CN1177648A - PC concrete iron and method for producing same - Google Patents
PC concrete iron and method for producing same Download PDFInfo
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- CN1177648A CN1177648A CN97115010A CN97115010A CN1177648A CN 1177648 A CN1177648 A CN 1177648A CN 97115010 A CN97115010 A CN 97115010A CN 97115010 A CN97115010 A CN 97115010A CN 1177648 A CN1177648 A CN 1177648A
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 26
- 239000004567 concrete Substances 0.000 title description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title 2
- 229910052742 iron Inorganic materials 0.000 title 1
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 49
- 239000010959 steel Substances 0.000 claims abstract description 49
- 238000000034 method Methods 0.000 claims abstract description 39
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 12
- 239000000203 mixture Substances 0.000 claims abstract description 11
- 230000003014 reinforcing effect Effects 0.000 claims description 58
- 238000005496 tempering Methods 0.000 claims description 34
- 238000010791 quenching Methods 0.000 claims description 24
- 230000000171 quenching effect Effects 0.000 claims description 22
- 229910000734 martensite Inorganic materials 0.000 claims description 15
- 238000003466 welding Methods 0.000 claims description 15
- 229910052796 boron Inorganic materials 0.000 claims description 11
- 229910052804 chromium Inorganic materials 0.000 claims description 11
- 229910052759 nickel Inorganic materials 0.000 claims description 11
- 229910052719 titanium Inorganic materials 0.000 claims description 11
- 229910052750 molybdenum Inorganic materials 0.000 claims description 8
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000012535 impurity Substances 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- 238000012360 testing method Methods 0.000 description 32
- 230000000052 comparative effect Effects 0.000 description 12
- 238000010438 heat treatment Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 7
- 210000003205 muscle Anatomy 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 238000007669 thermal treatment Methods 0.000 description 5
- 210000001519 tissue Anatomy 0.000 description 5
- 239000011150 reinforced concrete Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- 239000004615 ingredient Substances 0.000 description 3
- 238000005482 strain hardening Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 2
- 230000033001 locomotion Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 229910001563 bainite Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 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
- 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
- C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires 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
- 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
- C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
- C21D1/22—Martempering
-
- 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
- C21D8/06—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
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—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
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
Abstract
The present invention provides a method for production of PC steel bar having tensile strength of 1080 N/mm or above, and having a high uniform elongation and low yield ratio, excellent in relaxation characteristic at a high temperature. The steel, which has a composition containing, by weight, 0.5-0.7% C, 0.2-2.0% Mn, and 2.0-5.0% of (Si+Al), is hardened from 1160-1300 DEG C and then tempered in usual working procedure ,having no use for transformative working procedure.
Description
The present invention relates to the manufacture method of the good PC reinforcing bar of good PC reinforcing bar of uniformly extension and high temperature relaxation property and high uniformly extension and low yielding ratio, high temperature relaxation property.This PC reinforcing bar is used for PC works such as PC bar, PC pipe.
The PC reinforcing bar is the high-strength parts that are used for prestressed reinforced concrete.In JISG3109 and JISG3137, the PC reinforcing bar is defined as B kind (tensile strength 〉=1080N/mm
2, endurance 〉=930N/mm
2, unit elongation: more than 5%, lax value is (normal temperature is measured, bearing strength test: 0.7 * tensile strength, 1000 one hour values) and C kind (tensile strength 〉=1230N/mm below 4%
2, endurance 〉=1080N/mm
2, unit elongation: below 5%, lax value: (normal temperature is measured, bearing strength test: 0.7 * tensile strength, 1000 one hour values) below 4%.In JISG3137, stipulated D kind (tensile strength 〉=1420N/mm
2, endurance 〉=1275N/mm
2, unit elongation: more than 5%, lax value: (normal temperature mensuration, bearing strength test: 0.7 * tensile strength, 1000 one hour values) 4% below.But, uniform elongation, surrender when the lax value of high temperature and be not prescribed.
The prestressed reinforced concrete structure thing produces flexural failure sometimes when earthquake.In order to prevent it, using the PC reinforcing bar of high uniform elongation is effective to improving bend ductility.Recently, from the shock resistance viewpoint, require the PC reinforcing bar to have low yielding ratio and high uniform elongation.Even because the uniform elongation height of reinforcing bar, if but the yield ratio height, then when concrete produced the crack, the PC reinforcing bar at this position can produce local deformaton, even fracture.
These PC reinforcing bar times spent are used for concrete lateral confinement.At this moment, on the PC reinforcing bar, want the spot welding horizontal bar to use.Therefore, require the PC reinforcing bar not only before spot welding, the uniformly extension characteristic will be arranged, and the uniformly extension characteristic after the welding also must be good.
When making prestressed reinforced concrete pipe or bar,, usually be in 180～200 ℃, 10 atmospheric environment, to carry out the steam high-pressure curing in order to shorten curing time.But the shortcoming of steam high-pressure curing is the PC Steel Relaxation increase in the concrete.Therefore wish to have a kind of PC reinforcing bar that slackness is little under above-mentioned high temperature.
In the prior art, the technology of improving the high temperature relaxation property is arranged also.But,,, all have variety of issue though some motions are arranged for uniformly extension and both double excellent reinforcing bars of high temperature relaxation property.
The method of the special fair 3-79410 number announcement of Japanese patent gazette is the method that invests the slight curves distortion below 2% when tempering.The method that discloses for Te Kaiping 3-28351 number is while be to process or carry out that plastic working improves that temperature makes its inversion attitude and the method that forms ultra-fine grain structure with 900～400 ℃.The spy opens the method that discloses clear 58-120738 number, is to adopt wet type straight line machine to implement the refrigerative method when aligning.The method that discloses for Te Kaiping 8-158010 number is the method for the Si+Al addition of increase by 2%～5%.But the fair 3-79410 of above-mentioned spy number, spy are opened flat 3-28351 number, spy and are opened in the method that clear 58-120738 number each communique disclose, and the operation of the distortion of investing all must be arranged, so productivity is poor.In addition, the spy opens the method that discloses flat 8-158010 number, though productivity is good, uniformly extension and high temperature relaxation property are at 1450N/mm
2Its uniform elongation is 5% under the intensity of level, compares the raising of the leap of can not saying so with 3% of present situation.In addition, because its yield ratio is up to more than 0.95, so in concrete structure, its high uniform elongation in fact may be inoperative.In addition, in these communiques, all do not relate to the technology that realizes low yielding ratio.
On the other hand, in the design at beam column junction surface, a kind ofly can absorb the aseismic design of violent earthquake energy and extremely gaze at, this beam column junction surface post when violent earthquake does not destroy, and makes the beam plastic hingeization.According to this design, must adopt intensity more than the B kind specification of JISG3109 (JISG3137), uniform elongation is at the PC reinforcing bar more than 8%.Seeing prior art from the intensity viewpoint, nearly all is with 1420N/mm
2It more than is object.Relate to be equivalent to B kind or C kind specification, tensile strength is at 1080N/mm
2Above 1420N/mm
2The motion of following PC reinforcing bar has special public clear 55-8577 communique and special public clear 56-21811 communique.But in the technology that public clear 55-8577 communique of above-mentioned spy and special public clear 56-21811 disclose, the unit elongation that reaches is, extension 8～9% that the former is disrumpent feelings, and latter's uniformly extension is about 3.3～4.6%, can not satisfy the uniformly extension 8% of the actual requirement of this intensity level.
