WO2016041491A1 - 一种550MPa级的耐高温管线钢及其制造方法 - Google Patents

一种550MPa级的耐高温管线钢及其制造方法 Download PDF

Info

Publication number
WO2016041491A1
WO2016041491A1 PCT/CN2015/089697 CN2015089697W WO2016041491A1 WO 2016041491 A1 WO2016041491 A1 WO 2016041491A1 CN 2015089697 W CN2015089697 W CN 2015089697W WO 2016041491 A1 WO2016041491 A1 WO 2016041491A1
Authority
WO
WIPO (PCT)
Prior art keywords
high temperature
pipeline steel
resistant pipeline
temperature resistant
grade high
Prior art date
Application number
PCT/CN2015/089697
Other languages
English (en)
French (fr)
Inventor
胡平
郑磊
章传国
Original Assignee
宝山钢铁股份有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 宝山钢铁股份有限公司 filed Critical 宝山钢铁股份有限公司
Priority to CA2960903A priority Critical patent/CA2960903C/en
Priority to US15/512,209 priority patent/US11085098B2/en
Publication of WO2016041491A1 publication Critical patent/WO2016041491A1/zh

Links

Classifications

    • 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
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • 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
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing 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
    • 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
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • 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
    • 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
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B2001/225—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length by hot-rolling
    • 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
    • C21D2211/004—Dispersions; Precipitations
    • 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
    • C21D2211/005—Ferrite

