CN104294174B - A kind of Large Heat Input Welding high-strength hot-rolled steel bar and production technology thereof - Google Patents
A kind of Large Heat Input Welding high-strength hot-rolled steel bar and production technology thereof Download PDFInfo
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- CN104294174B CN104294174B CN201410621729.0A CN201410621729A CN104294174B CN 104294174 B CN104294174 B CN 104294174B CN 201410621729 A CN201410621729 A CN 201410621729A CN 104294174 B CN104294174 B CN 104294174B
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—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
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- 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
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/08—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires for concrete reinforcement
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- 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
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- 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
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- 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
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- 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
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Abstract
The present invention is a kind of Large Heat Input Welding high-strength hot-rolled steel bar, composition: C:0.27-0.29%, Si:0.15-0.17%, Mn:1.11-1.13%, P:0.007-0.009%, S:0.001-0.003%, Als:0.057-0.059%, Nb:0.005-0.007%, V:0.06-0.08%, Ti:0.035-0.037%, Ni:0.05-0.07%, Cu:0.07-0.09%, Cr:0.6-0.8%, Mo:0.53-0.55%, B:0.007-0.009%, lanthanum: 0.07-0.09%, cerium: 0.03-0.05%, praseodymium: 0.01-0.03%, all the other are Fe; The present invention can effectively improve reinforced steel bar strength and welding heat influence area toughness.
Description
Technical field
The invention belongs to welding high strength cast iron technical field, particularly a kind of Large Heat Input Welding high-strength hot-rolled steel bar and production technology thereof.
Background technology
Weld heat input >=the 50kJ/cm of steel in welding procedure can be referred to as Large Heat Input Welding in the past, and data shows at present, and the actual welding heat input of electro-gas (enclosed) welding Large Heat Input Welding has exceeded 500kJ/cm even. Under so large weld heat input, heat affected area (HAZ) tissue of traditional low-alloy high-strength steel (HSLA) will sharply be grown up, and the intensity of welding position and toughness will have larger decline, and easily produce welding cold cracking problem. In addition, for traditional thermo-mechanical rolling (TMCP) technology, along with the raising of reinforced steel bar strength and the increase of thickness, must improve carbon equivalent guarantee traditional performance, but carbon equivalent improves the welding performance that can worsen again steel plate. Existing high tensile reinforcement does not have the performance of anti-Large Heat Input Welding, can not adopt the Large Heat Input Welding method that exceedes 50kJ/cm to carry out welding when welding, and efficiency of construction is low, can not meet the requirement of Large Heat Input Welding, and welding efficiency is low.
Summary of the invention
Technical problem to be solved by this invention is, the shortcoming existing for above prior art, a kind of Large Heat Input Welding high-strength hot-rolled steel bar and production technology thereof are proposed, reinforcing bar has the field trash that a large amount of small and disperseds distribute, complex inclusion quantity containing Ti oxide, nitride all exceeds several times than traditional reinforcing bar, can effectively improve reinforced steel bar strength and welding heat influence area toughness.
The technical scheme that the present invention solves above technical problem is:
A kind of Large Heat Input Welding high-strength hot-rolled steel bar, chemical composition containing just like following percentage by weight: C:0.27-0.29%, Si:0.15-0.17%, Mn:1.11-1.13%, P:0.007-0.009%, S:0.001-0.003%, Als:0.057-0.059%, Nb:0.005-0.007%, V:0.06-0.08%, Ti:0.035-0.037%, Ni:0.05-0.07%, Cu:0.07-0.09%, Cr:0.6-0.8%, Mo:0.53-0.55%, B:0.007-0.009%, lanthanum: 0.07-0.09%, cerium: 0.03-0.05%, praseodymium: 0.01-0.03%, all the other are Fe and inevitable impurity, carbon equivalent 0.4-0.8%, the complex inclusion quantity containing Ti oxide that is of a size of 0.2-3.5 μ m in reinforcing bar is 1200-1400/mm2; The MnS complex inclusion quantity that size is greater than 50 μ m is 6-7/cm2, the complex inclusion quantity that size is greater than 5 μ m is less than 2/mm2; Through >=large hot the input after welding of 50-200kJ/cm, welding coarse grain zone-40 DEG C ballistic work mean value is greater than 50J; Reinforcing bar tissue signature is: austenite grain boundary place is pro-eutectoid ferrite, average grain size 65-67 μ m, and area occupied mark is less than 40%; Austenite crystal inside is fine acicular ferrite, and area occupied mark is greater than 60%.
