite Stainless Steel, avoids coagulation defect, it is a problem in the urgent need to address.To the high nitrogen martensitic steel being used as bearing, gear, mould, adopt aluminium deoxidation can make to produce a large amount of aluminium nitride in steel, the too much aluminium nitride of intercrystalline precipitation can cause the hot-short of steel and cause forging transverse crack, and easily becomes fatigue cracking source, obviously reduces its fatigue property.How effectively to reduce the oxygen level in high nitrogen Martensite Stainless Steel, reducing the generation of harmful nitrogenize aluminum inclusion, is also the problem that pressurized Induction Melting height nitrogen Martensite Stainless Steel must solve.In addition, because adding of nitrogen makes the resistance to deformation of high nitrogen Martensite Stainless Steel increase, in order to improve the hot workability of high nitrogen Martensite Stainless Steel, sulphur content in steel must be controlled at lower level.
Summary of the invention
The method of low aluminium height nitrogen Martensite Stainless Steel is smelted in a kind of induction of pressurizeing provided by the invention, be applicable to smelt composition and be: C:0.1 ~ 0.6%, Mn:0 ~ 5%, Cr:12 ~ 24%, Si :≤1%, Mo:0 ~ 3%, N:0.1 ~ 0.6%, Ni:0 ~ 2%, V:0 ~ 1%, Al≤0.02%, S≤0.002%, Fe: the target steel grade of surplus.
Core concept of the present invention is: after metallurgical raw material is melting down in pressurization induction furnace, first adopts vacuum carbon deoxidization technique that the oxygen level in molten steel is reduced to certain level; Add silicon and the further deep deoxidation of nickel magnesium alloy, adding of nickel magnesium alloy there is certain sweetening effectiveness simultaneously; Finally add a certain amount of rare earth, carry out dark desulfurization, also oxygen level can be reduced to lower level simultaneously.This technique avoids aluminium deoxidation to cause generating a large amount of aluminum nitride inclusions thing, effectively can reduce the sulphur content in steel simultaneously.Smelted by rational Match and pressure of casting, avoid coagulation defect, accurately control the nitrogen content in steel, obtain nitrogen content 0.1 ~ 0.6%, aluminium content≤0.02%, uniform composition, dense structure low aluminium height nitrogen Martensite Stainless Steel.
The present invention is a kind of method utilizing pressurization induction to smelt low aluminium height nitrogen Martensite Stainless Steel, and its concrete steps are as follows.
(1) determine to smelt and casting pressure preparing burden according to formula: according to steel grade target component and smelting temperature, according to the solubleness formula of nitrogen in steel 1., calculate and smelt pressure p, and according to formula 2. calculate casting pressure p '; In conjunction with raw materials for metallurgy composition and the quality that steel ingot Mass Calculation desired raw material will be smelted, preparation raw materials for metallurgy, raw material comprises: technically pure iron, chromium metal or ferrochrome, metal molybdenum or molybdenum-iron, metallic nickel, manganese metal or electrolytic manganese, industrial silicon, vanadium metal or vanadium iron, graphite, nickel magnesium alloy, cerium or lanthanum etc.; In steel ingot, aim carbon content basis is added the carbon of 3 ~ 10% again, target Si content basis is added the silicon of 1 ~ 5% again, for deoxidation; Adding quality for what will smelt ingot quality 0.04 ~ 0.2% is the nickel magnesium alloy of 20% containing magnesium, and recovery rate is 10 ~ 30%, carries out deep deoxidation, and reduces sulphur content; Add quality for smelting cerium or the lanthanum of ingot quality 0.004 ~ 0.03%, recovery rate is 20 ~ 40%, for dark desulfurization.
Steel grade target component is respectively by mass percentage: C:0.1 ~ 0.6%, Mn:0 ~ 5%, Cr:12 ~ 24%, Si :≤1%, Mo:0 ~ 3%, N:0.1 ~ 0.6%, Ni:0 ~ 2%, V:0 ~ 1%, Al≤0.02%, S≤0.002%, Fe: surplus.
Smelt the calculation formula of pressure p 1.:
In formula: p is for smelting pressure, and unit is MPa; For standard atmospheric pressure, be 0.101325MPa; T is smelting temperature, and unit is K.
Casting pressure p ' calculation formula 2.:
In formula: p' is casting pressure, and unit is MPa.
(2) cloth: by according to the crucible will smelting the good technically pure iron of steel ingot Mass Calculation, pressurization induction furnace put into by chromium metal or ferrochrome, metal molybdenum or molybdenum-iron, metallic nickel, is placed in feeding chamber successively by accounting for the graphite of graphite total mass 40% ~ 80%, industrial silicon, manganese metal or electrolytic manganese, vanadium metal or vanadium iron, remaining 20% ~ 60% graphite, nickel magnesium alloy, cerium or lanthanum etc.
