CN110468341A - A kind of 1400MPa grades of delayed fracture resistance high-strength bolt and manufacturing method - Google Patents
A kind of 1400MPa grades of delayed fracture resistance high-strength bolt and manufacturing method Download PDFInfo
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- CN110468341A CN110468341A CN201910746593.9A CN201910746593A CN110468341A CN 110468341 A CN110468341 A CN 110468341A CN 201910746593 A CN201910746593 A CN 201910746593A CN 110468341 A CN110468341 A CN 110468341A
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- bolt
- delayed fracture
- strength
- strength bolt
- 1400mpa
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- 230000003111 delayed effect Effects 0.000 title claims abstract description 41
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 18
- 239000010949 copper Substances 0.000 claims abstract description 35
- 238000010791 quenching Methods 0.000 claims abstract description 31
- 238000005496 tempering Methods 0.000 claims abstract description 31
- 230000000171 quenching effect Effects 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims abstract description 24
- 229910052802 copper Inorganic materials 0.000 claims abstract description 10
- 239000011159 matrix material Substances 0.000 claims abstract description 9
- 239000002245 particle Substances 0.000 claims abstract description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 5
- 239000010959 steel Substances 0.000 claims description 43
- 229910000831 Steel Inorganic materials 0.000 claims description 42
- 238000004321 preservation Methods 0.000 claims description 21
- 238000010438 heat treatment Methods 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 8
- 239000012535 impurity Substances 0.000 claims description 8
- 229910001566 austenite Inorganic materials 0.000 claims description 7
- 238000002791 soaking Methods 0.000 claims description 6
- 239000004615 ingredient Substances 0.000 claims description 5
- 229910000734 martensite Inorganic materials 0.000 claims description 5
- 239000002994 raw material Substances 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 3
- 238000000465 moulding Methods 0.000 claims description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- 229910003178 Mo2C Inorganic materials 0.000 claims description 2
- 238000003754 machining Methods 0.000 claims description 2
- 230000000717 retained effect Effects 0.000 claims description 2
- 229910006299 γ-FeOOH Inorganic materials 0.000 claims description 2
- 238000012360 testing method Methods 0.000 abstract description 12
- 229910052720 vanadium Inorganic materials 0.000 abstract description 9
- 230000008602 contraction Effects 0.000 abstract description 7
- 238000005260 corrosion Methods 0.000 abstract description 7
- 230000007797 corrosion Effects 0.000 abstract description 7
- 229910052750 molybdenum Inorganic materials 0.000 abstract description 7
- 238000005275 alloying Methods 0.000 abstract description 6
- 238000001556 precipitation Methods 0.000 abstract description 5
- 229910052758 niobium Inorganic materials 0.000 abstract description 4
- 238000005191 phase separation Methods 0.000 abstract description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 3
- 229910052799 carbon Inorganic materials 0.000 abstract description 3
- 229910052729 chemical element Inorganic materials 0.000 abstract description 2
- 229910017464 nitrogen compound Inorganic materials 0.000 abstract description 2
- 150000002830 nitrogen compounds Chemical class 0.000 abstract description 2
- 229910052761 rare earth metal Inorganic materials 0.000 abstract description 2
- 229910052719 titanium Inorganic materials 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 15
- 229910052739 hydrogen Inorganic materials 0.000 description 9
- 239000001257 hydrogen Substances 0.000 description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 8
- 238000002360 preparation method Methods 0.000 description 8
- 239000000470 constituent Substances 0.000 description 7
- 239000013078 crystal Substances 0.000 description 7
- 238000010792 warming Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 238000005204 segregation Methods 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 230000001965 increasing effect Effects 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- YLZOPXRUQYQQID-UHFFFAOYSA-N 3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]propan-1-one Chemical compound N1N=NC=2CN(CCC=21)CCC(=O)N1CCN(CC1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F YLZOPXRUQYQQID-UHFFFAOYSA-N 0.000 description 1
- 101100434462 Arabidopsis thaliana ADS3 gene Proteins 0.000 description 1
- 240000002853 Nelumbo nucifera Species 0.000 description 1
- 235000006508 Nelumbo nucifera Nutrition 0.000 description 1
- 235000006510 Nelumbo pentapetala Nutrition 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000010813 municipal solid waste Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000013517 stratification Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21H—MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
- B21H3/00—Making helical bodies or bodies having parts of helical shape