The production technology of Large Heat Input Welding high-strength hot-rolled steel bar, carry out according to the following steps:
(i) the reinforcing bar of having smelted is sent into heating furnace and be heated to 1310-1330 DEG C, through the first refrigerating work procedure, reinforcing bar fast speed is cooled to 670-690 DEG C online, then in quenching unit water or quenching liquid carry out for time 25-27 quench second, then be heated to 890-910 DEG C of tempering through tempering heating furnace, then be cooled to normal temperature by the second process for cooling; The first refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 7-9 DEG C/s by reinforcing bar water-cooled to 1120-1150 DEG C, then air cooling is to 750-770 DEG C, then adopt water-cooled with the cooldown rate of 1-3 DEG C/s by reinforcing bar water-cooled to 670-690 DEG C; The second refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 11-13 DEG C/s, reinforcing bar is chilled to room temperature;
(ii) reinforcing bar is hot-rolled down to required size, hot-rolled temperature is 1130-1150 DEG C, then through the 3rd refrigerating work procedure, reinforcing bar fast speed is cooled to 670-690 DEG C online, then is cooled to normal temperature by the 4th process for cooling; The 3rd refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 7-9 DEG C/s, reinforcing bar is chilled to 670-690 DEG C; The 4th refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 1-3 DEG C/s by reinforcing bar water-cooled to 520-550 DEG C, then air cooling is to 450-470 DEG C, then adopt water-cooled with the cooldown rate of 5-7 DEG C/s by reinforcing bar water-cooled to room temperature;
(iii) the reinforcing bar after hot rolling is carried out to eddy-current heating, heating-up temperature is 870-890 DEG C, the reinforcing bar again eddy-current heating being completed directly carries out Quenching Treatment with high pressure spray jetting or quenching liquid without insulation, quench cooling rate 15-17 DEG C/s, makes reinforcing bar temperature be cooled to the following 10-30 DEG C of Ms point;
(iv) the reinforcing bar after quenching is heated to 720-740 DEG C through tempering heating furnace, is incubated 35-37 second;
(v) the reinforcing bar after tempering is cooled to 370-390 DEG C through the 5th refrigerating work procedure by reinforcing bar fast speed online, is then heated to 790-810 DEG C through heating furnace, then is cooled to normal temperature by the 6th process for cooling; The 5th refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 3-5 DEG C/s, reinforcing bar is chilled to 370-390 DEG C; The 6th refrigerating work procedure: adopt water-cooled with the cooldown rate of 11-13 DEG C/s by reinforcing bar water-cooled to room temperature;
By the control of above process conditions, the complex inclusion containing Ti oxide and nitride that a large amount of small and disperseds that generate distribute, make reinforcing bar in the time of large heat input welding, form a large amount of intragranular acicular ferrites at 1400-1500 DEG C of high temperature position, form austenite crystal refinement intergranular structure at the middle low temperature position of 970-1100 DEG C simultaneously, the toughness of welding heat affected zone is increased substantially.
Advantage of the present invention is: by the setting of the process conditions in restriction and the cooperated technique for producing of reinforcing bar chemical composition of the present invention, " lanthanum ", " cerium " and " praseodymium " particularly in composition, are increased, and in technique, twice after " heating ", " hot rolling " and " tempering " is cooling, can in reinforcing bar, can form the field trash that a large amount of small and disperseds distribute, the complex inclusion quantity containing Ti oxide that is of a size of 0.2-3.5 μ m all exceeds several times than traditional reinforcing bar, be conducive to pinning austenite crystal refinement intergranular structure, improve CGHAZ toughness; Can make large scale complex inclusion quantity in reinforcing bar lower than the quantity in traditional reinforcing bar, be of value to and reduce postwelding micro-crack source, there is high normal temperature comprehensive mechanical property and good low-temperature flexibility; By production control process conditions, the complex inclusion containing Ti oxide, nitride that a large amount of small and disperseds that generate distribute, reinforcing bar is in the time of large heat input welding, the 1400-1500 DEG C of high temperature position near melt run forms a large amount of intragranular acicular ferrites, form austenite crystal refinement intergranular structure at the middle low temperature position of 970-1100 DEG C simultaneously, the toughness of welding heat affected zone is increased substantially; Can make to contain in reinforcing bar of the present invention the equally distributed tiny complex inclusion containing Ti oxide, nitride etc. of a large amount of disperses, these field trashes have increased the nucleation site of ferrite and pearlitic transformation after reinforcing bar tempering in cooling procedure, make the even tissue of reinforcing bar from surface to center, solved the inhomogeneous difficult problem of traditional rebar surface core structure.
