CN107217201A - A kind of marine drilling platform containing rare earth spud leg 600MPa seamless steel pipes and its production method - Google Patents

A kind of marine drilling platform containing rare earth spud leg 600MPa seamless steel pipes and its production method Download PDF

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Publication number
CN107217201A
CN107217201A CN201710500229.5A CN201710500229A CN107217201A CN 107217201 A CN107217201 A CN 107217201A CN 201710500229 A CN201710500229 A CN 201710500229A CN 107217201 A CN107217201 A CN 107217201A
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rare earth
600mpa
seamless steel
drilling platform
spud leg
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Inventor
丰小冬
贺景春
涛雅
兰金亮
姜海龙
张行刚
姚晓乐
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Baotou Iron and Steel Group Co Ltd
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Baotou Iron and Steel Group Co Ltd
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Priority to CN201710500229.5A priority Critical patent/CN107217201A/en
Publication of CN107217201A publication Critical patent/CN107217201A/en
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    • 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
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • 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
    • C21C7/072—Treatment with gases
    • 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
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • C21D9/085—Cooling or quenching
    • 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
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • 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
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • 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
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • 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
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • 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
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • 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
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • 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
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • 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
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium

Abstract

The invention discloses a kind of marine drilling platform containing rare earth spud leg 600MPa seamless steel pipes and its production method.The raw material of the seamless steel pipe is made up of percentage by weight for 90% blast-melted and 10% heavy-duty waste steel；The chemical composition of pipe is respectively by weight percentage：C0.07‑0.13；Si 0.20‑0.40；Mn 1.20‑1.40；P≤0.015；S≤0.005；Cr1.30‑1.50；Mo 0.30‑0.50；Nb 0.02‑0.06；Ti 0.01‑0.03；Al 0.01‑0.04；Rare earth elements RE 0.0005 0.0030；Cu<0.10；Ni<0.10；Surplus is matrix Fe and undetectable micro impurity element.The seamless steel pipe that the present invention is provided has production cost low, and production difficulty is small, the excellent advantage of mechanical property.

Description

A kind of marine drilling platform containing rare earth spud leg 600MPa seamless steel pipes and its production Method
Technical field
The present invention relates to ferrous metal smelting and metal-pressed machine field, more particularly to a kind of marine drilling containing rare earth Platform leg 600MPa seamless steel pipes and its production method
Background technology
Marine drilling platform spud leg seamless steel pipe, is chronically at that stratum is wriggled, high pressure sea water washes away and the evil such as corrode It is on active service under bad environment, therefore, steel pipe is faced with the puzzlement of the destructive accident such as corrosion cracking and fatigue fracture.Both destruction shapes Formula is generally all catastrophic, can bring many massive losses such as human, financial, and material resources, to adapt to this harshness of marine environment Military service operating mode, a kind of spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth of JP hair.
Through retrieval, similar background technology has：" fatigue strength >=560MPa marine drilling platform steel and its producer Method " (number of patent application：201410197337.6), there is problems with and shortcoming in it：Due in steel containing noble element Ni and Cu, production cost is of a relatively high, production technology is relative complex, production difficulty is relatively large；
Through retrieval, similar background technology also has：A kind of " marine drilling platform steel " (number of patent application： 201210435768.2), there is problems with and shortcoming in it：Due to containing noble element Ni and Cu in steel, production cost is relative It is higher；
Through retrieval, similar background technology also has：A kind of " preparation method of marine drilling platform steel " (patent application Number：201210435770.X), there is problems with and shortcoming in it：Due to containing noble element Ni and Cu, production technology phase in steel It is relatively large to complicated, production difficulty.
The content of the invention
In order to solve the above technical problems, the present invention provides the spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth And its production method.
The present invention provides a kind of spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth, and its raw material is by weight percent Than being constituted for 90% blast-melted and 10% heavy-duty waste steel；The chemical composition of pipe is respectively by weight percentage：C 0.07-0.13；Si 0.20-0.40；Mn 1.20-1.40；P≤0.015；S≤0.005；Cr 1.30-1.50；Mo 0.30- 0.50；Nb 0.02-0.06；Ti 0.01-0.03；Al 0.01-0.04；Rare earth elements RE 0.0005-0.0030；Cu<0.10； Ni<0.10；Surplus is matrix Fe and undetectable micro impurity element.
