CA3157822C - Normalized uoe welded pipe and manufacturing method thereof - Google Patents
Normalized uoe welded pipe and manufacturing method thereof Download PDFInfo
- Publication number
- CA3157822C CA3157822C CA3157822A CA3157822A CA3157822C CA 3157822 C CA3157822 C CA 3157822C CA 3157822 A CA3157822 A CA 3157822A CA 3157822 A CA3157822 A CA 3157822A CA 3157822 C CA3157822 C CA 3157822C
- Authority
- CA
- Canada
- Prior art keywords
- normalized
- welded pipe
- uoe
- pipe
- uoe welded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 28
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 46
- 239000010959 steel Substances 0.000 claims abstract description 46
- 238000005096 rolling process Methods 0.000 claims abstract description 42
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 229910052729 chemical element Inorganic materials 0.000 claims abstract description 6
- 238000009749 continuous casting Methods 0.000 claims abstract description 6
- 238000001816 cooling Methods 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 9
- 238000004513 sizing Methods 0.000 claims description 8
- 229910052802 copper Inorganic materials 0.000 claims description 7
- 230000009467 reduction Effects 0.000 claims description 7
- 229910052804 chromium Inorganic materials 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- 229910052758 niobium Inorganic materials 0.000 claims description 6
- 238000009628 steelmaking Methods 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 5
- 229910052717 sulfur Inorganic materials 0.000 claims description 5
- 229910000859 α-Fe Inorganic materials 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 229910001562 pearlite Inorganic materials 0.000 claims description 4
- 229910001568 polygonal ferrite Inorganic materials 0.000 claims description 4
- 238000010606 normalization Methods 0.000 claims description 3
- 244000126002 Ziziphus vulgaris Species 0.000 claims 1
- 238000003723 Smelting Methods 0.000 abstract 1
- 230000005540 biological transmission Effects 0.000 abstract 1
- 238000003466 welding Methods 0.000 description 28
- 230000000052 comparative effect Effects 0.000 description 14
- 239000010949 copper Substances 0.000 description 13
- 238000000034 method Methods 0.000 description 13
- 230000008569 process Effects 0.000 description 13
- 239000000243 solution Substances 0.000 description 12
- 229910001566 austenite Inorganic materials 0.000 description 9
- 238000005728 strengthening Methods 0.000 description 8
- 230000008901 benefit Effects 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 238000005275 alloying Methods 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 230000006835 compression Effects 0.000 description 5
- 238000007906 compression Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000003801 milling Methods 0.000 description 3
- 230000006911 nucleation Effects 0.000 description 3
- 238000010899 nucleation Methods 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000004113 Sepiolite Substances 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000005253 cladding Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 125000004433 nitrogen atom Chemical group N* 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000001953 recrystallisation Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000009864 tensile test Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- RMLPZKRPSQVRAB-UHFFFAOYSA-N tris(3-methylphenyl) phosphate Chemical compound CC1=CC=CC(OP(=O)(OC=2C=C(C)C=CC=2)OC=2C=C(C)C=CC=2)=C1 RMLPZKRPSQVRAB-UHFFFAOYSA-N 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011238 particulate composite Substances 0.000 description 1
- 238000005504 petroleum refining Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
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
- C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
-
- 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
- C21D1/26—Methods of annealing
- C21D1/28—Normalising
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
- B21C37/08—Making tubes with welded or soldered seams
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/18—Submerged-arc welding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/23—Arc welding or cutting taking account of the properties of the materials to be welded
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/235—Preliminary treatment
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- 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
- C21D7/00—Modifying the physical properties of iron or steel by deformation
- C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
- C21D7/10—Modifying the physical properties of iron or steel by deformation by cold working of the whole cross-section, e.g. of concrete reinforcing bars
- C21D7/12—Modifying the physical properties of iron or steel by deformation by cold working of the whole cross-section, e.g. of concrete reinforcing bars by expanding tubular bodies
-
- 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
- C21D8/021—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular fabrication or treatment of ingot or slab
-
- 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
- C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
- C21D8/105—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies 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
- 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
- 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
- C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
- C21D9/505—Cooling thereof
-
- 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
- C22C38/16—Ferrous alloys, e.g. steel alloys containing 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
-
- 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
- C22C38/48—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
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2101/00—Articles made by soldering, welding or cutting
- B23K2101/18—Sheet panels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/02—Iron or ferrous alloys
- B23K2103/04—Steel or steel 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- 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
- C21D2211/009—Pearlite
Abstract
A normalized UOE welded pipe in mass percentage of chemical elements is: 0.14-0.18% of C, 0.15-0.30% of Si, 1.20-1.50% of Mn, =0.15% of Cu, =0.15% of Ni, =0.15% of Cr, 0.010-0.030% of Nb, 0.005-0.020% of Ti, 0.001-0.005% of Ca, 0.020-0.050% of Al, =0.0005% of B, the balance being Fe and unavoidable impurity elements. The manufacturing method of the normalized UOE welded pipe comprises steps: (1) smelting and continuous casting; (2) steel plate rolling; (3) UOE pipe manufacturing; (4) entire pipe normalizing; (5) finishing: controlling the diameter growth rate to 0.6-2%. The normalized low-yield-ratio welded pipe has an increased caliber, thereby improving transmission efficiency, significantly lowering costs in comparison to seamless steel pipes, and increasing economic efficiency.
Description
Description Normalized UOE Welded Pipe and Manufacturing Method thereof Technical field The present invention relates to a steel pipe and a manufacturing method thereof, in particular to a welded pipe and a manufacturing method thereof.
Background Since high-temperature steam transportation pipelines used in the petroleum refining industry need to be in service at high temperature for a long time, there is a high demand for microstructure uniformity of materials. Generally, the normalized, modulated and other heat-treated seamless steel pipes are adopted for their good microstructure uniformity, however, the seamless steel pipes are limited by diameter, and cannot meet the large capacity steam transportation needs of some engineering projects. As a result, it can only be achieved by increasing the number of pipeline, leading to increased costs.
For example: Chinese patent having publication number of CN105821335A, published on August 3, 2016, and entitled as "Low-cost ultra-low temperature normalized steel having excellent weldability for pipeline and production method thereof' discloses an ultra-low temperature normalized steel for pipeline. In the technical solution disclosed in this patent, a lower content of C
is employed and V is added.
For another example, Chinese patent having publication number of CN104862612A, published on August 26, 2015, and entitled as "4601ViPa-grade low-temperature-resistant normalized steel, steel pipe, and a manufacturing method for steel pipe" discloses a 460 MPa-grade low-temperature-resistant normalized steel. In the technical solution disclosed in this patent document, the product Date Recue/Date Received 2022-04-12 actually produced is a seamless steel pipe rather than a welded pipe, and a plurality of alloying elements such as Cu, Ni, Cr, Mo, and V are added into the composition design of the technical solution disclosed in this patent.
For another example: Chinese patent having publication number of CN102719737A, published on October 10, 2012, and entitled as "High-toughness normalized steel sheet with yield strength of 460 1ViPa and manufacturing method thereof' discloses a high-toughness normalized steel sheet with a yield strength of 460 MPa. In the technical solution disclosed in this patent, the chemical composition of which contains high content of V and N, and thus adopting a design concept of VN
fine crystal and precipitation strengthening.
On this basis, it is expected to obtain a normalized welded pipe having low yield ratio which can meet the requirements of microstructure uniformity for high-temperature steam transportation, and has an increased diameter, thereby improving transportation efficiency, significantly lowering the costs in comparison to seamless steel pipes and increasing economic benefits.
Summary of the Invention One of the aspects of the present invention is to provide a normalized UOE
welded pipe having low yield ratio. The normalized UOE welded pipe having low yield ratio is mainly made of C and Mn and a small amount of Cu, Ni, Cr and Nb alloying elements, so that the normalized UOE welded pipe having low yield ratio would have better economic efficiency and can provide better weldability while satisfying the demand for strength.
In order to achieve the above aspect, the present invention provides a normalized UOE welded pipe having low yield ratio, and comprising the following chemical elements in percentage by mass:
C: 0.14-0.18%, Si: 0.15-0.30%, Mn: 1.20-1.50%, Cu<0.15%, Ni<0.15%, Cr<0.15%, Nb: 0.010-0.030%, Ti: 0.005-0.020%, Ca: 0.001-0.005%, Al: 0.020-0.050%, B<0.0005%, the balance being Fe and unavoidable impurities.
Background Since high-temperature steam transportation pipelines used in the petroleum refining industry need to be in service at high temperature for a long time, there is a high demand for microstructure uniformity of materials. Generally, the normalized, modulated and other heat-treated seamless steel pipes are adopted for their good microstructure uniformity, however, the seamless steel pipes are limited by diameter, and cannot meet the large capacity steam transportation needs of some engineering projects. As a result, it can only be achieved by increasing the number of pipeline, leading to increased costs.
For example: Chinese patent having publication number of CN105821335A, published on August 3, 2016, and entitled as "Low-cost ultra-low temperature normalized steel having excellent weldability for pipeline and production method thereof' discloses an ultra-low temperature normalized steel for pipeline. In the technical solution disclosed in this patent, a lower content of C
is employed and V is added.