Definitions

  • the invention relates to a steel product and a manufacturing method thereof, in particular to a high temperature resistant pipeline steel and a manufacturing method thereof.
  • oil sand resources as a supplementary alternative resource have attracted more and more attention.
  • the scale of commercial exploitation is expanding day by day, and the output is increasing year by year.
  • oil sand mining in the prior art mainly achieves mining by injecting high-temperature steam into oil sands deposits below the surface to reduce the viscosity of the oil sands, thereby improving the fluidity of the oil sands.
  • Pipeline steels that transport these high-temperature steam need to take into account both the material strength and the service service temperature.
  • conventional pipeline steel is mainly used for long-distance transportation of conventional petroleum and natural gas resources, its main concern is the room temperature strength properties of steel materials.
  • these conventional pipeline steels When passing through the permafrost regions and seismic zones, these conventional pipeline steels also need to meet certain room temperature plastic properties, ie, resistance to large strains or low yield ratios, from the point of view of strain design.
  • traditional pipeline steels also need to meet certain toughness requirements, especially low temperature toughness requirements.
  • the traditional pipeline steel mainly focuses on the improvement of room temperature strength, plasticity and low temperature toughness, and does not pay attention to high temperature strength. Therefore, the pipeline steel used now is not completely suitable for the exploitation of oil sands ore.
  • the traditional pipeline steel needs to add as little C and Mn, Mo, Cr, Cu, Ni, V and other alloying elements as possible to obtain a lower carbon equivalent from the viewpoint of improving weldability; Due to the limited content of alloying elements added, it has limited effect on solid solution strengthening and precipitation strengthening, which requires manufacturing processes such as lower finish rolling temperature, large rolling deformation and fast
  • the cooling rate is used to achieve grain and microstructure refinement, while using low temperature phase change microstructure to achieve high strength and high toughness simultaneously.
  • lower alloying elements reduce the initial strength of the material.
  • lower finish rolling temperatures, greater deformation, and rapid cooling can increase the initial strength, these factors in turn reduce the high temperature structural stability of the material, which is detrimental to the high temperature strength of the material.
  • the publication number is CN1584097A, and the publication date is February 23, 2005.
  • the Chinese patent document entitled "High-strength and high-toughness conveying pipeline steel and its preparation method” relates to a pipeline steel material.
  • the chemical element components (wt.%) in the pipeline steel material are: C: 0.010 to 0.060; Si: 0.15 to 0.40, Mn: 1.61 to 2.00; P: 0.0031 to 0.018; S ⁇ 0.003; Cu: 0.10 to 0.40.
  • Japanese Patent Publication No. JP2012-241271A published on Dec. 10, 2012, entitled "A High-Strength Acid-Resistant Line Pipe with Excellent Crush Resistance and Its Manufacturing Method” discloses a pipeline tube.
  • the composition of each chemical element in the line pipe is (wt.%): C: 0.02-0.08%, Si: 0.01-0.50%, Mn: 0.5-1.5%, P ⁇ 0.01%, S ⁇ 0.001%, Cu ⁇ 1.0%, Ni ⁇ 1.0%, Nb: 0.002 ⁇ 0.100%, Ti: 0.005 ⁇ 0.050%, V: 0.005 ⁇ 0.100%, Mo ⁇ 0.5%, Cr: ⁇ 1.0%, Al ⁇ 0.06%, Ca: 0.0005 to 0.0040%, O: ⁇ 0.0030%, Mg: 0.0005 to 0.0040%, and the balance is Fe and unavoidable impurities.
  • the object of the present invention is to provide a high temperature resistant pipeline steel of 550 MPa grade, which has excellent high temperature mechanical properties, and its yield strength and tensile strength can reach 520 MPa and 645 MPa respectively at 200-400 ° C. .
  • the room temperature strength of the high temperature resistant pipeline steel can be 550 MPa grade and above 625 MPa grade (corresponding to the strength grade requirement of X80), so the pipeline steel can achieve normal service work at room temperature and at 200 to 400 °C.
  • the present invention provides a 550 MPa grade high temperature resistant pipeline steel whose chemical element mass distribution ratio is:
  • Nb 0.035 to 0.080%
  • V 0.005 to 0.054%
  • the balance is Fe and other unavoidable impurities.
  • the unavoidable impurities in the technical solution of the present invention mainly refer to the P element and the S element, which are liable to form defects such as segregation and inclusion, which are disadvantageous to the toughness of the material.
  • P ⁇ 0.010% is controlled, and S ⁇ 0.005% is controlled.
  • C is the most basic strengthening element in steel. On the one hand, it can function as a gap solid solution strengthening, and on the other hand, it can form a carbide precipitate with an alloying element to function as a precipitation strengthening. C can form fine nano-scale carbides with the microalloying elements Nb and V to further play a role of precipitation strengthening. In addition, C is also a necessary austenite stabilizing element, which can improve the hardenability of steel and increase the strength of steel. However, as the C content increases, the toughness and weldability of the steel will gradually decrease.
  • the C content of the 550 MPa grade high temperature resistant pipeline steel according to the present invention needs to be controlled to be 0.061 to 0.12 wt.%.
  • Mn is the most basic alloying element in low-alloy high-strength steel, and it can function as a solid solution strengthening. To a certain extent, increasing the content of Mn element can increase the strength of the material while maintaining the toughness of the material. In addition, Mn is an element that enlarges the austenite phase region, which can lower the phase transition temperature of austenite to ferrite of steel, contribute to obtaining fine phase change products, and can improve the toughness of the material. However, when the Mn content in the material is too large, it is easy to cause center segregation of the continuous casting billet. It causes uneven composition and organization of the heart and other thickness positions, especially at high temperatures, which is detrimental to high temperature performance. At the same time, the excessive Mn content in the material is also detrimental to the effect of increasing the strength. Therefore, in the technical solution of the present invention, the content of the Mn element needs to be in the range of 1.70 to 2.20 wt.%.
  • Mo can be used as a solid solution strengthening element to increase the strength of the material.
  • Mo can also improve the hardenability of the material and delay the transformation of ferrite in the steel, so that the material can be obtained at a lower cooling rate.
  • Mo can increase the solid solubility of Nb, so that more Nb can precipitate fine NbC at a lower temperature, thereby improving the precipitation strengthening effect and further increasing the strength of the material.
  • Mo can also reduce the diffusion coefficient of C, improve the stability of the structure, and help the material to obtain higher high temperature strength.
  • Mo element content promotes the formation of M-A islands, which is detrimental to the toughness and uniformity of the material, and also increases the manufacturing cost. Therefore, in order to exert the effect of enhancing the strengthening of the Mo element in the technical solution of the present invention and to avoid excessive addition of the Mo element to affect the toughness and the uniformity of the structure, it is necessary to control the Mo content to be 0.15 to 0.39 wt.%.
  • Cu/Ni As a solid solution strengthening element, Cu and Ni can increase the strength. In addition, Cu can improve the corrosion resistance of steel, and Ni can improve the toughness of steel and improve the hot brittleness of Cu in steel. In addition, Cu can also reduce the diffusion coefficient of C in steel, improve the stability of the structure, and help the material to obtain higher high temperature strength. In view of this, the Cu content in the 550 MPa grade high temperature resistant pipeline steel according to the present invention should be controlled to be 0.15 to 0.30 wt.%, and the Ni content should also be controlled to be 0.15 to 0.50 wt.%.
  • Nb can delay the austenite recrystallization and increase the austenite recrystallization temperature of the steel, which is beneficial to reduce the rolling mill load. Secondly, Nb can also lower the phase transition temperature and delay the ferrite transformation, thereby refining the grain and structure, thereby increasing the strength of the material. Finally, Nb can also combine with C to form a fine precipitated phase of NbC during hot rolling and subsequent cooling, thereby acting as a precipitation strengthening, thereby increasing the strength of the material.
  • the amount of Nb added in the 550 MPa grade high temperature resistant pipeline steel of the present invention should be controlled to be 0.035 to 0.080 wt.%.
  • V is a typical precipitation strengthening element that can combine with C to form VC.
  • VC precipitation temperature It is lower than TiC and NbC, which can be precipitated during hot rolling and subsequent cooling.
  • the VC size is small, which is beneficial to increase the strength of the material.
  • an excessive amount of V adversely affects the toughness of the material. Therefore, the V content of the 550 MPa grade high temperature resistant pipeline steel according to the present invention needs to be set to 0.005 to 0.054 wt.%.
  • Ti can be combined with N to form TiN to act as a fixed N, thereby improving the toughness of the material. With about 0.02 wt.% of Ti, it is possible to fix 60 ppm (0.006%) or less of N in the steel. In the continuous casting process, Ti can also form TiN with N. During the heating process, TiN formed at a high temperature can also function to hinder austenite grain growth and coarsening. The TiN formed by the Ti element is also advantageous for improving the impact toughness of the heat affected zone of the weld. The combination of Ti and N consumes N element, which also allows more Nb to be solid-solved at a high temperature to inhibit recrystallization. Therefore, in the technical solution of the present invention, the Ti content needs to be controlled to be 0.005 to 0.030 wt.%.
  • Al element is mainly used for deoxidation of steel.
  • the nitride formed by Al and N can improve the toughness of the heat affected zone of the weld, but the increase of the Al content causes the formation of Al oxide in the steel, thereby reducing the toughness of the base metal and the heat affected zone of the weld. Therefore, the Al content in the 550 MPa grade high temperature resistant pipeline steel according to the present invention needs to be set in the range of 0.015 to 0.040 wt.%.