The present invention makes in view of the above problems, its purpose be to provide a kind of do not need to invest the operation of distortion and that can make with common operation, that uniformly extension and high temperature relaxation property are all excellent, tensile strength at 1080N/mm
2Above 1420N/mm
2Following PC reinforcing bar.
Another object of the present invention provide the operation that does not need to invest distortion and that can make with common operation, that low yielding ratio and uniformly extension and high temperature relaxation property are all excellent, tensile strength at 1080N/mm
2The manufacture method of above PC reinforcing bar.
Another object of the present invention provides the also good PC reinforcing bar and the manufacture method thereof of uniformly extension characteristic of a postwelding.
In order to realize this purpose, the present inventor has carried out research with keen determination.Result verification increase Si and Al addition be favourable for uniformly extension and high temperature relaxation property.Also verified from high temperature to the high material of C amount quench for have high uniform elongation and low yielding ratio, the high temperature relaxation property is favourable.
The present invention is based on that above-mentioned research makes.
PC reinforcing bar of the present invention is,
The first, in weight %, contain C:0.2～0.7%, Mn:0.2～3.0%, (Si%+Al%): 2.0～5.0%;
Basically be the tissue that tempered martensite constitutes, and the carbide in the tempered martensite is mean diameter fine granular below 0.1 μ m, tensile strength: 1080N/mm
2Above 1420N/mm
2Below, uniformly extension and the good PC reinforcing bar of high temperature relaxation property.
Second, the composition of steel is in weight %, also contain from Nb:0.01～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, Mo:0.05～0.5%, select in Cu:0.2～1.0% more than a kind or 2 kinds, uniformly extension and the good PC reinforcing bar of high temperature relaxation property.
The 3rd, the composition of steel is in weight %, by C:0.2～0.7%, Mn:0.23.0%, (Si%+Al%): 2.0～5.0% and from Nb:0.01～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, that selects in Mo:0.05～0.5% and Cu:0.2～1.0% constitutes with Fe and inevitable impurity more than a kind or 2 kinds
Basically be the tissue that tempered martensite constitutes, and the carbide in the tempered martensite is mean diameter fine granular below 0.1 μ m, tensile strength: 1080N/mm
2Above 1420N/mm
2Below, uniformly extension and the good PC reinforcing bar of high temperature relaxation property.
The 4th, tensile strength 〉=1080N/mm
2, endurance 〉=930N/mm
2The PC reinforcing bar.
The 5th, tensile strength 〉=1230N/mm
2, endurance 〉=1080N/mm
2The PC reinforcing bar.
The 6th, C amount: 0.2～0.5wt%, be used for carrying out after spot welding and the spot welding PC reinforcing bar of tempering energising usefulness.
The manufacture method of PC reinforcing bar of the present invention is:
The first, in weight %, the steel that contains C:0.5～0.7%, Mn:0.2～2.0%, 2.0%≤Si+Al≤5.0%, from 1160 ℃～1300 ℃ quenchings, tempering then becomes and has 1080N/mm
2The manufacture method of the PC reinforcing bar that uniformly extension above tensile strength, high and low yielding ratio, high temperature relaxation property are good.
Second, in weight %, contain C:0.5～0.7%, Mn:0.2～2.0%, 2.0%≤Si+Al≤5.0%, also contain Nb:0.01～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, Mo:0.05～0.5%, the steel more than a kind or 2 kinds in Cu:0.2～1.0%, from 1160 ℃～1300 ℃ quenchings, tempering then becomes and has 1080N/mm
2The manufacture method of the P C reinforcing bar that uniformly extension above tensile strength, high and low yielding ratio, high temperature relaxation property are good.
The 3rd, in weight %, by C:0.5～0.7%, Mn:0.2～2.0%, 2.0%≤Si+Al≤5.0% and from Nb:0.01～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, the steel of selecting in Mo:0.05～0.5% and Cu:0.2～1.0% that constitutes with Fe of the remnants of defeated troops and inevitable impurity more than a kind or 2 kinds is from 1160 ℃～1300 ℃ quenchings, tempering then becomes and has 1080N/mm
2The manufacture method of the PC reinforcing bar that uniformly extension above tensile strength, high and low yielding ratio, high temperature relaxation property are good.
The 4th, tensile strength 〉=1230N/mm
2, endurance 〉=1080N/mm
2The intensity level, uniform elongation is more than 10.0%, yield ratio is below 0.87%, the lax value of high temperature is in the manufacture method of the good PC reinforcing bar of the high uniformly extension below 8% and low yielding ratio, high temperature relaxation property.
The 5th, tensile strength 〉=1420N/mm
2, endurance 〉=1275N/mm
2The intensity level, uniform elongation is more than 8.0%, yield ratio is below 0.9%, the lax value of high temperature is in the manufacture method of the good PC reinforcing bar of the high uniformly extension below 8% and low yielding ratio, high temperature relaxation property.
The 6th, tensile strength 〉=1080N/mm
2, endurance 〉=930N/mm
2The intensity level, uniform elongation is more than 11.0%, yield ratio is below 0.85%, the lax value of high temperature is in the manufacture method of the good PC reinforcing bar of the high uniformly extension below 8% and low yielding ratio, high temperature relaxation property.
The 7th, tempering temperature is the manufacture method of the good PC reinforcing bar of uniformly extensions more than 600 ℃, high and low yielding ratio, high temperature relaxation property.
Below, illustrate that composition of the present invention limits reason and creates conditions.
<C>
C improves hardenability, the necessary element of raising intensity.If not enough 0.2wt% then can not guarantee the intensity of PC reinforcing bar.If surpassed 0.7wt%, the side extensibility is poor.Therefore, the C amount should be 0.2～0.7wt%.On the other hand, under the situation that the some postwelding uses, if surpassed 0.5wt%, then spot weldability is poor.Therefore, under the situation of spot welding PC reinforcing bar, the C amount should be 0.2～0.5wt%.The element that C still makes tempering temperature rise under the condition of the addition that increases Si+Al, can reduce surrender and when improve uniformly extension.When not enough 0.5wt%, extensibility is greatly improved.
<Si，Al>
Si and Al use as deoxidation material, and be not only favourable to relaxation property, also can improve uniform elongation.But during the quantity not sufficient 2.0wt% of Si+Al, its effect reduces, when surpassing 5.0wt%, and relaxation property and spot-welded on variation.Therefore, the amount of Si+Al should be 2.0wt%～5.0wt%.
<Mn>
Mn and Si similarly use as deoxidation material, and similarly are the raising hardenabilities and improve the necessary element of intensity with C.But when it used quantity not sufficient 0.2wt%, effect reduced, and when surpassing 3.0wt%, processibility significantly reduces.Therefore, the consumption of Mn should be 0.2～3.0wt%.In particular for when obtaining good processibility, the amount of Mn is preferably in below the 2.0wt%.