For another example, Chinese patent having publication number of CN104862612A, published on August 26, 2015, and entitled as "4601ViPa-grade low-temperature-resistant normalized steel, steel pipe, and a manufacturing method for steel pipe" discloses a 460 MPa-grade low-temperature-resistant normalized steel. In the technical solution disclosed in this patent document, the product Date Recue/Date Received 2022-04-12 actually produced is a seamless steel pipe rather than a welded pipe, and a plurality of alloying elements such as Cu, Ni, Cr, Mo, and V are added into the composition design of the technical solution disclosed in this patent.
For another example: Chinese patent having publication number of CN102719737A, published on October 10, 2012, and entitled as "High-toughness normalized steel sheet with yield strength of 460 1ViPa and manufacturing method thereof' discloses a high-toughness normalized steel sheet with a yield strength of 460 MPa. In the technical solution disclosed in this patent, the chemical composition of which contains high content of V and N, and thus adopting a design concept of VN
fine crystal and precipitation strengthening.
On this basis, it is expected to obtain a normalized welded pipe having low yield ratio which can meet the requirements of microstructure uniformity for high-temperature steam transportation, and has an increased diameter, thereby improving transportation efficiency, significantly lowering the costs in comparison to seamless steel pipes and increasing economic benefits.
Summary of the Invention One of the aspects of the present invention is to provide a normalized UOE
welded pipe having low yield ratio. The normalized UOE welded pipe having low yield ratio is mainly made of C and Mn and a small amount of Cu, Ni, Cr and Nb alloying elements, so that the normalized UOE welded pipe having low yield ratio would have better economic efficiency and can provide better weldability while satisfying the demand for strength.
In order to achieve the above aspect, the present invention provides a normalized UOE welded pipe having low yield ratio, and comprising the following chemical elements in percentage by mass:
C: 0.14-0.18%, Si: 0.15-0.30%, Mn: 1.20-1.50%, Cu<0.15%, Ni<0.15%, Cr<0.15%, Nb: 0.010-0.030%, Ti: 0.005-0.020%, Ca: 0.001-0.005%, Al: 0.020-0.050%, B<0.0005%, the balance being Fe and unavoidable impurities.
2 Date Recue/Date Received 2022-04-12 In the normalized UOE welded pipe with low yield ratio of the invention, the design principles for each chemical element are as follows:
C: in the normalized UOE welded pipe having low yield ratio of the invention, C is the most basic strengthening element. C dissolved in steel, on one hand, plays the role of solid solution strengthening, while on the other hand, C element is an essential element for pearlite formation in the normalized steel, which can increase tensile strength, and obtain a low yield ratio. However, if the mass percentage of C is too high, carbides with large size will be formed during welding process, which is not preferred. On this basis, the mass percentage of C is controlled to 0.14-0.18% in the normalized UOE welded pipe having low yield ratio of the present invention.
Si: in the normalized UOE welded pipe having low yield ratio of the invention, Si is a solid solution strengthening element, and is also a deoxidizing element in steel at the same time, however, if the mass percentage of Si is too high, the welding properties of the steel will be deteriorated, and also leads to formation of red iron claddings on the surface of the steel plate. On this basis, the mass percentage of Si is controlled to 0.15-0.30% in the normalized UOE welded pipe having low yield ratio of the invention.
Mn: in the normalized UOE welded pipe having low yield ratio of the invention, Mn is one of the most effective and economical solid solution strengthening elements, which can effectively improve the strength of normalized steel, but Mn is an element that easily segregates which causes generation of a hard phase structure with low toughness in the center of the steel plate, leading to toughness reduction. On this basis, the mass percentage of Mn is controlled to 1.20-1.50% in the normalized UOE welded pipe having low yield ratio of the invention.
Cu: in the normalized UOE welded pipe having low yield ratio of the invention, Cu is a solid solution strengthening element that helps to resist softening of welding heat affected zones and also increases
C: in the normalized UOE welded pipe having low yield ratio of the invention, C is the most basic strengthening element. C dissolved in steel, on one hand, plays the role of solid solution strengthening, while on the other hand, C element is an essential element for pearlite formation in the normalized steel, which can increase tensile strength, and obtain a low yield ratio. However, if the mass percentage of C is too high, carbides with large size will be formed during welding process, which is not preferred. On this basis, the mass percentage of C is controlled to 0.14-0.18% in the normalized UOE welded pipe having low yield ratio of the present invention.
Si: in the normalized UOE welded pipe having low yield ratio of the invention, Si is a solid solution strengthening element, and is also a deoxidizing element in steel at the same time, however, if the mass percentage of Si is too high, the welding properties of the steel will be deteriorated, and also leads to formation of red iron claddings on the surface of the steel plate. On this basis, the mass percentage of Si is controlled to 0.15-0.30% in the normalized UOE welded pipe having low yield ratio of the invention.
Mn: in the normalized UOE welded pipe having low yield ratio of the invention, Mn is one of the most effective and economical solid solution strengthening elements, which can effectively improve the strength of normalized steel, but Mn is an element that easily segregates which causes generation of a hard phase structure with low toughness in the center of the steel plate, leading to toughness reduction. On this basis, the mass percentage of Mn is controlled to 1.20-1.50% in the normalized UOE welded pipe having low yield ratio of the invention.
Cu: in the normalized UOE welded pipe having low yield ratio of the invention, Cu is a solid solution strengthening element that helps to resist softening of welding heat affected zones and also increases
3 Date Recue/Date Received 2022-04-12 the corrosion resistance of steel, but Cu has a rather low melting point and if the mass percentage of Cu is too high, it is easy to form brittle cracks on the surface of the hot-rolled steel plate. On this basis, the mass percentage of Cu is controlled to Cu<0.15% in the normalized UOE welded pipe having low yield ratio of the invention.
Ni: in the normalized UOE welded pipe having low yield ratio of the invention, Ni is a solid solution strengthening element, which plays a major role in forming a particulate composite phase with Cu elements to avoid the occurrence of "copper cracking". However, as Ni elements are expensive, thus, the mass percentage of Ni is controlled to Ni<0.15% in the normalized UOE
welded pipe having low yield ratio of the invention.
Cr: in the normalized UOE welded pipe having low yield ratio of the invention, Cr is an important element to improve the hardenability of the steel, and contributes to improve the microstructure uniformity in the thickness direction of the thick steel plate while improving the strength, but the mass percentage of Cr too high would cause excessive high strength and reduced toughness. On this basis, the mass percentage of Cr is controlled to Cr<0.15% in the normalized UOE welded pipe having low yield ratio of the invention.
Nb: in the normalized UOE welded pipe having low yield ratio of the invention, Nb may act to drag austenite grain boundaries during rough rolling, which helps to inhibit the growth of recrystallized austenite and refine the original austenite. In addition, strain-induced precipitation of Nb (N, C) particles during finish rolling has a precipitation strengthening effect, and may also promote polygonal ferrite nucleation, achieving the effect of grain refinement. If the mass percentage of Nb is too high, Nb cannot be completely dissolved during slab heating due to the limitation of the solubility product of C and Nb. On this basis, the mass percentage of Nb is controlled to 0.010-0.030% in the normalized UOE welded pipe having low yield ratio of the invention.
Ti: in the normalized UOE welded pipe having low yield ratio of the invention, Ti is a strong
Ni: in the normalized UOE welded pipe having low yield ratio of the invention, Ni is a solid solution strengthening element, which plays a major role in forming a particulate composite phase with Cu elements to avoid the occurrence of "copper cracking". However, as Ni elements are expensive, thus, the mass percentage of Ni is controlled to Ni<0.15% in the normalized UOE
welded pipe having low yield ratio of the invention.
Cr: in the normalized UOE welded pipe having low yield ratio of the invention, Cr is an important element to improve the hardenability of the steel, and contributes to improve the microstructure uniformity in the thickness direction of the thick steel plate while improving the strength, but the mass percentage of Cr too high would cause excessive high strength and reduced toughness. On this basis, the mass percentage of Cr is controlled to Cr<0.15% in the normalized UOE welded pipe having low yield ratio of the invention.
Nb: in the normalized UOE welded pipe having low yield ratio of the invention, Nb may act to drag austenite grain boundaries during rough rolling, which helps to inhibit the growth of recrystallized austenite and refine the original austenite. In addition, strain-induced precipitation of Nb (N, C) particles during finish rolling has a precipitation strengthening effect, and may also promote polygonal ferrite nucleation, achieving the effect of grain refinement. If the mass percentage of Nb is too high, Nb cannot be completely dissolved during slab heating due to the limitation of the solubility product of C and Nb. On this basis, the mass percentage of Nb is controlled to 0.010-0.030% in the normalized UOE welded pipe having low yield ratio of the invention.
Ti: in the normalized UOE welded pipe having low yield ratio of the invention, Ti is a strong
4 Date Recue/Date Received 2022-04-12 carbonitride forming element, which can play a role in fixing interstitial N
atoms. TiN has high thermal stability and can prevent the growth of austenite grains during slab heating and process of rough rolling recrystallization. In addition, TiN can also prevent the growth of grains in the heat affected zones during welding, improving the welding performance of the steel.
As the effect can be achieved with a small amount of Ti, the mass percentage of Ti is controlled to 0.005-0.020% in the normalized UOE welded pipe having low yield ratio of the invention.
Ca: in the normalized UOE welded pipe having low yield ratio of the invention, a small amount of Ca is added to control the morphology of sulfides, avoiding the formation of long-strip-shaped MnS, but the agglomeration of CaS and CaO will also occur when the mass percentage of Ca is too high.