(3) load melting: to start vacuum pump, pressurization induction furnace internal pressure is evacuated to below 10Pa, close vacuum pump; Energising heats up, and increases the power of induction furnace gradually, melts raw materials for metallurgy in crucible.
(4) deoxidation: after treating in crucible that raw materials for metallurgy is melting down, high-purity argon gas to 10 ~ 50kPa is filled with in pressurization induction furnace, the graphite accounting for graphite total mass 40% ~ 80% is added in molten steel, start vacuum pump, start to carry out carbon deoxygenation, until vacuum tightness to below 10Pa and liquid level is steady, no longer includes bubble and produces; If period reaction is too violent, vacuum pump, suitably reduction power can be closed and be filled with a small amount of high-purity argon gas, continuing again to vacuumize after liquid level is steady.After vacuum carbon deoxidization terminates, add industrial silicon, further deoxidation.
(5) alloying: high pure nitrogen to the pressure being filled with purity >=99.999% in pressurization induction furnace is smelting pressure p, then in molten steel, add manganese metal or electrolytic manganese, vanadium metal or vanadium iron successively by feeding chamber, remaining 20% ~ 60% graphite carries out alloying, add nickel magnesium alloy and cerium or lanthanum afterwards and carry out deep deoxidation and dark desulfurization, and 5 ~ 10min is incubated at 1540 ~ 1580 DEG C of temperature, alloying element is uniformly distributed in molten steel.
(6) pressurization casting: high pure nitrogen to the furnace pressure being filled with purity >=99.999% in pressurization induction furnace is p', then casts at 1540 ~ 1580 DEG C; After casting terminates, keep more than 20 minutes, lower furnace pressure gradually afterwards, take out steel ingot.
The method of low aluminium height nitrogen Martensite Stainless Steel is smelted in a kind of induction of pressurizeing provided by the invention, it is characterized in that: because vanadium can improve hardness, the wear resistance of martensitic steel, crystal grain thinning, and the solubleness of nitrogen can be significantly improved, the present invention, in conjunction with nitrogen solubility thermomechanical analysis and experimental study, proposes to consider vanadium to the smelting calculation of pressure formula of nitrogen solubility effect 1..Under the condition that steel grade target component and smelting temperature are determined, can calculate to obtain and smelt pressure p.
The method of low aluminium height nitrogen Martensite Stainless Steel is smelted in a kind of induction of pressurizeing provided by the invention, it is characterized in that: for avoiding in high nitrogen Martensite Stainless Steel process of setting, due to through the very low high temperature ferrite area of nitrogen solubility, nitrogen in steel solubleness is caused to decline, causing producing nitrogen pore, the generation of this problem can be avoided by improving casting pressure.According to experimental study, the present invention propose for the lower high nitrogen Martensite Stainless Steel casting pressure p of nitrogen solubility ' calculation formula 2..
The method of low aluminium height nitrogen Martensite Stainless Steel is smelted in a kind of induction of pressurizeing provided by the invention, it is characterized in that: add in steel for avoiding reductor aluminium, be combined with nitrogen and generate harmful aluminum nitride inclusions thing, the present invention adopts vacuum carbon deoxidization, silicon deoxidation and nickel magnesium alloy deoxidation to combine, can effectively by the Control for Oxygen Content in steel within 20 × 10-6, obtain nitrogen content 0.1 ~ 0.6%, the low aluminium height nitrogen Martensite Stainless Steel of aluminium content≤0.02%.
The method of low aluminium height nitrogen Martensite Stainless Steel is smelted in a kind of induction of pressurizeing provided by the invention, it is characterized in that: in alloying latter stage, in molten steel, add nickel magnesium alloy can be reduced to a certain degree by sulphur content, and add a small amount of cerium or lanthanum, for dark desulfurization, make sulphur content≤0.002%, the hot workability of steel grade can be improved, can prevent from ftractureing in the hot procedures such as forging, rolling.
The method of low aluminium height nitrogen Martensite Stainless Steel is smelted in a kind of induction of pressurizeing provided by the invention, it is characterized in that: under preventing oxygen level is very high, pressure is very low in molten steel condition, add carbon and uncontrollable reaction between carbon and oxygen occurs, molten steel vigorous splash may be caused, before vacuum carbon deoxidization, in stove, be filled with 10 ~ 50kPa high-purity argon gas, add the graphite accounting for graphite total mass 40% ~ 80% afterwards, restart vacuum pump, reaction between carbon and oxygen is carried out under controlled condition.Being filled with high-purity argon gas is because argon gas is lower than the solubleness of nitrogen in molten steel, is filled with nitrogen and molten steel can be made to dissolve part nitrogen, may cause molten steel splash when follow-up vacuumizing due to the spilling of nitrogen, and then produce dangerous.