- B21H3/02—Making helical bodies or bodies having parts of helical shape external screw-threads ; Making dies for thread 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/32—Soft annealing, e.g. spheroidising
-
- 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
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/58—Oils
-
- 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
- C21D9/0093—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for screws; for bolts
-
- 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
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
-
- 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
- C22C38/02—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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B35/00—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws
-
- 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
- C21D2211/001—Austenite
-
- 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
- C21D2211/008—Martensite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a kind of 1400MPa grades of delayed fracture resistance high-strength bolt and manufacturing methods, contain the alloying elements such as Mo, Cu, V in its chemical element, using high temperature quenching, two stages tempering method for treating, make to be tempered abundant disperse educt copper-rich phase ε-Cu and VC, Mo in matrix2The tiny Second Phase Particle such as C, so that bolt is when reaching 1400MPa intensity rank, resistance for delayed fracture and corrosion resistance with higher.The high-strength bolt makes full use of the precipitation phase separation that phase separation and Mo, V, Nb, Ti etc. is precipitated and forms special carbon, nitrogen compound of alloying element cu, make the tensile strength of bolt between 1445MPa-1510MPa, the contraction percentage of area is in 50-56%, elongation after fracture is not less than 10%, the delayed fracture strength ratio of constant load notch tension test is in 0.63-0.71, and being not added with rare earth element, cost is relatively low.
Description
Technical field
The present invention relates to a kind of high-strength bolt and manufacturing methods, and in particular to a kind of 1400MPa grade of the element containing Cu is resistance to
Delayed fracture high-strength bolt and manufacturing method.
Background technique
The development of the industries such as automobile, machinery, building, light industry, to all kinds of fasteners (such as bolt, screw, nut) of manufacture
The material used proposes requirement higher and higher.As the high performance of automobile and lightweight, building structure high stratification and
Overlength of bridge etc. proposes higher design stress and light-weighted requirement to the bolt as connection parts.In this regard, most having
The measure of effect is the high intensity of bolting steel.It is produced in bolt use process due to the hydrogen of external environment intrusion or in bolt
The hydrogen invaded when surface granosealing in bolt in the process easily makes high-strength bolt that delayed fracture occur, even if being included in each national standard
In 12.9 grades of even 11.9 grade bolts, also have occurred multiple delayed fracture accident during being actually on active service, thus it is used
Range is restricted.
Summary of the invention
Goal of the invention: in order to improve high-strength bolt resistance for delayed fracture in actual use and corrosion resistance
Can, the present invention provides a kind of 1400MPa grades of delayed fracture resistance high-strength bolt.
It is a further object of the present invention to provide a kind of manufacturing methods of above-mentioned high-strength bolt.
Technical solution: a kind of 1400MPa grades of delayed fracture resistance high-strength bolt of the present invention, the element group of the bolt
At containing C:0.38-0.45% by percentage to the quality；Si≤0.25%；Mn:0.30-0.60%；P≤0.015%；S≤
0.010%；Cr:0.90-1.10%；Mo:0.50-0.60%；V:0.15-0.35%；Nb:0.02-0.04%；Cu:0.5-
0.8%；Al≤0.030%；Ti≤0.01%, N:0.009-0.018%, surplus are Fe and inevitable impurity；The bolt
Metallographic structure be tempered martensite and retained austenite.
The matrix surface of the raw material steel wire rod of the bolt has passivating film, and the ingredient of the passivating film includes alpha-feooh
With γ-FeOOH.
Further, tempered martensite accounts for 98% in the metallographic structure of the bolt, and residual austenite body tissue accounts for 2%.
Specifically, the control of element principle of the high-strength bolt is described as follows:
C: obtaining required intensity rank in order to quench, after tempering, C content must 0.25% or more, but with C content
Increasing, the intensity of steel increases, and plasticity reduces, so that difficult forming, so that the delayed fracture sensibility of steel is further increased, such as day
The high strength bolting steel ADS3 of the 1300MPa grade delayed fracture resistance of this Sumitomo Metal Industries' exploitation is precisely due to C content is higher
(0.49%), it is degrading the cold-forming property of test steel.The C content of this patent is controlled in 0.38-0.45% for these reasons.