On this basis, the mass percentage of Ca is controlled to 0.001-0.005% in the normalized UOE
welded pipe having low yield ratio of the invention.
Al: in the normalized UOE welded pipe having low yield ratio of the invention, Al is an element added to the steel for deoxidation. The addition of an appropriate amount of Al is beneficial to refine the grains and improve the strength and toughness of the steel. On this basis, the mass percentage of Al is controlled to 0.020-0.050% in the normalized UOE welded pipe having low yield ratio of the invention.
B: in the normalized UOE welded pipe having low yield ratio of the invention, B is an element with strong hardenability, which can increase the strength but tends to precipitate at grain boundaries, which leads to a decrease in plasticity and toughness of the material. On this basis, the mass percentage of B is controlled to B<0.0005% in the normalized UOE welded pipe having low yield ratio of the invention.
Preferably, in the normalized UOE welded pipe of the invention, in the unavoidable impurities: P <
0.018%, S < 0.003%, N < 0.006%, and 0 < 0.005%.
Date Recue/Date Received 2022-04-12 In the above technical solution, it is considered that although a small amount of N can form TiN
particles having high melting point with Ti to achieve an effect of inhibiting coarsening of austenite grains during reheating, when the mass percentage of N is too high, interstitial N atoms will pin dislocations, significantly increasing the yield strength and yield ratio, and harming plasticity and toughness. On this basis, the mass percentage of N is controlled to N <
0.0060% in the normalized UOE welded pipe having low yield ratio of the invention.
Furthermore, given that 0 will form oxide inclusions in the steel, the mass percentage of 0 may be preferably controlled to be 0 < 0.0050%.
In addition, S and P are also unavoidable impurities in steel. S is prone to forming MnS inclusions, and has an elongated structure after rolling, while P is an element prone to segregation, and both elements reduce the toughness of the steel. Therefore, in the technical solution of the present invention, the mass percentage of S and P is controlled to S < 0.003% and P <
0.018%, respectively.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, the normalized UOE welded pipe has a microstructure of polygonal ferrite +
pearlite with uniform size.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, phase proportion of the ferrite is 50-90%, preferably 50-80%.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, the normalized UOE welded pipe has an outer diameter of 711-1016 mm.
Preferably, the normalized UOE welded pipe having low yield ratio of the invention has a yield strength of 290-450 MPa, a tensile strength of 415-655 MPa, and a yield ratio of < 0.80.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, pipe body, Date Recue/Date Received 2022-04-12 weld seam, and heat affected zones of the normalized UOE welded pipe with low yield ratio have an impact toughness that satisfies: impact energy at -10 C > 100 J.
Correspondingly, another aspect of the present invention is to provide a manufacturing method of the normalized UOE welded pipe having low yield ratio. According to the manufacturing method, low yield ratio and high toughness of the normalized UOE welded pipe having low yield ratio can be obtained, and the outer diameter of the normalized UOE welded pipe having low yield ratio can reach a large diameter of 711-1016 mm.
In order to achieve the above aspect, the present invention provides a manufacturing method of the normalized UOE welded pipe having low yield ratio, comprising steps of:
(1) steelmaking and continuous casting;
(2) rolling steel plate;
(3) manufacturing UOE pipe;
(4) normalizing the whole of the UOE pipe: controlling normalization temperature to 860-920 C, and holding time to 1.0-3.0 min/mm xwall thickness; and
atoms. TiN has high thermal stability and can prevent the growth of austenite grains during slab heating and process of rough rolling recrystallization. In addition, TiN can also prevent the growth of grains in the heat affected zones during welding, improving the welding performance of the steel.
As the effect can be achieved with a small amount of Ti, the mass percentage of Ti is controlled to 0.005-0.020% in the normalized UOE welded pipe having low yield ratio of the invention.
Ca: in the normalized UOE welded pipe having low yield ratio of the invention, a small amount of Ca is added to control the morphology of sulfides, avoiding the formation of long-strip-shaped MnS, but the agglomeration of CaS and CaO will also occur when the mass percentage of Ca is too high.
On this basis, the mass percentage of Ca is controlled to 0.001-0.005% in the normalized UOE
welded pipe having low yield ratio of the invention.
Al: in the normalized UOE welded pipe having low yield ratio of the invention, Al is an element added to the steel for deoxidation. The addition of an appropriate amount of Al is beneficial to refine the grains and improve the strength and toughness of the steel. On this basis, the mass percentage of Al is controlled to 0.020-0.050% in the normalized UOE welded pipe having low yield ratio of the invention.
B: in the normalized UOE welded pipe having low yield ratio of the invention, B is an element with strong hardenability, which can increase the strength but tends to precipitate at grain boundaries, which leads to a decrease in plasticity and toughness of the material. On this basis, the mass percentage of B is controlled to B<0.0005% in the normalized UOE welded pipe having low yield ratio of the invention.
Preferably, in the normalized UOE welded pipe of the invention, in the unavoidable impurities: P <
0.018%, S < 0.003%, N < 0.006%, and 0 < 0.005%.
Date Recue/Date Received 2022-04-12 In the above technical solution, it is considered that although a small amount of N can form TiN
particles having high melting point with Ti to achieve an effect of inhibiting coarsening of austenite grains during reheating, when the mass percentage of N is too high, interstitial N atoms will pin dislocations, significantly increasing the yield strength and yield ratio, and harming plasticity and toughness. On this basis, the mass percentage of N is controlled to N <
0.0060% in the normalized UOE welded pipe having low yield ratio of the invention.
Furthermore, given that 0 will form oxide inclusions in the steel, the mass percentage of 0 may be preferably controlled to be 0 < 0.0050%.
In addition, S and P are also unavoidable impurities in steel. S is prone to forming MnS inclusions, and has an elongated structure after rolling, while P is an element prone to segregation, and both elements reduce the toughness of the steel. Therefore, in the technical solution of the present invention, the mass percentage of S and P is controlled to S < 0.003% and P <
0.018%, respectively.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, the normalized UOE welded pipe has a microstructure of polygonal ferrite +
pearlite with uniform size.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, phase proportion of the ferrite is 50-90%, preferably 50-80%.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, the normalized UOE welded pipe has an outer diameter of 711-1016 mm.
Preferably, the normalized UOE welded pipe having low yield ratio of the invention has a yield strength of 290-450 MPa, a tensile strength of 415-655 MPa, and a yield ratio of < 0.80.
Preferably, in the normalized UOE welded pipe having low yield ratio of the invention, pipe body, Date Recue/Date Received 2022-04-12 weld seam, and heat affected zones of the normalized UOE welded pipe with low yield ratio have an impact toughness that satisfies: impact energy at -10 C > 100 J.
Correspondingly, another aspect of the present invention is to provide a manufacturing method of the normalized UOE welded pipe having low yield ratio. According to the manufacturing method, low yield ratio and high toughness of the normalized UOE welded pipe having low yield ratio can be obtained, and the outer diameter of the normalized UOE welded pipe having low yield ratio can reach a large diameter of 711-1016 mm.
In order to achieve the above aspect, the present invention provides a manufacturing method of the normalized UOE welded pipe having low yield ratio, comprising steps of:
(1) steelmaking and continuous casting;
(2) rolling steel plate;
(3) manufacturing UOE pipe;
(4) normalizing the whole of the UOE pipe: controlling normalization temperature to 860-920 C, and holding time to 1.0-3.0 min/mm xwall thickness; and
(5) sizing: controlling diameter expanding-ratio to 0.6-2%.
In the technical solution of the present invention, the present inventors have found through research that a UOE welded pipe made of a TMCP steel plate as raw material in the prior art will encounter the following two difficulties: firstly, after normalizing, the strength of the welded pipe becomes significantly lower than that of the TMCP steel plate and the strength has to be guaranteed by increasing the content of C or alloy elements, but this would affect the weldability of the steel plate;
secondly, when manufacturing welded pipes having large diameter, due to the influence of self-weight, the pipe shape will change during the normalizing process, particularly increasing the ovality, which requires subsequent sizing and this process would introduce large cold deformation and, as a result, demanding a lower yield ratio for the pipes.
Date Recue/Date Received 2022-04-12 In contrast, the manufacturing method according to the present invention makes it possible to directly normalize the whole of the pipe by reasonably controlling the alloying composition when the steel plate is manufactured into a welded pipe, and desired normalized UOE
welded pipe having low yield ratio will be obtained after sizing. Specifically, the normalizing temperature is controlled to 860-920 C in order to both guarantee sufficient austenitization and avoid excessive grain size, and a cross support frame can be placed at the pipe end to mitigate changes of the pipe shape. The holding time can be determined according to the actual wall thickness, which is controlled to be 1.0-3.0 min/mm xwall thickness. Given that the size of the welded pipe after the whole pipe normalizing will change greatly and the straightness and ovality cannot meet dimensional accuracy requirements, sizing is required for full-length diameter expansion. The reason for controlling the diameter expanding-ratio to 0.6-2% is that when the diameter expanding-ratio is less than 0.6%, the springback after expansion will rise and the resulting size will be difficult to meet the requirements;
and when the diameter expanding-ratio is greater than 2%, excessive cold deformation will lead to an increase of the yield strength and yield ratio and a decrease of plasticity allowance.
It should be noted that diameter expanding-ratio = (outer diameter of a welded pipe after diameter expansion - outer diameter of the welded pipe before diameter expansion)/outer diameter of the welded pipe before diameter expansion x 100%.