  • Ca:Ca is mainly used to achieve inclusion modification, so that the inclusion morphology is spheroidized and its distribution is uniform, thereby reducing the influence of inclusions on toughness and corrosion resistance.
  • an increase in the Ca content causes a bundle of inclusions, which in turn affects the corrosion resistance of the material. Therefore, the Ca content in the 550 MPa grade high temperature resistant pipeline steel according to the present invention needs to be controlled to be 0.005 to 0.035 wt.%.
  • the technical solution of the present invention is based on C-Mn steel, through Nb-V-Ti composite microalloying, precipitation-solid solution composite strengthening, and adding A variety of alloying elements such as Mo, Cu and Ni are used to increase the high temperature strength of the material.
  • Nb-V-Ti microalloying elements can play the role of fine crystal, fine structure and precipitation strengthening.
  • Mn-Mo-Cu has solid solution strengthening effect, in which Mo and Cu can reduce C
  • the diffusion coefficient can also improve the structural stability at high temperatures and increase the high temperature strength.
  • Mo can also strongly enhance the hardenability to promote the transformation of acicular ferrite or bainite structure. Thereby increasing the initial strength of the material and the structural stability at high temperatures, thereby increasing the high temperature strength of the material.
  • the core design of the technical solution of the present invention is to improve the high temperature strength of the material.
  • At least one of 0 ⁇ Si ⁇ 0.40%, 0 ⁇ Cr ⁇ 0.40%, and 0 ⁇ N ⁇ 0.005% is further contained in the 550 MPa grade high temperature resistant pipeline steel according to the present invention.
  • Si is mainly used for deoxidation of steel. At the same time, it can also play a role in improving the hardenability. However, when the Si content is too high, the toughness is lowered, especially the deterioration of the toughness of the heat affected zone of the weld, that is, the decrease in the weldability of the steel material. In view of this, in the technical solution of the present invention, the addition amount of Si should be controlled to be ⁇ 0.40 wt.%.
  • Cr is an element that increases the hardenability of steel and increases the strength of steel.
  • the addition amount of Cr is controlled to be ⁇ 0.40 wt.%.
  • N improves the strength of the steel by increasing the hardenability of the steel.
  • N adversely affects the toughness of the steel, and Ti can be fixed by adding Ti to improve the toughness of the material. Therefore, the N content of the 550 MPa grade high temperature resistant pipeline steel according to the present invention should be controlled to be less than 0.005 wt.%.
  • the microstructure of the 550 MPa grade high temperature resistant pipeline steel according to the present invention comprises a uniform acicular ferrite structure + a matrix formed by a small amount of M-A component (martensitic-residual austenite component).
  • M-A component martensitic-residual austenite component
  • the acicular ferrite structure is finer than the polygonal ferrite structure, which is beneficial to increase the high temperature strength through the interface strengthening; on the other hand, the acicular ferrite structure is more dislocation density than the martensite matrix. Low is beneficial to increase the high temperature strength by increasing the stability of the tissue at high temperatures.
  • the volume percentage of the M-A component is ⁇ 10%.
  • the MA component is obtained by transformation of supercooled austenite which is too late to change during the cooling process after controlled rolling. Its composition is different from the surrounding acicular ferrite to form a concentration gradient. The excessive volume percentage accelerates the diffusion of elements at high temperatures. It is not conducive to the stability of the tissue at high temperatures and is not good for high temperature strength.
  • the deformation coordination of the M-A component and the acicular ferrite are different, and the crack is easily generated between the two when the force is deformed, which is disadvantageous to the high temperature strength.
  • the matrix has an average effective grain size of ⁇ 8 ⁇ m. Limiting the effective grain size within this range further enhances the interface strengthening effect, thereby increasing the high temperature strength.
  • the small-angle grain boundary volume percentage in the matrix is 20 to 60%.
  • the small angle grain boundary refers to the grain boundary where the crystallographic upper phase difference is less than 15 degrees. Limiting the small-angle grain boundary content in the matrix to this range also improves the interface strengthening effect, thereby increasing the high-temperature strength.
  • carbides NbC, VC and carbonitrides (Nb, V) (C, N) precipitated by Nb and V are also dispersedly distributed on the substrate.
  • NbC, VC and (Nb, V) (C, N) at high temperatures The coarsening rate is low, and an effective precipitation strengthening effect can be maintained for a long period of time at a high temperature, thereby increasing the high temperature strength.
  • the carbides and carbonitrides have an average size of 5 to 50 nm. Limiting the size of the carbides and carbonitrides within this range is advantageous in producing a strong precipitation strengthening effect, thereby increasing the high temperature strength.
  • the present invention also provides a method for producing a 550 MPa grade high temperature resistant pipeline steel as described above, the method comprising the steps of: smelting, casting, slab heating, rough rolling, finish rolling, controlled cooling, air cooling to Room temperature.
  • the rough rolling and rolling temperature is 1100-1180 ° C
  • the rough rolling finishing temperature is 950-980 ° C.
  • the finish rolling rolling temperature is 850-900 ° C
  • the finishing rolling finishing temperature is 800-820 ° C
  • the finishing rolling compression The ratio is 4T to 8T, where T is the thickness of the finished steel sheet.
  • the formation of fine precipitates is promoted by strain-induced precipitation by using a large finish rolling reduction ratio, and the precipitation strengthening effect is enhanced, and fine precipitation is utilized.
  • higher finish temperatures improve the stability of the material's initial material structure to increase the high temperature strength of the material.
  • the temperature for starting the cooling is 750 to 780 ° C
  • the cooling rate is 15 to 30 ° C / s
  • the cooling temperature is 380 ⁇ 580 ° C.
  • the medium cooling rate and the higher cooling temperature can reduce the movable dislocation density in the initial structure to improve the structural stability of the material at high temperatures, thereby increasing the high temperature strength of the material.
  • the heating temperature is 1110 to 1250 °C.
  • the method for manufacturing the 550 MPa grade high temperature resistant pipeline steel according to the present invention is based on the addition of more alloying elements such as Nb, V, Ti, Mn, Mo and Cu to the composition design, and the key is to adopt TMCP controlled rolling and controlled cooling process to improve The high temperature strength of the material.
  • the 550 MPa grade high temperature resistant pipeline steel of the invention has excellent high temperature mechanical properties and good high temperature resistance, and its yield strength at 200-400 ° C
  • the tensile strength and tensile strength are 520 MPa and 645 MPa, respectively, and the room temperature yield strength and tensile strength are 550 MPa and 625 MPa, respectively, which can be used to transport the high temperature steam medium required for the oil sand in situ mining process.
  • the 550 MPa grade high temperature resistant pipeline steel of the present invention also has high toughness, good corrosion resistance and excellent welding processability.
  • the manufacturing method of the 550 MPa grade high temperature resistant pipeline steel according to the present invention improves the high temperature mechanical properties of the pipeline steel by using the controlled rolling and controlled cooling process, and particularly improves the room temperature strength and the high temperature strength of the pipeline steel.
  • the 550 MPa grade high temperature resistant pipeline steel of Examples A1-A6 was produced according to the following procedure:
  • rough rolling open rolling temperature is 1100-1180 ° C
  • finishing rolling temperature is 950-980 ° C
  • the finishing rolling temperature is 850-900 ° C, the finishing rolling temperature is 800-820 ° C; the finishing rolling compression ratio is 4T ⁇ 8T, where T is the thickness of the finished steel sheet;
  • Control cooling the temperature to start cooling is 750 ⁇ 780 ° C, the cooling rate is 15 ⁇ 30 ° C / s, the cooling temperature is 380 ⁇ 580 ° C;
  • Table 1 lists the mass ratios of the chemical elements of the examples A1 to A6 in the present case.
  • Table 2 lists the process parameters of the manufacturing method of the 550 MPa grade high temperature resistant pipeline steel of the examples A1-A6 of the present invention.
  • Example A6 The finished steel sheets in Examples A1 to A6 were subjected to rod tensile test, and the test temperatures in the tests were room temperature, 200 ° C, 250 ° C, 300 ° C, 350 ° C and 400 ° C, respectively, and the stretching obtained at the aforementioned temperature
  • the results of the performance parameters are shown in Table 3.
  • Table 3 lists the tensile performance parameters of the 550 MPa grade high temperature resistant pipeline steel in the examples A1-A6 at different temperatures.
  • Rt0.5 is the yield strength, which refers to the tensile stress corresponding to the total extension of the material gauge length of 0.5%
  • Rm is the tensile strength A50.8 when the gauge length is 50.8mm
  • A50 is the corresponding total elongation when the gauge length is 50 mm, and the round bar drawing of A50 measured in Table 3.
  • the sample has a diameter of 10 mm.
  • the pipeline steel plates in the above embodiments A1-A6 have a yield strength ⁇ 571 MPa at room temperature, a tensile strength ⁇ 682 MPa, an elongation ⁇ 21%, and at a high temperature (ie, 200 to 400).
  • the yield strength at °C is ⁇ 545Mpa
  • the tensile strength is ⁇ 679Mpa
  • the elongation is ⁇ 21%.
  • the tensile strength at room temperature of the pipeline steel in Examples A1-A6 can meet the strength level requirement equivalent to X80 (ie The room temperature yield strength and tensile strength are ⁇ 550MPa and ⁇ 625MPa, respectively, and the pipeline steel also has high yield strength and tensile strength at 200-400 °C.
  • the 550 MPa grade high temperature resistant pipeline steel of the invention can be used for manufacturing steam transportation pipelines with working service conditions of 200-400 ° C, and has wide market application prospects.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