Further, the RE is Ce and La norium：Their percentage by weight be respectively Ce account for 67%, La accounts for 33%.
The present invention also provides a kind of production method of the above-mentioned spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes, It in turn includes the following steps：
Molten iron is pre-processed, top and bottom combined blown converter smelting, and LF stoves refining, VD applications of vacuum, round billet continuous casting, cutting, pipe adds Heat, perforation, Continuous Seamless Tube Mill, sizing, cooling, sawing is heat-treated, and is aligned, flaw detection.
Further, in the process of the molten iron pretreatment：Pre-processed blast-melted so that S is reduced in molten iron To less than 0.010%；
In the process of top and bottom combined blown converter smelting：Pretreated molten iron and heavy-duty waste steel are added by design proportion respectively Top and bottom combined blown converter, is smelted using single slag technique, control finishing slag basicity and terminal target；Add alloy and carry out deoxidation alloying, Final deoxidizing is using there is aluminium deoxidation technique, and tapping process carries out pushing off the slag or skimmed, and lime is added after alloy is added in tapping process Block.
Further, in the process of LF stoves refining：Overall process blowing argon gas are refined, senior number is counted to using from rudimentary and gradually carries The mode of high programming rate heats temperature raising；Slag making desulfurization, composition adjustment and heating behaviour are carried out according to converter molten steel composition and temperature Make；Operated using white slag is made.
Further, the refining of LF stoves keeps bottom soft blow argon gas after terminating, and rare-earth wires are fed by predetermined addition.
Further, in the process for carrying out VD applications of vacuum：Vacuum≤0.10KPa, deep vacuum time >=13 point are set Clock.
Further, fixed length silico-calcium silk is fed after VD applications of vacuum terminate, feeds and 10~15 minutes soft blow argon gas is carried out after silk.
Further, in the process that the molten steel after VD applications of vacuum is carried out to round billet continuous casting：Using the perseverance of low pulling rate Casting speed control and electromagnetic agitation technique, control molten steel overheat, and strand is cut into circular pipe blank after aligning.
Further, the Technology for Heating Processing is specially：900 ± 10 DEG C are incubated after 40~60min carry out water quenching of coming out of the stove, 690 ± 20 DEG C are incubated after 70~90min carry out air cooling of coming out of the stove；Band temperature correction is performed after tempering straight, straightening temperature >=500 DEG C.
Relative to prior art, the spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth that the present invention is provided have Following advantage：
1), due to not containing noble element Ni and Cu, therefore production cost is relatively low, production difficulty is relatively small；
2), straight due to carrying out band temperature correction more than 500 DEG C, the residual stress of steel pipe is relatively low, residual stress：≤ 30MPa (is adopted Use ring cutting method)；
3), because the unique component design containing rare earth element combines ripe production technology so that the properties of steel pipe are excellent Different, specific performance index is as follows：
630~700MPa of yield strength；700~800MPa of tensile strength；400~450MPa of fatigue strength；Elongation percentage >= 21%；Traverse impact value a at 0 DEG Ckv≥130J/cm2；Grain size >=9.0 grade.
4), according to NACE Standard TM 0177-2005 standard A methods, one group of smooth tensile sample is vulcanized Thing stress corrosion cracking (SSCC) is tested, and the present invention is designed based on yield strength for 600MPa grade of steels, and experiment constant stress is 0.8Rt0.6(480MPa), by H2The solution A of S saturations is soaked for continuous 720 hours, and sample does not ftracture, also do not occur crackle.
Embodiment
In order that those skilled in the art more fully understand the present invention program, with reference to embodiment to this hair It is bright to be described in further detail.
The present invention provides a kind of spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth, and its raw material is by weight percent Than being constituted for 90% blast-melted and 10% heavy-duty waste steel；The chemical composition of pipe is respectively by weight percentage：C 0.07-0.13；Si 0.20-0.40；Mn 1.20-1.40；P≤0.015；S≤0.005；Cr 1.30-1.50；Mo 0.30- 0.50；Nb 0.02-0.06；Ti 0.01-0.03；Al 0.01-0.04；Rare earth elements RE 0.0005-0.0030；Cu<0.10； Ni<0.10；Surplus is matrix Fe and undetectable micro impurity element.
Preferably, the RE is Ce and La norium：Their percentage by weight is respectively that Ce accounts for 67%, La Account for 33%.