Si: the crystal boundary segregation of P, S of the oxidation and impurity element of autstenitic grain size when can promote steel high temperature can deteriorate
The resistance for delayed fracture of steel, while can also deteriorate the cold-forming property of steel, thus control Si≤0.25%.
Mn: it is austenite former and weak carbon formation element, all contains Mn element in almost all of steel.Mn member
The effective element of deoxidation, desulfurization when element is steel-making can also improve the harden ability and intensity of steel, but when Mn content is less than
When 0.3%, said effect can not be played.When the Mn constituent content in steel is higher, steel tempering is quenched, Mn and P have strong crystalline substance
Boundary is total to segregation tendency, thus the control of Mn constituent content is between 0.30-0.60%.
P: in solidification of molten steel, P easily forms microsegregation, then makes steel in crystal boundary segregation when austenitizing temperature is heated
Brittleness increase, delayed fracture property reduce, so should by the content of P control below 0.015%.
S: inevitable impurity thing when to make steel, S element can form MnS with Mn element in steel and be mingled with, while S element
Easily in grain boundaries segregation, thus need controller content below 0.010%.
Cr: having the function of improving the worried fire and corrosion resistance of steel, can be used as Carbide Precipitation in tempering, makes intensity
It is improved with delayed fracture resistance.In order to make Cr elemental composition play total use, Cr need to be made to be higher than 0.90%, if while Cr content surplus
It will affect cold-forming property, so the upper limit of Cr constituent content need to be controlled, preferred lower limit is below 1.10%.
Mo: the harden ability of steel can be effectively improved, while Mo element belongs to middle carbide, at appropriate time
When being tempered between flame range, alloy carbide can effectively be precipitated, to function as described above Mo ingredient, Mo constituent content need to be made
In 0.50-0.60%.
V: for carbide, can effectively refine crystal grain, and alloy carbide can be precipitated in tempering, these
Alloy carbide can effectively improve the intensity of steel, capture the free hydrogen in steel at the same time as hydrogen trap, prolonged with improving the resistance to of steel
Slow fracture property, in order to play these above-mentioned effects, the content of V element need to be 0.15% or more, but superfluous V content can make
Steel generates coarse carbide in rolling, reduces the cold-workability of steel, should control below 0.35%.
Nb: for carbide, can refine crystal grain, improve the toughness and intensity of steel, and content is lower than 0.02%
When, then said effect can not be played, is saturated when more than 0.04%, cost is increased.
Cu: can improve corrosion resistance, inhibit the intrusion of hydrogen, to further increase the resistance for delayed fracture of steel, work as Cu
The content of element is then unable to reach said effect when being lower than 0.5%, and Cu constituent content is then saturated when more than 0.8%, will be reduced
The intensity and resistance for delayed fracture of steel, while the cost that steel will be increased.
Al: other than it can form AlN refinement crystal grain, moreover it is possible to the oxygen in effective removal steel, is good deoxidier, but with
The increase carbonitride system inclusion content of Al constituent content increase, resistance for delayed fracture decline.Therefore Al constituent content
Preferably 0.030% or less.
Ti: easily forming TiN and TiC in rolling sequence, these second special phases can be used as hydrogen trap, but due to its capture
The effect of hydrogen does not have V, Nb element good, and the amount being added herein is few, below 0.01%.
N: can form tiny nitride with elements such as Al, Nb, V, to play the role of refining crystal grain, but a large amount of N members
The addition of element can make N segregation and crystal boundary reduce the intensity of grain boundaries, while will form coarse field trash, so its content is answered
Control is between 0.009-0.018%.
And a kind of manufacturing method of above-mentioned high-strength bolt of the present invention is the technical scheme adopted is that manufacturing process
Add including raw material spheroidizing → cold-drawn → spheroidizing → cold-heading molding → high temperature quenching → two stages tempering → machine
Work → rolled thread → surface granosealing；Wherein, high temperature quenching is that austenitizing is heated at 940-960 DEG C, keep the temperature 1h with
Cooling is quenched after upper, hardening media is oil；In the two stages tempering, first stage tempering is to quench to cool down in high temperature
Afterwards, sample is reheated to 450-550 DEG C, heat preservation 1-5h makes the abundant disperse analysis of the copper-rich phase ε-Cu being tempered in matrix
Out；Second stage tempering is continued with stove heating without cooling to 590-600 DEG C after being tempered in the first stage, and heat preservation 1-2h makes steel
In the tiny abundant disperse educt of Second Phase Particle.