The method of low aluminium height nitrogen Martensite Stainless Steel is smelted in a kind of induction of pressurizeing provided by the invention, adopt vacuum carbon deoxidization in conjunction with the mode of silicon deoxidation, nickel magnesium alloy deoxidation and rare earth desulfurization, effectively can reduce the oxygen in steel and sulphur content, avoid aluminium deoxidation to cause generating a large amount of aluminum nitride inclusions thing simultaneously; By reasonably smelting and pressure of casting, avoid producing the coagulation defects such as nitrogen precipitation, nitrogen pore, nitrogen content in accurate control steel, obtain uniform composition, dense structure, nitrogen content 0.1 ~ 0.6%, the low aluminium height nitrogen Martensite Stainless Steel of aluminium content≤0.02%, sulphur content≤0.002%.
Embodiment
Describe the specific embodiment of the present invention in detail below in conjunction with embodiment, but the specific embodiment of the present invention is not limited to following embodiment.
In illustrated embodiment of the present invention, smelting equipment is 25kg pressurized Induction Melting stove, and final vacuum is 0.1Pa, and top pressure is 6MPa, and power is 50kW, and batch is 20.0 ~ 21.5kg.
In illustrated embodiment of the present invention, the main component of raw materials for metallurgy used is in table 1.
Table 1 raw materials for metallurgy main component/wt.%
Embodiment one
Adopt pressurized Induction Melting 21.0kg target steel grade 30Cr15MoN0.4, its composition range is as shown in table 2.
Table 2 steel grade 30Cr15MoN0.4 composition range and target component/wt.%
(1) determine to smelt and casting pressure preparing burden: according to steel grade target component and smelting temperature in table 2 about 1550 DEG C, according to formula 1., 2. formula calculate: smeltings pressure p is 0.37MPa, pressure p of casting ' be 1.0MPa.Raw materials for metallurgy and quality as follows: technically pure iron 17250g, chromium metal 3240g, metal molybdenum 210g, manganese metal 90g, industrial silicon 101g, graphite 67g.Wherein graphite and industrial silicon add 6.8% and 3.1% respectively on target component basis, for deoxidation.In addition, add 21.0g and carry out deep deoxidation containing the nickel magnesium alloy of magnesium 20%, and add 10.5g cerium and carry out dark desulfurization.
(2) cloth: crucible technically pure iron, chromium metal, metal molybdenum being put into pressurization induction furnace, by accounting for the graphite of graphite total mass 60%, industrial silicon, manganese metal, remaining 40% graphite, nickel magnesium alloy, cerium be placed in feeding chamber successively.
(3) load melting: to start vacuum pump, induction furnace internal pressure is evacuated to 5.2Pa, close vacuum pump; Energising heats up, and initial power is 4kW, increases to 35kW gradually, melts raw materials for metallurgy in crucible.
(4) deoxidation: after treating in crucible that raw materials for metallurgy is melting down, the high-purity argon gas of purity >=99.999% is filled with to 30kPa in pressurization induction furnace, the graphite accounting for graphite total mass 60% is added in molten steel, start vacuum pump, start to carry out carbon deoxygenation, until vacuum tightness to 8.5Pa and liquid level is steady, no longer includes bubble and produces.Add industrial silicon afterwards, further deoxidation.
(5) alloying: high pure nitrogen to the pressure being filled with purity >=99.999% in induction furnace is 0.37MPa, then in molten steel, add manganese metal successively by feeding chamber, remaining 40% graphite carries out alloying, add nickel magnesium alloy afterwards and cerium carries out deep deoxidation and dark desulfurization, and 8min is incubated at 1545 ~ 1555 DEG C of temperature, alloy is uniformly distributed in molten steel.
(6) pressurization casting: high pure nitrogen to the furnace pressure being filled with purity >=99.999% in pressurization induction furnace is 1.0MPa, then casts at 1550 DEG C; After casting terminates rear maintenance 30min, lower furnace pressure gradually, take out steel ingot.
Smelt gained height nitrogen Martensite Stainless Steel 30Cr15MoN0.4 ingot casting without nitrogen pore, dense structure, composition is as shown in table 3.
Gained 30Cr15MoN0.4 composition/wt.% smelted by table 3
Embodiment two
Adopt pressurized Induction Melting 20.0kg target steel grade 50Cr18MoVN0.36, its composition range is as shown in table 4.
Table 4 steel grade 50Cr18MoVN0.36 composition range and target component/wt.%
(1) determine to smelt and casting pressure preparing burden: according to steel grade target component and smelting temperature in table 4 about 1550 DEG C, according to formula 1., 2. formula calculate: smeltings pressure p is 0.22MPa, pressure p of casting ' be 1.0MPa.Raw materials for metallurgy and quality as follows: technically pure iron 15950g, chromium metal 3529g, metal molybdenum 220g, manganese metal 64g, industrial silicon 97g, vanadium metal 40g, graphite 110g.Wherein graphite and industrial silicon add 5.7% and 4.8% respectively on target component basis, for deoxidation.In addition, interpolation 25.0g carries out deep deoxidation containing the nickel magnesium alloy of magnesium 20%, adds 12.0g Rare Earth Lanthanum and carries out dark desulfurization.