Accordingly, the present invention also provides a kind of life of the above-mentioned spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes Production method, it in turn includes the following steps：
Molten iron is pre-processed, top and bottom combined blown converter smelting, and LF stoves refining, VD applications of vacuum, round billet continuous casting, cutting, pipe adds Heat, perforation, Continuous Seamless Tube Mill, sizing, cooling, sawing is heat-treated, and is aligned, flaw detection.
Further, in the process of the molten iron pretreatment：Pre-processed blast-melted so that S is reduced in molten iron To less than 0.010%；
In the process of top and bottom combined blown converter smelting：Pretreated molten iron and heavy-duty waste steel are added by design proportion respectively Top and bottom combined blown converter, is smelted using single slag technique, control finishing slag basicity and terminal target；Add alloy and carry out deoxidation alloying, Final deoxidizing is using there is aluminium deoxidation technique, and tapping process carries out pushing off the slag or skimmed, and lime is added after alloy is added in tapping process Block.
Preferably, in the process of LF stoves refining：Overall process blowing argon gas are refined, senior number is counted to using from rudimentary and gradually steps up The mode of programming rate heats temperature raising；Slag making desulfurization, composition adjustment and warming temperature are carried out according to converter molten steel composition and temperature； Operated using white slag is made.
Preferably, the refining of LF stoves keeps bottom soft blow argon gas after terminating, and rare-earth wires are fed by predetermined addition.
Preferably, in the process for carrying out VD applications of vacuum：Vacuum≤0.10KPa, deep vacuum time >=13 minute are set.
Further, fixed length silico-calcium silk is fed after VD applications of vacuum terminate, feeds and 10~15 minutes soft blow argon gas is carried out after silk.
Further, in the process that the molten steel after VD applications of vacuum is carried out to round billet continuous casting：Using the perseverance of low pulling rate Casting speed control and electromagnetic agitation technique, control molten steel overheat, and strand is cut into circular pipe blank after aligning.
As the preferred scheme of the present invention, the Technology for Heating Processing is specially：Go out after 900 ± 10 DEG C of 40~60min of insulation Stove carries out carry out air cooling of being come out of the stove after water quenching, 690 ± 20 DEG C of 70~90min of insulation；Band temperature correction is performed after tempering straight, straightening temperature >= 500℃。
The spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth that the present invention is provided are with percentage by weight 90% It is blast-melted to be used as raw material with 10% heavy-duty waste steel.Its technological process of production is：Blast-melted located in advance to above-mentioned first Reason, then together adds top and bottom combined blown converter with above-mentioned heavy-duty waste steel and is smelted, then the molten steel smelted is loaded into steel ladle Refined into furnaceman LF position, VD stations are entered after the completion of refining and carry out Fruit storage, then carry out round billet continuous casting, and will Continuous casting billet cuts into pipe, and then continuously cast billet for pipe-making is heated, and enters eleven punch 11 to the pipe heated and tandem rolling becomes Continuous Seamless Tube Mill, feeding cold bed cooling after sizing is carried out to tube rolling, then implements sawing, the steel pipe cut is heat-treated, then Aligned, most afterwards through carrying out flaw detection, eligible is steel pipe finished product.
Above-mentioned brief description of the process is：Molten iron pretreatment → top and bottom combined blown converter smelting → LF stoves refining → VD applications of vacuum → round billet continuous casting → cutting → heating of pipe blank → perforation → Continuous Seamless Tube Mill → sizing → cooling → sawing → heat treatment → aligning → spy Wound.
Details are as follows for its specific embodiment：
1st, pre-processed blast-melted so that the amount containing S (percentage by weight) in molten iron be reduced to 0.010% with Under；
2nd, pretreated molten iron is blended into top and bottom combined blown converter, adds (percentage by weight) 10% heavy-duty waste steel, used Single slag technique is smelted, control finishing slag basicity and terminal target, is added alloy and is carried out deoxidation alloying, final deoxidizing, which is used, aluminium deoxidation Technique, tapping process pushing off the slag or must be skimmed, and lime block is added after alloy is added in tapping process；
3rd, carried out in LF stoves concise：Overall process normal blowing argon gas on request are refined, senior number is counted to gradually using from rudimentary The mode for improving programming rate heats temperature raising；Slag making desulfurization, composition adjustment and heating are carried out according to converter molten steel composition and temperature Operation；Operated using white slag is made；
4th, the refining of LF stoves keeps bottom soft blow argon gas after terminating, and rare-earth wires are fed by predetermined addition.
