CN103695785A - Steel for low-temperature and high-pressure pipeline connector and manufacturing method of continuous casting round billet thereof - Google Patents
Steel for low-temperature and high-pressure pipeline connector and manufacturing method of continuous casting round billet thereof Download PDFInfo
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Abstract
The invention relates to steel for a low-temperature and high-pressure pipeline connector and a manufacturing method of a continuous casting round billet thereof. The steel for the low-temperature and high-pressure pipeline connector disclosed by the invention comprises the following components by weight percent: 0.12-0.16% of C, 0.15-0.30% of Si, 1.20-1.45% of Mn, P not more than 0.025%, S not more than 0.015%, 0.15-0.25% of Cr, 0.04-0.10% of V, 0.02-0.05% of Nb, 0.015-0.040% of Alt, H not more than 2.0*10<-4>%, 120*10<-4>% to 260*10<-4>% of N, T.O not more than 15*10<-4>%, and the balance being Fe and inevitable impurities. The steel for the low-temperature and high-pressure pipeline connector provided by the invention has the advantages that the cleanliness is high, components are stable, the welding property is excellent, the strength, the tenacity and the low-temperature impact tenacity are high, and the like.
Description
Technical field
The invention belongs to metallurgical technology field, be specifically related to the manufacture method of steel and continuous cast round billets thereof for a kind of cryogenic high pressure conduit coupling.
Background technology
For the long pipeline apart from transporting low temperature, high pressure oil, Sweet natural gas, requirement for the manufacture of web member between pipeline and pipeline (for example, flange, threeway, elbow, valve etc.) steel when thering is good welding property, guarantee that web member inside can bear the variation of ambient temperature and the impacts of different the produced complexing action power of vibration, deadweight and outer weight-carrying capacity and geographical position such as high pressure, low temperature.Therefore, the steel of manufacturing above-mentioned conduit coupling must have good welding property, high strength, good plasticity and toughness, especially should have good low temperature (≤-51 ℃) impelling strength.
At present, steel for the manufacture of above-mentioned web member are mainly to adopt 16Mn, 20#, Q345E etc. at home, and the external main American Standard ASTMA105/A105M piping element that adopts is used the standards such as carbon steel and low alloy steel forging with carbon steel forging and ASTMA350/A350M-2007 conduit component, relate to A105, A350 steel series.But above-mentioned steel exist low-temperature performance unsettled shortcoming, especially low temperature (≤-51 ℃) impelling strength fluctuation large, on the low side, be difficult to meet the demands, become the bottleneck of steel for the above-mentioned web member of restriction.
Summary of the invention
The object of the present invention is to provide a kind of cryogenic high pressure conduit coupling that can solve at least one technical problem in above a plurality of technical problem manufacture method of steel and continuous cast round billets thereof.
According to cryogenic high pressure conduit coupling steel of the present invention, comprise by percentage to the quality following composition: C:0.12%～0.16%, Si:0.15%～0.30%, Mn:1.20%～1.45%, P≤0.025%, S≤0.015%, Cr:0.15%～0.25%, V:0.04%～0.10%, Nb:0.02%～0.05%, Al
t: 0.015%～0.040%, H≤2.0 * 10
-4%, N:120 * 10
-4%～260 * 10
-4%, T.O≤15 * 10
-4%, surplus is Fe and inevitable impurity.
Wherein, each component concentration can also be: C:0.12%～0.14%, Si:0.18%～0.25%, Mn:1.30%～1.40%, P≤0.020%, S≤0.010%, Cr:0.20%～0.25%, V:0.05%～0.10%, Al
t: 0.020%～0.035%, H≤1.5 * 10
-4%, N:150 * 10
-4%～230 * 10
-4%.
The present invention also provides the continuous cast round billets of a kind of above-mentioned cryogenic high pressure conduit coupling with steel.