公开了一种550MPa级的耐高温管线钢，其化学元素质量百分比为：0.061％≤C≤0.120％，1.70％≤Mn≤2.20％，0.15％≤Mo≤0.39％，0.15％≤Cu≤0.30％，0.15％≤Ni≤0.50％，0.035％≤Nb≤0.080％，0.005％≤V≤0.054％，0.005％≤Ti≤0.030％，0.015％≤Al≤0.040％，0.005％≤Ca≤0.035％，余量为Fe和不可避免的杂质元素。还公开了该550MPa级的耐高温管线钢的制造方法，包括步骤：冶炼，铸造，板坯加热，粗轧，精轧，控制冷却，空冷至室温。该管线钢具备优异的高温力学性能。

Description

一种550MPa级的耐高温管线钢及其制造方法 技术领域
本发明涉及一种钢材产品及其制造方法，尤其涉及一种耐高温管线钢及其制造方法。
背景技术
随着常规石油、天然气资源可开采量的日益减少，作为补充替代资源的油砂资源越来越受到人们的关注，商业化开采的规模日渐扩展，产量逐年升高。目前，现有技术中油砂开采主要是通过向地表以下的油砂矿藏注入高温蒸汽以降低油砂的粘稠度，从而提高油砂的流动性来实现开采。输送这些高温蒸汽的管线钢就需要考虑到材料强度和工作服役温度这两个因素。但是，由于传统管线钢主要是用于常规石油、天然气资源的长距离输送，因此，其主要关注的是钢材料的室温强度性能。当经过冻土地区和地震带地区，从应变设计的角度考虑，这些传统的管线钢还需满足一定的室温塑性性能，即抗大应变能力或低屈强比。此外，还考虑到一定的阻碍起裂和裂纹捕获的能力，传统的管线钢还需要满足一定的韧性要求，尤其是低温韧性的要求。总之，传统管线钢主要关注于室温强度、塑性和低温韧性的改善，并不关注高温强度，因此，现在所采用的管线钢并不是完全适用于油砂矿的开采。
一方面，传统管线钢从改善焊接性的角度出发，需要尽可能少地添加C和Mn、Mo、Cr、Cu、Ni、V等合金元素的含量，以获得较低的碳当量；另一方面，由于加入的合金元素含量受到限制，其能够起到固溶强化和析出强化的作用有限，这就需要借助制造工艺，例如，采用较低的终轧温度、较大的轧制变形量以及快速的冷却速度来实现晶粒和组织的细化，同时利用低温相变组织的方式来同时获得高强度高韧性。不过，较低的合金元素会降低材料的初始强度。此外，虽然较低的终轧温度、较大的变形量和快冷可以提高初始强度，但是，这些因素又会降低材料的高温组织稳定性，其不利于材料的高温强度。为了获得抗大变形能力或低屈强比，还需要通过设计令钢材形成双相组织。然而，双相组织之间的化学元素浓度差扩散快也会降低材料的高温组织稳定性，也不利于材料的高温强度。
由于目前油砂开采所需输送蒸汽温度约350℃，因此，十分有必要获得一种具有良好的高温强度的耐热管线钢来用于油砂资源的开采。
公开号为CN1584097A，公开日为2005年2月23日，名称为“高强度高韧性输送管线钢及其制备方法”的中国专利文献涉及一种管线钢材料。该管线钢材料中的各化学元素成分(wt.％)为：C：0.010～0.060；Si：0.15～0.40，Mn：1.61～2.00；P：0.0031～0.018；S≤0.003；Cu：0.10～0.40；Ni：0.1～0.4；Nb：0.051～0.09；Ti：≤0.025；Mo：0.1～0.4。
公布号为JP2012-241271A，公布日为2012年12月10日，名称为“一种具有优异的抗压溃性能且高强度耐酸性管线管及其制造方法”的日本专利文献公开了一种管线管。该管线管中的各化学元素质量百分含量为(wt.％)的成份组成：C：0.02～0.08％，Si：0.01～0.50％，Mn：0.5～1.5％，P＜0.01％，S＜0.001％，Cu≤1.0％，Ni≤1.0％，Nb：0.002～0.100％，Ti：0.005～0.050％，V：0.005～0.100％，Mo≤0.5％，Cr：≤1.0％，Al≤0.06％，Ca：0.0005～0.0040％，O：≤0.0030％，Mg：0.0005～0.0040％，余量由Fe及不可避免的杂质。
公开号为US20120247605A1，公开日为2012年10月4日，名称为“一种高强度无钼且通过温度控制轧制成型无加速冷却的低合金X80钢板”的美国专利文献公开了一种低合金X80钢板，其各化学元素的质量百分含量为：C：0.05～0.09％，Mn：1.7～1.95％，P＜0.015％，S＜0.003％，Nb：0.075～0.1％，Ti：0.01～0.02％，V：0.01～0.03％，Mo：≤0.003，Al：0.02～0.055％，余量由Fe及不可避免的杂质。
上述这些已经公开的管线管专利均未解决管线管的耐高温性能。
发明内容
本发明的目的在于提供一种550MPa级的耐高温管线钢，该耐高温管线钢具有优异的高温力学性能，其在200～400℃下屈服强度和抗拉强度分别可以达到520MPa级和645MPa级以上。此外，该耐高温管线钢的室温强度可以550MPa级和625MPa级以上(相当于X80的强度级别要求)，因此该管线钢在室温和在200～400℃的条件下都能够实现正常服役工作。
为了实现上述目的，本发明提供了一种550MPa级的耐高温管线钢，其化学元素质量百分配比为：
C：0.061～0.120％；
Mn：1.70～2.20％；
Mo：0.15～0.39％；
Cu：0.15～0.30％；
Ni：0.15～0.50％；
Nb：0.035～0.080％；
V：0.005～0.054％；
Ti：0.005～0.030％；
Al：0.015～0.040％；
Ca：0.005～0.035％；
余量为Fe和其他不可避免的杂质。
本发明的技术方案中不可避免的杂质主要是指P元素和S元素，其易形成偏析、夹杂等缺陷，对材料的韧性不利。本技术方案中控制P≤0.010％，并控制S≤0.005％。
本发明所述的550MPa级的耐高温管线钢中的各化学元素的设计原理为：
C：C是钢中最基本的强化元素。一方面，其可以起到间隙固溶强化的作用，另一方面，其可以与合金元素形成碳化物析出以起到析出强化的作用。C可与微合金元素Nb、V形成细小的纳米级的碳化物从而进一步地起到析出强化的作用。另外，C也是必要的奥氏体稳定化元素，其可以提高钢的淬透性，并提高钢的强度。但是，随着C含量的升高，钢的韧性、焊接性能都会逐步降低。此外，随着C含量的升高，NbC的完全固溶温度也会相应升高，这样，如果要完全固溶NbC，则轧制所需的加热温度也会随之升高，并且会促进高温下NbC过早析出而粗化。因此，本发明所述的550MPa级的耐高温管线钢中C含量需要控制在0.061～0.12wt.％。