5th, VD applications of vacuum are carried out：Vacuum≤0.10KPa, deep vacuum time >=13 minute；
6th, feeding fixed length silico-calcium silk, feeds and 10~15 minutes blowing argon gas is carried out after silk.By the molten steel after VD applications of vacuum Round billet continuous casting is carried out, using the permanent casting speed control and electromagnetic agitation technique of low pulling rate；Control molten steel overheat；Strand is by aligning Afterwards, it is cut into circular pipe blank.
Chemical composition chemical examination is carried out to pipe, the chemical composition of pipe should meet following requirements (percentage by weight %)：C 0.07-0.13；Si 0.20-0.40；Mn 1.20-1.40；P≤0.015；S≤0.005；Cr 1.30-1.50；Mo 0.30- 0.50；Nb 0.02-0.06；Ti 0.01-0.03；Al 0.01-0.04；Rare earth elements RE 0.0005-0.0030；Cu<0.10； Ni<0.10；Surplus is matrix Fe and undetectable micro impurity element.
Steel grades design considerations is as follows：
C is to improve one of intensity and the maximally effective element of quenching degree, it is considered to steel pipe hydrogen sulfide corrosion-resistant performance and impact The requirement of energy, improves Mn/C ratios as far as possible, and C content is controlled between 0.07~0.13%；
Si plays the role of deoxidation, but content more than 0.40% when be unfavorable for hydrogen sulfide corrosion resistant, therefore the control of Si contents exists Between 0.20~0.40%；
Mn plays the role of solution strengthening, can expand austenitic area, reduce austenite to ferritic transition temperature, Jin Erxi Change ferrite crystal grain, improve the toughness and tenacity of steel, and can compensate for the loss of strength caused by low C, but Mn too high levels can be produced Segregation, easily produces the MnS field trashes to HIC crack-sensitivities, and therefore, Mn contents are controlled between 1.20~1.40%；
Cr can improve the intensity and quenching degree of steel, and can be in steel surface one layer of passivating film of formation, with hydrogen sulfide corrosion resistant And oxidation resistance, while Cr can improve carbon dioxide corrosion resistant, and S absorption can be suppressed, therefore, addition 1.30~1.50% Cr；
Mo can increase quenching degree, improve temper resistance, while the passivating film of densification can also be formed on surface, with sulfur resistive Change the ability of hydrogen-type corrosion, and spot corrosion can be improved, therefore, the Mo of addition 0.30~0.50%；
Nb can concentrate precipitation in the form of Nb (CN) particle, it is suppressed that the recrystallization of austenite, while mutagenesis forming core, is produced Dislocation substructure, reaches refined crystalline strengthening；
Ti is strong nitride forming element, and Ti can catch the N dissociated in steel, and disperse is analysed in the form of TiN particles Go out, strong pinning austenite grain boundary, so as to reach effect of refined crystalline strengthening, improve the toughness of heat affected area, improve the welding of steel Performance；
P can cause microsegregation, be easily caused quenched martensite formation micro-flaw, the aggregate source as hydrogen therefore, will P content is controlled below 0.015%；
The increase of S contents can dramatically increase HIC sensitiveness, in order to reach S in preferable hydrogen sulfide corrosion resistant effect, steel Content should be controlled below 0.005%；
Al has good deoxidizing capacity, and can fining austenite grains, the corrosion resistance of raising steel, by Al content control System is between 0.01~0.04%；
Cleaning molten steel can be played, improve non-metallic inclusion form, reduce spot corrosion and reinforcing crystal boundary by adding RE elements Deng effect, so as to obtain the effect of the impact flexibility for improving steel and hydrogen sulfide corrosion resistance energy.
The rare earth element is Ce, La norium：Their percentage by weight is respectively：Ce accounts for 67%, La Account for 33%.
By components tests are qualified and sufur printing is not more than 2.0 grades of continuous casting circular tube blank and carries out tubulation, tubulation process is as follows：
Pipe is put into heating furnace to be heated, the temperature of each bringing-up section of heating furnace, each section of temperature is continuously checked and control The control range of degree is shown in Table 1：
Each section of temperature control (DEG C) of the rotary heating furnace of table 1
One section of heating Two sections of heating Three sections of heating Four sections of heating Five sections of heating Six sections of heating
1050~1120 1150~1250 1250~1290 1240~1300 1240~1300 1240~1300
Each section of temperature of heating furnace is automatically controlled with microcomputer and recorded automatically.