The present invention also provides a kind of method of manufacturing above-mentioned continuous cast round billets, and the method comprises following operation successively: (1) electric furnace just refines operation: burden structure adopts steel scrap and molten iron; Add slag material in the process of carrying out slag free tapping after, then add containing aluminium deoxidizer; Control molten clear carbon >=0.50%, molten clear phosphorus≤0.025wt%, control just furnace smelting endpoint C and be 0.08%～0.10%, terminal P≤0.015%, tapping temperature is 1620 ℃～1680 ℃; Wherein, in described burden structure, the mass percent of molten iron is 55%～75%; The add-on of described slag material is 12kg～18kg with respect to steel per ton; The described add-on containing aluminium deoxidizer is 1.5kg～3.0kg with respect to steel per ton; (2) LF refining procedure: the molten steel temperature of furnaceman LF position is controlled to 1510～1560 ℃, adopts the complex deoxidization mode of carbon dust and silicon carbide diffusive deoxidation and the strong deoxidation phase of feeding aluminum steel to carry out deoxidation, adopt the mode nitrogen pick-up of nitrogen-containing alloy or low nitrogen blowing; Before tapping, feeding silicon-calcium wire is done rotten processing and deep deoxidation to inclusion; Wherein, described aluminum steel consumption is 1.0kg～1.5kg with respect to steel per ton, and described calcium line consumption is 0.010kg～0.015kg with respect to steel per ton, and described tapping temperature is 1610 ℃～1640 ℃; (3) VD vacuum outgas operation: keep 10min～20min below vacuum tightness 67Pa, be preferably 15min～20min.H content after vacuum-treat in molten steel is 1.5 * 10
-4below wt%; Molten steel is after atmospheric pressure state is got back in vacuum refinement, and argon bottom-blowing flow is 120L/min～260L/min, and pressure is 0.20MPa～0.40MPa, and keeping the soft blow time is 15min～25min; (4) continuous casting working procedure: carry out the operation of constant temperature, permanent pulling rate, constant level; (5) strand slow cooling operation: the continuous cast round billets of pointing out in described operation (3) is cooling through secondary cooling zone, rectify and to put, to transport rod road and be transferred to after cold bed, carry out slow cooling insulation; Wherein, the slow cooling time is more than 48 hours, and hanging out temperature is below 250 ℃.
Wherein, in operation (1), slag material is comprised of fritting low melting point slag supplying agent and lime; The weight ratio of fritting low melting point slag supplying agent and lime is 1:1～1.3:1; Fritting low melting point slag supplying agent comprises following composition: CaO:40wt%～60wt%, SiO
2: 5wt%～15wt%, Al
2o
3: 20wt%～35wt%, MgO:5wt%～15wt%.
Wherein, in operation (1), add also add after slag material alloy, alloy be in silicomanganese, ferromanganese, ferrochrome and nitrogen-containing alloy any one or multiple.
Wherein, in operation (2), the LF refining white slag hold-time is more than 20min, controls finishing slag main component mass percent to be: CaO:45%～55%, SiO
2: 8%～12%, Al
2o
3: 20%～25%, MgO:5%～8%, FeO+MnO≤0.5%.
Wherein, in operation (2), for same batch, the fluctuation range of controlling the mass percent of following compositions in the molten steel after refining is: C: ± 0.01%, Si: ± 0.03%, Mn: ± 0.02%, Cr: ± 0.02%, V: ± 0.01%, Nb: ± 0.01%, Al: ± 0.005%, N: ± 0.0015%.
Wherein, in operation (4), the liquid level of cast tundish molten steel is 850mm～900mm, and end stirring parameter is 300A/9.0Hz, 15 ℃～25 ℃ of molten steel cast superheating temperature; Cooling each section of water yield partition ratio of continuous casting is: cold one section 25%, two cold two section 20%, two cold three section 15%, two cold four section 10% of sufficient roller section 30%, two; Specific water 0.28L/kg～0.32L/kg.
Wherein, in operation (5), strand straightening temperature is more than 930 ℃.
According to cryogenic high pressure conduit coupling steel provided by the invention, have that cleanliness factor is high, stable components, welding property are good, high-strength, high-ductility, low temperature (51 ℃) impelling strength AK
vthe advantages such as>=30J.
With steel, the form with continuous cast round billets exists above-mentioned conduit coupling provided by the invention, can be used for manufacturing conduit coupling, and this continuous cast round billets has good surface and internal soundness, dense structure, even.
According to the preparation method of the continuous cast round billets for cryogenic high pressure conduit coupling provided by the invention, resulting conduit coupling all improves a lot by cleanliness factor, dense structure's property, the homogeneity of continuous cast round billets, meets and manufactures low temperature, the requirement of pressure piping web member.
Embodiment
In the present invention, if no special instructions, the per-cent adopting is mass percent.It should be noted that in the present invention, do not have the operation of describing in detail to be the state of the art, do not repeat them here.
Cryogenic high pressure conduit coupling of the present invention comprises following composition by percentage to the quality with steel: C:0.12%～0.16%, Si:0.15%～0.30%, Mn:1.20%～1.45%, P≤0.025%, S≤0.015%, Cr:0.15%～0.25%, V:0.04%～0.10%, Nb:0.02%～0.05%, Al
t: 0.015%～0.040%, H≤2.0 * 10
-4%, N:120 * 10
-4%～260 * 10
-4%, T.O≤15 * 10
-4%, surplus is Fe and inevitable impurity.