Preferably, in the manufacturing method according to the present invention, a slab is obtained after steelmaking and continuous casting in step (1), and in step (2), the slab is rolled to a steel plate, the rolling includes rough rolling and finish rolling and controlling a heating temperature of slab to 1110-1180 C, a rough rolling temperature to 960-1080 C, a finish rolling temperature to 770-850 C, and controlling a total finish rolling reduction rate to 70-80%.
In the above solution, since heating temperature is an important factor influencing the original austenite grain size during the slab heating process, the heating temperature is controlled to 1110-1180 C in order to obtain better final properties of the normalized UOE welded pipe having low Date Recue/Date Received 2022-04-12 yield ratio of the present invention.
In addition, given that finish rolling is performed in a non-recrystallized zone, rolling deformation can accumulate strain energy storage and deformation bands in austenite, which is conducive to phase transformation and nucleation. The lower the finish rolling temperature, the less prone to recovery the strain accumulation, but the finish rolling temperature should be at Ar3 point or above.
Therefore, in the technical solution of the present invention, the finish rolling temperature range is 770-850 C and the total finish rolling reduction rate is controlled to be >
70% so as to obtain sufficient strain accumulation. Meanwhile, the total finish rolling reduction rate should not be too large and should be controlled to be in the range of 70-80% in order to give consideration to the rough rolling reduction rate to achieve the effect of recrystallization and refinement of austenite grains.
Preferably, in the manufacturing method according to the present invention, in step (2), controlled cooling is performed after rolling, with a cooling rate of 15-40 C/s, and the cooling is stopped at 400-550 C.
In the above solution, the reason for controlled cooling is that: the cooling after rolling is a phase transformation process of deformed austenite, and an appropriate cooling rate and the stopping temperature for cooling are conducive to ferrite nucleation to obtain a refined structure. Thus, preferably, the cooling rate can be controlled to be in the range of 15-40 C/s and the stopping temperature for cooling can be controlled in the range of 400-550 C.
Compared with the prior art, the normalized UOE welded pipe having low yield ratio of the present invention has the following advantages and beneficial effects:
The normalized UOE welded pipe having low yield ratio of the present invention is mainly made of C and Mn, and a very small amount of Cu, Ni, Cr and Nb alloying elements without any Mo, so that Date Recue/Date Received 2022-04-12 the normalized UOE welded pipe having low yield ratio will have better economic benefits.
In addition, the normalized UOE welded pipe having low yield ratio of the present invention has a uniform structure, and has a low yield ratio while meeting the demands for strength. In addition, the normalized UOE welded pipe having low yield ratio of the present invention has higher impact toughness and is very suitable for producing a large-diameter normalized welded pipe having a large diameter of, e.g., an outer diameter of 711-1016 mm.
In addition to the above advantages and beneficial effects achieved, the manufacturing method of the invention can make the final obtained UOE welded pipe have better properties after the whole pipe normalizing, especially having a low yield ratio while meeting the demands for strength, which is very conducive to the manufacture of large-diameter welded pipes.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a typical metallographic structure of the normalized UOE welded pipe having low yield ratio in Embodiment 2.
DETAILED DESCRIPTION
The normalized low-yield-ratio UOE welded pipe and the manufacturing method thereof of the invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the explanation and description do not constitute an improper limitation on the technical solution of the invention.
Embodiments 1-6 and Comparative examples 1-2 Normalized UOE welded pipes in Embodiments 1-6 are manufactured by using the following steps:
(1) steelmaking and continuous casting: wherein steelmaking may employ converter steelmaking, and LF+RH refining; the content of each chemical element is controlled in accordance with the composition design of the present invention, followed by continuous casting, so as to satisfy slab Date Recue/Date Received 2022-04-12 thickness in continuously casting / finished product thickness > 10.
(2) rolling steel plate: controlling the heating temperature of slab to 1110-1180 C, the rough rolling temperature range to 960-1080 C, the finish rolling temperature range to 770-850 C, and controlling the total finish rolling reduction rate to be 70-80%; then, controlled cooling is performed after rolling with a cooling rate of 15-40 C/s, and the cooling is stopped at 400-550 C.
(3) manufacturing UOE pipe;
(4) normalizing the whole of the UOE pipe: the normalization temperature is controlled to be 860-920 C, and the holding time is controlled to 1.0-3.0 min/mm x wall thickness.
(5) Sizing: the diameter expanding-ratio is controlled to 0.6-2%.
In some embodiments, UOE pipe manufacturing includes the following steps:
(3a) arc guiding plate welding: welding an arc guiding plate at the four corners of the steel plate, which plays the role of arc guiding during welding.
(3b) Edge and bevel dimension milling: obtaining an upper bevel slope of 32-42 and a lower bevel slope of 32-47 for a good welding morphology by a reasonable bevel dimension design to ensure the welding quality.
(3c) C-forming: i.e., edge pre-bending, the edges of the steel plate are bent into a desired shape by means of a bending device to meet the curvature requirements of subsequent 0-forming.
(3d) U-forming: the pre-bent steel plate is pressed into a U shape based on the diameter of the desired welded pipe.
Date Recue/Date Received 2022-04-12 (3e) 0-forming: the steel plate after U-forming is pressed into an 0 shape by a mold having matched diameter with the desired welded pipe. The compression ratio of the 0-forming is controlled to 0.16-0.22%, because if the compression ratio of the 0-forming is lower than 0.16%, the compression deformation of the welded pipe will be too low and causing an opening too large due to springback after forming, while if the compression ratio of the 0-forming is higher than 0.22%, the contact part of the bevel at the plate edge will easily cause deformation damage, which affects the subsequent welding. Specifically, compression ratio of 0-forming = (Tr x (outer diameter after pre-welding -wall thickness) - width after edge milling) / width after edge milling x 100%.
(3f) High pressure water washing and drying: the inner and outer surface of a slotted welded pipe after the 0-forming is subjected to high pressure water washing to remove contamination of iron oxide cladding, grease, dust, etc., and then the welded pipe enters a drying oven at a drying temperature of 100 C-300 C.
(3g) Pre-welding: the slotted welded pipe after the 0-forming is pre-welded by CO2 or Ar+CO2 gas shielded welding to ensure the arc stability during subsequent inside welding and outside welding.
(3h) Inside welding: inside welding is performed on the welded pipe by a 3-wire or 4-wire submerged arc welding process based on the wall thickness, wherein the first wire adopts direct current electrode negative, while the second, third and fourth wires adopt alternating current and all have a welding wire diameter of 4 mm. For the first wire, the current is 1100-1300A and the voltage is 30-35V; for the second wire, the current is 600-950A and the voltage is 31-37V; for the third wire, the current is 500-700A and the voltage is 33-39V; and for the fourth wire, the current is 400-600A
and the voltage is 35-41V. The welding speed is 1.3-1.9 m/min. The inside welding flux needs to be dried in the range of 250-450 C for greater than or equal to 2h.
(3i) Outside welding: outside welding is performed on the welded pipe by a 3-wire or 4-wire submerged arc welding process according to the wall thickness, wherein the first wire adopts direct Date Recue/Date Received 2022-04-12 current electrode negative, while the second, third and fourth wires adopt alternating current and all have a welding wire diameter of 4 mm. For the first wire, the current is 1150-1350A and the voltage is 31-367V; for the second wire, the current is 650-1000Aand the voltage is 33-39V; for the third wire, the current is 550-750A and the voltage is 35-41V; and for the fourth wire, the current is 400-600A and the voltage is 36-42V. The welding speed is 1.2-1.8 m/min. The outside welding flux needs to be dried in the range of 250-450 C for greater than or equal to 2h.
(3j) Diameter expansion: the full length of the welded pipe is subjected to diameter expansion to meet the size requirements of the specific welded pipe with a diameter expanding-ratio ranging from 0.7-1.1%.
The normalized UOE welded pipes in Comparative examples 1-2 adopts the same process as that in Embodiments 1-6 except for chemical composition, steel plate rolling process parameters, and the whole pipe normalizing process, as specifically shown in Table 1 and Table 2.
Table 1 lists the mass percentage of each chemical element of the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2. In particular, the content of each element in Embodiments 1-6 is within the range of the composition designed for the present invention, while the contents of some elements in Comparative examples 1-2 are different from those of the invention.
Table 1 (%, the balance being Fe and other unavoidable impurities other than P, S, 0 and N) No. C Si Mn S P Cu Ni Cr Nb Ti Ca Al B
Embodiment 1 0.14 0.21 1.45 0.0023 0.008 0.12 0.14 0.01 0.027 0.008 0.0019 0.032 0.0003 0.003 0.003 Embodiment 2 0.15 0.26 1.39 0.0014 0.012 0.06 0.09 0.09 0.023 0.012 0.0024 0.046 0.0002 0.004 0.002 Embodiment 3 0.16 0.17 1.24 0.0017 0.009 0.01 0.01 0.14 0.022 0.013 0.0045 0.037 0.0003 0.004 0.003 Embodiment 4 0.16 0.20 1.35 0.0019 0.010 0.01 0.01 0.01 0.020 0.015 0.0013 0.033 0.0004 0.003 0.002 Date Recue/Date Received 2022-04-12 Embodiment 5 0.16 0.18 1.41 0.0008 0.006 0.08 0.13 0.12 0.012 0.0160.0031 0.028 0.0003 0.004 0.004 Embodiment 6 0.17 0.28 1.38 0.001 0.0070.11 0.14 0.14 0.016 0.019 0.0034 0.022 0.0003 0.003 0.004 Comparative example 1 0.15 0.23 1.02 0.0016 0.012 0.01 0.01 0.13 0.024 0.012 0.0018 0.036 0.0003 0.003 0.004 Comparative example 2 0.10 0.21 1.14 0.0016 0.009 0.09 0.11 0.09 0.008 0.012 0.0023 0.027 0.0004 0.003 0.003 Table 2 lists the specific process parameters for the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2. In particular, the process parameters in Embodiments 1-6 are within the scope of the invention, while the steel plate finish rolling temperature, the stopping temperature for cooling, and the whole pipe normalizing process in Comparative example 1 are different from those in the invention and the whole pipe normalizing process in Comparative example 2 is different from that in the invention.