<Nb、Ti、B、Ni、Cr、Mo、Cu>
Nb, Ti, B, Ni, Cr, Mo, each element of Cu are the elements that can improve hardenability, according to the intensity and the toughness of required reinforcing bar, add wherein more than a kind or 2 kinds.But, can not get above-mentioned effect at least if consumption is crossed.Too much can not further improve effect.Therefore, its consumption should be Nb:0.01～0.1wt%, Ti:0.01～0.05wt%, B:0.0003～0.005wt%, Ni:0.2～1.0wt%, Cr:0.1～1.0wt%, Mo:0.05～0.5wt% and Cu:0.2～1.0wt%.
＜metal structure 〉
PC reinforcing bar of the present invention is the tissue that tempered martensite constitutes basically, and the carbide in the tempered martensite is mean diameter fine granular below 0.1 μ m.What is called is the tissue that tempered martensite constitutes basically, is meant so long as in the not damaged scope of the characteristic of tempered martensite, also can contain other tissue, for example bainite, ferrite.
The variation of the carbide morphology in the tempered martensite, the easy degree that produces by the space or to the influence of work hardening has a significant impact uniformly extension.Carbide morphology is if shaft-like or tabular, and then itself splits easily, and the stress concentration of leading section is big and be easy to generate the space, so uniform elongation reduces.Therefore, carbide morphology is necessary for granular.In addition, even carbide morphology is granular,, then be not easy work hardening, so the size of granular carbide should be below 0.1 μ m if its mean diameter surpasses 0.1 μ m.
＜manufacture method 〉
The manufacture method of PC reinforcing bar of the present invention is the steel that mentioned component is arranged according to the molten fixture of well-established law, round steel is carried out cold working such as hot rolling or drawing and obtains reinforcing bar base material, again this reinforcing bar base material is carried out a series of thermal treatment (quenching, tempering etc.).Do not need to invest the operation of distortion in the manufacture method of PC reinforcing bar of the present invention.
Quenching temperature has big influence by the variation of particle diameter to yield ratio.And also significantly improve uniformly extension thereupon.When 1160 ℃ of quenching temperature less thaies, particle diameter is little, and the little amplitude of yield ratio reduces, so quenching temperature should be more than 1160 ℃.In addition, if quenching temperature has surpassed 1300 ℃, then decarburization is remarkable, so should be below 1300 ℃.
In order to significantly improve uniformly extension, quenching temperature is preferably in more than 600 ℃.
The characteristic of＜PC reinforcing bar 〉
With the PC reinforcing bar that this manufacturing process obtains, the intensity (1080N/mm of B kind specification
2More than) person, uniform elongation is more than 8.0%.Intensity (the 1230N/mm of C kind specification
2More than) person, uniform elongation is more than 6%, the lax value of high temperature is below 8%.In addition, by the high steel of quench hot C content, the intensity (tensile strength 〉=1080N/mm of B kind specification
2, endurance 〉=930N/mm
2) person, uniform elongation is more than 11.0%, and yield ratio is below 0.85, and the lax value of high temperature is below 8%.Intensity (tensile strength 〉=the 1230N/mm of C kind specification
2, endurance 〉=1080N/mm
2) person, uniform elongation is more than 10.0%, and yield ratio is below 0.87, and the lax value of high temperature is below 8%.Intensity (tensile strength 〉=the 1420N/mm of D kind specification
2, endurance 〉=1275N/mm
2) person, uniform elongation is more than 8.0%, and yield ratio is below 0.9, and the lax value of high temperature is below 8%.
In addition, implementing on the PC reinforcing bar of the present invention under the situation of spot welding,, can guarantee good uniformly extension and high temperature relaxation property by after spot welding, carrying out the tempering energising.
The method according to this invention does not need to invest the operation of distortion, available common operation manufacturing, and, can provide tensile strength at 1080N/mm
2More than, high uniform elongation and low yielding ratio, the good PC reinforcing bar of high temperature relaxation property.Therefore, can increase substantially productivity, improve the reliability of prestressed reinforced concrete structure widely, be extremely useful to construction industry.
Fig. 1 is the figure of the temperature cycle in the relaxation test of expression high temperature.
The following describes better embodiment of the present invention.
(embodiment 1)
Steel of the present invention (No.1～13) and comparative steel (No.14～19) conduct test steel with component shown in the table 1.Round steel to diameter 24mm is rolled, the round steel of diameter 23mm is carried out drawing, carries out Q-tempering with ratio-frequency heating then.Thermal treatment is not limited to ratio-frequency heating.Here, quenching temperature is 930 ℃～1100 ℃, and tempering is that each test steel is carried out with 2 standards, so that obtain the B kind among the JISG3109 (JISG3137) and the intensity of C kind specification.Then, they are carried out tension test.The mensuration of uniform elongation is carried out like this: every 2d (d is a diameter) makes a mark on the test material, locates more than broken part 5d, measures as gauge length with 10d.The result of tension test is as shown in table 2.Relaxation test is at room temperature to use the method for JISG3109 (JISG3137 too) to carry out.Though stipulated 1000 one hour values from 1994,, still estimated specifically with 10 former one hour values for for simplicity.That is, at room temperature, 70% stress of effect specification tensile strength is measured the loading variable quantity after 10 hours, uses with the ratio of initial loading and estimates.In addition, the high temperature relaxation test is to carry out under 180 ℃, pays 70% the stress add the specification tensile strength, and with pattern heating cooling shown in Figure 1, determination test begins the loading variation after 23 hours, uses with the ratio of initial loading and estimates.Carbide morphology in the tempered martensite and size are with extracting the residue method out, using the infiltration type electron microscope observation.The diameter of carbide carries out 5 visuals field with 89000 times to be observed, and calculates mean value.Its result is as shown in table 2.
As shown in table 2, the steel of the present invention from No.1 to No.13, the intensity (tensile strength 〉=1080N/mm of its B kind specification
2, endurance 〉=930N/mm
2) person, uniform elongation is more than 8.0%, the lax value of high temperature is below 8%.Intensity (tensile strength 〉=the 1230N/mm of C kind specification
2, endurance 〉=1080N/mm
2) person, uniform elongation is more than 6%, the lax value of high temperature is below 8%.Two specific characters all increase substantially than existing steel characteristic.In addition, the carbide in the tempered martensite is granular, and its diameter is all below 0.1 μ m.
In contrast to this, though comparative steel No.14 also has good relaxation property, because C content has surpassed 0.7wt%, so carbide is thick, extensibility is poor.No.15 is because Mn has surpassed 3.0wt%, so extensibility is poor.No.16 is because the quantity not sufficient 2wt% of Si+Al, thus not only can not get enough uniform elongations, and also relaxation property is also poor.In addition, the carbide in this comparative steel is shaft-like.No.1 7 is because the amount of Si+Al has surpassed 5wt%, so relaxation property reduces.Though No.18 and No.19 chemical ingredients are suitable, the form of carbide is shaft-like among the No.18, though the form of carbide is that granular its diameter has surpassed 0.1 μ m among the No.19, so uniform elongation is low.