In order further to improve the performance of steel for cryogenic high pressure conduit coupling of the present invention, cryogenic high pressure conduit coupling of the present invention can be further defined to the composition of steel: C:0.12%～0.14%, Si:0.18%～0.25%, Mn:1.30%～1.40%, P≤0.020%, S≤0.010%, Cr:0.20%～0.25%, V:0.05%～0.10%, Nb:0.02%～0.05%, Al
t: 0.020%～0.035%, H≤1.5 * 10
-4%, N:150 * 10
-4%～230 * 10
-4%, T.O≤15 * 10
-4%, surplus is Fe and inevitable impurity.
Below cryogenic high pressure conduit coupling of the present invention is elaborated by the Design Mechanism of the main component in steel.
C: improve intensity and the hardness of steel, reduce mould, toughness and welding property.Carbon content is difficult for reaching requirement lower than 0.12% intensity and mechanical property; Higher than 0.16% be difficult to meet to material mould, toughness and welding property, especially low temperature impact properties requirement.
Si: dissolve in ferrite, improve intensity, the hardness of steel, reduction is moulded, toughness; And significantly improving the yield tensile ratio of steel, minimum content could play useful effect 0.15% time; Content is higher, while particularly coexisting with Mn, easily cause coarse grains, increases temper brittleness, significantly improve the brittle transition temperature of steel, general requirement in conjunction with cryogenic high pressure conduit coupling of the present invention with steel, is defined as 0.15%～0.30% by Si content, is preferably 0.18%～0.25%.
Mn: dissolve in ferrite, strengthening matrix, obviously improve the hardening capacity of steel, refine pearlite tissue, improves mechanical property, and content can not meet the mechanics of materials and the requirement of cold resistance energy lower than 1.20%; Content higher than 1.45% time, increases the welding crack tendency of material, affects material welding property.
P, S: improve the cutting ability of steel, significantly reduce plasticity and the toughness of steel, increase the tendency that steel cracks, worsen the comprehensive mechanical property of material, should reduce its content as far as possible.Cryogenic high pressure conduit coupling of the present invention adopts P≤0.025% and S≤0.015% with steel; Be preferably P≤0.020%, S≤0.010%.
Cr: obviously improve intensity and the hardening capacity of steel, improve wear resistance and resistance to corrosion simultaneously, but too high levels, easily increase the temper brittleness of steel; The use properties requirement of steel for cryogenic high pressure conduit coupling according to the present invention, design chromium content is 0.15%～0.25%, is preferably 0.20%～0.25%.
V: crystal grain thinning tissue, improve grain coarsening temperature, reduce the superheated susceptivity of steel, improve intensity and the toughness of steel, and improve its plasticity and toughness, increase temper resistance, reduce the crack sensitivity of material.It is 0.04%～0.10% that cryogenic high pressure conduit coupling of the present invention adopts V content with steel; Be preferably 0.05%～0.10%.
Nb: crystal grain thinning and precipitation strength effect, the coarsened grain temperature of raising steel, superheated susceptivity and the temper brittleness of reduction steel, intensity and toughness and the wriggling drag of raising steel.Meanwhile, can reduce gas content in steel and improve low-temperature performance and the corrosive nature of steel, content effect higher than 0.05% time increases not obvious.Consider the performance requriements of steel for web member, designing cryogenic high pressure conduit coupling of the present invention is 0.02%～0.05% with steel employing Nb content.
Al
t: refer to Holo-Al content.Main crystal grain thinning, deoxidation, fixed nitrogen, improve the toughness of steel, improves the comprehensive mechanical property of steel, and content can not play useful effect lower than 0.015%; Content higher than 0.040% time, forms Al
2o
3hard inclusions probability increases, and reduces the fatigue lifetime of steel, worsens low-temperature impact toughness, meanwhile, easily causes molten steel secondary oxidation, reduces Molten Steel Flow, worsens the quality of steel.Cryogenic high pressure conduit coupling of the present invention is preferably Al with steel
t: 0.020%～0.035%.
T.O: refer to total oxygen content.Content increases, and the cleanliness factor of steel reduces, and steel inclusion increases, and total oxygen content is higher than 15 * 10
-4during %, will significantly reduce that steel is moulded, toughness and fatigue property, worsen the comprehensive mechanical property of steel.
H: content is higher than 2.0 * 10
-4%, steel easily produces white point, spot segregation, repeated stress failure etc., significantly worsens the quality of steel, even causes steel to scrap.