Date Recue/Date Received 2022-04-12 o Table 2 Da 5' x UOE pipe Whole Sizing Specificati o K, Total UOE
pipe c Rough Finish Cooling manufacturi pipe diamete on (mm) o Heating fmish Coolin manufacturi Holding 0 . rolling rolling stopping ng- normalizin r (0 outer 5' No. temperat rolling g rate ng-time temperatu temperatur temperatu diameter g expandi diameter x x ure ( C) reductio ( C/s) compressio (min) CD re ( C) e ( C) re ( C) expanding- temperatur ng-ratio wall CD n rate n ratio (%) =
ratio (%) e ( C) (%) thickness) CD
N.) Embodime c) 1120 970-1050 780-830 73% 19 430 0.17 0.8 900 35 1.4 0914x18.4 N.) F>) nt 1 c) 1' r7s) Embodime 1140 975-1055 780-830 72% 23 440 0.18 0.95 910 35 1.5 0914x17.5 nt 2 Embodime 1140 970-1065 790-840 77% 26 480 0.21 1.1 870 25 1.0 0711x15.8 nt 3 P
.
Embodime , u, 1150 965-1060 790-840 78% 34 520 0.2 1.05 870 25 0.9 0711x14.3 , nt 4 N) N) .
Embodime r.,"
1170 965-1060 790-840 77% 30 460 0.18 0.85 880 30 1.3 0813x15.8 , nt 5 .
, , N) Embodime 01016x17.
1170 965-1060 790-840 75% 28 460 0.2 0.85 880 30 1.2 nt 6 Comparati ye example 1140 990-1065 850-920 77% 26 600 0.21 1.1 940 30 1.0 0711x15.8 Comparati ve example 1140 970-1065 790-840 77% 26 480 0.21 1.1 940 30 1.0 0711x15.8 Note: rough rolling and finish rolling include a plurality of passes with a certain duration, so the rough rolling and finish rolling are completed by controlling the temperature to be within the temperature range.
The mechanical properties of the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2 of the invention are tested, and the phase proportions are calculated, wherein a tensile test is performed on a Zwick Z330 tensile testing device by using a round bar specimen according to the ASTM A370 standard, an impact test is performed on a Zwick PSW750 impact testing device by using a full-size Charpy impact specimen (10 x 10 x 55 mm) according to the ASTM A370 standard, and the phase proportions are calculated according to the ASTM E562 standard by calculating the two-phase volume fraction.
Date Recue/Date Received 2022-04-12 .) Table 3 lists the test results of the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2.
FD.
x CD
K-, Table 3 o O
Pipe body impact, - Weld seam impact, -Heat affected zone Ferrite phase w Pipe body transverse stretching (round bar) .6 10 C/J
10 C/J impact, -10 C/J proportion/%
x No.
O Tensile Yield 0 Yield strength/MPa Elongation/% 1 2 3 Average 1 2 3 Average 1 2 3 Average . strength/MPa ratio 0.
N.) Embodiment 1 342 539 0.63 34 r..) r;) Embodiment 2 372 568 0.65 33 i' Embodiment 3 334 505 0.66 29 r..) Embodiment 4 317 479 0.66 28 215 255 Embodiment 5 405 603 0.67 30 214 201 Embodiment 6 439 641 0.68 31 225 219 Comparative example 1 279 443 0.63 31 143 168 , Comparative example 2 261 402 0.65 32 136 145 143 117 93 108 106 122 116 109 106 93 u, , N) N) N) N) N) , , , N) It can be seen from Table 3 that the normalized UOE welded pipe having low yield ratio in the embodiments of the present invention has a yield strength of 290-450MPa, a tensile strength of 415-655MPa, and a yield ratio of < 0.80, and the impact toughness of the pipe body, the weld seam, and the heat affected zones of the normalized UOE welded pipe having low yield ratio satisfies the requirement that the impact energy at -10 C is > 100 J. Both strength and toughness in the comparative examples are lower than those in the embodiments.
Further, it can be seen from Table 2 that the normalized UOE welded pipe having low yield ratio in the embodiments of the present invention has larger diameter and specifically, an outer diameter in the range of 711-1016 mm.
Fig. 1 is a typical metallographic structure of the normalized UOE welded pipe having low yield ratio in Embodiment 2.
As shown in Fig. 1, the microstructure of the normalized UOE welded pipe having low yield ratio in Embodiment 2 is polygonal ferrite + pearlite with uniform size, and the two-phase volume fraction is calculated according to the ASTM E562 standard, wherein the ferrite phase proportion is 80%.
In conclusion, it can be seen that the normalized UOE welded pipe having low yield ratio of the invention is mainly made of C and Mn and a very small amount of Cu, Ni, Cr and Nb alloying elements without any Mo so as to achieve better economic benefits for the normalized UOE welded pipe having low yield ratio.
In addition, the normalized UOE welded pipe having low yield ratio of the invention has a uniform structure, and has a low yield ratio while meeting the demands for strength.
In addition, the normalized UOE welded pipe having low yield ratio of the present invention has higher impact toughness and is very suitable for producing a large-diameter normalized welded pipe having a large Date Recue/Date Received 2022-04-12 diameter of, e.g., an outer diameter of 711-1016 mm In addition to the above advantages and beneficial effects achieved, the manufacturing method of the invention can make the final obtained UOE welded pipe have better properties after the whole pipe normalizing, especially having a low yield ratio while meeting the demands for strength, which is very conducive to the manufacture of large-diameter welded pipes.
It should be noted that the prior art portion within the protection scope of the invention is not limited to the embodiments given in the application, and all prior art not inconsistent with the technical solution of the present invention, including but not limited to prior patents, prior publications, prior public uses, or the like, may be included within the protection scope of the present invention.
In addition, the combination of the technical features in the present disclosure is not limited to the combination described in the claims or the combination described in the specific examples. All technical features described herein can be freely combined in any way, unless contradicts between each other.
It should also be noted that the above-listed examples are only specific examples of the present invention. Obviously, the present invention should not be unduly limited to such specific examples.
Changes or modifications that can be directly or easily derived from the present disclosure by those skilled in the art are intended to be within the protection scope of the present invention.
Date Recue/Date Received 2022-04-12
In the technical solution of the present invention, the present inventors have found through research that a UOE welded pipe made of a TMCP steel plate as raw material in the prior art will encounter the following two difficulties: firstly, after normalizing, the strength of the welded pipe becomes significantly lower than that of the TMCP steel plate and the strength has to be guaranteed by increasing the content of C or alloy elements, but this would affect the weldability of the steel plate;
secondly, when manufacturing welded pipes having large diameter, due to the influence of self-weight, the pipe shape will change during the normalizing process, particularly increasing the ovality, which requires subsequent sizing and this process would introduce large cold deformation and, as a result, demanding a lower yield ratio for the pipes.
Date Recue/Date Received 2022-04-12 In contrast, the manufacturing method according to the present invention makes it possible to directly normalize the whole of the pipe by reasonably controlling the alloying composition when the steel plate is manufactured into a welded pipe, and desired normalized UOE
welded pipe having low yield ratio will be obtained after sizing. Specifically, the normalizing temperature is controlled to 860-920 C in order to both guarantee sufficient austenitization and avoid excessive grain size, and a cross support frame can be placed at the pipe end to mitigate changes of the pipe shape. The holding time can be determined according to the actual wall thickness, which is controlled to be 1.0-3.0 min/mm xwall thickness. Given that the size of the welded pipe after the whole pipe normalizing will change greatly and the straightness and ovality cannot meet dimensional accuracy requirements, sizing is required for full-length diameter expansion. The reason for controlling the diameter expanding-ratio to 0.6-2% is that when the diameter expanding-ratio is less than 0.6%, the springback after expansion will rise and the resulting size will be difficult to meet the requirements;
and when the diameter expanding-ratio is greater than 2%, excessive cold deformation will lead to an increase of the yield strength and yield ratio and a decrease of plasticity allowance.
It should be noted that diameter expanding-ratio = (outer diameter of a welded pipe after diameter expansion - outer diameter of the welded pipe before diameter expansion)/outer diameter of the welded pipe before diameter expansion x 100%.
Preferably, in the manufacturing method according to the present invention, a slab is obtained after steelmaking and continuous casting in step (1), and in step (2), the slab is rolled to a steel plate, the rolling includes rough rolling and finish rolling and controlling a heating temperature of slab to 1110-1180 C, a rough rolling temperature to 960-1080 C, a finish rolling temperature to 770-850 C, and controlling a total finish rolling reduction rate to 70-80%.