Mn：Mn是低合金高强钢中最基本的合金元素，其可以起到固溶强化的作用。在一定程度范围内，增加Mn元素的含量可以在提高材料强度的同时保持材料的韧性。此外，Mn还是扩大奥氏体相区的元素，其可以降低钢的奥氏体→铁素体的相变温度，有助于获得细小的相变产物，并能够提高材料的强韧性。但是，材料中的Mn含量过多时，容易令连铸坯发生中心偏析， 造成心部和其它厚度位置的成分和组织不均，尤其在高温下会加剧扩散，对高温性能产生不利。与此同时，材料中的含有过多的Mn元素也不利于充分发挥提高强度的作用。由此，在本发明的技术方案中，需要将Mn元素的含量在1.70～2.20wt.％的范围之间。
Mo：一方面Mo可以作为固溶强化元素来提高材料的强度，另一方面Mo还可以提高材料的淬透性，推迟钢中铁素体相变，使得材料在较低的冷速下也可以获得针状铁素体组织或贝氏体组织，并通过降低相变温度来细化组织，从而提高材料的强度。再者，Mo可以提高Nb的固溶度，使得更多的Nb能够在更低温度情况下析出细小的NbC，从而改善析出强化效果，进而提升材料的强度。Mo还可以降低C的扩散系数，改善组织稳定性，有利于材料获得较高的高温强度。不过，Mo元素含量过多会促进M-A岛的形成，对材料的韧性和组织均匀性均不利，并且还会增加制造成本。故而，为了在本发明的技术方案中发挥Mo元素提高强化的作用，并避免Mo元素的过度添加而影响韧性和组织均匀性，需要将Mo含量控制在0.15～0.39wt.％。
Cu/Ni：作为固溶强化元素，Cu和Ni可以提高强度。此外，Cu还可以改善钢的耐蚀性，Ni则可以改善钢的韧性，并改善Cu在钢中引起的热脆性。另外，Cu还可以降低钢中C的扩散系数，改善组织的稳定性，有利于材料获得较高的高温强度。鉴于此，在本发明所述的550MPa级的耐高温管线钢中Cu含量应该控制为0.15～0.30wt.％，且Ni含量也应该控制为0.15～0.50wt.％。
Nb：首先，Nb可以起到延迟奥氏体再结晶，提高钢的奥氏体再结晶温度的作用，有利于减小轧机负荷。其次，Nb还可以降低相变温度、推迟铁素体相变，从而起到细化晶粒和组织的作用，进而提高材料的强度。最后，Nb还可以在热轧过程中和随后冷却过程中与C结合形成NbC的细小析出相，从而起到析出强化的作用，进而提高材料的强度。但是，过高含量的Nb并不能够完全固溶，不仅发挥不了作用而且会增加额外生产成本，并且过高含量的Nb会使得NbC在高温下过早析出，形成尺寸较大的NbC，反而会不利于材料通过析出强化来提高强度。因此，在本发明的550MPa级的耐高温管线钢中Nb的添加量应该控制在0.035～0.080wt.％。
V：V是典型的析出强化元素，它能够与C结合形成VC。VC的析出温 度低于TiC、NbC，其可以在热轧和随后的冷却过程中析出，VC尺寸细小，有利于提高材料的强度。但是，含量过多的V会对材料的韧性造成不利影响。因而，本发明所述的550MPa级的耐高温管线钢中V含量需要设定为0.005～0.054wt.％。
Ti：Ti可以与N结合形成TiN，以起到固定N的作用，从而改善材料的韧性。采用约为0.02wt.％的Ti即可以固定钢中60ppm(0.006％)以下的N。在连铸过程中，Ti也可以与N形成TiN。在加热过程中，在高温下形成的TiN还可以起到阻碍奥氏体晶粒长大粗化的作用。由Ti元素所形成的TiN也有利于改善焊接热影响区的冲击韧性。Ti与N结合会消耗N元素，这也可以使得更多Nb在高温下固溶以起到抑制再结晶的作用。为此，本发明的技术方案中Ti含量需要控制为0.005～0.030wt.％。
Al：Al元素主要是用于钢的脱氧。Al和N所形成的氮化物可以改善焊接热影响区的韧性，但是，Al含量的增加会使得钢中形成Al的氧化物，从而会降低母材和焊接热影响区的韧性。因此，在本发明所述的550MPa级的耐高温管线钢中Al含量需要设定在0.015～0.040wt.％的范围之间。
Ca：Ca主要用于实现夹杂物改性，使得夹杂物形态球化并且使得其分布均匀，从而减少夹杂物对韧性和耐蚀性的影响。不过，Ca含量增加会形成束状夹杂，这又会对材料的耐蚀性能造成影响。因此，在本发明所述的550MPa级的耐高温管线钢中Ca含量需要控制为0.005～0.035wt.％。
根据上文所述的各化学元素的设计原理可以知道，本发明的技术方案是在C-Mn钢的基础上，通过Nb-V-Ti复合微合金化、析出-固溶复合强化，并添加较多的Mo、Cu及Ni等多种合金元素来提高材料的高温强度。首先，Nb-V-Ti微合金元素能够起到细晶、细化组织的作用以及析出强化作用，其次，Mn-Mo-Cu具有固溶强化作用，其中，加入的Mo和Cu可以降低C的扩散系数，也可以改善高温下的组织稳定性，提高高温强度，与此同时，Mo还能够强烈地提高淬透性，以起到促进针状铁素体组织或贝氏体组织转变的作用，从而提高材料的初始强度和高温下的组织稳定性，进而提高材料的高温强度。
与现有的管线钢相比较，本发明的技术方案的核心设计之处在于提高材料的高温强度。
进一步地，在本发明所述的550MPa级的耐高温管线钢中还含有0<Si≤0.40％、0<Cr≤0.40％和0<N≤0.005％的至少其中之一。
Si主要用于钢的脱氧。同时，其还可以起到一定的提高淬透性的作用。但是，当Si含量过高时，则会导致韧性降低，尤其是焊接热影响区韧性的恶化，即导致钢材料焊接性能的降低。鉴于此，在本发明的技术方案中，Si的添加量应该控制为≤0.40wt.％。
Cr是提高钢的淬透性而提高钢的强度的元素。但是，随着Cr含量的增加，钢的冷裂敏感性也会逐步增大，对焊接热影响区的韧性和焊接性能都会产生不利。基于这一原因，本发明的技术方案中将Cr的添加量控制为≤0.40wt.％。
N是通过提高钢的淬透性来提高钢的强度的，但是，N会对钢的韧性产生不利影响，可以通过加入Ti形成TiN固定来改善材料的韧性。为此，本发明所述的550MPa级的耐高温管线钢中N含量应该控制在0.005wt.％以下。
本发明所述的550MPa级的耐高温管线钢的微观组织包括均匀的针状铁素体组织+少量M-A组元(马氏体-残余奥氏体组元)形成的基体。一方面，针状铁素体组织相比多边形铁素体组织更细小，有利于通过界面强化提高高温强度；另一方面，针状铁素体组织相比马氏体组织基体中位错密度更低，有利于通过提高高温下的组织稳定性提高高温强度。
进一步地，所述M-A组元的体积百分比≤10％。M-A组元是由在控轧后冷却过程中来不及转变的过冷奥氏体转变得到，其成分与其周围针状铁素体不同从而形成浓度梯度，其体积百分比过高会加速高温下元素的扩散，不利于高温下的组织稳定性，对高温强度不利。另外，M-A组元与针状铁素体两者的变形协调性不同，受力变形时裂纹容易在两者间萌生，对高温强度不利。
进一步地，所述基体的平均有效晶粒尺寸≤8μm。将有效晶粒尺寸限定在该范围内可以进一步提高界面强化效果，从而提高高温强度。
更进一步地，基体中的小角度晶界体积百分含量为20～60％。小角度晶界是指晶体学上位相差小于15度的晶界。将基体中的小角度晶界含量限定在该范围内也可以提高界面强化效果，从而提高高温强度。
进一步地，所述基体上还弥散分布有由Nb、V沉淀析出的碳化物NbC、VC和碳氮化物(Nb，V)(C，N)。NbC、VC和(Nb，V)(C，N)高温下 的粗化速率较低，高温下可以长期维持有效的析出强化作用，从而提高高温强度。