(embodiment 2)
In steel of the present invention of component shown in the table 1 (No.1～13) and the comparative steel (No.14～19), with the test steel of C content below 0.5wt%, being rolled into diameter is the round muscle of 8mm, and being drawn into diameter is the abnormity circle muscle of 7.1mm, carries out Q-tempering with ratio-frequency heating then.Thermal treatment is not limited to ratio-frequency heating.Quenching temperature is 930 ℃～1100 ℃, and tempering is to carry out under the felicity condition of the B kind specification intensity in obtaining JISG3109 (JISG3137).The reinforcing bar of making is carried out spot welding under following welding conditions, tension test and relaxation test are carried out in welding back tempering and energising.
Welding tempered condition: welding current=2500A, temper current=2700A, power cycles number=2, plus-pressure=410N, spiral bar=SWRM8-3.2mm φ.
Uniformly extension and relaxation test method are as hereinbefore.Its result of table 3 expression.As seen from Table 3, steel of the present invention is switched on by tempering at a postwelding, also can guarantee the uniform elongation more than 6%, has good relaxation property.
Table 1 table 1 (wt%)
Notes) the * mark represents to break away from the scope of the invention
| ??No. | ????C | ???Si | ????Mn | ?????P | ?????S | ????A1 | ???Si+Al | ???Nb | ???Ti | ????B | ????Ni | ???Cr | ???Mo | ????Cu | |
| Steel of the present invention | ???1 ???2 ???3 ???4 ???5 ???6 ???7 ???8 ???9 ??10 ??11 ??12 ??13 | ???0.22 ???0.33 ???0.46 ???0.65 ???0.32 ???0.31 ???0.3 ???0.33 ???0.32 ???0.32 ???0.32 ???0.30 ???0.31 | ??3.02 ??3.04 ??2.98 ??3.01 ??3.54 ??4.01 ??3.52 ??3.08 ??3.05 ??2.03 ??2.52 ??4.08 ??4.02 | ???0.72 ???0.69 ???0.65 ???0.68 ???0.73 ???0.74 ???0.73 ???1.54 ???2.56 ???0.73 ???0.72 ???2.01 ???2.74 | ???0.007 ???0.006 ???0.008 ???0.008 ???0.007 ???0.007 ???0.007 ???0.007 ???0.005 ???0.005 ???0.007 ???0.007 ???0.005 | ???0.008 ???0.008 ???0.008 ???0.009 ???0.007 ???0.008 ???0.006 ???0.008 ???0.008 ???0.008 ???0.009 ???0.008 ???0.006 | ???0.023 ???0.021 ???0.022 ???0.02 ???0.027 ???0.022 ???1.28 ???0.021 ???0.024 ???0.024 ???0.021 ???0.022 ???0.024 | ???3.04 ???3.06 ???3.00 ???3.03 ???3.57 ???4.03 ???4.80 ???3.1 ???3.07 ???2.05 ???2.54 ???4.1 ???4.04 | ??0.04 ??0.04 | ??0.02 ??0.02 ??0.02 | ???0.002 ???0.003 ???0.003 | ???0.5 ???0.5 | ???0.5 ???0.8 | ???0.1 ???0.2 | ????0.3 |
| Comparative steel | ??14 ??15 ??16 ??17 ??18 ??19 | ???0.73 *???0.31 ???0.32 ???0.31 ???0.66 ???0.68 | ??2.53 ??3.56 ??1.01 ??4.03 ??1.15 ??2.26 | ???0.72 ???3.18 *???0.71 ???0.72 ???2.78 ???0.68 | ???0.006 ???0.006 ???0.007 ???0.007 ???0.007 ???0.006 | ???0.006 ???0.006 ???0.008 ???0.007 ???0.008 ???0.008 | ???0.035 ???0.020 ???0.021 ???1.21 ???1.26 ???0.029 | ???2.57 ???3.58 ???1.03 *???5.24 *???2.41 ???2.29 | ??0.03 | ??0.02 | ???0.002 |
Table 2
*Mark represents to break away from the scope of the invention
| ????No. | Quenching temperature (℃) | Tempering temperature (℃) | Tension test | Relaxation test | Carbide morphology | Carbide diameter (μ m) | |||||
| 0.2% endurance (N/mm 2) | Tensile strength (N/mm 2) | Unit elongation (%) | Uniformly extension (%) | Normal temperature (%) | ???180℃ ???(％) | ||||||
| Steel of the present invention | 1, (B kind) 1, (C kind) 2, (B kind) 2, (C kind) 3, (B kind) 3, (C kind) 4, (B kind) 4, (C kind) 5, (B kind) 5, (C kind) 6, (B kind) 6, (C kind) 7, (B kind) 7, (C kind) 8, (B kind) 8, (C kind) 9, (B kind) 9, (C kind) 10, (B kind) 10, (C kind) 11, (B kind) 11, (C kind) 12, (B kind) 12, (C kind) 13, (B kind) 13, (C kind) | ??1040 ??1040 ??1020 ??1020 ??990 ??990 ??960 ??960 ??1080 ??1080 ??1090 ??1090 ??1100 ??1100 ??1000 ??1000 ??980 ??980 ??940 ??940 ??960 ??960 ??1070 ??1070 ??1040 ??1040 | ??630 ??560 ??670 ??600 ??690 ??620 ??710 ??630 ??695 ??630 ??730 ??665 ??670 ??600 ??670 ??600 ??680 ??610 ??680 ??600 ??710 ??610 ??740 ??670 ??740 ??675 | ???1056 ???1215 ???1090 ???1223 ???1068 ???1231 ???1084 ???1211 ???1041 ???1170 ???1060 ???1183 ???1051 ???1177 ???1058 ???1207 ???1078 ???l219 ???1136 ???1256 ???1123 ???1270 ???1066 ???1210 ???1054 ???1208 | ????1132 ????1267 ????1168 ????1275 ????1145 ????1284 ????1162 ????1263 ????1143 ????1250 ????1150 ????1250 ????1154 ????1257 ????1134 ????1259 ????1155 ????1271 ????1169 ????1286 ????1155 ????1300 ????1156 ????1279 ????1143 ????1277 | ????17.8 ????15.6 ????17.5 ????15.8 ????17.6 ????15.2 ????18 ????15.1 ????19.3 ????16.2 ????20.3 ????16.6 ????19.6 ????16.4 ????17.4 ????15.5 ????18.9 ????16.2 ????17.5 ????12.9 ????16.6 ????13.7 ????21.5 ????17.2 ????22.8 ????18.1 | ????8?5 ????6.8 ????8.4 ????6.9 ????8.6 ????6.7 ????8.4 ????6.9 ????12.1 ????8.3 ????13.?2 ????10.3 ????12.2 ????7.9 ????8.6 ????7.0 ????9?0 ????7.2 ????8.2 ????6.1 ????8.8 ????6.4 ????14.1 ????11.2 ????14.8 ????11.8 | ???0.54 ???0.53 ???0.41 ???0.43 ???0.39 ???0.38 ???0.39 ???0.40 ???0.41 ???0.44 ???0.38 ???0.38 ???0.48 ???0.49 ???0.53 ???0.52 ???0.54 ???0.53 ???0.55 ???0.57 ???0.58 ???0.59 ???0.50 ???0.54 ???0.55 ???0.53 | ????6?5 ????6.6 ????6.4 ????6.2 ????6.0 ????6.0 ????6?1 ????6.3 ????6.3 ????6.5 ????5.9 ????6.3 ????6.5 ????6.4 ????6.5 ????6.4 ????6.8 ????6.7 ????6.3 ????6.5 ????6.5 ????6.8 ????6.2 ????6.5 ????6.5 ????6.2 | Granular granular granular | ?????0.02 ?????0.01 ?????0.03 ?????0.02 ?????0.05 ?????0.03 ?????0.09 ?????0.06 ?????0.03 ?????0.02 ?????0.02 ?????0.01 ?????0.03 ?????0.02 ?????0.04 ?????0.02 ?????0.05 ?????0.03 ?????0.04 ?????0.03 ?????0.04 ?????0.02 ?????0.02 ?????0.01 ?????0.03 ?????0.02 |