In the above solution, since heating temperature is an important factor influencing the original austenite grain size during the slab heating process, the heating temperature is controlled to 1110-1180 C in order to obtain better final properties of the normalized UOE welded pipe having low Date Recue/Date Received 2022-04-12 yield ratio of the present invention.
In addition, given that finish rolling is performed in a non-recrystallized zone, rolling deformation can accumulate strain energy storage and deformation bands in austenite, which is conducive to phase transformation and nucleation. The lower the finish rolling temperature, the less prone to recovery the strain accumulation, but the finish rolling temperature should be at Ar3 point or above.
Therefore, in the technical solution of the present invention, the finish rolling temperature range is 770-850 C and the total finish rolling reduction rate is controlled to be >
70% so as to obtain sufficient strain accumulation. Meanwhile, the total finish rolling reduction rate should not be too large and should be controlled to be in the range of 70-80% in order to give consideration to the rough rolling reduction rate to achieve the effect of recrystallization and refinement of austenite grains.
Preferably, in the manufacturing method according to the present invention, in step (2), controlled cooling is performed after rolling, with a cooling rate of 15-40 C/s, and the cooling is stopped at 400-550 C.
In the above solution, the reason for controlled cooling is that: the cooling after rolling is a phase transformation process of deformed austenite, and an appropriate cooling rate and the stopping temperature for cooling are conducive to ferrite nucleation to obtain a refined structure. Thus, preferably, the cooling rate can be controlled to be in the range of 15-40 C/s and the stopping temperature for cooling can be controlled in the range of 400-550 C.
Compared with the prior art, the normalized UOE welded pipe having low yield ratio of the present invention has the following advantages and beneficial effects:
The normalized UOE welded pipe having low yield ratio of the present invention is mainly made of C and Mn, and a very small amount of Cu, Ni, Cr and Nb alloying elements without any Mo, so that Date Recue/Date Received 2022-04-12 the normalized UOE welded pipe having low yield ratio will have better economic benefits.
In addition, the normalized UOE welded pipe having low yield ratio of the present invention has a uniform structure, and has a low yield ratio while meeting the demands for strength. In addition, the normalized UOE welded pipe having low yield ratio of the present invention has higher impact toughness and is very suitable for producing a large-diameter normalized welded pipe having a large diameter of, e.g., an outer diameter of 711-1016 mm.
In addition to the above advantages and beneficial effects achieved, the manufacturing method of the invention can make the final obtained UOE welded pipe have better properties after the whole pipe normalizing, especially having a low yield ratio while meeting the demands for strength, which is very conducive to the manufacture of large-diameter welded pipes.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a typical metallographic structure of the normalized UOE welded pipe having low yield ratio in Embodiment 2.
DETAILED DESCRIPTION
The normalized low-yield-ratio UOE welded pipe and the manufacturing method thereof of the invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the explanation and description do not constitute an improper limitation on the technical solution of the invention.
Embodiments 1-6 and Comparative examples 1-2 Normalized UOE welded pipes in Embodiments 1-6 are manufactured by using the following steps:
(1) steelmaking and continuous casting: wherein steelmaking may employ converter steelmaking, and LF+RH refining; the content of each chemical element is controlled in accordance with the composition design of the present invention, followed by continuous casting, so as to satisfy slab Date Recue/Date Received 2022-04-12 thickness in continuously casting / finished product thickness > 10.
(2) rolling steel plate: controlling the heating temperature of slab to 1110-1180 C, the rough rolling temperature range to 960-1080 C, the finish rolling temperature range to 770-850 C, and controlling the total finish rolling reduction rate to be 70-80%; then, controlled cooling is performed after rolling with a cooling rate of 15-40 C/s, and the cooling is stopped at 400-550 C.
(3) manufacturing UOE pipe;
(4) normalizing the whole of the UOE pipe: the normalization temperature is controlled to be 860-920 C, and the holding time is controlled to 1.0-3.0 min/mm x wall thickness.
(5) Sizing: the diameter expanding-ratio is controlled to 0.6-2%.
In some embodiments, UOE pipe manufacturing includes the following steps:
(3a) arc guiding plate welding: welding an arc guiding plate at the four corners of the steel plate, which plays the role of arc guiding during welding.
(3b) Edge and bevel dimension milling: obtaining an upper bevel slope of 32-42 and a lower bevel slope of 32-47 for a good welding morphology by a reasonable bevel dimension design to ensure the welding quality.
(3c) C-forming: i.e., edge pre-bending, the edges of the steel plate are bent into a desired shape by means of a bending device to meet the curvature requirements of subsequent 0-forming.
(3d) U-forming: the pre-bent steel plate is pressed into a U shape based on the diameter of the desired welded pipe.
Date Recue/Date Received 2022-04-12 (3e) 0-forming: the steel plate after U-forming is pressed into an 0 shape by a mold having matched diameter with the desired welded pipe. The compression ratio of the 0-forming is controlled to 0.16-0.22%, because if the compression ratio of the 0-forming is lower than 0.16%, the compression deformation of the welded pipe will be too low and causing an opening too large due to springback after forming, while if the compression ratio of the 0-forming is higher than 0.22%, the contact part of the bevel at the plate edge will easily cause deformation damage, which affects the subsequent welding. Specifically, compression ratio of 0-forming = (Tr x (outer diameter after pre-welding -wall thickness) - width after edge milling) / width after edge milling x 100%.
(3f) High pressure water washing and drying: the inner and outer surface of a slotted welded pipe after the 0-forming is subjected to high pressure water washing to remove contamination of iron oxide cladding, grease, dust, etc., and then the welded pipe enters a drying oven at a drying temperature of 100 C-300 C.
(3g) Pre-welding: the slotted welded pipe after the 0-forming is pre-welded by CO2 or Ar+CO2 gas shielded welding to ensure the arc stability during subsequent inside welding and outside welding.
(3h) Inside welding: inside welding is performed on the welded pipe by a 3-wire or 4-wire submerged arc welding process based on the wall thickness, wherein the first wire adopts direct current electrode negative, while the second, third and fourth wires adopt alternating current and all have a welding wire diameter of 4 mm. For the first wire, the current is 1100-1300A and the voltage is 30-35V; for the second wire, the current is 600-950A and the voltage is 31-37V; for the third wire, the current is 500-700A and the voltage is 33-39V; and for the fourth wire, the current is 400-600A
and the voltage is 35-41V. The welding speed is 1.3-1.9 m/min. The inside welding flux needs to be dried in the range of 250-450 C for greater than or equal to 2h.
(3i) Outside welding: outside welding is performed on the welded pipe by a 3-wire or 4-wire submerged arc welding process according to the wall thickness, wherein the first wire adopts direct Date Recue/Date Received 2022-04-12 current electrode negative, while the second, third and fourth wires adopt alternating current and all have a welding wire diameter of 4 mm. For the first wire, the current is 1150-1350A and the voltage is 31-367V; for the second wire, the current is 650-1000Aand the voltage is 33-39V; for the third wire, the current is 550-750A and the voltage is 35-41V; and for the fourth wire, the current is 400-600A and the voltage is 36-42V. The welding speed is 1.2-1.8 m/min. The outside welding flux needs to be dried in the range of 250-450 C for greater than or equal to 2h.
(3j) Diameter expansion: the full length of the welded pipe is subjected to diameter expansion to meet the size requirements of the specific welded pipe with a diameter expanding-ratio ranging from 0.7-1.1%.
The normalized UOE welded pipes in Comparative examples 1-2 adopts the same process as that in Embodiments 1-6 except for chemical composition, steel plate rolling process parameters, and the whole pipe normalizing process, as specifically shown in Table 1 and Table 2.
Table 1 lists the mass percentage of each chemical element of the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2. In particular, the content of each element in Embodiments 1-6 is within the range of the composition designed for the present invention, while the contents of some elements in Comparative examples 1-2 are different from those of the invention.
Table 1 (%, the balance being Fe and other unavoidable impurities other than P, S, 0 and N) No. C Si Mn S P Cu Ni Cr Nb Ti Ca Al B
Embodiment 1 0.14 0.21 1.45 0.0023 0.008 0.12 0.14 0.01 0.027 0.008 0.0019 0.032 0.0003 0.003 0.003 Embodiment 2 0.15 0.26 1.39 0.0014 0.012 0.06 0.09 0.09 0.023 0.012 0.0024 0.046 0.0002 0.004 0.002 Embodiment 3 0.16 0.17 1.24 0.0017 0.009 0.01 0.01 0.14 0.022 0.013 0.0045 0.037 0.0003 0.004 0.003 Embodiment 4 0.16 0.20 1.35 0.0019 0.010 0.01 0.01 0.01 0.020 0.015 0.0013 0.033 0.0004 0.003 0.002 Date Recue/Date Received 2022-04-12 Embodiment 5 0.16 0.18 1.41 0.0008 0.006 0.08 0.13 0.12 0.012 0.0160.0031 0.028 0.0003 0.004 0.004 Embodiment 6 0.17 0.28 1.38 0.001 0.0070.11 0.14 0.14 0.016 0.019 0.0034 0.022 0.0003 0.003 0.004 Comparative example 1 0.15 0.23 1.02 0.0016 0.012 0.01 0.01 0.13 0.024 0.012 0.0018 0.036 0.0003 0.003 0.004 Comparative example 2 0.10 0.21 1.14 0.0016 0.009 0.09 0.11 0.09 0.008 0.012 0.0023 0.027 0.0004 0.003 0.003 Table 2 lists the specific process parameters for the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2. In particular, the process parameters in Embodiments 1-6 are within the scope of the invention, while the steel plate finish rolling temperature, the stopping temperature for cooling, and the whole pipe normalizing process in Comparative example 1 are different from those in the invention and the whole pipe normalizing process in Comparative example 2 is different from that in the invention.