Detailed description of the invention
Embodiment 1
The present embodiment is a kind of Large Heat Input Welding high-strength hot-rolled steel bar, the chemical composition containing just like following percentage by weight: C:0.27%, Si:0.16%, Mn:1.11%, P:0.009%, S:0.001%, Als:0.057%, Nb:0.006%, V:0.06%, Ti:0.035%, Ni:0.05%, Cu:0.07%, Cr:0.6%, Mo:0.53%, B:0.007%, lanthanum: 0.07%, cerium: 0.03%, praseodymium: 0.01%, all the other are Fe and inevitable impurity, carbon equivalent 0.4-0.8%.
The production technology of the Large Heat Input Welding high-strength hot-rolled steel bar of the present embodiment, carry out according to the following steps:
(i) the reinforcing bar of having smelted is sent into heating furnace and be heated to 1310 DEG C, through the first refrigerating work procedure, reinforcing bar fast speed is cooled to 670 DEG C online, then in quenching unit water or quenching liquid carry out for time 25 seconds quench, then be heated to 890 DEG C of tempering through tempering heating furnace, then be cooled to normal temperature by the second process for cooling; The first refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 7 DEG C/s by reinforcing bar water-cooled to 1120 DEG C, then air cooling to 750 DEG C, then adopt water-cooled with the cooldown rate of 1 DEG C/s by reinforcing bar water-cooled to 670 DEG C; The second refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 11 DEG C/s, reinforcing bar is chilled to room temperature;
(ii) reinforcing bar is hot-rolled down to required size, hot-rolled temperature is 1130 DEG C, then through the 3rd refrigerating work procedure, reinforcing bar fast speed is cooled to 670 DEG C online, then is cooled to normal temperature by the 4th process for cooling; The 3rd refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 7 DEG C/s, reinforcing bar is chilled to 670 DEG C; The 4th refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 1 DEG C/s by reinforcing bar water-cooled to 520 DEG C, then air cooling to 450 DEG C, then adopt water-cooled with the cooldown rate of 5 DEG C/s by reinforcing bar water-cooled to room temperature;
(iii) the reinforcing bar after hot rolling is carried out to eddy-current heating, heating-up temperature is 870 DEG C, the reinforcing bar again eddy-current heating being completed directly carries out Quenching Treatment with high pressure spray jetting or quenching liquid without insulation, and 15 DEG C/s of quench cooling rate makes reinforcing bar temperature be cooled to following 10 DEG C of Ms point;
(iv) the reinforcing bar after quenching is heated to 720 DEG C through tempering heating furnace, is incubated 35 seconds;
(v) the reinforcing bar after tempering is cooled to 370 DEG C through the 5th refrigerating work procedure by reinforcing bar fast speed online, is then heated to 790 DEG C through heating furnace, then is cooled to normal temperature by the 6th process for cooling; The 5th refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 3 DEG C/s, reinforcing bar is chilled to 370 DEG C; The 6th refrigerating work procedure: adopt water-cooled with the cooldown rate of 11 DEG C/s by reinforcing bar water-cooled to room temperature.
The complex inclusion quantity containing Ti oxide that is of a size of 0.2-3.5 μ m in the present embodiment reinforcing bar is 1200-1210/mm2; The MnS complex inclusion quantity that size is greater than 50 μ m is 6/cm2, size is greater than the 1.5/mm of complex inclusion quantity of 5 μ m2; Through >=large hot the input after welding of 50-200kJ/cm, welding coarse grain zone-40 DEG C ballistic work mean value is greater than 50J; Reinforcing bar tissue signature is: austenite grain boundary place is pro-eutectoid ferrite, average grain size 65 μ m, and area occupied mark is less than 40%; Austenite crystal inside is fine acicular ferrite, and area occupied mark is greater than 60%. By the control of above process conditions, the complex inclusion containing Ti oxide and nitride that a large amount of small and disperseds that generate distribute, make reinforcing bar in the time of large heat input welding, form a large amount of intragranular acicular ferrites at 1400-1500 DEG C of high temperature position, form austenite crystal refinement intergranular structure at the middle low temperature position of 970-1100 DEG C simultaneously, the toughness of welding heat affected zone is increased substantially.