Hot tool must measured before, had to check for before rolling, handled roller-way, it is to avoid scratch tube wall.
The seamless steel pipe of required specification is rolled into after the pipe heated is perforated in corresponding continuous rolling-tube unit, during rolling Every batch at least carries out once heat sampling, checks physical dimension；Scale sawing, dimensional accuracy inspection are carried out after being cooled down on cold bed Qualified steel pipe is heat-treated again；Furnace temperature, thermal-stable and the cooling water flow of quenching heating furnace are controlled, to ensure quenching Quality；The furnace temperature and thermal-stable of control tempering heating furnace, to ensure tempering quality.
Heat treating regime is：900 ± 10 DEG C of 40~60min of insulation carry out water quenching, and 690 ± 20 DEG C of 70~90min of insulation enter Row air cooling, performs band temperature correction directly, straightening temperature >=500 DEG C after tempering.Steel pipe is carried out by branch flaw detection.
By above-mentioned technical process, the spud leg of marine drilling platform containing rare earth 600MPa of the present invention can be produced Seamless steel pipe.
Relative to prior art, the spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth that the present invention is provided have Following advantage：
1), due to not containing noble element Ni and Cu, therefore production cost is relatively low, production difficulty is relatively small；
2), straight due to carrying out band temperature correction more than 500 DEG C, the residual stress of steel pipe is relatively low, residual stress：≤ 30MPa (is adopted Use ring cutting method)；
3), because the unique component design containing rare earth element combines ripe production technology so that the properties of steel pipe are excellent Different, specific performance index is as follows：
630~700MPa of yield strength；700~800MPa of tensile strength；400~450MPa of fatigue strength；Elongation percentage >= 21%；Traverse impact value a at 0 DEG Ckv≥130J/cm2；Grain size >=9.0 grade.
4), according to NACE Standard TM 0177-2005 standard A methods, one group of smooth tensile sample is vulcanized Thing stress corrosion cracking (SSCC) is tested, and the present invention is designed based on yield strength for 600MPa grade of steels, and experiment constant stress is 0.8Rt0.6(480MPa), by H2The solution A of S saturations is soaked for continuous 720 hours, and sample does not ftracture, also do not occur crackle.
With reference to embodiment, the present invention is expanded on further：
Embodiment 1-3
Raw material is by weight percentage：Blast-melted 90%, heavy-duty waste steel 10%.
The technological process of production order be：Molten iron pretreatment → top and bottom combined blown converter smelting → LF stoves refining → VD applications of vacuum → round billet continuous casting → cutting → heating of pipe blank → perforation → Continuous Seamless Tube Mill → sizing → cooling → sawing → heat treatment → aligning → spy Wound.
The specific technological process of production is as described below：
By 90 tons it is blast-melted with " metal magnesium powder " make desulfating and deoxidation pretreatment, the amount containing S in molten iron is reduced to (weight Percentage) less than 0.010%.
90 tons of described preprocessed molten irons are blended into 100 tonnes of top and bottom combined blown converter, 10 tons of heavy-duty waste steels are added, Then smelted using single slag technique, finishing slag basicity carries out deoxidation alloying by 3.0 controls using silicomanganese, ferromanganese and ferrochrome, Final deoxidizing uses alfer, and is added in tapping process, and the necessary pushing off the slag of tapping process, pushing off the slag failure must skim, tap During alfer add after add 200kg lime blocks.
The molten steel smelted is loaded into steel ladle to be refined into furnaceman LF position：Normal blowing argon gas on request during refining, Count to senior number using from rudimentary and gradually step up heat temperature raising by the way of programming rate；Carried out according to converter molten steel composition and temperature Slag making desulfurization, composition adjustment and warming temperature；Using white slag operation is made, ferro-niobium, molybdenum-iron and ferro-titanium are added in the middle and later periods.
Bottom soft blow argon gas is kept after the refining of LF stoves terminates, the rare earth of certain length is fed by predetermined addition Silk.
Then VD applications of vacuum are carried out again to the molten steel refined：Deep vacuum≤0.10KPa, deep vacuum time >=13 point Clock；The silicon-calcium wire of certain length is fed again, feeds and 12 minutes soft blow argon gas are kept after silk.