(2) cloth: crucible technically pure iron, chromium metal, metal molybdenum being put into pressurization induction furnace, by accounting for the graphite of graphite total mass 55%, industrial silicon, manganese metal, vanadium metal, remaining 45% graphite, nickel magnesium alloy, Rare Earth Lanthanum be placed in feeding chamber successively.
(3) load melting: to start vacuum pump, induction furnace internal pressure is evacuated to 6.5Pa, close vacuum pump; Energising heats up, and initial power is 4kW, increases to 34kW gradually, melts raw materials for metallurgy in crucible.
(4) deoxidation: after treating in crucible that raw materials for metallurgy is melting down, the high-purity argon gas of purity >=99.999% is filled with to 20kPa in pressurization induction furnace, the graphite accounting for graphite total mass 55% is added in molten steel, start vacuum pump, start to carry out carbon deoxygenation, until vacuum tightness to 6.5Pa and liquid level is steady, no longer includes bubble and produces.Add industrial silicon afterwards, further deoxidation.
(5) alloying: high pure nitrogen to the pressure being filled with purity >=99.999% in induction furnace is 0.22MPa, then in molten steel, add manganese metal successively by feeding chamber, vanadium metal, remaining 45% graphite carries out alloying, add nickel magnesium alloy afterwards and Rare Earth Lanthanum carries out deep deoxidation and dark desulfurization, and 10min is incubated at 1548 ~ 1558 DEG C of temperature, alloy is uniformly distributed in molten steel.
(6) pressurization casting: high pure nitrogen to the furnace pressure being filled with purity >=99.999% in pressurization induction furnace is 1.0MPa, then casts at 1553 DEG C; After casting terminates rear maintenance 35min, lower furnace pressure gradually, take out steel ingot.
Smelt gained height nitrogen Martensite Stainless Steel 50Cr18MoVN0.36 ingot casting without nitrogen pore, dense structure, composition is as shown in table 5.
Gained 50Cr18MoVN0.36 composition/wt.% smelted by table 5
Embodiment three
Adopt pressurized Induction Melting 20.5kg target steel grade 12Cr16MoNiVN0.5, its composition range is as shown in table 6.
Table 6 steel grade 12Cr16MoNiVN0.5 composition range and target component/wt.%
(1) determine to smelt and casting pressure preparing burden: according to steel grade target component and smelting temperature in table 6 about 1550 DEG C, according to formula 1., 2. formula calculate: smeltings pressure p is 0.46MPa, pressure p of casting ' be 1.2MPa.Raw materials for metallurgy and quality as follows: technically pure iron 16470g, chromium metal 3349g, metal molybdenum 205g, metallic nickel 205g, manganese metal 110g, industrial silicon 77g, vanadium metal 61.5g, graphite 26g.Wherein graphite and industrial silicon add 7.0% and 3.0% respectively on target component basis, for deoxidation.In addition, interpolation 20.5g carries out deep deoxidation containing the nickel magnesium alloy of magnesium 20%, adds 10.3g Rare Earth Lanthanum and carries out desulfurization.
(2) cloth: crucible technically pure iron, chromium metal, metal molybdenum, metallic nickel being put into pressurization induction furnace, by accounting for the graphite of graphite total mass 70%, industrial silicon, manganese metal, vanadium metal, remaining 30% graphite, nickel magnesium alloy, Rare Earth Lanthanum be placed in feeding chamber successively.
(3) load melting: to start vacuum pump, induction furnace internal pressure is evacuated to 6.3Pa, close vacuum pump; Energising heats up, and initial power is 4kW, increases to 36kW gradually, melts raw materials for metallurgy in crucible.
(4) deoxidation: after treating in crucible that raw materials for metallurgy is melting down, the high-purity argon gas of purity >=99.999% is filled with to 25kPa in pressurization induction furnace, the graphite accounting for graphite total mass 70% is added in molten steel, start vacuum pump, start to carry out carbon deoxygenation, until vacuum tightness to 5.5Pa and liquid level is steady, no longer includes bubble and produces.Add industrial silicon afterwards, further deoxidation.
(5) alloying: high pure nitrogen to the pressure being filled with purity >=99.999% in induction furnace is 0.46MPa, then in molten steel, add manganese metal successively by feeding chamber, vanadium metal, remaining 30% graphite carries out alloying, add nickel magnesium alloy afterwards and Rare Earth Lanthanum carries out deep deoxidation and dark desulfurization, and 12min is incubated at 1546 ~ 1554 DEG C of temperature, alloy is uniformly distributed in molten steel.