Embodiment 2
The present embodiment is a kind of Large Heat Input Welding high-strength hot-rolled steel bar, the chemical composition containing just like following percentage by weight: C:0.29%, Si:0.17%, Mn:1.12%, P:0.008%, S:0.002%, Als:0.059%, Nb:0.005%, V:0.08%, Ti:0.037%, Ni:0.06%, Cu:0.09%, Cr:0.7%, Mo:0.54%, B:0.008%, lanthanum: 0.08%, cerium: 0.04%, praseodymium: 0.02%, all the other are Fe and inevitable impurity, carbon equivalent 0.4-0.8%.
The production technology of the Large Heat Input Welding high-strength hot-rolled steel bar of the present embodiment, carry out according to the following steps:
(i) the reinforcing bar of having smelted is sent into heating furnace and be heated to 1320 DEG C, through the first refrigerating work procedure, reinforcing bar fast speed is cooled to 680 DEG C online, then in quenching unit water or quenching liquid carry out for time 26 seconds quench, then be heated to 900 DEG C of tempering through tempering heating furnace, then be cooled to normal temperature by the second process for cooling; The first refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 8 DEG C/s by reinforcing bar water-cooled to 1130 DEG C, then air cooling to 760 DEG C, then adopt water-cooled with the cooldown rate of 2 DEG C/s by reinforcing bar water-cooled to 680 DEG C; The second refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 12 DEG C/s, reinforcing bar is chilled to room temperature;
(ii) reinforcing bar is hot-rolled down to required size, hot-rolled temperature is 1140 DEG C, then through the 3rd refrigerating work procedure, reinforcing bar fast speed is cooled to 680 DEG C online, then is cooled to normal temperature by the 4th process for cooling; The 3rd refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 8 DEG C/s, reinforcing bar is chilled to 680 DEG C; The 4th refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 2 DEG C/s by reinforcing bar water-cooled to 530 DEG C, then air cooling to 460 DEG C, then adopt water-cooled with the cooldown rate of 6 DEG C/s by reinforcing bar water-cooled to room temperature;
(iii) the reinforcing bar after hot rolling is carried out to eddy-current heating, heating-up temperature is 880 DEG C, the reinforcing bar again eddy-current heating being completed directly carries out Quenching Treatment with high pressure spray jetting or quenching liquid without insulation, and 16 DEG C/s of quench cooling rate makes reinforcing bar temperature be cooled to following 20 DEG C of Ms point;
(iv) the reinforcing bar after quenching is heated to 730 DEG C through tempering heating furnace, is incubated 36 seconds;
(v) the reinforcing bar after tempering is cooled to 380 DEG C through the 5th refrigerating work procedure by reinforcing bar fast speed online, is then heated to 800 DEG C through heating furnace, then is cooled to normal temperature by the 6th process for cooling; The 5th refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 45 DEG C/s, reinforcing bar is chilled to 380 DEG C; The 6th refrigerating work procedure: adopt water-cooled with the cooldown rate of 12 DEG C/s by reinforcing bar water-cooled to room temperature.
The complex inclusion quantity containing Ti oxide that is of a size of 0.2-3.5 μ m in the present embodiment reinforcing bar is 1350-1400/mm2; The MnS complex inclusion quantity that size is greater than 50 μ m is 7/cm2, size is greater than the 1/mm of complex inclusion quantity of 5 μ m2; Through >=large hot the input after welding of 50-200kJ/cm, welding coarse grain zone-40 DEG C ballistic work mean value is greater than 50J; Reinforcing bar tissue signature is: austenite grain boundary place is pro-eutectoid ferrite, average grain size 66 μ m, and area occupied mark is less than 40%; Austenite crystal inside is fine acicular ferrite, and area occupied mark is greater than 60%. By the control of above process conditions, the complex inclusion containing Ti oxide and nitride that a large amount of small and disperseds that generate distribute, make reinforcing bar in the time of large heat input welding, form a large amount of intragranular acicular ferrites at 1400-1500 DEG C of high temperature position, form austenite crystal refinement intergranular structure at the middle low temperature position of 970-1100 DEG C simultaneously, the toughness of welding heat affected zone is increased substantially.