Further, in high temperature quenching process, the high-strength bolt of 16mm, soaking time 1h are less than for diameter；
For the high-strength bolt of diameter 16mm or more, soaking time is greater than 1h.
In second stage tempering process, the tiny Second Phase Particle of disperse educt includes VC and Mo2C。
The utility model has the advantages that quenched containing alloying elements such as Mo, Cu, V in the chemical element of the high-strength bolt using high temperature,
Two stages tempering method for treating makes to be tempered abundant disperse educt copper-rich phase (ε-Cu) and VC, Mo in matrix2C etc. is tiny
Second Phase Particle, so that bolt is when reaching 1400MPa intensity rank, resistance for delayed fracture with higher and corrosion-resistant energy
Power.It makes full use of the precipitation elements such as phase separation and Mo, V, Nb, Ti of alloying element cu to form special carbon, nitrogen compound
Phase separation is precipitated, makes the tensile strength of bolt between 1445MPa-1510MPa, the contraction percentage of area is in 50-56%, elongation of having no progeny
Rate is not less than 10%, and the delayed fracture strength ratio of constant load notch tension test is not added with rare earth element in 0.63-0.71,
Advantage of lower cost.
Detailed description of the invention
Fig. 1 is the structure microphoto of high-strength bolt of the present invention.
Specific embodiment
The present invention is described in further details below with reference to embodiment.
A kind of 1400MPa grades of delayed fracture resistance high-strength bolts disclosed in this invention, chemical component is with quality percentage
Contain C:0.38-0.45% than meter；Si≤0.25%；Mn:0.30-0.60%；P≤0.015%；S≤0.010%；Cr:
0.90-1.10%；Mo:0.50-0.60%；V:0.15-0.35%；Nb:0.02-0.04%；Cu:0.5-0.8%；Al≤
0.030%；Ti≤0.01%, N:0.009-0.018%, surplus are Fe and inevitable impurity.Manufacturing process includes former material
Pellet annealing → cold-drawn → spheroidizing → cold-heading molding → high temperature quenching → two stages tempering → machining → rolled thread
→ surface granosealing.
Specifically, the characteristics of high temperature quenching is according to the alloying elements such as Mo, Cu, V are contained in raw material bolting steel,
Heat austenitizing under 940-960 DEG C of higher temperature, heat preservation 1h or more makes in steel the alloying elements such as Mo, Cu, V completely or portion
It point dissolves in austenite, quenching cooling is carried out using oil, the higher martensite of above-mentioned alloy content and residual is obtained after quenching is cooling
Remaining austenite；
In the two stages tempering, first stage tempering is to be reheated to sample after high temperature quenching is cooling
450-550 DEG C, heat preservation 1-5h makes the abundant disperse educt of copper-rich phase ε-Cu being tempered in matrix cause dispersion-strengthened action, together
When can induce the precipitations of the element carbides such as Mo, V in Cu element Precipitation and Cu Element segregation, enhance its hydrogen trap work
With improving the resistance for delayed fracture and corrosion resistance of bolt；Second stage tempering is after being tempered in the first stage without cold
But continue with stove heating to 590-600 DEG C, keep the temperature 1-2h, the heat preservation in the stage makes VC, Mo in steel2The tiny Second Phase Particle such as C
Abundant disperse educt, causes dispersion-strengthened action, so that bolt obtains higher toughness plasticity and still by higher tempering temperature
Intensity with higher.
More specifically, in high temperature quenching process, the high-strength bolt of 16mm is less than for diameter, soaking time is
1h；For the high-strength bolt of diameter 16mm or more, soaking time is greater than 1h.