N: can play solution strengthening and precipitation strength effect, be very strong formation and stable austenite element, forms stable nitride with V, Nb, Ti, Al in steel etc., will greatly improve intensity, hardness and the anti-fatigue performance of steel.But N too high levels can cause timeliness and the blue shortness phenomenon of steel; Meanwhile, cause the defects such as the segregation of steel, loose and bubble to produce, increase steel inclusion, significantly worsen the toughness of steel.Therefore, the design of N content is relevant with the nitride forming element content existing in steel.Consider the performance requriements of steel for web member, it is 120 * 10 that cryogenic high pressure conduit coupling of the present invention adopts N content with steel
-4%～260 * 10
-4%, is preferably 150 * 10
-4%～230 * 10
-4%.
In addition, in order further to improve performance, to cryogenic high pressure conduit coupling of the present invention, with the content of steel, can also carry out following restriction:
Ti: strong carbon, nitride forming element, solution strengthening effect is strong, reduce the toughness of sosoloid, crystal grain thinning, to improve tempering stable, have secondary hardening effect, but when content surpasses 0.020%, the resistance to low temperature of material obviously reduces, therefore, be preferably Ti≤0.02% in steel for cryogenic high pressure conduit coupling of the present invention.
Cu: as the harmful residual element in steel, content higher than 0.25% time, reduces the moulding of steel, toughness, and continuously cast bloom easily produces star-like crack.Therefore, be preferably Cu≤0.25% in steel for cryogenic high pressure conduit coupling of the present invention.
Web member in the present invention can be flange, threeway, elbow, valve etc.With steel, the form with continuous cast round billets exists cryogenic high pressure conduit coupling of the present invention.
The manufacture method of continuous cast round billets for low temperature high pressure gas conduit coupling provided by the invention, comprises following production process: electric furnace just refines operation → LF refining procedure → VD vacuum outgas operation → continuous casting working procedure → strand slow cooling operation → check, finishing procedure; Refer to specifically:
(1) electric furnace just refines operation: adopt the burden structure of steel scrap and molten iron, in burden structure, the mass percent of molten iron accounts for 55%～75%; Electric furnace has just refined in the process of carrying out slag free tapping, adds the mixing slag material being comprised of fritting low melting point slag supplying agent and lime.Add after described mixing slag material, then add alloy and contain aluminium deoxidizer; In addition, control molten clear carbon >=0.50%, molten clear phosphorus≤0.025%, controls just furnace smelting endpoint C and is 0.08%～0.10%, P≤0.015%, and tapping temperature is 1620 ℃～1680 ℃.
Wherein, the add-on of mixing slag material is 12kg/t steel～18kg/t steel, and mixing slag material is preferably fritting low melting point slag supplying agent and lime mixes by weight 1:1～1.3:1.Further preferred fritting low melting point slag supplying agent comprises the component of following mass percent: CaO:40wt%～60wt%, SiO
2: 5wt%～15wt%, Al
2o
3: 20wt%～35wt%, MgO:5wt%～15wt%.The alloy adding is one or more in silicomanganese, ferromanganese and ferrochrome, nitrogen-containing alloy, but the invention is not restricted to this, and concrete alloy adds kind and add-on to determine according to the composition of steel.Add-on containing aluminium deoxidizer is 1.5kg/t steel～3.0kg/t steel.
In addition, in electric furnace just refines operation, electric furnace used is preferably basic electric arc furnace.
(2) LF(LADLE FURNACE) refining procedure: refining furnace adopts LF stove, adopts the complex deoxidization mode deoxidation of carbon dust and silicon carbide diffusive deoxidation and the strong deoxidation phase of feeding aluminum steel, utilizes the mode nitrogen pick-up of nitrogen-containing alloy or low nitrogen blowing.Before tapping, feeding silicon-calcium wire is done rotten processing and deep deoxidation to inclusion.To furnaceman LF position molten steel temperature, be controlled at 1510～1560 ℃, be preferably 1530～1550 ℃.Molten steel through operations such as power transmission slag, residue adjustment, line feeding, stirrings, completes deoxidation, desulfurization at refining furnace, and removal is mingled with, and adjusting component is controlled the treating processess such as temperature.The complex deoxidization mode deoxidation that adopts silicon carbide diffusive deoxidation and feed the strong deoxidation phase of aluminum steel before analyzing a sample.Before tapping, feeding calcium line is done rotten processing and deep deoxidation to inclusion.Wherein, aluminum steel consumption is 1.0kg/t steel～1.5kg/t steel, and calcium line consumption is 0.010kg/t steel-0.015kg/t steel.Tapping temperature is controlled at 1610～1640 ℃, is preferably 1620～1630 ℃.
In addition, in above-mentioned LF refining procedure, LF refining white slag hold-time>=20min, preferably the hold-time is 25～35min, controls finishing slag main component mass percent: CaO:45%～55%, SiO
2: 8%～12%, Al
2o
3: 20%～25%, FeO+MnO≤0.5%, MgO:5%～8%.