Embodiment 3
The present embodiment is a kind of Large Heat Input Welding high-strength hot-rolled steel bar, the chemical composition containing just like following percentage by weight: C:0.28%, Si:0.15%, Mn:1.13%, P:0.007%, S:0.003%, Als:0.058%, Nb:0.007%, V:0.07%, Ti:0.036%, Ni:0.07%, Cu:0.08%, Cr:0.8%, Mo:0.55%, B:0.009%, lanthanum: 0.09%, cerium: 0.05%, praseodymium: 0.03%, all the other are Fe and inevitable impurity, carbon equivalent 0.4-0.8%.
The production technology of the Large Heat Input Welding high-strength hot-rolled steel bar of the present embodiment, carry out according to the following steps:
(i) the reinforcing bar of having smelted is sent into heating furnace and be heated to 1330 DEG C, through the first refrigerating work procedure, reinforcing bar fast speed is cooled to 690 DEG C online, then in quenching unit water or quenching liquid carry out for time 27 seconds quench, then be heated to 910 DEG C of tempering through tempering heating furnace, then be cooled to normal temperature by the second process for cooling; The first refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 9 DEG C/s by reinforcing bar water-cooled to 1150 DEG C, then air cooling to 770 DEG C, then adopt water-cooled with the cooldown rate of 3 DEG C/s by reinforcing bar water-cooled to 690 DEG C; The second refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 13 DEG C/s, reinforcing bar is chilled to room temperature;
(ii) reinforcing bar is hot-rolled down to required size, hot-rolled temperature is 1150 DEG C, then through the 3rd refrigerating work procedure, reinforcing bar fast speed is cooled to 690 DEG C online, then is cooled to normal temperature by the 4th process for cooling; The 3rd refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 9 DEG C/s, reinforcing bar is chilled to 690 DEG C; The 4th refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 3 DEG C/s by reinforcing bar water-cooled to 550 DEG C, then air cooling to 470 DEG C, then adopt water-cooled with the cooldown rate of 7 DEG C/s by reinforcing bar water-cooled to room temperature;
(iii) the reinforcing bar after hot rolling is carried out to eddy-current heating, heating-up temperature is 890 DEG C, the reinforcing bar again eddy-current heating being completed directly carries out Quenching Treatment with high pressure spray jetting or quenching liquid without insulation, and 17 DEG C/s of quench cooling rate makes reinforcing bar temperature be cooled to following 30 DEG C of Ms point;
(iv) the reinforcing bar after quenching is heated to 740 DEG C through tempering heating furnace, is incubated 37 seconds;
(v) the reinforcing bar after tempering is cooled to 390 DEG C through the 5th refrigerating work procedure by reinforcing bar fast speed online, is then heated to 810 DEG C through heating furnace, then is cooled to normal temperature by the 6th process for cooling; The 5th refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 5 DEG C/s, reinforcing bar is chilled to 390 DEG C; The 6th refrigerating work procedure: adopt water-cooled with the cooldown rate of 13 DEG C/s by reinforcing bar water-cooled to room temperature.
The complex inclusion quantity containing Ti oxide that is of a size of 0.2-3.5 μ m in the present embodiment reinforcing bar is 1300-1350/mm2; The MnS complex inclusion quantity that size is greater than 50 μ m is 6.5/cm2, the complex inclusion quantity that size is greater than 5 μ m is less than 2/mm2; Through >=large hot the input after welding of 50-200kJ/cm, welding coarse grain zone-40 DEG C ballistic work mean value is greater than 50J; Reinforcing bar tissue signature is: austenite grain boundary place is pro-eutectoid ferrite, average grain size 67 μ m, and area occupied mark is less than 40%; Austenite crystal inside is fine acicular ferrite, and area occupied mark is greater than 60%. By the control of above process conditions, the complex inclusion containing Ti oxide and nitride that a large amount of small and disperseds that generate distribute, make reinforcing bar in the time of large heat input welding, form a large amount of intragranular acicular ferrites at 1400-1500 DEG C of high temperature position, form austenite crystal refinement intergranular structure at the middle low temperature position of 970-1100 DEG C simultaneously, the toughness of welding heat affected zone is increased substantially.
In addition to the implementation, the present invention can also have other embodiments. All employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection domain of requirement of the present invention.