Four groups of high-strength bolts are prepared respectively using the above method as embodiment, specific as follows:
Embodiment 1: preparation 14mm high-strength bolt, the mass percent of chemical component are as follows: C:0.43%；Si:
0.14%；Mn:0.30%；P:0.003%；S:0.010%；Cr:1.10%；Mo:0.50%；V:0.33%；Nb:0.04%；
Cu:0.53%；Al:0.01%；Ti≤0.01%；N:0.009-0.018%, surplus are Fe and impurity.High temperature quenching and two ranks
Section tempering specifically include that be warming up to 940 DEG C after keep the temperature 1h, then oil quenching, is reheated to 450 DEG C after being cooled to room temperature,
1.5h is kept the temperature, is continuously heating to 590 DEG C after heat preservation, keeps the temperature 1.5h, takes out air-cooled after heat preservation, is passing through above-mentioned technique
The tensile strength of process rear bolt be 1503MPa, the contraction percentage of area 51.26%, elongation after fracture 12.2%, constant load lack
The delayed fracture strength ratio of mouth tension test is 0.63.
Embodiment 2: preparation 16mm high-strength bolt, the mass percent of chemical component are as follows: C:0.45%；Si:
0.25%；Mn:0.30%；P:0.003%；S:0.010%；Cr:1.00%；Mo:0.55%；V:0.35%；Nb:0.037%；
Cu:0.65%；Al:0.03%；Ti≤0.01%；N:0.009-0.018%, surplus are Fe and inevitable impurity.High temperature
It quenches and two stages tempering specifically includes that and keeps the temperature 1.5h after being warming up to 940 DEG C, then oil quenching, after being cooled to room temperature again
It is heated to 500 DEG C, keeps the temperature 2h, 590 DEG C are continuously heating to after heat preservation, keep the temperature 1h, take out air-cooled after heat preservation, passing through
The tensile strength of above-mentioned technical process rear bolt be 1467MPa, the contraction percentage of area 53.12%, elongation after fracture 13.1%,
The delayed fracture strength ratio of constant load notch tension test is 0.66.
Embodiment 3: preparation 20mm high-strength bolt, the mass percent of chemical component are as follows: C:0.38%；Mn:
0.60%；P:0.015%；S:0.010%；Cr:0.9%；Mo:0.6%；V:0.25%；Nb:0.03%；Cu:0.8%；Al:
0.01%；Ti≤0.01%；N:0.009-0.018%, surplus are Fe and inevitable impurity.High temperature quenching and two stages return
Fire processing specifically includes that be warming up to 950 DEG C after keep the temperature 1.5h, then oil quenching is reheated to 520 DEG C after being cooled to room temperature, protects
Warm 3h, is continuously heating to 600 DEG C after heat preservation, keep the temperature 2h, taken out after heat preservation it is air-cooled, after above-mentioned technical process
The tensile strength of bolt is 1445MPa, the contraction percentage of area 55.34%, elongation after fracture 14.1%, constant load notch tensile
The delayed fracture strength ratio of test is 0.68.
Embodiment 4: preparation 16mm high-strength bolt, the mass percent of chemical component are as follows: C:0.40%；Si:
0.14%；Mn:0.45%；P:0.003%；S:0.010%；Cr:1.10%；Mo:0.55%；V:0.15%；Nb:0.02%；
Cu:0.75%；Al:0.01%；Ti≤0.01%；N:0.009-0.018%, high temperature quenching and two stages tempering are mainly wrapped
It includes: keeping the temperature 1.2h after being warming up to 960 DEG C, then oil quenching, 550 DEG C are reheated to after being cooled to room temperature, keep the temperature 5h, heat preservation terminates
After be continuously heating to 600 DEG C, keep the temperature 2h, taken out after heat preservation it is air-cooled, it is strong in the tension Jing Guo above-mentioned technical process rear bolt
Degree is 1456MPa, the contraction percentage of area 54.27%, elongation after fracture 15.2, the delayed fracture of constant load notch tension test
Intensity ratio is 0.71.
It is also provided below in order to embody the performance advantage of 1400MPa grade delayed fracture resistance high-strength bolt of the invention
Five groups of comparative examples.The ingredient and preparation process scheme of five groups of comparative examples are substantially consistent with embodiment 1, except that: it is right
Cu is not contained in ratio 1；Although containing Cu in comparative example 2-1 and 2-2, its content is not within the scope of restriction of the invention；
Manufacturing process's manufacture bolt not according to the invention in comparative example 3；Although consistent with manufacturing process of the invention in comparative example 4,
But its first stage tempering temperature does not limit in range in the present invention；Correspondingly, the second stage tempering temperature of comparative example 5 is not
It is limited in range in the present invention.