In addition, in described LF refining procedure, adjusting component alloy used is one or more in ferromanganese, ferrochrome, nitrogen-containing alloy, vanadium iron, ferro-niobium.Adopting bottom blowing nitrogen mode is molten steel nitrogen pick-up, and alloy adds kind and quantity and nitrogen bottom blowing time, can determine according to concrete analysis result.
In addition, in described LF refining procedure, the refining of LF stove makes molten steel implement Narrow Composition Control, for same batch, the fluctuation range of controlling the mass percent of following compositions in the molten steel after refining is C: ± 0.01%, Si: ± 0.03%, Mn, Cr: ± 0.02%, V, Nb: ± 0.01%, Al: ± 0.005%, N: ± 0.0015%.
After LF stove tapping, also take off slag operation before entering VD vacuum outgas operation, take off the 30%-80% that the quantity of slag is total slag amount.
(3) VD(VACUUM DEGASSING) vacuum outgas operation: vacuum refining furnace adopts VD stove, mainly completes the de-H of molten steel, further promotes inclusion floating, cleaning molten steel.Ladle is to furnaceman VD position, and thermometric, vacuumizes and carry out Fruit storage, in the following hold-time of vacuum tightness 67Pa, is 10min～20min, is preferably 15min～20min.H≤2.0 * 10 after vacuum-treat
-4wt%, is preferably H≤1.5 * 10
-4wt%.Molten steel is after atmospheric pressure state is got back in vacuum refinement, and the treatment stage of entering soft blow, controlling argon bottom-blowing flow is 120L/min～260L/min, pressure is 0.25MPa～0.35Mpa, keeping the soft blow time is 15min～25min, and wherein soft blow state is top of the slag fine motion, and molten steel is not exposed.
(4) continuous casting working procedure: carry out " three perseverances " operation of constant temperature, permanent pulling rate, constant level; adopt the built-in mouth of a river+argon blowing seal of the large bag long nozzle+tundish of argon blowing seal submerged nozzle, ladle and tundish all to add a cover the full guard Prepared by Low Superheat Pouring of insulation, tundish molten steel face employing low-carbon (LC) high alkalinity insulating covering agent and carbonization rice husk double-layer heat insulation; mold liquid level is controlled automatically; end induction stirring; dynamically weak cold water distribution, multiple spot continuous straightening technology.
In addition, in described continuous casting working procedure, normal cast tundish molten steel liquid level 850mm～900mm, end stirring parameter: 300A/9.0Hz, 15 ℃～25 ℃ of molten steel cast superheating temperature, cooling each section of water yield partition ratio of continuous casting is: sufficient roller section 30%, two cold one section 25%, two cold two section 20%, two cold three section 15%, two cold four section 10%, specific water 0.28L/kg～0.32L/kg.
In addition, adopt the continuous withdrawal straightening machine of embedded six frame, strand straightening temperature >=930 ℃, preferably strand straightening temperature is 930～950 ℃, and further preferably strand straightening temperature is 935～945 ℃.When specifications section is Ф 350mm, pulling rate is controlled at 0.35-0.45m/min.
(5) strand slow cooling operation: continuous cast round billets is cooling through secondary cooling zone, rectify and put, transport rod road and be transferred to after cold bed, proceeds in time burial pit slow cooling, and adds a cover insulation.Slow cooling time >=48h, is preferably 48～56h.Hang out temperature≤250 ℃, be preferably 150～50 ℃.
(6) in above-mentioned strand slow cooling operation (5) afterwards, the present invention also can comprise check, finishing procedure.Be specially: check the surface quality of continuous cast round billets and to the internal soundness analysis of testing, and finishing grinding process is carried out in continuous cast round billets surface and end.
" kg/t steel " in the present invention refers to: with respect to the amount (kg) of steel per ton.
Below in conjunction with specific embodiment, the present invention is further described.
Below to adopt different technical parameters to prepare low temperature high pressure gas conduit coupling of the present invention (for example, flange, threeway, elbow, valve etc.) to use continuous cast round billets specific embodiment.By continuous casting heat, be numbered 1#, 2#, 3# respectively as embodiment 1, embodiment 2, embodiment 3.
1, electric furnace just refines in operation, and the major control processing parameter of three embodiment is in Table 1,2.Wherein, the electric furnace of employing is electric arc furnace.
The first refining process of table 1 electric furnace main technologic parameters
Table 2 electric furnace has just refined the main technologic parameters of rear tapping
| Numbering | Tapping temperature (℃) | Mix slag material (kg/t) | Containing aluminium deoxidizer consumption (kg/t) |
| Embodiment 1 | 1647 | 13 | 2.4 |
| Embodiment 2 | 1656 | 12 | 2.5 |
| Embodiment 3 | 1651 | 14 | 2.4 |
2, LF refining procedure, major control processing parameter and the finishing slag main component of three embodiment are listed in respectively table 3 and table 4.