(6) pressurization casting: high pure nitrogen to the furnace pressure being filled with purity >=99.999% in pressurization induction furnace is 1.2MPa, then casts at 1548 DEG C; After casting terminates rear maintenance 25min, lower furnace pressure gradually, take out steel ingot.
Smelt gained height nitrogen Martensite Stainless Steel 12Cr16MoNiVN0.5 ingot casting without nitrogen pore, dense structure, composition is as shown in table 7.
Gained 12Cr16MoNiVN0.5 composition/wt.% smelted by table 7
Meanwhile, the ingot casting of pore-free, uniform composition can be obtained by control cast and freezing pressure.
Claims (2)
1. utilize pressurization induction to smelt a method for low aluminium height nitrogen Martensite Stainless Steel, it is characterized in that, said method comprising the steps of:
(1) according to steel grade target component and smelting temperature, according to the solubleness formula of nitrogen in steel 1., calculate and smelt pressure p, and according to formula 2. calculate casting pressure p '; In conjunction with raw materials for metallurgy composition and the quality that steel ingot Mass Calculation desired raw material will be smelted, preparation raw materials for metallurgy, raw material comprises: technically pure iron, chromium metal or ferrochrome, metal molybdenum or molybdenum-iron, metallic nickel, manganese metal or electrolytic manganese, industrial silicon, vanadium metal or vanadium iron, graphite, nickel magnesium alloy, cerium or lanthanum etc.; In steel ingot, aim carbon content basis is added the carbon of 3 ~ 10% again, target Si content basis is added the silicon of 1 ~ 5% again, for deoxidation; Add that will to smelt ingot quality 0.04 ~ 0.2% containing magnesium be the nickel magnesium alloy of 20%, recovery rate is 10 ~ 30%, carries out deep deoxidation; Add and will smelt ingot quality 0.004 ~ 0.03% cerium or lanthanum, recovery rate is 20 ~ 40%, for dark desulfurization;
Smelt the calculation formula of pressure p 1.:
In formula: p is for smelting pressure, and unit is MPa; p
Θfor standard atmospheric pressure, be 0.101325MPa; T is smelting temperature, and unit is K;
Casting pressure p ' calculation formula 2.:
In formula: p' is casting pressure, and unit is Mpa;
(2) by according to the crucible will smelting the good technically pure iron of steel ingot Mass Calculation, pressurization induction furnace put into by chromium metal or ferrochrome, metal molybdenum or molybdenum-iron, metallic nickel, feeding chamber is placed in successively by accounting for the graphite of graphite total mass 40% ~ 80%, industrial silicon, manganese metal or electrolytic manganese, vanadium metal or vanadium iron, remaining 20% ~ 60% graphite, nickel magnesium alloy, cerium or lanthanum etc.;
(3) start vacuum pump, pressurization induction furnace internal pressure is evacuated to below 10Pa, close vacuum pump; Energising heats up, and increases the power of induction furnace gradually, melts raw materials for metallurgy in crucible;
(4) after treating in crucible that raw materials for metallurgy is melting down, high-purity argon gas to 10 ~ 50kPa is filled with in pressurization induction furnace, the graphite accounting for graphite total mass 40% ~ 80% is added in molten steel, start vacuum pump, start to carry out carbon deoxygenation, until vacuum tightness to below 10Pa and liquid level is steady, no longer includes bubble and produces; If period reacts too violent, close vacuum pump, suitably reduction power and be also filled with a small amount of high-purity argon gas, continue again to vacuumize after liquid level is steady; After vacuum carbon deoxidization terminates, add industrial silicon, further deoxidation;
(5) high pure nitrogen to the pressure being filled with purity >=99.999% in pressurization induction furnace is smelting pressure p, then in molten steel, add manganese metal or electrolytic manganese, vanadium metal or vanadium iron successively by feeding chamber, remaining 20% ~ 60% graphite carries out alloying, add nickel magnesium alloy and cerium or lanthanum afterwards and carry out deep deoxidation and dark desulfurization, and 5 ~ 10min is incubated at 1540 ~ 1580 DEG C of temperature, alloying element is uniformly distributed in molten steel;
(6) high pure nitrogen to the furnace pressure being filled with purity >=99.999% in pressurization induction furnace is p', then casts at 1540 ~ 1580 DEG C; After casting terminates, keep more than 20 minutes, lower furnace pressure gradually afterwards, take out steel ingot.