更进一步地，所述碳化物和碳氮化物的平均尺寸为5～50nm。将碳化物和碳氮化物的尺寸限定在该范围内有利于产生强烈的析出强化作用，从而提高高温强度。
相应地，本发明还提供了生产如上文所述的550MPa级的耐高温管线钢的制造方法，该制造方法包括步骤：冶炼，铸造，板坯加热，粗轧，精轧，控制冷却，空冷至室温。
进一步地，在本发明所述的550MPa级的耐高温管线钢的制造方法的粗轧步骤中，粗轧开轧温度为1100-1180℃，粗轧终轧温度为950-980℃。
进一步地，在本发明所述的550MPa级的耐高温管线钢的制造方法的精轧步骤中，精轧开轧温度为850-900℃，精轧终轧温度为800-820℃，精轧压缩比为4T～8T，其中T为成品钢板的厚度。
在本发明的技术方案中，在Nb-V-Ti复合微合金化的基础上，利用较大的精轧压缩比，通过应变诱导析出促进细小析出相的形成，提高析出强化作用，利用细小析出相来提高材料的高温强度。较高的精轧温度则可以改善材料初始材料组织的稳定性，从而来提高材料的高温强度。
更进一步地，在本发明所述的550MPa级的耐高温管线钢的制造方法的控制冷却步骤中，开始冷却的温度为750～780℃，冷却速度为15～30℃/s，停冷温度为380～580℃。
在冷却步骤中，采用中等冷却速度和较高的停冷温度可以降低初始组织中可动位错密度，以改善材料在高温下的组织稳定性，从而提高材料的高温强度。
更进一步地，在本发明所述的550MPa级的耐高温管线钢的制造方法的板坯加热步骤中，加热温度为1110～1250℃。
本发明所述的550MPa级的耐高温管线钢的制造方法在成分设计添加较多Nb、V、Ti、Mn、Mo和Cu等合金元素的基础上，关键采用了TMCP控轧控冷工艺来提高材料的高温强度。
较之于现有技术中的管线钢，本发明所述的550MPa级的耐高温管线钢兼具优异的高温力学性能和良好的耐高温性能，其在200～400℃下的屈服强 度和抗拉强度分别大于等于520MPa和645MPa，其室温屈服强度和抗拉强度分别大于等于550MPa和625MPa，其能够用于输送油砂就地开采过程中所需的高温蒸汽介质。
此外，本发明所述的550MPa级的耐高温管线钢还具有较高的韧性，良好的耐腐蚀性以及优良的焊接加工性能。
本发明所述的550MPa级的耐高温管线钢的制造方法由于采用了控轧控冷工艺，提高了管线钢的高温力学性能，尤其提高了管线钢的室温强度和高温强度。
具体实施方式
下面将根据具体实施例对本发明所述的550MPa级的耐高温管线钢及其制造方法做出进一步说明，但是具体实施例和相关说明并不构成对于本发明的技术方案的不当限定。
实施例A1-A6
按照下述步骤制造实施例A1-A6中的550MPa级的耐高温管线钢：
1)冶炼：转炉或电炉冶炼，并控制实施例A1-A6中的各化学元素的质量百分配比如表1所示；
2)铸造：铸成板坯；
3)板坯加热：加热温度为1110～1250℃；
4)粗轧：粗轧开轧温度为1100-1180℃，终轧温度为950-980℃；
5)精轧：精轧开轧温度为850-900℃，终轧温度为800-820℃；精轧压缩比为4T～8T，其中T为成品钢板的厚度；
6)控制冷却：开始冷却的温度为750～780℃，冷却速度为15～30℃/s，停冷温度为380～580℃；
7)空冷至室温，最终获得实施例A1-A6中的550MPa级的耐高温管线钢，具体步骤中所涉及的工艺参数详见表2。
表1列出了本案实施例A1-A6的各化学元素的质量百分配比。
表1.(wt.％，余量为Fe以及除了P和S以外的其他不可避免的杂质)
序号 C Mn Mo Cu Ni Nb V Ti Al Ca Si Cr N P S
A1 0.062 2.15 0.16 0.28 0.48 0.079 0.010 0.026 0.018 0.020 0.25 0.28 0.003 0.008 0.0022
A2 0.111 1.73 0.36 0.24 0.30 0.036 0.050 0.020 0.022 0.019 0.20 0.36 0.004 0.008 0.0035
A3 0.105 1.75 0.32 0.17 0.18 0.041 0.020 0.016 0.017 0.022 0.21 0.19 0.004 0.007 0.0040
A4 0.070 2.05 0.18 0.28 0.42 0.065 0.025 0.024 0.023 0.018 0.24 0.22 0.003 0.009 0.0035
A5 0.079 1.96 0.25 0.20 0.25 0.054 0.040 0.020 0.022 0.023 0.24 0.18 0.004 0.007 0.0020
A6 0.089 1.85 0.30 0.16 0.18 0.048 0.050 0.016 0.016 0.028 0.22 0.18 0.003 0.009 0.0030
表2列出了本案实施例A1-A6的550MPa级的耐高温管线钢的制造方法的工艺参数。
表2.
Figure PCTCN2015089697-appb-000001
对于实施例A1-A6中的成品钢板进行棒状拉伸性能检验，检验中的试验温度分别为室温、200℃、250℃、300℃、350℃和400℃，在前述温度下所获得的拉伸性能参数的结果具体如表3所示。
表3列出了本案实施例A1-A6中的550MPa级的耐高温管线钢在不同温度下的拉伸性能参数。
表3.
Figure PCTCN2015089697-appb-000002
Figure PCTCN2015089697-appb-000003
*注：(1)Rt0.5为屈服强度，指材料标距长度产生0.5％的总延伸时对应的拉伸应力；(2)Rm为抗拉强度A50.8为标距长度为50.8mm时对应的总延伸率，表3中测A50.8的圆棒试样直径为12.8mm；(3)A50为标距长度为50mm时对应的总延伸率，表3中测A50的圆棒拉伸试样直径为10mm。
从表3中可以看出，上述各实施例A1-A6中的管线钢钢板在室温下的屈服强度≥571Mpa，抗拉强度≥682Mpa，延伸率≥21％，其在高温下(即200～400℃下)的屈服强度≥545Mpa，抗拉强度≥679Mpa，延伸率≥21％，由此可以说明实施例A1-A6中的管线钢的室温拉伸强度可满足相当于X80的强度级别要求(即室温屈服强度和抗拉强度分别达到≥550MPa和≥625MPa)，且该管线钢在200～400℃下也具备有较高的屈服强度和抗拉强度。
本发明所述的550MPa级的耐高温管线钢可以用于制造工作服役条件为200～400℃的蒸汽输送用管道，其具有广泛的市场应用前景。
需要注意的是，以上列举的仅为本发明的具体实施例，显然本发明不限于以上实施例，随之有着许多的类似变化。本领域的技术人员如果从本发明公开的内容直接导出或联想到的所有变形，均应属于本发明的保护范围。