Table 3LF refining major control processing parameter
Table 4LF refining finishing slag main component (mass percent, %)
| Numbering | CaO | SiO 2 | Al 2O 3 | MgO | FeO | MnO |
| Embodiment 1 | 52.06 | 10.81 | 23.81 | 5.42 | 0.26 | 0.01 |
| Embodiment 2 | 50.13 | 11.25 | 20.28 | 6.50 | 0.28 | 0.01 |
| Embodiment 3 | 49.57 | 9.34 | 22.70 | 7.94 | 0.32 | 0.01 |
3, in VD vacuum outgas operation, the major control processing parameter of three embodiment is listed in table 5, wherein, before ladle enters VD stove, removes the refining slag of 60wt%.
Processing parameter is controlled in the vacuum refinement of table 5VD stove
4, in continuous casting working procedure, three embodiment all adopt full arc shape three machine three stream sides/circle base alloy steel continuous casting machine continuous castings, arc radius is R12m, circle base specification is Ф 350mm, normal cast tundish molten steel liquid level 850mm～900mm, mold liquid level is controlled automatically, end stirring parameter: 300A/9.0Hz, 15 ℃～25 ℃ of molten steel cast superheating temperature, the weak cold water distribution of dynamic gas one fog cooling, cooling each section of water yield partition ratio is: sufficient roller section 30%, two cold one section 25%, two cold two section 20%, two cold three section 15%, two cold four section 10%; Adopt embedded six frame continuous straightening withdrawal straightening machines, strand straightening temperature reaches 935 ℃～942 ℃, and other control processing parameter in Table 6.
Table 6 continuous casting is controlled processing parameter
5, strand slow cooling operation
Continuous cast round billets is cooling through secondary cooling zone, aligning, transportation rod road are transferred to after cold bed, proceeds in time burial pit slow cooling, and adds a cover insulation, and slow cooling time 52h, hangs out 130 ℃～70 ℃ of temperature.
Below the chemical composition of continuous cast round billets for the low temperature high pressure gas conduit coupling (flange, threeway, elbow, valve etc.) of three embodiment acquisitions, in Table 7; And three embodiment Ф 350mm continuous cast round billets steel low power, the examination of nonmetallic inclusion results of producing, in Table 8, table 9.
Composition in table 7 steel of the present invention (mass percent, %)
By table 7, can find out that by preparation method of the present invention, producing chemical Composition Control in low temperature, high pressure gas conduit coupling (flange, threeway, elbow, valve etc.) use continuous cast round billets steel stablizes, the refining of LF stove makes molten steel realize Narrow Composition Control, same batch: C: ± 0.01%, Si: ± 0.03%, Mn, Cr: ± 0.02%, V, Nb: ± 0.01%, Al: ± 0.005%, N: ± 0.0015%.
Table 8 continuous cast round billets macrostructure (level)
Table 9 continuous cast round billets non-metallic inclusion of the present invention (level)
By table 8 and table 9, can be found out: preparation method of the present invention produces low temperature, high pressure gas conduit coupling (flange, threeway, elbow, valve etc.) has dense structure, even with continuous cast round billets, and cleanliness factor is compared with high.
Manufacture method by cryogenic high pressure conduit coupling provided by the invention with steel and continuous cast round billets thereof, has following beneficial effect:
(1) composition in appropriate design steel, suitably reduce carbon content, increase manganese, chromium content, add niobium, vanadium, nitrogen micro alloying element, crystal grain thinning, significantly improve steel strength, reduce production costs, control certain aluminium content, improve molten steel cleanness, strictly limited harmful residual element content, to guarantee steel welding property, intensity, tough sexual satisfaction service requirements, (low-temperature impact toughness of 51 ℃ reaches AK significantly to improve the low-temperature impact toughness of material
v>=30J).
(2) in just refining of electric furnace, adopt and improve molten iron ratio, the mixing slag material that adds fritting low melting point slag material and lime to form after stove, carry out slag modification, add the technique means such as aluminium matter reductor strengthening pre-deoxidation, reduce as early as possible dissolved oxygen content in steel, the utmost point is slagging early, for refining furnace creates good conditions.
(3) LF refining utilizes technology and the vacuum deaeration refinings such as the deoxidation of complex deoxidization mode, the refining of high alkalinity refining slag, Narrow Composition Control, low nitrogen blowing nitrogen pick-up of the diffusive deoxidation of carbon dust+silicon carbide and feeding aluminum steel strong deoxidation phase, and the measures such as enough vacuum outgas time, soft blow time that guarantee have guaranteed molten steel cleanness, improved ingredient stability.