Claims (6)
1. a Large Heat Input Welding high-strength hot-rolled steel bar, is characterized in that: the chemical composition containing just like following percentage by weight: C:0.27-0.29％，Si：0.15-0.17％，Mn：1.11-1.13％，P：0.007-0.009％，S：0.001-0.003％，Als：0.057-0.059％、Nb：0.005-0.007％，V：0.06-0.08％，Ti：0.035-0.037％，Ni：0.05-0.07％，Cu:0.07-0.09%, Cr:0.6-0.8%, Mo:0.53-0.55%, B:0.007-0.009%, lanthanum: 0.07-0.09%, cerium:0.03-0.05%, praseodymium: 0.01-0.03%, all the other are Fe and inevitable impurity; Carbon equivalent 0.4-0.8%;
The complex inclusion quantity containing Ti oxide that is of a size of 0.2-3.5 μ m in described reinforcing bar is 1200-1400/mm2; ChiThe very little MnS complex inclusion quantity that is greater than 50 μ m is 6-7/cm2, the complex inclusion quantity that size is greater than 5 μ m is less than 2Individual/mm2; Through >=large hot the input after welding of 50-200kJ/cm, welding coarse grain zone-40 DEG C ballistic work mean value is greater than 50J; Reinforcing barTissue signature is: austenite grain boundary place is pro-eutectoid ferrite, average grain size 65-67 μ m, and area occupied mark is less than 40%;Austenite crystal inside is fine acicular ferrite, and area occupied mark is greater than 60%;
The production technology of described Large Heat Input Welding high-strength hot-rolled steel bar, carry out according to the following steps:
(i) the reinforcing bar of having smelted is sent into heating furnace and is heated to 1310-1330 DEG C, online through the first refrigerating work procedure by cold reinforcing bar fast speedBut arrive 670-690 DEG C, then in quenching unit water or quenching liquid carry out for time 25-27 quench second, then pass through temperingHeating furnace is heated to 890-910 DEG C of tempering, then is cooled to normal temperature by the second process for cooling;
Described the first refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 7-9 DEG C/s by reinforcing bar water-cooledTo 1120-1150 DEG C, then air cooling is to 750-770 DEG C, then adopts water-cooled with the cooldown rate of 1-3 DEG C/s by reinforcing bar water-cooled extremely670-690℃；
Described the second refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 11-13 DEG C/s, reinforcing bar is chilled to chamberTemperature;
(ii) reinforcing bar is hot-rolled down to required size, hot-rolled temperature is 1130-1150 DEG C, then through the 3rd refrigerating work procedure, reinforcing bar is fast onlineSpeed is cooled to 670-690 DEG C, then is cooled to normal temperature by the 4th process for cooling;
Described the 3rd refrigerating work procedure: adopt compressed air or vaporific quenching liquid with the cooldown rate of 7-9 DEG C/s, reinforcing bar to be chilled to670-690℃；
Described the 4th refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 1-3 DEG C/s by reinforcing bar water-cooledTo 520-550 DEG C, then air cooling is to 450-470 DEG C, then adopt water-cooled with the cooldown rate of 5-7 DEG C/s by reinforcing bar water-cooled to room temperature;
(iii) the reinforcing bar after hot rolling is carried out to eddy-current heating, heating-up temperature is 870-890 DEG C, then the reinforcing bar that eddy-current heating is completed withoutInsulation is directly carried out Quenching Treatment with high pressure spray jetting or quenching liquid, quench cooling rate 15-17 DEG C/s, makes reinforcing bar temperature coolingTo the following 10-30 DEG C of Ms point;
(iv) the reinforcing bar after quenching is heated to 720-740 DEG C through tempering heating furnace, is incubated 35-37 second;
(v) the reinforcing bar after tempering is cooled to 370-390 DEG C through the 5th refrigerating work procedure by reinforcing bar fast speed online, then passes through heating furnaceBe heated to 790-810 DEG C, then be cooled to normal temperature by the 6th process for cooling;
Described the 5th refrigerating work procedure: adopt compressed air or vaporific quenching liquid with the cooldown rate of 3-5 DEG C/s, reinforcing bar to be chilled to370-390℃；
Described the 6th refrigerating work procedure: adopt water-cooled with the cooldown rate of 11-13 DEG C/s by reinforcing bar water-cooled to room temperature.