Date Recue/Date Received 2022-04-12 o Table 2 Da 5' x UOE pipe Whole Sizing Specificati o K, Total UOE
pipe c Rough Finish Cooling manufacturi pipe diamete on (mm) o Heating fmish Coolin manufacturi Holding 0 . rolling rolling stopping ng- normalizin r (0 outer 5' No. temperat rolling g rate ng-time temperatu temperatur temperatu diameter g expandi diameter x x ure ( C) reductio ( C/s) compressio (min) CD re ( C) e ( C) re ( C) expanding- temperatur ng-ratio wall CD n rate n ratio (%) =
ratio (%) e ( C) (%) thickness) CD
N.) Embodime c) 1120 970-1050 780-830 73% 19 430 0.17 0.8 900 35 1.4 0914x18.4 N.) F>) nt 1 c) 1' r7s) Embodime 1140 975-1055 780-830 72% 23 440 0.18 0.95 910 35 1.5 0914x17.5 nt 2 Embodime 1140 970-1065 790-840 77% 26 480 0.21 1.1 870 25 1.0 0711x15.8 nt 3 P
.
Embodime , u, 1150 965-1060 790-840 78% 34 520 0.2 1.05 870 25 0.9 0711x14.3 , nt 4 N) N) .
Embodime r.,"
1170 965-1060 790-840 77% 30 460 0.18 0.85 880 30 1.3 0813x15.8 , nt 5 .
, , N) Embodime 01016x17.
1170 965-1060 790-840 75% 28 460 0.2 0.85 880 30 1.2 nt 6 Comparati ye example 1140 990-1065 850-920 77% 26 600 0.21 1.1 940 30 1.0 0711x15.8 Comparati ve example 1140 970-1065 790-840 77% 26 480 0.21 1.1 940 30 1.0 0711x15.8 Note: rough rolling and finish rolling include a plurality of passes with a certain duration, so the rough rolling and finish rolling are completed by controlling the temperature to be within the temperature range.
The mechanical properties of the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2 of the invention are tested, and the phase proportions are calculated, wherein a tensile test is performed on a Zwick Z330 tensile testing device by using a round bar specimen according to the ASTM A370 standard, an impact test is performed on a Zwick PSW750 impact testing device by using a full-size Charpy impact specimen (10 x 10 x 55 mm) according to the ASTM A370 standard, and the phase proportions are calculated according to the ASTM E562 standard by calculating the two-phase volume fraction.
Date Recue/Date Received 2022-04-12 .) Table 3 lists the test results of the normalized UOE welded pipe in Embodiments 1-6 and Comparative examples 1-2.
FD.
x CD
K-, Table 3 o O
Pipe body impact, - Weld seam impact, -Heat affected zone Ferrite phase w Pipe body transverse stretching (round bar) .6 10 C/J
10 C/J impact, -10 C/J proportion/%
x No.
O Tensile Yield 0 Yield strength/MPa Elongation/% 1 2 3 Average 1 2 3 Average 1 2 3 Average . strength/MPa ratio 0.
N.) Embodiment 1 342 539 0.63 34 r..) r;) Embodiment 2 372 568 0.65 33 i' Embodiment 3 334 505 0.66 29 r..) Embodiment 4 317 479 0.66 28 215 255 Embodiment 5 405 603 0.67 30 214 201 Embodiment 6 439 641 0.68 31 225 219 Comparative example 1 279 443 0.63 31 143 168 , Comparative example 2 261 402 0.65 32 136 145 143 117 93 108 106 122 116 109 106 93 u, , N) N) N) N) N) , , , N) It can be seen from Table 3 that the normalized UOE welded pipe having low yield ratio in the embodiments of the present invention has a yield strength of 290-450MPa, a tensile strength of 415-655MPa, and a yield ratio of < 0.80, and the impact toughness of the pipe body, the weld seam, and the heat affected zones of the normalized UOE welded pipe having low yield ratio satisfies the requirement that the impact energy at -10 C is > 100 J. Both strength and toughness in the comparative examples are lower than those in the embodiments.
Further, it can be seen from Table 2 that the normalized UOE welded pipe having low yield ratio in the embodiments of the present invention has larger diameter and specifically, an outer diameter in the range of 711-1016 mm.
Fig. 1 is a typical metallographic structure of the normalized UOE welded pipe having low yield ratio in Embodiment 2.
As shown in Fig. 1, the microstructure of the normalized UOE welded pipe having low yield ratio in Embodiment 2 is polygonal ferrite + pearlite with uniform size, and the two-phase volume fraction is calculated according to the ASTM E562 standard, wherein the ferrite phase proportion is 80%.
In conclusion, it can be seen that the normalized UOE welded pipe having low yield ratio of the invention is mainly made of C and Mn and a very small amount of Cu, Ni, Cr and Nb alloying elements without any Mo so as to achieve better economic benefits for the normalized UOE welded pipe having low yield ratio.
In addition, the normalized UOE welded pipe having low yield ratio of the invention has a uniform structure, and has a low yield ratio while meeting the demands for strength.
In addition, the normalized UOE welded pipe having low yield ratio of the present invention has higher impact toughness and is very suitable for producing a large-diameter normalized welded pipe having a large Date Recue/Date Received 2022-04-12 diameter of, e.g., an outer diameter of 711-1016 mm In addition to the above advantages and beneficial effects achieved, the manufacturing method of the invention can make the final obtained UOE welded pipe have better properties after the whole pipe normalizing, especially having a low yield ratio while meeting the demands for strength, which is very conducive to the manufacture of large-diameter welded pipes.
It should be noted that the prior art portion within the protection scope of the invention is not limited to the embodiments given in the application, and all prior art not inconsistent with the technical solution of the present invention, including but not limited to prior patents, prior publications, prior public uses, or the like, may be included within the protection scope of the present invention.
In addition, the combination of the technical features in the present disclosure is not limited to the combination described in the claims or the combination described in the specific examples. All technical features described herein can be freely combined in any way, unless contradicts between each other.
It should also be noted that the above-listed examples are only specific examples of the present invention. Obviously, the present invention should not be unduly limited to such specific examples.
Changes or modifications that can be directly or easily derived from the present disclosure by those skilled in the art are intended to be within the protection scope of the present invention.
Date Recue/Date Received 2022-04-12
Claims (9)
1. A normalized UOE welded pipe, comprising the following chemical elements in percentage by mass:
C: 0.14-0.18%, Si: 0.15-0.30%, Mn: 1.20-1.50%, Cu<0.15%, Ni<0.15%, Cr<0.15%, Nb:
0.010-0.030%, Ti: 0.005-0.020%, Ca: 0.001-0.005%, Al: 0.020-0.050%, B<0.0005%, the balance being Fe and unavoidable impurities, wherein the normalized UOE welded pipe has a microstructure of polygonal ferrite + pearlite.
C: 0.14-0.18%, Si: 0.15-0.30%, Mn: 1.20-1.50%, Cu<0.15%, Ni<0.15%, Cr<0.15%, Nb:
0.010-0.030%, Ti: 0.005-0.020%, Ca: 0.001-0.005%, Al: 0.020-0.050%, B<0.0005%, the balance being Fe and unavoidable impurities, wherein the normalized UOE welded pipe has a microstructure of polygonal ferrite + pearlite.
2. The normalized UOE welded pipe as claimed in claim 1, wherein in the unavoidable impurities:
P < 0.018%, S < 0.003%, N < 0.006%, and 0 < 0.005%.
P < 0.018%, S < 0.003%, N < 0.006%, and 0 < 0.005%.
3. The normalized UOE welded pipe as claimed in claim 1, wherein phase proportion of the ferrite is 50-90%.
4. The normalized UOE welded pipe as claimed in claim 1, wherein the normalized UOE welded pipe has an outer diameter of 711-1016 mm.
5. The normalized UOE welded pipe as claimed in claim 1, wherein the nomialized UOE welded pipe has a yield strength of 290-450 MPa, a tensile strength of 415-655 MPa and a yield ratio of < 0.80.
6. The normalized UOE welded pipe as claimed in claim 1 or 5, wherein pipe body, weld seam, and heat affected zones of the normalized UOE welded pipe have an impact toughness that satisfies: impact energy at -100C > 100 J.
7. A manufacturing method of the normalized UOE welded pipe as claimed in any one of claims Date Recue/Date Received 2023-06-06 1-6, comprising the steps of:
(1) steelmaking and continuous casting to obtain a slab;
(2) rolling the slab to form a steel plate;
(3) manufacturing UOE pipe;
(4) normalizing the UOE pipe, wherein the normalizing comprises controlling a normalization temperature to 860-920 C, and a holding time to 1.0-3.0 min/mm x wall thickness;
and (5) sizing, wherein the sizing comprises controlling a diameter expanding-ratio to 0.6-2%.