| Comparative steel | 14 (B kinds) 14 (C kind), 15 (B kinds) 15 (C kind), 16 (B kinds) 16 (C kind), 17 (B kinds) 17 (C kind), 18 (B kinds) 18 (C kind), 19 (B kinds) 19 (C kind) | ??930 ??930 ??1030 ??1030 ??930 ??930 ??1100 ??1100 ??940 ??940 ??930 ??930 | ??730 ??630 ??695 ??630 ??620 ??530 ??710 ??615 ??730 ??650 ??710 ??600 | ???1119 ???1235 ???1045 ???1193 ???1128 ???1256 ???1060 ???1203 ???1062 ???1220 ???1115 ???1224 | ????1151 ????1264 ????1147 ????1275 ????1161 ????1286 ????1150 ????1272 ????1156 ????1275 ????1149 ????1267 | ????11.2 ????10.7 ????13.1 ????12.2 ????11.8 ????11.6 ????20.2 ????16.4 ????17.3 ????15.5 ????11.5 ????10.6 | ????5.6 *????5.2 *????6.3 *????5.4 *????5.8 *????5.8 *????12.9 ????10.1 ????7.3 *????5.7 *????5.9 *????5.6 * | ???0.45 ???0.47 ???0.44 ???0.47 ???0.73 ???0.78 ???0.87 ???0.89 ???0.68 ???0.67 ???0.46 ???0.47 | ????5.8 ????6.0 ????6.8 ????6.8 ???10.2 *???11.0 *???11.5 *???11.3 *????9.7 *????9.5 *????5.8 ????6.3 | Granular shaft-like *Shaft-like *Granular shaft-like *Shaft-like *Granular | ?????0.17 *?????0.14 *0.07 0.05 0.15 (length) 0.12 (length), 0.03 0.02 0.2 (length) 0.17 (length) 0.14*?????0.11 * |
Table 3
Annotate)
*Mark represents to break away from the scope of the invention
| ??No. | Quenching temperature (℃) | Tempering temperature (℃) | Tension test | Loose test | |||||
| 0.2% endurance (N/mm 2) | Tensile strength (N/mm 2) | Unit elongation (%) | Uniformly extension (%) | Normal temperature (%) | ???180℃ ????(％) | ||||
| Steel of the present invention | ??1 ??2 ??3 ??4 ??5 ??6 ??7 ??8 ??9 ?10 ?11 ?12 ?13 | ???1040 ???1020 ????990 ????- ???1080 ???1090 ???1100 ???1000 ????980 ????940 ????960 ???1070 ???1040 | ????630 ????670 ????690 ?????- ????695 ????730 ????670 ????670 ????680 ????680 ????710 ????740 ????740 | ????1048 ????1078 ????1045 ?????- ????1037 ????1055 ????1045 ????1039 ????1068 ????1032 ????1021 ????1056 ????1050 | ???1128 ???1165 ???1123 ????- ???1142 ???1148 ???1150 ???1130 ???1149 ???1166 ???1152 ???1151 ???1139 | ???13.2 ???13.5 ???14.2 ????- ???13.9 ???12.8 ???13.1 ???14.5 ???13.7 ???13.7 ???14.1 ???12.9 ???13.0 | ????6.5 ????6.3 ????6.5 ?????- ????6.7 ????6.9 ????6.8 ????6.3 ????6.5 ????6.4 ????6.7 ????6.3 ????6.3 | ???0.55 ???0.46 ???0.41 ????- ???0.39 ???0.40 ???0.47 ???0.52 ???0.57 ???0.60 ???0.56 ???0.47 ???0.51 | ?????6.6 ?????6.6 ?????6.0 ??????- ?????6.1 ?????6.0 ?????6.7 ?????6.2 ?????6.5 ?????6.3 ?????6.8 ?????6.6 ?????6.5 |
| Comparative steel | ?14 ?15 ?16 ?17 | ????- ???1030 ????930 ???1100 | ?????- ????695 ????620 ????710 | ?????- ????1034 ????1115 ????1047 | ????- ???1142 ???1154 ???1145 | ????- ???12.9 ???11.5 ????6.5 | ?????- ????5.9 *????5.7 *????3.2 * | ?????- ????0.41 ????0.71 ????0.87 | ??????- ?????7.2 ????10.8 *????12.1 * |
(embodiment 3)
As the test steel, be rolled into the round muscle of diameter 8mm with the steel of component shown in the table 4, the abnormity that is drawn into diameter 7.1mm is justified muscle, carries out Q-tempering with ratio-frequency heating then.Thermal treatment is not limited to ratio-frequency heating.Quenching temperature is 1160 ℃～1300 ℃ (examples of the present invention), and tempering is to carry out under the felicity condition of C kind in obtaining JISG3109 (JISG3137) or D kind specification intensity.Then they are carried out tension test.The mensuration of uniformly extension is carried out like this: every 2d (d is a diameter) makes a mark on the test material, locates more than broken part 5d, measures as gauge length with 10d.The result of tension test is as shown in table 5.Relaxation test is at room temperature to use the method for JISG3109 (JISG3137 too) to carry out.Though stipulated 1000 one hour values from l994,, still estimated similarly to Example 1 specifically with 10 former one hour values for for simplicity.In addition, the high temperature relaxation test is to carry out under 180 ℃, pays 70% the stress add the specification tensile strength, and with pattern heating cooling shown in Figure 1, determination test begins the loading variation after 23 hours, uses with the ratio of initial loading and estimates.Its result is as shown in table 5.
As shown in table 5, in the example of the present invention of No.1～No.13, the intensity (tensile strength 〉=1230N/mm of its C kind specification
2, endurance 〉=1080N/mm
2) person, uniform elongation is more than 10.0%, and yield ratio is below 0.87, and the lax value of high temperature is below 8%.Intensity (tensile strength 〉=the 1420N/mm of D kind specification
2, endurance 〉=1275N/mm
2) person, uniform elongation is more than 8%, and yield ratio is below 0.90, and the lax value of high temperature is below 8%.Two characteristics all increase substantially than existing steel characteristic.In addition, in order to significantly improve uniform elongation,,, can obtain the intensity of D kind specification, guarantee the uniform elongation more than 8% easily with the high tempering more than 600 ℃ with the steel of component of the present invention though tempering temperature is preferably in more than 600 ℃.