2. Large Heat Input Welding high-strength hot-rolled steel bar as claimed in claim 1, is characterized in that: contain just like following weight percentThe chemical composition of ratio: C:0.27%, Si:0.16%, Mn:1.11%, P:0.009%, S:0.001%, Als:0.057%,Nb：0.006％，V：0.06％，Ti：0.035％，Ni：0.05％，Cu：0.07％，Cr：0.6％，Mo：0.53％，B：0.007%, lanthanum: 0.07%, cerium: 0.03%, praseodymium: 0.01%, all the other are Fe and inevitable impurity.
3. Large Heat Input Welding high-strength hot-rolled steel bar as claimed in claim 1, is characterized in that: contain just like following weight percentThe chemical composition of ratio: C:0.29%, Si:0.17%, Mn:1.12%, P:0.008%, S:0.002%, Als:0.059%,Nb：0.005％，V：0.08％，Ti：0.037％，Ni：0.06％，Cu：0.09％，Cr：0.7％，Mo：0.54％，B：0.008%, lanthanum: 0.08%, cerium: 0.04%, praseodymium: 0.02%, all the other are Fe and inevitable impurity.
4. Large Heat Input Welding high-strength hot-rolled steel bar as claimed in claim 1, is characterized in that: contain just like following weight percentThe chemical composition of ratio: C:0.28%, Si:0.15%, Mn:1.13%, P:0.007%, S:0.003%, Als:0.058%,Nb：0.007％，V：0.07％，Ti：0.036％，Ni：0.07％，Cu：0.08％，Cr：0.8％，Mo：0.55％，B：0.009%, lanthanum: 0.09%, cerium: 0.05%, praseodymium: 0.03%, all the other are Fe and inevitable impurity.
5. Large Heat Input Welding high-strength hot-rolled steel bar as claimed in claim 1, is characterized in that: its production technology is by following stepSuddenly carry out:
(i) the reinforcing bar of having smelted is sent into heating furnace and be heated to 1310 DEG C, through the first refrigerating work procedure, reinforcing bar fast speed is cooled to online670 DEG C, then in quenching unit water or quenching liquid carry out for time quench for 25 seconds, be then heated to through tempering heating furnace890 DEG C of tempering, then be cooled to normal temperature by the second process for cooling;
Described the first refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 7 DEG C/s by reinforcing bar water-cooledTo 1120 DEG C, then air cooling to 750 DEG C, then adopt water-cooled with the cooldown rate of 1 DEG C/s by reinforcing bar water-cooled to 670 DEG C;
Described the second refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 11 DEG C/s, reinforcing bar is chilled to room temperature;
(ii) reinforcing bar is hot-rolled down to required size, hot-rolled temperature is 1130 DEG C, then online through the 3rd refrigerating work procedure by reinforcing bar fast speedBe cooled to 670 DEG C, then be cooled to normal temperature by the 4th process for cooling;
Described the 3rd refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 7 DEG C/s, reinforcing bar is chilled to 670 DEG C;
Described the 4th refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 1 DEG C/s by reinforcing bar water-cooledTo 520 DEG C, then air cooling to 450 DEG C, then adopt water-cooled with the cooldown rate of 5 DEG C/s by reinforcing bar water-cooled to room temperature;
(iii) the reinforcing bar after hot rolling is carried out to eddy-current heating, heating-up temperature is 870 DEG C, then the reinforcing bar that eddy-current heating is completed withoutInsulation is directly carried out Quenching Treatment with high pressure spray jetting or quenching liquid, and 15 DEG C/s of quench cooling rate, makes reinforcing bar temperature be cooled to MsFollowing 10 DEG C of point;
(iv) the reinforcing bar after quenching is heated to 720 DEG C through tempering heating furnace, is incubated 35 seconds;
(v) the reinforcing bar after tempering is cooled to 370 DEG C through the 5th refrigerating work procedure by reinforcing bar fast speed online, then adds through heating furnaceHot to 790 DEG C, then be cooled to normal temperature by the 6th process for cooling;
Described the 5th refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 3 DEG C/s, reinforcing bar is chilled to 370 DEG C;
Described the 6th refrigerating work procedure: adopt water-cooled with the cooldown rate of 11 DEG C/s by reinforcing bar water-cooled to room temperature.