(4) continuous casting is by adopting " three permanent operations ", full guard Prepared by Low Superheat Pouring; mold liquid level is controlled automatically; end induction stirring; dynamically weak cold water distribution; multiple spot continuous straightening, enters burial pit slow cooling, adds a cover the technology such as insulation, has guaranteed continuous cast round billets surface quality, cleanliness factor, homogeneity of structure and compactness; reduce structural stress and thermal stresses, avoided the generation of internal fissure.
(4) adopt preparation method provided by the invention can produce birth high (T.O≤15 * 10 of cleanliness factor
-4%, N:120 * 10
-4%～260 * 10
-4%, non-metallic inclusion A, B, C, D≤1.5 grade), the continuous cast round billets of homogeneous (macrostructure≤1.0 grade, flawless, subsurface bubble), meets low temperature, pressure piping web member (flange, threeway, elbow, valve etc.) material performance requirement.
Although illustrate particularly and described the present invention with reference to exemplary embodiment of the present invention, but those skilled in the art will appreciate that, in the situation that do not depart from as claims and their the spirit and scope of the present invention that equivalent limited, can make the various changes in form and details at this.Should only in descriptive meaning rather than for the object of restriction, consider embodiment.Therefore, scope of the present invention is not to be limited by the specific embodiment of the present invention, but is limited by claims, and all differences within the scope of this will be interpreted as comprising in the present invention.
Claims (10)
1. a cryogenic high pressure conduit coupling steel, it is characterized in that, comprise by percentage to the quality following composition: C:0.12%～0.16%, Si:0.15%～0.30%, Mn:1.20%～1.45%, P≤0.025%, S≤0.015%, Cr:0.15%～0.25%, V:0.04%～0.10%, Nb:0.02%～0.05%, Al
t: 0.015%～0.040%, H≤2.0 * 10
-4%, N:120 * 10
-4%～260 * 10
-4%, T.O≤15 * 10
-4%, surplus is Fe and inevitable impurity.
2. cryogenic high pressure conduit coupling steel according to claim 1, it is characterized in that, described C:0.12%～0.14%, described Si:0.18%～0.25%, described Mn:1.30%～1.40%, described P≤0.020%, described S≤0.010%, described Cr:0.20%～0.25%, described V:0.05%～0.10%, described Al
t: 0.020%～0.035%, described H≤1.5 * 10
-4%, described N:150 * 10
-4%～230 * 10
-4%.
3. the continuous cast round billets of steel for the cryogenic high pressure conduit coupling described in a claim 1 or 2.
4. a method of manufacturing the continuous cast round billets described in claim 3, is characterized in that, comprises successively following operation:
(1) electric furnace just refines operation: burden structure adopts steel scrap and molten iron; Add slag material in the process of carrying out slag free tapping after, then add containing aluminium deoxidizer; Control molten clear carbon >=0.50%, molten clear phosphorus≤0.025wt%, control just furnace smelting endpoint C and be 0.08%～0.10%, terminal P≤0.015%, tapping temperature is 1620 ℃～1680 ℃;
Wherein, in described burden structure, the mass percent of molten iron is 55%～75%; The add-on of described slag material is 12kg～18kg with respect to steel per ton; The described add-on containing aluminium deoxidizer is 1.5kg～3.0kg with respect to steel per ton;
(2) LF refining procedure: the molten steel temperature of furnaceman LF position is controlled to 1510～1560 ℃, adopts the complex deoxidization mode of carbon dust and silicon carbide diffusive deoxidation and the strong deoxidation phase of feeding aluminum steel to carry out deoxidation, adopt the mode nitrogen pick-up of nitrogen-containing alloy or low nitrogen blowing; Before tapping, feeding silicon-calcium wire is done rotten processing and deep deoxidation to inclusion;
Wherein, described aluminum steel consumption is 1.0kg～1.5kg with respect to steel per ton, and described calcium line consumption is 0.010kg～0.015kg with respect to steel per ton, and described tapping temperature is 1610 ℃～1640 ℃;
(3) VD vacuum outgas operation: keep 10min～20min below vacuum tightness 67Pa, the H content after vacuum-treat in molten steel is 2.0 * 10
-4below wt%; Molten steel is after atmospheric pressure state is got back in vacuum refinement, and argon bottom-blowing flow is 120L/min～260L/min, and pressure is 0.20MPa～0.40MPa, and keeping the soft blow time is 15min～25min;
(4) continuous casting working procedure: carry out the operation of constant temperature, permanent pulling rate, constant level;
(5) strand slow cooling operation: the continuous cast round billets of pointing out in described operation (3) is cooling through secondary cooling zone, rectify and to put, to transport rod road and be transferred to after cold bed, carry out slow cooling; Wherein, the slow cooling time is more than 48 hours, and hanging out temperature is below 250 ℃.