In contrast to this, comparative example No.14 contains quantity not sufficient because of C, and No.16 is because of the quantity not sufficient of Si+Al, so tempering temperature is low, yield ratio does not significantly reduce, uniform elongation also significantly variation, promptly in D kind specification, be 4～5%, in C kind specification, be 7% about.Though No.15 and No.17 tempering temperature height, yield ratio are low, but owing to its C content, Mn content have all surpassed appropriate amount, so its uniform elongation is lower than the present invention, the uniform elongation of the uniform elongation that can not reach target value, promptly can not cross the specification requirement of C kind more than 10.0%, the specification requirement of D kind is more than 8%.Though its chemical ingredients of No.18 is suitable, reach 1100 ℃ because quenching temperature is low, so yield ratio does not reduce, uniform elongation does not reach target value yet.
(embodiment 4)
As the test steel, be rolled into the round muscle of diameter 24mm with the steel of component shown in the table 4, the abnormity that is drawn into diameter 23mm is justified muscle, carries out Q-tempering with ratio-frequency heating then.Thermal treatment is not limited to ratio-frequency heating.Quenching temperature is 1160 ℃～1300 ℃ (the present invention), and tempering is to carry out under the felicity condition of the B kind specification intensity in obtaining JISG3109 (JISG3137).Then they are carried out tension test and relaxation test.Test method is identical with embodiment 3.
Heat-treat condition and the mechanism's character that obtains are as shown in table 6.In the example of the present invention of No.1～No.13, the intensity person of its B kind specification, uniform elongation is more than 11.0%, and yield ratio is below 0.85, and the lax value of high temperature is below 8%.Two characteristics all increase substantially than existing steel.And among the comparative example No.14, because its C contains quantity not sufficient, owing to the quantity not sufficient that contains of its Si+Al, so tempering temperature is lower than the present invention example, similarly to Example 3, yield ratio does not significantly reduce among the No.16, and uniform elongation is also poor, only reaches 8% in B kind specification.Among No.15 and the No.17,, can not reach target value, promptly can not reach this uniform elongation more than 11.0% of B kind specification requirement though tempering temperature height, yield ratio are low.No.18 though its chemical ingredients is suitable, reaches 1100 ℃ because quenching temperature is low also similarly to Example 3, so yield ratio does not reduce, uniform elongation does not reach target value yet.
The Chemical Composition of table 4 test steel
| ???NO | ???C???????Si??????Mn???????P?????S??????Al????Si+Al???Nb????Ti????B??????Ni?????Cr??????Mo???Cu | |
| Steel of the present invention | ???1 ???2 ???3 ???4 ???5 ???6 ???7 ???8 ???9 ???10 ???11 ???12 ???13 | ??0.52????3.02????0.7?????0.007??0.007??0.02???3.04?????????0.02??0.002 ??0.6?????3.01????0.68????0.008??0.009??0.02???3.03?????????0.02??0.002 ??0.68????3.06????0.68????0.007??0.009??0.02???3.08 ??0.62????3.55????0.72????0.009??0.008??0.03???3.58 ??0.61????2.27????0.76????0.009??0.008??0.02???2.29 ??0.59????2.51????0.72????0.007??0.007??2.13???4.64 ??0.6?????3.01????0.38????0.007??0.009??0.03???3.04 ??0.62????3.06????1.2?????0.007??0.007??0.02???3.08 ??0.62????3.09????1.85????0.008??0.007??0.020??3.11 ??0.60????3.02????0.7?????0.007??0.008??0.020??3.04???0.02??0.02???0.002 ??0.60????3.04????0.7?????0.009??0.008??0.030??3.07?????????0.02???0.002????????0.5??????0.1 ??0.58????3.02????0.72????0.007??0.008??0.020??3.04??????????????????????0.32 ??0.60????3.04????0.74????0.008??0.008??0.030??3.07??????????????????????0.28???????????????????0.2 |
| Comparative steel | ???14 ???15 ???16 ???17 ???18 | ??0.32 *??3.02????0.72????0.007??0.007??0.02???3.04?????????0.02???0.002 ??0.78 *??3.01????0.7?????0.007??0.008??0.020??3.03???0.02??0.02???0.0020 ??0.58????1.53????0.8?????0.008??0.008??0.260??1.79 *????????????????????0.3????0.5??????0.1 ??0.6?????3.04????3.12 *??0.007??0.008??0.02???3.06 ??0.6?????3.01????0.68????0.008??0.009??0.02???3.03???0.02??0.002 |
The mechanical properties of table 5 test steel
| ?NO. | Seed is other | Quenching temperature (℃) | Tempering temperature (℃) | Endurance N/mm2 | Tensile strength N/mm2 | Disrumpent feelings unit elongation (%) | Uniformly extension (%) | Yield ratio | The lax value of normal temperature (%) | 180 ℃ of relaxs (%) | |
| Steel of the present invention | ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9 ?10 ?11 ?12 ?13 | ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C | ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1250 ??1250 ??1200 ??1200 ??1200 ??1200 ??1250 ??1250 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 | ???630 ???720 ???670 ???745 ???700 ???760 ???690 ???760 ???640 ???720 ???650 ???730 ???670 ???745 ???670 ???745 ???680 ???755 ???670 ???745 ???670 ???745 ???670 ???745 ???670 ???745 | ??1310 ??1101 ??1306 ??1087 ??1281 ??1085 ??1283 ??1081 ??1310 ??1091 ??1278 ??1082 ??1300 ??1122 ??1286 ??1083 ??1288 ??1089 ??1310 ??1095 ??1312 ??1088 ??1302 ??1092 ??1304 ??1084 | ??1456 ??1265 ??1489 ??1295 ??1490 ??1292 ??1475 ??1303 ??1472 ??1283 ??1452 ??1288 ??1444 ??1290 ??1478 ??1274 ??1481 ??1297 ??1489 ??1288 ??1474 ??1280 ??1480 ??1285 ??1465 ??1290 | ???13.2 ???15.6 ???13.4 ???16 ???14 ???16.8 ???13.8 ???16.7 ???13 ???15.4 ???13 ???15.6 ???13.1 ???15.8 ???13.8 ???16.5 ???14.2 ???16.6 ???13.5 ???16.2 ???13.4 ???16.1 ???13.8 ???16.5 ???13.7 ???16.2 | ????8.2 ????10.1 ????8.5 ????10.3 ????8.7 ????10.5 ????8.7 ????10.6 ????8.2 ????10.1 ????8.1 ????10 ????8.4 ????10.1 ????8.6 ????10.7 ????8.6 ????10.7 ????8.5 ????10.2 ????8.4 ????10.4 ????8.4 ????10.4 ????8.3 ????10.5 | ?????0.90 ?????0.87 ?????0.88 ?????0.84 ?????0.86 ?????0.84 ?????0.87 ?????0.83 ?????0.89 ?????0.85 ?????0.88 ?????0.84 ?????0.90 ?????0.87 ?????0.87 ?????0.85 ?????0.87 ?????0.84 ?????0.88 ?????0.85 ?????0.89 ?????0.85 ?????0.88 ?????0.85 ?????0.89 ?????0.84 | ???0.62 ???0.61 ???0.68 ???0.72 ???0.62 ???0.65 ???0.66 ???0.66 ???0.68 ???0.72 ???0.63 ???0.69 ???0.70 ???0.72 ???0.69 ???0.65 ???0.62 ???0.64 ???0.70 ???0.72 ???0.63 ???0.63 ???0.65 ???0.66 ???0.62 ???0.70 | ????6.3 ????6.2 ????6.0 ????6.1 ????6.7 ????6.3 ????7.0 ????6.1 ????5.9 ????6.1 ????6.3 ????6.2 ????7.2 ????6.2 ????5.8 ????6.3 ????6.0 ????6.2 ????6.6 ????6.4 ????7.1 ????6.1 ????6.8 ????6.1 ????5.6 ????6.2 |
| Comparative steel | ?14 ?15 ?16 ?17 ?18 | ??D ??C ??D ??C ??D ??C ??D ??C ??D ??C | ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1200 ??1100 *??1100 * | ???520 ???600 ???720 ???780 ???590 ???685 ???680 ???760 ???670 ???745 | ??1410 ??1184 ??1285 ??1065 ??1384 ??1199 ??1278 ??1088 ??1368 ??1147 | ??1469 ??1260 ??1460 ??1268 ??1457 ??1275 ??1469 ??1295 ??1471 ??1289 | ???10.3 ???15.8 ???12.6 ???14.8 ????7.9 ???10.2 ???12.5 ???14.3 ???13.6 ???15.9 | ????4.9 ????6.9 ????7.3 ????9.4 ????4.2 ????6.8 ????7.2 ????9.5 ????5.9 ????7.3 | ?????0.96 ?????0.94 ?????0.88 ?????0.84 ?????0.95 ?????0.94 ?????0.87 ?????0.84 ?????0.93 ?????0.89 | ???0.68 ???0.47 ???0.65 ???0.62 ???0.78 ???0.76 ???0.63 ???0.65 ???0.68 ???0.73 | ????6.8 ????6.9 ????6.7 ????6.1 ????8.0 ????7.5 ????6.5 ????6.7 ????6.1 ????6.2 |
The mechanical properties of table 6 test steel
| ?No. | Species | Quenching temperature (℃) | Tempering temperature (℃) | Endurance N/mm2 | Tensile strength N/mm2 | Disrumpent feelings unit elongation (9) | Uniform elongation (%) | Yield ratio | The lax value of normal temperature (%) | 180 ℃ of relaxs (%) | |
| Steel of the present invention | ??1 ??2 ??3 ??4 ??5 ??6 ??7 ??8 ??9 ?10 ?11 ?12 ?13 | ??B ??B ??B ??B ??B ??B ??B ??B ??B ??B ??B ??B ??B | ??1200 ??1200 ??1200 ??1200 ??1200 ??1250 ??1200 ??1200 ??1250 ??1200 ??1200 ??1200 ??1200 | ???740 ???780 ???810 ???800 ???750 ???760 ???780 ???780 ???790 ???780 ???780 ???780 ???780 | ???1005 ???968 ???964 ???940 ???984 ???937 ???1000 ???958 ???961 ???967 ???944 ???955 ???972 | ??1182 ??1180 ??1175 ??1160 ??1186 ??1143 ??1176 ??1154 ??l172 ??1165 ??1137 ??1150 ??1185 | ??17.6 ??18 ??18.9 ??18.6 ??17.4 ??17.6 ??17.6 ??18.5 ??18.4 ??18.3 ??18.2 ??18.5 ??18.2 | ???11.6 ???11.8 ???12.2 ???12.1 ???11.8 ???11.7 ???12.0 ???12.2 ???12.2 ???11.9 ???12.0 ???11.9 ???12.1 | ???0.85 ???0.82 ???0.82 ???0.81 ???0.83 ???0.82 ???0.85 ???0.83 ???0.82 ???0.83 ???0.83 ???0.83 ???0.82 | ???0.62 ???0.70 ???0.65 ???0.64 ???0.70 ???0.66 ???0.72 ???0.67 ???0.63 ???0.70 ???0.64 ???0.66 ???0.66 | ????6.3 ????6.2 ????6.4 ????6.6 ????6.0 ????6.2 ????6.8 ????6.1 ????6.2 ????6.5 ????6.6 ????6.6 ????5.9 |
| Comparative steel | ?14 ?15 ?16 ?17 ?18 | ??B ??B ??B ??B ??B | ??1200 ??1200 ??1200 ??1200 ??1100 * | ???670 ???790 ???700 ???790 ???780 | ???1080 ???980 ???1042 ???973 ???1018 | ??1174 ??1195 ??1133 ??1186 ??1170 | ??17.8 ??16.9 ??12.4 ??16.2 ??17.9 | ????8.4 ???10.6 ????8.3 ???10.8 ????9.5 | ???0.92 ???0.82 ???0.92 ???0.82 ???0.87 | ???0.51 ???0.65 ???0.76 ???0.64 ???0.71 | ????6.4 ????6.4 ????7.8 ????6.5 ????6.2 |
Claims (13)
1. uniformly extension and the good PC reinforcing bar of high temperature relaxation property is characterized in that, in weight %, contain C:0.2～0.7%, Mn:0.2～3.0%, (Si%+Al%): 2.0～5.0%;
Basically be the tissue that tempered martensite constitutes, and the carbide in the tempered martensite is mean diameter fine granular below 0.1 μ m, tensile strength: 1080N/mm
2Above 1420N/mm
2Below.
2. the good PC reinforcing bar of uniformly extension and high temperature relaxation property according to claim 1, it is characterized in that, in weight %, the composition of steel also contains from Nb:0.0 1～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, Mo:0.05～0.5%, the composition of selecting in Cu:0.2～1.0% more than a kind or 2 kinds.
3. uniformly extension and the good PC reinforcing bar of high temperature relaxation property, it is characterized in that, in weight %, the composition of steel is by C:0.2～0.7%, Mn:0.2～3.0%, (Si%+Al%): 2.0～5.0% and from Nb:0.0 1～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, Mo:0.05～0.5%, composition of selecting in Cu:0.2～1.0% more than a kind or 2 kinds and the Fe of the remnants of defeated troops and inevitable impurity constitute
Basically be the tissue that tempered martensite constitutes, and the carbide in the tempered martensite is mean diameter fine granular below 0.1 μ m, below the above 1420N/mm2 of tensile strength: 1080N/mm2.
4. as uniformly extension and the good PC reinforcing bar of high temperature relaxation property as described in the claim 1 to 3 each, it is characterized in that tensile strength 〉=1080N/mm2, endurance 〉=930N/mm2.
5. as uniformly extension and the good PC reinforcing bar of high temperature relaxation property as described in the claim 1 to 3 each, it is characterized in that tensile strength 〉=1230N/mm2, endurance 〉=1080N/mm2.
6. as uniformly extension and the good PC reinforcing bar of high temperature relaxation property as described in the claim 1 to 5 each, it is characterized in that, C amount: 0.2～0.5wt%, be used for carrying out tempering energising purposes after spot welding and the spot welding.