Claims (13)

  1. 一种550MPa级的耐高温管线钢，其化学元素质量百分配比为：0.061％≤C≤0.120％，1.70％≤Mn≤2.20％，0.15％≤Mo≤0.39％，0.15％≤Cu≤0.30％，0.15％≤Ni≤0.50％，0.035％≤Nb≤0.080％，0.005％≤V≤0.054％，0.005％≤Ti≤0.030％，0.015％≤Al≤0.040％，0.005％≤Ca≤0.035％，余量为Fe和不可避免的杂质元素。
  2. 如权利要求1所述的550MPa级的耐高温管线钢，其特征在于，还含有0<Si≤0.40％、0<Cr≤0.40％和0<N≤0.005％的至少其中之一。
  3. 如权利要求1所述的550MPa级的耐高温管线钢，其特征在于，其微观组织包括均匀的针状铁素体组织+少量M-A组元形成的基体。
  4. 如权利要求3所述的550MPa级的耐高温管线钢，其特征在于，所述M-A组元的体积百分比≤10％。
  5. 如权利要求3所述的550MPa级的耐高温管线钢，其特征在于，所述基体的平均有效晶粒尺寸≤8μm。
  6. 如权利要求5所述的550MPa级的耐高温管线钢，其特征在于，其中基体中的小角度晶界体积百分含量为20～60％。
  7. 如权利要求3所述的550MPa级的耐高温管线钢，其特征在于，所述基体上还弥散分布有由Nb、V沉淀析出的碳化物NbC、VC和碳氮化物(Nb，V)(C,N)。
  8. 如权利要求7所述的550MPa级的耐高温管线钢，其特征在于，所述碳化物和碳氮化物的平均尺寸为5～50nm。
  9. 如权利要求1～8中任意一项所述的550MPa级的耐高温管线钢的制造方法，其特征在于，包括步骤：冶炼，铸造，板坯加热，粗轧，精轧，控制冷却，空冷至室温。
  10. 如权利要求9所述的550MPa级的耐高温管线钢的制造方法，其特征在于，在所述粗轧步骤中，粗轧的开轧温度为1100-1180℃，粗轧的终轧温度为950-980℃。
  11. 如权利要求9或10所述的550MPa级的耐高温管线钢的制造方法，其特征在于，在所述精轧步骤中，精轧的开轧温度为850-900℃，精轧的终轧 温度为800-820℃，精轧压缩比为4T-8T，其中T为成品钢板的厚度。
  12. 如权利要求9所述的550MPa级的耐高温管线钢的制造方法，其特征在于，在所述控制冷却步骤中，开始冷却的温度为750-780℃，冷却速度为15-30℃/s，停冷温度为380-580℃。
  13. 如权利要求9所述的550MPa级的耐高温管线钢的制造方法，其特征在于，在所述板坯加热步骤中，加热温度为1110-1250℃。
PCT/CN2015/089697 2014-09-19 2015-09-16 一种550MPa级的耐高温管线钢及其制造方法 WO2016041491A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CA2960903A CA2960903C (en) 2014-09-19 2015-09-16 Grade 550mpa high-temperature resistant pipeline steel and method of manufacturing same
US15/512,209 US11085098B2 (en) 2014-09-19 2015-09-16 Grade 550MPA high-temperature resistant pipeline steel and method of manufacturing same

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201410483553.7 2014-09-19
CN201410483553.7A CN104264054B (zh) 2014-09-19 2014-09-19 一种550MPa级的耐高温管线钢及其制造方法

Publications (1)

Publication Number Publication Date
WO2016041491A1 true WO2016041491A1 (zh) 2016-03-24

Family

ID=52155626

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2015/089697 WO2016041491A1 (zh) 2014-09-19 2015-09-16 一种550MPa级的耐高温管线钢及其制造方法

Country Status (4)

Country Link
US (1) US11085098B2 (zh)
CN (1) CN104264054B (zh)
CA (1) CA2960903C (zh)
WO (1) WO2016041491A1 (zh)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104264054B (zh) * 2014-09-19 2017-02-22 宝山钢铁股份有限公司 一种550MPa级的耐高温管线钢及其制造方法
CN107881421B (zh) * 2016-09-29 2019-09-03 宝钢湛江钢铁有限公司 550MPa级耐高温且有良好低温止裂韧性的管线钢及其制造方法
CN107688718B (zh) * 2017-09-15 2022-11-18 中国核电工程有限公司 一种避免使用阻尼器的高温管道抗动力载荷的设计方法
KR102020415B1 (ko) * 2017-12-24 2019-09-10 주식회사 포스코 저항복비 특성이 우수한 고강도 강재 및 그 제조방법
WO2020065372A1 (en) * 2018-09-25 2020-04-02 Arcelormittal High strength hot rolled steel having excellent scale adhesivness and a method of manufacturing the same
TWI681062B (zh) * 2019-03-25 2020-01-01 中國鋼鐵股份有限公司 耐粗晶鋼材及其製作方法與評估方法
CN110373613B (zh) * 2019-08-05 2021-05-07 钢铁研究总院 一种100MPa级抗震阻尼器用低屈服点钢及其制备方法
CN113832415A (zh) * 2020-06-23 2021-12-24 宝山钢铁股份有限公司 一种x80级耐高温管线钢及其制造方法
CN112593038B (zh) * 2020-12-23 2022-04-19 河北燕山钢铁集团有限公司 L245管线钢的冶炼浇注工艺
CN114150209B (zh) * 2021-11-16 2022-10-25 山东钢铁集团日照有限公司 一种屈服强度不小于550MPa的高性能桥梁钢及其制备方法和应用
CN115505852B (zh) * 2022-10-26 2023-04-07 河北普阳钢铁有限公司 一种耐蚀农机用钢材及其制造方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1715435A (zh) * 2004-06-30 2006-01-04 宝山钢铁股份有限公司 具有抗hic性能x80管线钢及其热轧板制造方法
CN1715434A (zh) * 2004-06-30 2006-01-04 宝山钢铁股份有限公司 高强度高韧性x80管线钢及其热轧板制造方法
JP2008248330A (ja) * 2007-03-30 2008-10-16 Jfe Steel Kk 低降伏比高強度高靱性鋼管およびその製造方法
CN101649425A (zh) * 2009-09-08 2010-02-17 武汉钢铁(集团)公司 低裂纹敏感性高韧性x120管线钢及其制造方法
CN104264054A (zh) * 2014-09-19 2015-01-07 宝山钢铁股份有限公司 一种550MPa级的耐高温管线钢及其制造方法