2. the method utilizing pressurization induction to smelt low aluminium height nitrogen Martensite Stainless Steel according to claim 1, it is characterized in that, described steel grade target component comprises by mass percentage: the carbon of 0.1 ~ 0.6%, the manganese of 0 ~ 0.5%, 12 ~ 24% chromium, be no more than the silicon of 1%, molybdenum, the nitrogen of 0.1 ~ 0.6%, nickel, the vanadium of 0 ~ 1%, the aluminium being no more than 0.02%, the sulphur, the surplus that are no more than 0.002% of 0 ~ 2% of 0 ~ 3% is iron and inevitable impurity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510864235.XA CN105463298B (en) | 2015-12-01 | 2015-12-01 | A kind of method that low-aluminium high nitrogen martensitic stain less steel is smelted in sensing of pressurizeing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510864235.XA CN105463298B (en) | 2015-12-01 | 2015-12-01 | A kind of method that low-aluminium high nitrogen martensitic stain less steel is smelted in sensing of pressurizeing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105463298A true CN105463298A (en) | 2016-04-06 |
| CN105463298B CN105463298B (en) | 2017-07-11 |
Family
ID=55601450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510864235.XA Active CN105463298B (en) | 2015-12-01 | 2015-12-01 | A kind of method that low-aluminium high nitrogen martensitic stain less steel is smelted in sensing of pressurizeing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105463298B (en) |
Cited By (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106011676A (en) * | 2016-06-30 | 2016-10-12 | 芜湖地心引力运动科技有限公司 | High-toughness high-abrasion resistance metallic material for sports equipment and preparation method thereof |
| CN106011625A (en) * | 2016-06-30 | 2016-10-12 | 芜湖地心引力运动科技有限公司 | High-rigidity metallic material for sports equipment and preparation method thereof |
| CN106011371A (en) * | 2016-06-24 | 2016-10-12 | 东北大学 | Pressurizing induction and pressurizing electroslag remelting duplex high-nitrogen steel smelting method |
| CN106048397A (en) * | 2016-06-30 | 2016-10-26 | 芜湖地心引力运动科技有限公司 | Wear-resistant metal material for sports equipment and preparation method thereof |
| CN106222545A (en) * | 2016-08-31 | 2016-12-14 | 浙江天马轴承有限公司 | A kind of stainless preparation method of high nitrogen alloy |
| CN106244941A (en) * | 2016-08-31 | 2016-12-21 | 浙江天马轴承有限公司 | A kind of preparation method of high nitrogen stainless steel |
| CN106435376A (en) * | 2016-06-29 | 2017-02-22 | 东北大学 | High-strength high-yield-elongation cold-rolled steel sheet and manufacturing method thereof |
| CN106435333A (en) * | 2016-08-31 | 2017-02-22 | 浙江天马轴承有限公司 | Preparation method for high-nitrogen high-nickel stainless steel |
| CN106636858A (en) * | 2016-10-24 | 2017-05-10 | 江苏星火特钢有限公司 | Method for producing high-anticorrosive high-nitrogen super austenitic stainless steel |
| CN110093582A (en) * | 2019-05-14 | 2019-08-06 | 东北大学 | A method of gas nitriding smelts COST-FB2 steel under condition of negative pressure |
| JP2019196530A (en) * | 2018-05-11 | 2019-11-14 | 株式会社デンソー | Martensitic stainless steel |
| CN111334702A (en) * | 2020-03-20 | 2020-06-26 | 浙江天马轴承集团有限公司 | Preparation method of high-strength high-nitrogen rare earth stainless bearing steel |
| CN112048677A (en) * | 2020-08-28 | 2020-12-08 | 阳江十八子刀剪制品有限公司 | Martensite stainless steel for cutter and preparation method thereof |
| CN112195419A (en) * | 2020-11-23 | 2021-01-08 | 浙江宝武钢铁有限公司 | Preparation method of corrosion-resistant high-nitrogen stainless steel |
| CN112899438A (en) * | 2021-01-15 | 2021-06-04 | 东北大学 | Method for duplex smelting of high-nitrogen steel by pressurized ladle refining and pressurized electroslag remelting |
| CN113025819A (en) * | 2021-02-24 | 2021-06-25 | 成都先进金属材料产业技术研究院股份有限公司 | Method for recycling spectrum pure graphite crucible |
| CN113046623A (en) * | 2021-03-10 | 2021-06-29 | 东北大学 | Preparation and use methods of nickel-based rare earth magnesium intermediate alloy for molten steel alloying |
| CN113549735A (en) * | 2021-07-21 | 2021-10-26 | 东北大学 | Method for preparing ultralow-oxygen bearing steel ingot by vacuum induction smelting |
| CN113802069A (en) * | 2021-09-18 | 2021-12-17 | 恒碧沃金属材料(上海)有限公司 | Novel die steel material and preparation method thereof |
| CN114525458A (en) * | 2022-02-21 | 2022-05-24 | 东北大学 | TWIP steel based on carbon and nitrogen synergy and method for preparing nitrogen-containing TWIP steel |