7. one kind has 1080N/mm
2The manufacture method of the PC reinforcing bar that uniform elongation above tensile strength, high and low yielding ratio, high temperature relaxation property are good, it is characterized in that, in weight %, the steel that contains C:0.5～0.7%, Mn:0.2～2.0%, 2.0%≤Si%+Al%≤5.0%, from 1160～1300 ℃ of quenchings, tempering then.
8. one kind has 1080N/mm
2The manufacture method of the PC reinforcing bar that uniform elongation above tensile strength, high and low yielding ratio, high temperature relaxation property are good, it is characterized in that, in weight %, contain C:0.5～0.7%, Mn:0.2～2.0%, 2.0%≤Si%+Al%≤5.0%, also contain Nb:0.01～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, Mo:0.05～0.5%, the steel of composition more than a kind or 2 kinds in Cu:0.2～1.0% is from 1160 ℃～1300 ℃ quenchings, tempering then.
9. one kind has 1080N/mm
2Above tensile strength, high uniform elongation and low yielding ratio, the manufacture method of the PC reinforcing bar that the high temperature relaxation property is good, it is characterized in that, in weight %, by C:0.5～0.7%, Mn:0.2～2.0%, 2.0%≤Si%+Al%≤5.0% and Nb:0.01～0.1%, Ti:0.01～0.05%, B:0.0003～0.005%, Ni:0.2～1.0%, Cr:0.1～1.0%, the steel that composition more than a kind or 2 kinds in Mo:0.05～0.5% and Cu:0.2～1.0% and the Fe of the remnants of defeated troops and inevitable impurity constitute, from 1160 ℃～1300 ℃ quenchings, tempering then.
10. as each the described manufacture method in the claim 7 to 9, it is characterized in that tensile strength 〉=1230N/mm
2, endurance 〉=1080N/mm
2The intensity level, uniform elongation is more than 10.0%, yield ratio is below 0.87%, the lax value of high temperature is below 8%.
11. each the described manufacture method as in the claim 7 to 9 is characterized in that tensile strength 〉=1420N/mm
2, endurance 〉=1275N/mm
2The intensity level, uniform elongation is more than 8.0%, yield ratio is below 0.9%, the lax value of high temperature is below 8%.
12. each the described manufacture method as in the claim 7 to 9 is characterized in that tensile strength 〉=1080N/mm
2, endurance 〉=930N/mm
2The intensity level, uniform elongation is more than 11.0%, yield ratio is below 0.85%, the lax value of high temperature is below 8%.
13. each the described manufacture method as in the claim 7 to 12 is characterized in that tempering temperature is more than 600 ℃.
Applications Claiming Priority (12)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP184943/96 | 1996-07-15 | ||
| JP184943/1996 | 1996-07-15 | ||
| JP18494396 | 1996-07-15 | ||
| JP012558/97 | 1997-01-27 | ||
| JP1255897 | 1997-01-27 | ||
| JP012558/1997 | 1997-01-27 | ||
| JP147866/97 | 1997-06-05 | ||
| JP147865/97 | 1997-06-05 | ||
| JP147865/1997 | 1997-06-05 | ||
| JP9147865A JPH1081936A (en) | 1996-07-15 | 1997-06-05 | Pc steel bar excellent in uniform elongation and high temperature relaxation characteristic |
| JP147866/1997 | 1997-06-05 | ||
| JP9147866A JPH10265904A (en) | 1997-01-27 | 1997-06-05 | Production of pc steel bar having high uniform elongation, low yield ratio, and excellent high temperature relaxation characteristic |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1177648A true CN1177648A (en) | 1998-04-01 |
| CN1066491C CN1066491C (en) | 2001-05-30 |
Family
ID=27455832
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97115010A Expired - Lifetime CN1066491C (en) | 1996-07-15 | 1997-07-15 | PC concrete iron and method for producing same |
Country Status (5)
| Country | Link |
|---|---|
| KR (1) | KR100266934B1 (en) |
| CN (1) | CN1066491C (en) |
| AU (1) | AU709908B2 (en) |
| ID (1) | ID17549A (en) |
| MY (1) | MY119789A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104831183A (en) * | 2015-05-29 | 2015-08-12 | 武钢集团昆明钢铁股份有限公司 | 1080MPa high-strength corrosion-resistance twisted steel for prestressed structure and preparation method of 1080MPa high-strength corrosion-resistance twisted steel |
| CN107365891A (en) * | 2016-03-28 | 2017-11-21 | 高周波热錬株式会社 | Constructional Steel |
| CN109182904A (en) * | 2018-09-26 | 2019-01-11 | 山东钢铁股份有限公司 | A kind of armored concrete fire resisting reinforcing bar and preparation method thereof |
| CN111187994A (en) * | 2020-02-17 | 2020-05-22 | 本钢板材股份有限公司 | Steel C60 hot-rolled coil for high-C cutter and preparation method thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU709908B2 (en) * | 1996-07-15 | 1999-09-09 | Nkk Corporation | Steel bar for prestressed concrete and method for producing the same |
| US20060191603A1 (en) | 2005-02-25 | 2006-08-31 | Popielas Frank W | Lower strength material for MLS active layers |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58120738A (en) * | 1982-01-12 | 1983-07-18 | Hokkai Koki Kk | Manufacture of pc steel wire and steel rod |
| JP3468828B2 (en) * | 1994-04-08 | 2003-11-17 | 新日本製鐵株式会社 | Manufacturing method of high strength PC steel rod |
| AU709908B2 (en) * | 1996-07-15 | 1999-09-09 | Nkk Corporation | Steel bar for prestressed concrete and method for producing the same |
-
1997
- 1997-07-09 AU AU28537/97A patent/AU709908B2/en not_active Expired
- 1997-07-11 MY MYPI97003143A patent/MY119789A/en unknown
- 1997-07-14 KR KR1019970032621A patent/KR100266934B1/en active IP Right Grant
- 1997-07-15 CN CN97115010A patent/CN1066491C/en not_active Expired - Lifetime
- 1997-07-15 ID IDP972453A patent/ID17549A/en unknown
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104831183A (en) * | 2015-05-29 | 2015-08-12 | 武钢集团昆明钢铁股份有限公司 | 1080MPa high-strength corrosion-resistance twisted steel for prestressed structure and preparation method of 1080MPa high-strength corrosion-resistance twisted steel |
| CN107365891A (en) * | 2016-03-28 | 2017-11-21 | 高周波热錬株式会社 | Constructional Steel |
| CN109182904A (en) * | 2018-09-26 | 2019-01-11 | 山东钢铁股份有限公司 | A kind of armored concrete fire resisting reinforcing bar and preparation method thereof |
| CN111187994A (en) * | 2020-02-17 | 2020-05-22 | 本钢板材股份有限公司 | Steel C60 hot-rolled coil for high-C cutter and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1066491C (en) | 2001-05-30 |
| KR980009479A (en) | 1998-04-30 |
| AU709908B2 (en) | 1999-09-09 |
| KR100266934B1 (en) | 2000-09-15 |
| ID17549A (en) | 1998-01-08 |
| MY119789A (en) | 2005-07-29 |
| AU2853797A (en) | 1998-02-05 |
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