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5937328B2 (ja) * 1980-09-05 1984-09-08 新日本製鐵株式会社 耐サワ−特性のすぐれた鋼管用熱延鋼材の製造方法
EP0288054B1 (en) * 1987-04-24 1993-08-11 Nippon Steel Corporation Method of producing steel plate with good low-temperature toughness
JP4082464B2 (ja) * 1995-12-28 2008-04-30 Ｊｆｅスチール株式会社 高強度高靭性大径溶接鋼管の製造方法
JP3869747B2 (ja) * 2002-04-09 2007-01-17 新日本製鐵株式会社 変形性能に優れた高強度鋼板、高強度鋼管および製造方法
CN1487101A (zh) * 2002-09-30 2004-04-07 中国科学院金属研究所 一种提高现有针状铁素体管线钢强度的方法
CN100398684C (zh) * 2005-12-22 2008-07-02 宝山钢铁股份有限公司 超高强度x100管线钢及其热轧板制造方法
EP2240618B1 (en) * 2007-12-04 2013-01-23 Posco High-strength steel sheet with excellent low temperature toughness and manufacturing method thereof
CN101906568B (zh) * 2010-08-12 2011-12-07 中国石油天然气集团公司 一种高钢级大应变管线钢和钢管的制造方法
CN101926568A (zh) * 2010-09-02 2010-12-29 苏州星岛金属制品有限公司 一种可调靠背的椅子
WO2014143702A2 (en) * 2013-03-15 2014-09-18 Am/Ns Calvert Llc Line pipe steels and process of manufacturing
JP6235221B2 (ja) * 2013-03-28 2017-11-22 Ｊｆｅスチール株式会社 低温靭性および耐水素脆性を有する耐磨耗厚鋼板およびその製造方法
JP5633664B1 (ja) * 2013-03-29 2014-12-03 Ｊｆｅスチール株式会社 鋼材および水素用容器ならびにそれらの製造方法
JP5783229B2 (ja) * 2013-11-28 2015-09-24 Ｊｆｅスチール株式会社 熱延鋼板およびその製造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1715435A (zh) * 2004-06-30 2006-01-04 宝山钢铁股份有限公司 具有抗hic性能x80管线钢及其热轧板制造方法
CN1715434A (zh) * 2004-06-30 2006-01-04 宝山钢铁股份有限公司 高强度高韧性x80管线钢及其热轧板制造方法
JP2008248330A (ja) * 2007-03-30 2008-10-16 Jfe Steel Kk 低降伏比高強度高靱性鋼管およびその製造方法
CN101649425A (zh) * 2009-09-08 2010-02-17 武汉钢铁(集团)公司 低裂纹敏感性高韧性x120管线钢及其制造方法
CN104264054A (zh) * 2014-09-19 2015-01-07 宝山钢铁股份有限公司 一种550MPa级的耐高温管线钢及其制造方法

Also Published As

Publication number Publication date
CN104264054A (zh) 2015-01-07
US11085098B2 (en) 2021-08-10
CA2960903C (en) 2020-07-21
CA2960903A1 (en) 2016-03-24
US20170283901A1 (en) 2017-10-05
CN104264054B (zh) 2017-02-22

Similar Documents

Publication Publication Date Title
WO2016041491A1 (zh) 一种550MPa级的耐高温管线钢及其制造方法
US10378073B2 (en) High-toughness hot-rolling high-strength steel with yield strength of 800 MPa, and preparation method thereof
WO2015030210A1 (ja) 耐サワー性、耐圧潰特性及び低温靭性に優れた厚肉高強度ラインパイプ用鋼板とラインパイプ
CN102851587B (zh) 抗变形x80-x100管线钢板
JP5900303B2 (ja) 鋼板内の材質均一性に優れた耐サワーラインパイプ用高強度鋼板とその製造方法
JP5958450B2 (ja) 耐硫化物応力腐食割れ性に優れた油井用低合金高強度継目無鋼管およびその製造方法
WO2007023806A1 (ja) ラインパイプ用継目無鋼管およびその製造方法
WO2016119500A1 (zh) 一种具有高止裂性能的钢板及其制造方法
JP5884201B2 (ja) 引張強さ５４０ＭＰａ以上の高強度ラインパイプ用熱延鋼板
JP5903880B2 (ja) 耐サワー特性と溶接熱影響部靭性に優れたラインパイプ用高強度鋼板及びその製造方法
CN109023069B (zh) NbC纳米颗粒强化X80塑性管用钢板及其制造方法
JP5884202B2 (ja) 高強度ラインパイプ用熱延鋼板
JP5991175B2 (ja) 鋼板内の材質均一性に優れたラインパイプ用高強度鋼板とその製造方法
CN102373387A (zh) 大应变冷弯管用钢板及其制造方法
CN109136756B (zh) NbC纳米颗粒强化X90塑性管用钢板及其制造方法
CN109023068B (zh) Vc纳米颗粒强化x90塑性管用钢板及其制造方法
WO2014114158A1 (zh) 一种高强度钢板及其制造方法
CN109957709B (zh) 一种含v大变形x70m管线钢板及其制造方法
JP6468302B2 (ja) 高強度油井用鋼管用素材および該素材を用いた高強度油井用鋼管の製造方法
WO2016056216A1 (ja) ラインパイプ用鋼板及びその製造方法とラインパイプ用鋼管
CN109112402B (zh) Vc纳米颗粒强化x80塑性管用钢板及其制造方法
CA3032502C (en) Sucker rod steel and manufacturing method thereof
WO2019179354A1 (zh) 一种耐低温高强高韧油套管及其制造方法
JP5672658B2 (ja) 耐ｈｉｃ特性と溶接熱影響部靭性に優れたラインパイプ用高強度鋼板およびその製造方法
CN107779744B (zh) 一种贝氏体型x100级无缝管线管及其制造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15843031

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2960903

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 15512209

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15843031

Country of ref document: EP

Kind code of ref document: A1