The big bag of molten steel after VD applications of vacuum is hung on into ladle turret 5 machines 5 of progress and flows round billet continuous casting, is adopted during continuous casting With the fixed speed control and electromagnetic agitation technique of low pulling rate；Molten steel overheat Δ T≤30 DEG C；Strand, which goes out behind secondary cooling region, to be carried out Aligning, is then circular pipe blank with gas flame cuttiug.
It is to specificationPipe samplingization, examine, (percentage by weight contains its chemical composition result of laboratory test Amount) it is shown in Table 2.
The chemical composition testing result (weight %) of table 2
The rare earth elements RE is by weight percentage：The norium that 67% Ce+33% La is constituted, its Chemical composition and its content are qualified.
Sufur printing：1.0 grades are no more than, macroscopic examination is qualified.
It will change, examine qualified pipe to carry out tubulation, tubulation process is as follows：
In order that pipe has good rolling performance, each bringing-up section temperature of heating furnace is continuously detected and controlled, is protected Card heating is thorough uniform without overheating, and the temperature that each section of annular furnace is shown in Table 1.
Each section of temperature of heating furnace is automatically controlled with microcomputer and recorded automatically.
Hot tool must measured before, had to check for before rolling, handled roller-way, it is to avoid scratch tube wall.
By the pipe heated perforate afterSpecification is rolled into continuous rolling-tube unit isSeamless steel pipe, every batch carry out once heat sampling, check physical dimension；It is cooled down on cold bed Length saw is carried out afterwards to cut；The steel pipe of dimensional accuracy passed examination is heat-treated again：Control furnace temperature, the heating of quenching heating furnace steady Qualitative and cooling water flow, to ensure to quench quality；The furnace temperature and thermal-stable of control tempering heating furnace, to ensure to be tempered matter Amount.
Heat treating regime is：900 DEG C are incubated after 50min after carry out water quenching of coming out of the stove, 690 DEG C of insulation 80min progress sky of coming out of the stove It is cold.
Band temperature correction is carried out after steel pipe tempering straight, straightening temperature control is at 530~550 DEG C.To the steel pipe after aligning by prop up into Row flaw detection.
By above-mentioned technique productions and nondestructiving inspecting test, eligible becomes " offshore drill containing rare earth of the present invention The finished product of well platform leg 600MPa seamless steel pipes ", sample is produced with it and carries out mechanical property and metal lographic examination.
By examining, 1~embodiment of embodiment 3 produces the mechanical property of seamless steel pipe and metal lographic examination the results are shown in Table 3.Sulphur Compound stress corrosion cracking performance (SSCC performances) assay is shown in Table 4.
The mechanical property and metal lographic examination result of the steel pipe of table 3
Rt0.6(MPa) Rm(MPa) A (%) KV(J/cm2) Fatigue strength (MPa) Residual stress Tissue Grain size
Embodiment 1 643 726 24 164 411 22MPa It is tempered S+B 10 grades
Embodiment 2 662 751 23 152 423 24MPa It is tempered S+B 10 grades
Embodiment 3 683 775 22 143 436 27MPa It is tempered S+B 10 grades
Control sample 659 731 22 105 403 31MPa It is tempered S 9.5 level
Note：Impact specimen be transverse direction, test temperature be 0 DEG C；Control sample produces seamless steel with 1~embodiment of embodiment 3 The specification of pipe is identical with Technology for Heating Processing.
The sulfide-stress cracking performance of table 4 (SSCC performances) assay
Embodiment 1 Constant stress 480MPa, by H2S saturation solution As continuous 720 hours immersions, smooth tensile samples do not ftracture
Embodiment 2 Constant stress 480MPa, by H2S saturation solution As continuous 720 hours immersions, smooth tensile samples do not ftracture
Embodiment 3 Constant stress 480MPa, by H2S saturation solution As continuous 720 hours immersions, smooth tensile samples do not ftracture
Control sample Constant stress 480MPa, by H2The immersion in continuous 352 hours of S saturation solution As, smooth tensile sample cracking
As shown in the above, the spud leg of marine drilling platform containing rare earth prepared by the method provided using the present invention is used The yield strength of 600MPa seamless steel pipes be 630~700MPa, fatigue strength be 400~450MPa, 0 DEG C when traverse impact value ≥130J/cm2.The product of the present invention has that production cost is low, toughness and tenacity matching is high, even tissue is tiny, residual stress is low, The characteristics of hydrogen sulfide corrosion-resistant.