The high-strength bolt finished product technical parameter of comparative example 1-6 as described above is as follows:
Comparative example 1 is free of Cu: being 1486MPa, the contraction percentage of area in the tensile strength Jing Guo above-mentioned technical process rear bolt
It is 52.13%, the delayed fracture strength of constant load notch tension test is than 0.52, it is seen that the intensity of steel is declined, but is declined
Amplitude is little, is free of Cu element due to comparing example 1, and when being corroded by the external world, bolt surface cannot generate the passivating film of protection matrix,
A possibility that increasing hydrogen intrusion steel matrix, to reduce its resistance for delayed fracture.
The Cu content of comparative example 2-1 is less than 0.5%: being in the tensile strength Jing Guo above-mentioned technical process rear bolt
1507MPa, the delayed fracture strength of constant load notch tension test is than 0.54.It can be seen that content containing Cu is too low, enhancing can not be played
Steel intensity itself and the corrosion resistance for improving steel, although the intensity with comparative example 1 of steel is not much different at this time, its is resistance to prolong
Slow fracture property is poor.
The Cu content of comparative example 2-2 is greater than 0.8%: being in the tensile strength Jing Guo above-mentioned technical process rear bolt
1386MPa.It can be seen that too high levels containing Cu, the intensity of steel further declines, and has been unable to satisfy the performance of 1400MPa intensity rank
It is required that.
The manufacturing process not according to the invention of comparative example 3 manufactures 14mm bolt: the quenching of its high temperature and two stages tempering
It specifically includes that and keeps the temperature 1h after being warming up to 940 DEG C, then oil quenching, 450 DEG C are reheated to after being cooled to room temperature, keep the temperature 1.5h, protect
Take out air-cooled after temperature, then 1 be continuously heating to 590 DEG C again, keep the temperature 1.5h, taken out after heat preservation it is air-cooled, by upper
State technical process rear bolt tensile strength be 1389MPa, the delayed fracture strength of constant load notch tension test than 0.56,
Intensity has been unable to satisfy the performance requirement of 1400MPa intensity rank, and delayed fracture property is also weaker.
Although comparative example 4 is consistent with manufacturing process of the invention, first stage tempering temperature is not in limit of the invention
Determine in range: preparation 14mm high-strength bolt, high temperature quenching and two stages tempering are specifically included that and are protected after being warming up to 940 DEG C
Warm 1h, then oil quenching, is reheated to 580 DEG C after being cooled to room temperature, keeps the temperature 1.5h, 590 DEG C are continuously heating to after heat preservation,
Keep the temperature 1.5h, taken out after heat preservation it is air-cooled, the tensile strength Jing Guo above-mentioned technical process rear bolt be 1452MPa, dead load
The delayed fracture strength of lotus notch tension test is than 0.55, and at this time although the intensity of steel is met the requirements, but its delayed fracture resistance
Performance is poor.
The second stage tempering temperature of comparative example 5 does not limit in range in the present invention: preparation 14mm high-strength bolt, high temperature
Quenching and two stages tempering specifically include that and keep the temperature 1h after being warming up to 940 DEG C, and then oil quenching, adds again after being cooled to room temperature
Heat keeps the temperature 1.5h, is continuously heating to 620 DEG C after heat preservation to 450 DEG C, keeps the temperature 1.5h, takes out air-cooled after heat preservation, is passing through
The tensile strength for crossing above-mentioned technical process rear bolt is 1483MPa, the delayed fracture strength ratio of constant load notch tension test
0.51, similar with comparative example 4, at this time although the intensity of steel is met the requirements, but its resistance for delayed fracture is poor.
As it can be seen that the high-strength bolt of method preparation is designed and prepared using ingredient of the invention, in tensile strength and Nai Yan
There is apparent advantage on slow fracture property.