| CN114855094A (en) * | 2022-05-23 | 2022-08-05 | 东北大学 | Corrosion-resistant antibacterial martensitic stainless steel and preparation method and application thereof |
| CN115612924A (en) * | 2022-09-19 | 2023-01-17 | 攀钢集团攀枝花钢铁研究院有限公司 | Ferrite/martensite heat-resistant steel for lead-bismuth pile and preparation method thereof |
| CN115838893A (en) * | 2022-12-21 | 2023-03-24 | 湖南华菱涟源钢铁有限公司 | Method for improving magnesium solubility in steel |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102002640A (en) * | 2010-09-09 | 2011-04-06 | 中国兵器工业第五二研究所 | Method for preparing high nitrogen steel by adopting pressurized induction |
| CN103374685A (en) * | 2012-04-23 | 2013-10-30 | 钢铁研究总院 | Stainless steel material and manufacturing method thereof |
| CN103924031A (en) * | 2014-04-22 | 2014-07-16 | 钢铁研究总院 | Method for smelting high-nitrogen steel by vacuum induction positive-pressure furnace |
| CN104862609A (en) * | 2015-03-13 | 2015-08-26 | 东北大学 | Method for pressurized induction smelting of high nitrogen stainless steel through pressure control in stages |
-
2015
- 2015-12-01 CN CN201510864235.XA patent/CN105463298B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102002640A (en) * | 2010-09-09 | 2011-04-06 | 中国兵器工业第五二研究所 | Method for preparing high nitrogen steel by adopting pressurized induction |
| CN103374685A (en) * | 2012-04-23 | 2013-10-30 | 钢铁研究总院 | Stainless steel material and manufacturing method thereof |
| CN103924031A (en) * | 2014-04-22 | 2014-07-16 | 钢铁研究总院 | Method for smelting high-nitrogen steel by vacuum induction positive-pressure furnace |
| CN104862609A (en) * | 2015-03-13 | 2015-08-26 | 东北大学 | Method for pressurized induction smelting of high nitrogen stainless steel through pressure control in stages |
Cited By (28)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106011371A (en) * | 2016-06-24 | 2016-10-12 | 东北大学 | Pressurizing induction and pressurizing electroslag remelting duplex high-nitrogen steel smelting method |
| CN106435376A (en) * | 2016-06-29 | 2017-02-22 | 东北大学 | High-strength high-yield-elongation cold-rolled steel sheet and manufacturing method thereof |
| CN106048397A (en) * | 2016-06-30 | 2016-10-26 | 芜湖地心引力运动科技有限公司 | Wear-resistant metal material for sports equipment and preparation method thereof |
| CN106011676A (en) * | 2016-06-30 | 2016-10-12 | 芜湖地心引力运动科技有限公司 | High-toughness high-abrasion resistance metallic material for sports equipment and preparation method thereof |
| CN106011625A (en) * | 2016-06-30 | 2016-10-12 | 芜湖地心引力运动科技有限公司 | High-rigidity metallic material for sports equipment and preparation method thereof |
| CN106222545A (en) * | 2016-08-31 | 2016-12-14 | 浙江天马轴承有限公司 | A kind of stainless preparation method of high nitrogen alloy |
| CN106244941A (en) * | 2016-08-31 | 2016-12-21 | 浙江天马轴承有限公司 | A kind of preparation method of high nitrogen stainless steel |
| CN106435333A (en) * | 2016-08-31 | 2017-02-22 | 浙江天马轴承有限公司 | Preparation method for high-nitrogen high-nickel stainless steel |
| CN106636858A (en) * | 2016-10-24 | 2017-05-10 | 江苏星火特钢有限公司 | Method for producing high-anticorrosive high-nitrogen super austenitic stainless steel |
| CN106636858B (en) * | 2016-10-24 | 2018-05-15 | 江苏星火特钢有限公司 | A kind of method for producing high anti-corrosion high-nitrogen super austenitic stainless steel |
| JP2019196530A (en) * | 2018-05-11 | 2019-11-14 | 株式会社デンソー | Martensitic stainless steel |
| WO2019216145A1 (en) * | 2018-05-11 | 2019-11-14 | 株式会社デンソー | Martensitic stainless steel |
| CN110093582A (en) * | 2019-05-14 | 2019-08-06 | 东北大学 | A method of gas nitriding smelts COST-FB2 steel under condition of negative pressure |
| CN110093582B (en) * | 2019-05-14 | 2020-05-01 | 东北大学 | Method for smelting COST-FB2 steel by gas phase nitriding under negative pressure condition |
| CN111334702A (en) * | 2020-03-20 | 2020-06-26 | 浙江天马轴承集团有限公司 | Preparation method of high-strength high-nitrogen rare earth stainless bearing steel |
| CN112048677A (en) * | 2020-08-28 | 2020-12-08 | 阳江十八子刀剪制品有限公司 | Martensite stainless steel for cutter and preparation method thereof |
| CN112195419A (en) * | 2020-11-23 | 2021-01-08 | 浙江宝武钢铁有限公司 | Preparation method of corrosion-resistant high-nitrogen stainless steel |
| CN112899438B (en) * | 2021-01-15 | 2022-03-01 | 东北大学 | Method for duplex smelting of high-nitrogen steel by pressurized ladle refining and pressurized electroslag remelting |
| CN112899438A (en) * | 2021-01-15 | 2021-06-04 | 东北大学 | Method for duplex smelting of high-nitrogen steel by pressurized ladle refining and pressurized electroslag remelting |