(1) steelmaking and continuous casting to obtain a slab;
(2) rolling the slab to form a steel plate;
(3) manufacturing UOE pipe;
(4) normalizing the UOE pipe, wherein the normalizing comprises controlling a normalization temperature to 860-920 C, and a holding time to 1.0-3.0 min/mm x wall thickness;
and (5) sizing, wherein the sizing comprises controlling a diameter expanding-ratio to 0.6-2%.
8. The manufacturing method as claimed in claim 7, wherein, in step (2), the rolling comprises controlling a heating temperature of slab to 1110-1180 C, a rough rolling temperature to 960-1080 C, a finish rolling temperature to 770-850 C and controlling total finish rolling reduction rate to 70-80%.
9. The manufacturing method as claimed in claim 7 or 8, wherein, in step (2), controlled cooling is performed after rolling, with a cooling rate of 15-40 C/s, and the cooling is stopped at 400-550 C.
Date Recue/Date Received 2023-06-06
Date Recue/Date Received 2023-06-06
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910998448.X | 2019-10-21 | ||
| CN201910998448.XA CN112760464A (en) | 2019-10-21 | 2019-10-21 | Normalizing type low-yield-ratio UOE welded pipe and manufacturing method thereof |
| PCT/CN2020/122336 WO2021078131A1 (en) | 2019-10-21 | 2020-10-21 | Normalized uoe welded pipe and manufacturing method therefor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA3157822A1 CA3157822A1 (en) | 2021-04-29 |
| CA3157822C true CA3157822C (en) | 2024-01-16 |
Family
ID=75619618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3157822A Active CA3157822C (en) | 2019-10-21 | 2020-10-21 | Normalized uoe welded pipe and manufacturing method thereof |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP7392134B2 (en) |
| CN (1) | CN112760464A (en) |
| CA (1) | CA3157822C (en) |
| DE (1) | DE112020005083T5 (en) |
| WO (1) | WO2021078131A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114406616A (en) * | 2022-01-24 | 2022-04-29 | 武汉市博钛新材料科技有限公司 | Seamless titanium vacuum cup welded pipe and production method thereof |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4071906B2 (en) * | 1999-11-24 | 2008-04-02 | 新日本製鐵株式会社 | Manufacturing method of steel pipe for high tension line pipe with excellent low temperature toughness |
| JP2009235460A (en) * | 2008-03-26 | 2009-10-15 | Sumitomo Metal Ind Ltd | High-strength uoe steel pipe excellent in earthquake-proof performance and low-temperature toughness of weld heat-affected zone |
| RU2011141268A (en) * | 2009-03-12 | 2013-04-20 | Сумитомо Метал Индастриз, Лтд. | THICK-STEEL STEEL RESISTANT TO HYDROGEN CRACKING AND THE STEEL PIPE MADE BY UOE TECHNOLOGY |
| CN101798654B (en) | 2010-04-09 | 2011-06-22 | 中国石油天然气集团公司 | Steel used for straight seam electric resistance welding petroleum casing and casing manufacturing method |
| JP5381900B2 (en) | 2010-05-27 | 2014-01-08 | 新日鐵住金株式会社 | ERW steel pipe for brace having excellent buckling resistance and manufacturing method thereof |
| JP5842358B2 (en) | 2010-10-12 | 2016-01-13 | Ｊｆｅスチール株式会社 | Non-tempered low yield ratio high tensile steel plate and method |
| CN102719737B (en) | 2012-07-23 | 2013-09-18 | 新余钢铁集团有限公司 | High-toughness normalizing steel plate with 460MPa yield strength and manufacturing method thereof |
| JP5910400B2 (en) | 2012-08-03 | 2016-04-27 | Ｊｆｅスチール株式会社 | Non-tempered low-yield ratio high-tensile steel plate and method for producing the same |
| CN102912228B (en) * | 2012-10-23 | 2015-12-02 | 鞍钢股份有限公司 | A kind of economical high-strength low-yield ratio pipe fitting steel and production method thereof |
| CN103194678B (en) * | 2013-03-26 | 2016-01-27 | 宝山钢铁股份有限公司 | A kind of UOE welded tube and manufacture method thereof |
| CN104862612A (en) | 2015-05-26 | 2015-08-26 | 宝山钢铁股份有限公司 | 460-MPa-grade low-temperature-resistant normalized steel, steel pipe and manufacturing method for steel pipe |
| JP2017020054A (en) * | 2015-07-07 | 2017-01-26 | コベルコ鋼管株式会社 | Stainless steel and stainless steel tube |
| CN105821335B (en) | 2016-06-15 | 2018-02-02 | 山东钢铁股份有限公司 | The inexpensive ultralow temperature normalizing type pipe line steel and its production method of a kind of excellent weldability |
| CN108070790A (en) * | 2016-11-13 | 2018-05-25 | 广东韶钢松山股份有限公司 | A kind of yield strength 390MPa grades of normalized steel plates and its manufacturing method |
| CN106567001B (en) | 2016-11-15 | 2019-02-19 | 马鞍山钢铁股份有限公司 | Cold-drawn ERW welds tube steel and its hot-rolled sheet coil and preparation method to one kind again |
-
2019
- 2019-10-21 CN CN201910998448.XA patent/CN112760464A/en active Pending
-
2020
- 2020-10-21 DE DE112020005083.1T patent/DE112020005083T5/en active Pending
- 2020-10-21 CA CA3157822A patent/CA3157822C/en active Active
- 2020-10-21 JP JP2022523238A patent/JP7392134B2/en active Active
- 2020-10-21 WO PCT/CN2020/122336 patent/WO2021078131A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| JP7392134B2 (en) | 2023-12-05 |
| CN112760464A (en) | 2021-05-07 |
| CA3157822A1 (en) | 2021-04-29 |
| WO2021078131A1 (en) | 2021-04-29 |
| DE112020005083T5 (en) | 2022-07-21 |
| JP2022552857A (en) | 2022-12-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5131411B2 (en) | ERW steel pipe for oil well and method for manufacturing ERW steel pipe for oil well | |
| CN111321345B (en) | Tempering type high-quality continuous pipe and manufacturing method thereof | |
| CN101270438B (en) | Normalized steel for resistance welding petroleum case pipe with low yield ratio, resistance welding casing tube and its manufacturing method | |
| CN101864542B (en) | Steel for high-frequency resistance straight weld oil well pipe and production method thereof | |
| CN102021497A (en) | Hot-rolled sheet coils of X80 pipe line steel and manufacturing method thereof | |
| CN102560284B (en) | High-strength high-toughness X100 pipeline steel hot-rolled steel strip and manufacturing method thereof | |
| CN104089109B (en) | A kind of 625MPa grades of UOE welded tube and its manufacture method | |
| WO2017193537A1 (en) | Economical hic-resistant x90 pipeline steel plate and manufacturing method therefor | |
| JP4824143B2 (en) | High strength steel pipe, steel plate for high strength steel pipe, and manufacturing method thereof | |
| CN101818308B (en) | Steel for longitudinal resistance welded pipe with low yield ratio and manufacturing method thereof | |
| JP5742123B2 (en) | High-tensile hot-rolled steel sheet for high-strength welded steel pipe for line pipe and method for producing the same | |
| CN104357756A (en) | Longitudinally-welded petroleum casing pipe capable of resisting stress corrosion of hydrogen sulfide and manufacturing method thereof | |
| CN102400062B (en) | X130 pipe line steel with low yield ratio and ultrahigh strength and manufacturing method of hot rolled flat plate of X130 pipe line steel | |
| CN104894492A (en) | Ultralow-temperature, large-diameter and WPHY80-level steel plate special for three-way pipe fitting and production method of steel plate | |
| CN103194678B (en) | A kind of UOE welded tube and manufacture method thereof | |
| CN105603313B (en) | A kind of low yield strength ratio oil casing pipe steel and manufacture method and the production method of sleeve pipe | |
| CA3157822C (en) | Normalized uoe welded pipe and manufacturing method thereof | |
| CN104561825A (en) | Low-cost X80 pipeline steel and manufacturing method thereof | |
| CN113637925B (en) | Steel for quenched and tempered continuous oil pipe, hot-rolled steel strip, steel pipe and manufacturing method thereof | |
| JP5991174B2 (en) | High-strength steel sheet for sour-resistant pipes with excellent material uniformity in the steel sheet and its manufacturing method | |
| CN105695882A (en) | J55-grade low-yield-ratio steel for electric resistance welding casing pipe and manufacturing method of J55-grade low-yield-ratio steel | |
| JP5000447B2 (en) | High strength ERW line pipe | |
| CN110629109B (en) | Ultra-large-diameter thick-wall UOE longitudinal submerged arc welded pipe and manufacturing method thereof | |
| CN107604246A (en) | Low cost S EW petroleum casing pipes hot continuous rolling coil of strip and its production method | |
| CN115433870B (en) | Low-cost quenched and tempered steel for continuous oil pipe, hot rolled steel strip, steel pipe and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request |
Effective date: 20220412 |
|
| EEER | Examination request |
Effective date: 20220412 |
|
| EEER | Examination request |
Effective date: 20220412 |
|
| EEER | Examination request |
Effective date: 20220412 |
|
| EEER | Examination request |
Effective date: 20220412 |
|
| EEER | Examination request |
Effective date: 20220412 |
|
| EEER | Examination request |
Effective date: 20220412 |
|
| EEER | Examination request |
Effective date: 20220412 |