Claims (6)
1. a kind of 1400MPa grades of delayed fracture resistance high-strength bolt, which is characterized in that the element of the bolt is formed with quality percentage
Contain C:0.38-0.45% than meter；Si≤0.25%；Mn:0.30-0.60%；P≤0.015%；S≤0.010%；Cr:
0.90-1.10%；Mo:0.50-0.60%；V:0.15-0.35%；Nb:0.02-0.04%；Cu:0.5-0.8%；Al≤
0.030%；Ti≤0.01%, N:0.009-0.018%, surplus are Fe and inevitable impurity；The metallographic structure of the bolt
For tempered martensite and retained austenite.
2. according to 1400MPa grades of delayed fracture resistance high-strength bolt described in claim 1, which is characterized in that the original of the bolt
The matrix surface of material steel wire rod has passivating film, and the ingredient of the passivating film includes alpha-feooh and γ-FeOOH.
3. according to 1400MPa grades of delayed fracture resistance high-strength bolt described in claim 1, which is characterized in that the tempered martensite
Body tissue accounts for 98%, residual austenite body tissue 2%.
4. a kind of manufacturing method of 1400MPa according to claim 1-3 grades of delayed fracture resistance high-strength bolts,
It is characterized in that, process includes raw material spheroidizing → cold-drawn → spheroidizing → cold-heading molding → high temperature quenching → two stages
Tempering → machining → rolled thread → surface granosealing；
Wherein, the high temperature quenching is that austenitizing is heated at 940-960 DEG C, and quenching cooling, quenching are situated between after heat preservation 1h or more
Matter is oil；
In the two stages tempering, first stage tempering is that sample is reheated to 450- after high temperature quenching is cooling
550 DEG C, heat preservation 1-5h makes the abundant disperse educt of copper-rich phase ε-Cu being tempered in matrix；Second stage tempering is in the first rank
Continue with stove heating without cooling to 590-600 DEG C after Duan Huihuo, heat preservation 1-2h makes the tiny abundant disperse of Second Phase Particle in steel
It is precipitated.
5. manufacturing method according to claim 4, which is characterized in that in high temperature quenching process, diameter is less than
The high-strength bolt of 16mm, soaking time 1h；For the high-strength bolt of diameter 16mm or more, soaking time is greater than 1h.
6. manufacturing method according to claim 4, which is characterized in that in second stage tempering process, disperse educt
Tiny Second Phase Particle includes VC and Mo2C。
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| CN201910746593.9A CN110468341B (en) | 2019-08-13 | 2019-08-13 | 1400 MPa-level delayed fracture-resistant high-strength bolt and manufacturing method thereof |
| PCT/CN2020/097868 WO2021027402A1 (en) | 2019-08-13 | 2020-06-24 | 1400 mpa grade delayed-fracture-resistant high-strength bolt and manufacturing method therefor |
| KR1020217043398A KR102668982B1 (en) | 2019-08-13 | 2020-06-24 | Manufacturing method of delayed failure-resistant high-strength bolts |
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|---|---|---|---|
| CN201910746593.9A CN110468341B (en) | 2019-08-13 | 2019-08-13 | 1400 MPa-level delayed fracture-resistant high-strength bolt and manufacturing method thereof |
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| CN110468341A true CN110468341A (en) | 2019-11-19 |
| CN110468341B CN110468341B (en) | 2020-09-25 |
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| WO (1) | WO2021027402A1 (en) |
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| CN111155031A (en) * | 2020-01-15 | 2020-05-15 | 南京福贝尔五金制品有限公司 | Atmospheric corrosion resistant high-strength bolt and manufacturing method thereof |
| WO2021027402A1 (en) * | 2019-08-13 | 2021-02-18 | 南京钢铁股份有限公司 | 1400 mpa grade delayed-fracture-resistant high-strength bolt and manufacturing method therefor |
| CN112575256A (en) * | 2020-11-26 | 2021-03-30 | 博耀能源科技有限公司 | High-strength and high-toughness large-diameter wind power bolt with shell/horse complex phase structure and preparation method thereof |
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| CN115679227A (en) * | 2022-11-04 | 2023-02-03 | 中铁隆昌铁路器材有限公司 | High-strength toughened bolt and heat treatment process thereof |
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Also Published As
| Publication number | Publication date |
|---|---|
| KR20220035340A (en) | 2022-03-22 |
| CN110468341B (en) | 2020-09-25 |
| WO2021027402A1 (en) | 2021-02-18 |
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