5. method according to claim 4, is characterized in that, in described operation (1), described slag material is comprised of fritting low melting point slag supplying agent and lime;
The weight ratio of described fritting low melting point slag supplying agent and described lime is 1:1～1.3:1;
Described fritting low melting point slag supplying agent comprises following composition: CaO:40wt%～60wt%, SiO
2: 5wt%～15wt%, Al
2o
3: 20wt%～35wt%, MgO:5wt%～15wt%.
6. method according to claim 4, is characterized in that, in described operation (1), add also add after described slag material alloy, described alloy be in silicomanganese, ferromanganese, ferrochrome and nitrogen-containing alloy any one or multiple.
7. method according to claim 4, is characterized in that, in described operation (2), the LF refining white slag hold-time is more than 20min, controls finishing slag main component mass percent to be:
CaO：45%～55%，SiO
2：8%～12%，Al
2O
3：20%～25%，MgO：5%～8%，FeO+MnO≤0.5%。
8. method according to claim 4, it is characterized in that, in described operation (2), for same batch, in molten steel after refining, the fluctuation range of the mass percent of following compositions is C: ± 0.01%, Si: ± 0.03%, Mn: ± 0.02%, Cr: ± 0.02%, V: ± 0.01%, Nb: ± 0.01%, Al: ± 0.005%, N: ± 0.0015%.
9. method according to claim 4, is characterized in that, in described operation (4), the liquid level of cast tundish molten steel is 850mm～900mm, and end stirring parameter is 300A/9.0Hz, 15 ℃～25 ℃ of molten steel cast superheating temperature; Cooling each section of water yield partition ratio of continuous casting is: cold one section 25%, two cold two section 20%, two cold three section 15%, two cold four section 10% of sufficient roller section 30%, two; Specific water 0.28L/kg～0.32L/kg.
10. method according to claim 4, is characterized in that, in described operation (5), strand straightening temperature is more than 930 ℃.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09201688A (en) * | 1996-01-22 | 1997-08-05 | Sumitomo Metal Ind Ltd | Manufacture of welded steel tube excellent in strength in weld zone |
| CN101542001A (en) * | 2007-03-30 | 2009-09-23 | 住友金属工业株式会社 | Low alloy steel for the pipe for oil well use and seamless steel pipe |
| CN101545073A (en) * | 2008-03-28 | 2009-09-30 | 株式会社神户制钢所 | High-strength steel sheet excellent in resistance to stress-relief annealing and in low-temperature joint toughness |
| CN101892432A (en) * | 2010-07-09 | 2010-11-24 | 天津钢管集团股份有限公司 | Manufacturing method of X70QS seamless line pipe for acid environment |
| CN102660711A (en) * | 2012-05-23 | 2012-09-12 | 莱芜钢铁集团有限公司 | Steel for petroleum casing connecting piece and manufacturing method thereof |
-
2013
- 2013-12-11 CN CN201310675081.0A patent/CN103695785B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09201688A (en) * | 1996-01-22 | 1997-08-05 | Sumitomo Metal Ind Ltd | Manufacture of welded steel tube excellent in strength in weld zone |
| CN101542001A (en) * | 2007-03-30 | 2009-09-23 | 住友金属工业株式会社 | Low alloy steel for the pipe for oil well use and seamless steel pipe |
| CN101545073A (en) * | 2008-03-28 | 2009-09-30 | 株式会社神户制钢所 | High-strength steel sheet excellent in resistance to stress-relief annealing and in low-temperature joint toughness |
| CN101892432A (en) * | 2010-07-09 | 2010-11-24 | 天津钢管集团股份有限公司 | Manufacturing method of X70QS seamless line pipe for acid environment |
| CN102660711A (en) * | 2012-05-23 | 2012-09-12 | 莱芜钢铁集团有限公司 | Steel for petroleum casing connecting piece and manufacturing method thereof |
Cited By (16)
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| CN103934423B (en) * | 2014-04-03 | 2016-03-30 | 莱芜钢铁集团有限公司 | A kind of method of the continuous cast round billets for the production of wind-power tower flange steel |
| CN104480404A (en) * | 2014-12-22 | 2015-04-01 | 山东钢铁股份有限公司 | Steel for high-pressure pipeline valve and manufacturing method of steel |
| CN106086298A (en) * | 2016-06-24 | 2016-11-09 | 山东钢铁股份有限公司 | A kind of smelting process of low-phosphorous low titanium low-sulfur steel |
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