Above to the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes and its producer provided by the present invention Method is described in detail.Specific case used herein is set forth to the principle and embodiment of the present invention, the above The explanation of embodiment is only intended to the method and its core concept for helping to understand the present invention.It should be pointed out that for the art Those of ordinary skill for, under the premise without departing from the principles of the invention, can also to the present invention carry out it is some improvement and repair Decorations, these are improved and modification is also fallen into the protection domain of the claims in the present invention.

Claims (10)

1. a kind of spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth, it is characterised in that its raw material is by weight percent Than being constituted for 90% blast-melted and 10% heavy-duty waste steel；The chemical composition of pipe is respectively by weight percentage：C 0.07-0.13；Si 0.20-0.40；Mn 1.20-1.40；P≤0.015；S≤0.005；Cr 1.30-1.50；Mo 0.30- 0.50；Nb0.02-0.06；Ti 0.01-0.03；Al 0.01-0.04；Rare earth elements RE 0.0005-0.0030；Cu<0.10； Ni<0.10；Surplus is matrix Fe and undetectable micro impurity element.
2. the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 1, it is characterised in that institute State the norium that RE is Ce and La：Their percentage by weight is respectively that Ce accounts for 67%, La and accounts for 33%.
3. the production method of the spud leg 600MPa seamless steel pipes of marine drilling platform containing rare earth described in claim 1 or 2, it is special Levy and be, in turn include the following steps：
Molten iron is pre-processed, top and bottom combined blown converter smelting, and LF stoves refining, VD applications of vacuum, round billet continuous casting, cutting, heating of pipe blank is worn Hole, Continuous Seamless Tube Mill, sizing, cooling, sawing is heat-treated, and is aligned, flaw detection.
4. the production method of the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 3, its It is characterised by, in the process of the molten iron pretreatment：Pre-processed blast-melted so that S is reduced to 0.010% in molten iron Below；
In the process of top and bottom combined blown converter smelting：Pretreated molten iron and heavy-duty waste steel are added into top bottom by design proportion respectively Combined blown converter, is smelted using single slag technique, control finishing slag basicity and terminal target；Add alloy and carry out deoxidation alloying, it is de- eventually Oxygen is using there is aluminium deoxidation technique, and tapping process carries out pushing off the slag or skimmed, and lime block is added after alloy is added in tapping process.
5. the production method of the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 3, its It is characterised by, in the process of LF stoves refining：Refine overall process blowing argon gas, using from it is rudimentary count to senior number gradually step up heating speed The mode of degree heats temperature raising；Slag making desulfurization, composition adjustment and warming temperature are carried out according to converter molten steel composition and temperature；Using making White slag is operated.
6. the production method of the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 3, its It is characterised by, the refining of LF stoves keeps bottom soft blow argon gas after terminating, and rare-earth wires are fed by predetermined addition.
7. the production method of the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 3, its It is characterised by, in the process for carrying out VD applications of vacuum：Vacuum≤0.10KPa, deep vacuum time >=13 minute are set.
8. the production method of the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 3, its It is characterised by, feeding fixed length silico-calcium silk, feeds and 10~15 minutes soft blow argon gas are carried out after silk after VD applications of vacuum terminate.
9. the production method of the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 3, its It is characterised by, in the process that the molten steel after VD applications of vacuum is carried out to round billet continuous casting：Using the permanent casting speed control of low pulling rate And electromagnetic agitation technique, molten steel overheat is controlled, strand is cut into circular pipe blank after aligning.
10. the production method of the spud leg of marine drilling platform containing rare earth 600MPa seamless steel pipes according to claim 3, its It is characterised by, the Technology for Heating Processing is specially：900 ± 10 DEG C are incubated after 40~60min come out of the stove carry out water quenching, 690 ± 20 DEG C Carry out air cooling of coming out of the stove is incubated after 70~90min；Band temperature correction is performed after tempering straight, straightening temperature >=500 DEG C.
CN201710500229.5A 2017-06-27 2017-06-27 A kind of marine drilling platform containing rare earth spud leg 600MPa seamless steel pipes and its production method Pending CN107217201A (en)

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