6. Large Heat Input Welding high-strength hot-rolled steel bar as claimed in claim 1, is characterized in that: its production technology is by following stepSuddenly carry out:
(i) the reinforcing bar of having smelted is sent into heating furnace and be heated to 1330 DEG C, through the first refrigerating work procedure, reinforcing bar fast speed is cooled to online690 DEG C, then in quenching unit water or quenching liquid carry out for time quench for 27 seconds, be then heated to through tempering heating furnace910 DEG C of tempering, then be cooled to normal temperature by the second process for cooling;
Described the first refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 9 DEG C/s by reinforcing bar water-cooledTo 1150 DEG C, then air cooling to 770 DEG C, then adopt water-cooled with the cooldown rate of 3 DEG C/s by reinforcing bar water-cooled to 690 DEG C;
Described the second refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 13 DEG C/s, reinforcing bar is chilled to room temperature;
(ii) reinforcing bar is hot-rolled down to required size, hot-rolled temperature is 1150 DEG C, then online through the 3rd refrigerating work procedure by reinforcing bar fast speedBe cooled to 690 DEG C, then be cooled to normal temperature by the 4th process for cooling;
Described the 3rd refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 9 DEG C/s, reinforcing bar is chilled to 690 DEG C;
Described the 4th refrigerating work procedure: adopt water-cooled to be combined with air cooling, first adopt water-cooled with the cooldown rate of 3 DEG C/s by reinforcing bar water-cooledTo 550 DEG C, then air cooling to 470 DEG C, then adopt water-cooled with the cooldown rate of 7 DEG C/s by reinforcing bar water-cooled to room temperature;
(iii) the reinforcing bar after hot rolling is carried out to eddy-current heating, heating-up temperature is 890 DEG C, then the reinforcing bar that eddy-current heating is completed withoutInsulation is directly carried out Quenching Treatment with high pressure spray jetting or quenching liquid, and 17 DEG C/s of quench cooling rate, makes reinforcing bar temperature be cooled to MsFollowing 30 DEG C of point;
(iv) the reinforcing bar after quenching is heated to 740 DEG C through tempering heating furnace, is incubated 37 seconds;
(v) the reinforcing bar after tempering is cooled to 390 DEG C through the 5th refrigerating work procedure by reinforcing bar fast speed online, then adds through heating furnaceHot to 810 DEG C, then be cooled to normal temperature by the 6th process for cooling;
Described the 5th refrigerating work procedure: adopt compressed air or vaporific quenching liquid, with the cooldown rate of 5 DEG C/s, reinforcing bar is chilled to 390 DEG C;
Described the 6th refrigerating work procedure: adopt water-cooled with the cooldown rate of 13 DEG C/s by reinforcing bar water-cooled to room temperature.
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| CN106591725A (en) * | 2016-12-15 | 2017-04-26 | 苏州科胜仓储物流设备有限公司 | High-strength steel girder for goods shelf and manufacturing method of high-strength steel girder |
| CN113322408B (en) * | 2020-02-28 | 2022-06-28 | 宝山钢铁股份有限公司 | High heat input welding EH550 MPa-grade quenched and tempered marine steel plate and manufacturing method thereof |
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| JPH02232315A (en) * | 1989-03-07 | 1990-09-14 | Nippon Steel Corp | Production of steel sheet having good toughness of welded joint |
| JPH0578740A (en) * | 1991-09-19 | 1993-03-30 | Nippon Steel Corp | Manufacture of steel excellent in low temperature toughness in weld heat affected zone |
| CN1338528A (en) * | 2001-08-06 | 2002-03-06 | 武汉钢铁(集团)公司 | Unmodified high-toughness low-temp steel for high-energy line welding and its production method |
| CN103451561A (en) * | 2013-08-16 | 2013-12-18 | 江苏省沙钢钢铁研究院有限公司 | Weather-resistant steel plate capable of performing high heat input welding and production method thereof |
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| JPH02232315A (en) * | 1989-03-07 | 1990-09-14 | Nippon Steel Corp | Production of steel sheet having good toughness of welded joint |
| JPH0578740A (en) * | 1991-09-19 | 1993-03-30 | Nippon Steel Corp | Manufacture of steel excellent in low temperature toughness in weld heat affected zone |
| CN1338528A (en) * | 2001-08-06 | 2002-03-06 | 武汉钢铁(集团)公司 | Unmodified high-toughness low-temp steel for high-energy line welding and its production method |
| CN103451561A (en) * | 2013-08-16 | 2013-12-18 | 江苏省沙钢钢铁研究院有限公司 | Weather-resistant steel plate capable of performing high heat input welding and production method thereof |
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