| CN113025819A (en) * | 2021-02-24 | 2021-06-25 | 成都先进金属材料产业技术研究院股份有限公司 | Method for recycling spectrum pure graphite crucible |
| CN113046623A (en) * | 2021-03-10 | 2021-06-29 | 东北大学 | Preparation and use methods of nickel-based rare earth magnesium intermediate alloy for molten steel alloying |
| CN113549735A (en) * | 2021-07-21 | 2021-10-26 | 东北大学 | Method for preparing ultralow-oxygen bearing steel ingot by vacuum induction smelting |
| CN113802069A (en) * | 2021-09-18 | 2021-12-17 | 恒碧沃金属材料(上海)有限公司 | Novel die steel material and preparation method thereof |
| CN114525458A (en) * | 2022-02-21 | 2022-05-24 | 东北大学 | TWIP steel based on carbon and nitrogen synergy and method for preparing nitrogen-containing TWIP steel |
| CN114855094A (en) * | 2022-05-23 | 2022-08-05 | 东北大学 | Corrosion-resistant antibacterial martensitic stainless steel and preparation method and application thereof |
| CN115612924A (en) * | 2022-09-19 | 2023-01-17 | 攀钢集团攀枝花钢铁研究院有限公司 | Ferrite/martensite heat-resistant steel for lead-bismuth pile and preparation method thereof |
| CN115612924B (en) * | 2022-09-19 | 2023-09-12 | 攀钢集团攀枝花钢铁研究院有限公司 | Ferrite/martensite heat-resistant steel for lead-bismuth pile and preparation method thereof |
| CN115838893A (en) * | 2022-12-21 | 2023-03-24 | 湖南华菱涟源钢铁有限公司 | Method for improving magnesium solubility in steel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105463298B (en) | 2017-07-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105463298B (en) | A kind of method that low-aluminium high nitrogen martensitic stain less steel is smelted in sensing of pressurizeing | |
| CN112899438B (en) | Method for duplex smelting of high-nitrogen steel by pressurized ladle refining and pressurized electroslag remelting | |
| CN102181806B (en) | Thick chromium-molybdenum steel plate for hydrogenation equipment and production method thereof | |
| CN106756485B (en) | A method of pressurization induction prepares high nitrogen steel with electroslag furnace under protective Ar gas remelting duplex | |
| CN103160729B (en) | Medium-carbon microalloyed steel for engineering machinery caterpillar chain piece and production process thereof | |
| CN103320704B (en) | High performance bearing steel and production method thereof | |
| CN104862609B (en) | Method for pressurized induction smelting of high nitrogen stainless steel through pressure control in stages | |
| CN106011371A (en) | Pressurizing induction and pressurizing electroslag remelting duplex high-nitrogen steel smelting method | |
| CN104357742B (en) | 420MPa high-thickness hot-rolled steel sheet for ocean engineering and production method thereof | |
| CN105908080A (en) | Preparation method for high-manganese steel for ocean platform and continuous casting slab of high-manganese steel | |
| CN102888550A (en) | Smelting method of high-purity and high-nitrogen duplex stainless steel | |
| CN104762559A (en) | Method for producing steel plate for hydrogen-contacting equipment | |
| CN104060157A (en) | Hypereutectic high-chromium white cast iron and preparation method thereof | |
| CN104561837A (en) | Steel plate made of pressure vessel steel ASTMA387CL11Gr2 and production method thereof | |
| CN105369131A (en) | Production method of Q420R steel of steel board for pressure container | |
| Zhu et al. | Effect of solidification pressure on phase transformation and precipitated phases of 30Cr15Mo1N ingot | |
| CN108950381A (en) | Normalizing type marine engineering equipment special thick low-alloy high strength steel plate and its production method | |
| CN114032461B (en) | High-nitrogen steel with high strength, low yield ratio and high corrosion resistance for marine engineering and preparation method thereof | |
| CN106048139A (en) | Nitrogen blowing alloying method for 18CrNiMo7-6 steel | |
| CN108048737A (en) | Main load-bearing part steel of drilling lifting means and preparation method thereof | |
| CN113046641B (en) | Low-vanadium nitrogen-containing hot work die steel and preparation method thereof | |
| CN114032441A (en) | Method for smelting ultra-low carbon stainless steel in vacuum induction furnace | |
| CN103725974A (en) | Novel low-cost wear-resistant pipe steel X65 steel plate and production method thereof | |
| CN109487155A (en) | High-voltage oil cylinder hydraulic stem non-hardened and tempered steel and its production method | |
| CN110564914A (en) | Method for improving low-temperature impact toughness of low-alloy bainite steel by rare earth microalloying |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |